Brachytherapy - Articles in Press

Rebuttal to Dr. Stock - Corrected Proof

W. James Morris, Ross Halperin, Ingrid Spadinger — 2010-09-01

As stated in the second sentence of our original submission, we do not question the existence of a dose response for low dose rate brachytherapy. We also agree that whole prostate D90 and V100 have been helpful in illuminating some aspects of the dose response. However the steep dose gradients at the periphery of the gland impose substantial uncertainty on D90 and V100 values, which like all dose volume metrics depend on postimplant prostate segmentation, which in turn is limited by image quality and subject to random and systematic errors and unquantifiable observer bias. Furthermore, D90 and V100 capture no information on regional dose distribution or extraprostatic doses, which may be at least as important as whole prostate metrics.

Acute bowel morbidity after prostate brachytherapy with cesium-131 - Corrected Proof

2010-08-27

Abstract: Purpose: The present study evaluates the severity and time to resolution of bowel symptoms in men undergoing prostate brachytherapy (PB) with cesium-131 (131Cs).Methods and Materials: A longitudinal, prospective study of patients who had undergone PB with 131Cs at a single institution was performed. All patients were asked to complete the Expanded Prostate Cancer Index Composite preoperatively and at 2 weeks and 1, 3, and 6 months postoperatively. Outcomes were analyzed using descriptive statistics and Student’s t test.Results: The first 142 patients to have undergone PB with 131Cs at our institution were included in the study. The mean Expanded Prostate Cancer Index Composite bowel summary score at baseline was 90.1±11.0 compared with 71.5±22.8 (p=0.000), 70.1±20.7, 87.1±13.8 (p=0.01), and 90.7±9.2 (p=0.70) at 2 weeks and 1, 3, and 6 months postoperatively, respectively.Conclusions: In men undergoing PB as monotherapy with 131Cs, bowel symptoms returned to baseline by 3 months after the procedure. For patients undergoing PB with 131Cs as part of combination therapy, bowel symptoms return to their post–external beam radiotherapy, pre-PB baseline by 3 months after the procedure.

Don Lawrence and the “k-capture” revolution - Corrected Proof

Jesse N. Aronowitz — 2010-08-27

Abstract: Purpose: The practice of brachytherapy was in steep decline in the mid-20th century, largely because of safety issues. This article explores the innovations that revitalized brachytherapy with special attention to the introduction of low-energy seeds for permanent implantation.Methods and Materials: Literature review; interviews; and the memos, records, and correspondence of Donald C. Lawrence.Results: Paul Harper first proposed the use of radionuclides that decay by k-capture in the 1950s. But it was the vision and tenacity of health physicist Donald Lawrence that led to the successful implementation of I-125 (in the 1960s) and Cs-131 (40 years later).

Combined radiofrequency ablation and high–dose rate brachytherapy for early-stage non–small-cell lung cancer - Corrected Proof

2010-08-27

Abstract: Purpose: This retrospective analysis reports the results of patients with early-stage inoperable non–small-cell lung cancer treated with radiofrequency ablation (RFA) followed by adjuvant high–dose rate (HDR) brachytherapy.Methods and Materials: Seventeen medically inoperable patients with biopsy-proven Stage I non–small-cell lung cancer were treated with RFA followed by single fraction HDR brachytherapy. Brachytherapy catheters were inserted immediately after RFA, and one fraction of HDR brachytherapy was delivered on the same day. Doses of brachytherapy ranged from 14.4 to 20Gy (median, 18Gy). Patients were followed clinically and radiographically to determine tumor control and toxicity profile.Results: Median followup time was 22 months. Of the 17 patients, 3 patients have recurred locally. Each of the patients with local recurrences was originally treated for T2 disease. In total, three of seven cases with T2N0 disease experienced local recurrences, whereas all 9 patients with T1 disease were controlled locally. Five of the 17 patients required a chest tube posttreatment, and 1 patient developed an empyema. There were no deaths within 1 month of treatment.Conclusions: RFA followed by HDR brachytherapy yields excellent local control with an acceptable toxicity profile for patients with otherwise inoperable early-stage lung cancer.

Point: The relationship between postimplant dose metrics and biochemical no evidence of disease following low dose rate prostate brachytherapy: Is there an elephant in the room? - Corrected Proof

W. James Morris, Ross Halperin, Ingrid Spadinger — 2010-08-27

We would like to draw the attention of your readers to the issue of dose response in low dose rate (LDR) prostate brachytherapy with specific reference to some recent publications, including our own. For the record, we regard the existence of a dose response in LDR prostate brachytherapy as a logical necessity, but there seems good reason to be skeptical about the sensitivity and general applicability of the postoperative dose metrics V100 and D90 used so often now as the principal measures of implant quality.

Robotic needle guide for prostate brachytherapy: Clinical testing of feasibility and performance - Corrected Proof

2010-08-23

Abstract: Purpose: Optimization of prostate brachytherapy is constrained by tissue deflection of needles and fixed spacing of template holes. We developed and clinically tested a robotic guide toward the goal of allowing greater freedom of needle placement.Methods and Materials: The robot consists of a small tubular needle guide attached to a robotically controlled arm. The apparatus is mounted and calibrated to operate in the same coordinate frame as a standard template. Translation in x and y directions over the perineum ±40mm are possible. Needle insertion is performed manually.Results: Five patients were treated in an institutional review board-approved study. Confirmatory measurements of robotic movements for initial 3 patients using infrared tracking showed mean error of 0.489mm (standard deviation, 0.328mm). Fine adjustments in needle positioning were possible when tissue deflection was encountered; adjustments were performed in 54 (30.2%) of 179 needles placed, with 36 (20.1%) of 179 adjustments of >2mm. Twenty-seven insertions were intentionally altered to positions between the standard template grid to improve the dosimetric plan or avoid structures such as pubic bone and blood vessels.Conclusions: Robotic needle positioning provided a means of compensating for needle deflections and the ability to intentionally place needles into areas between the standard template holes. To our knowledge, these results represent the first clinical testing of such a system. Future work will be incorporation of direct control of the robot by the physician, adding software algorithms to help avoid robot collisions with the ultrasound, and testing the angulation capability in the clinical setting.

Precedence for prostate brachytherapy - Corrected Proof

Jesse N. Aronowitz, Laval Grimard, Roger Robison — 2010-08-23

Abstract: Purpose: To identify the earliest practitioners of prostate brachytherapy.Methods and Materials: Review of contemporary literature.Results: Radiotherapy has been used for benign prostatic ailments as early as 1902. Prostate cancer was first treated by teletherapy in 1904. Several urologists, in Paris and Vienna, applied intracavitary radium for prostate disease in 1908–1909. We present evidence that Henri Minet was the first to perform prostate brachytherapy, as early as 1908.Conclusion: Brachytherapy has been used to treat prostate cancer for more than a century.

Prostatic length predicts functional outcomes after iodine-125 prostate brachytherapy - Corrected Proof

2010-08-20

Abstract: Purpose: To determine the value of prostatic length as a predictor of urinary morbidity after brachytherapy for prostate cancer.Methods and Materials: Between May 2002 and September 2008, 214 consecutive patients received brachytherapy for localized prostate cancer at our institution. A prospective analysis of factors predicting urinary toxicity was carried out for these patients. To evaluate urinary morbidity, the posttreatment International Prostate Symptom Score (IPSS) at 3, 9, and 18 months together with rates of urinary retention was recorded.Results: The mean patient age was 62 years, and the mean followup period was 24.4 months. The median IPSS before treatment was 5 (range, 0–20). This increased to 15 (0–33) at 3 months, before subsequently falling to 8 (0–31) and 6 (0–35) at 9 and 18 months, respectively. Twenty-six of 214 (12%) patients experienced urinary retention. Both prostatic length (p-value=0.001, <0.001) and volume (p-value=0.002, <0.001) correlated with a higher posttreatment IPSS at 3 and 9 months. In addition, prostate length and volume predicted those patients developing urinary retention requiring catheterization (p-value <0.001, <0.001). Pretreatment IPSS predicted IPSS at 3, 9, and 18 months (p-value <0.001, <0.001, and 0.011) but did not significantly correlate with retention rates. Other factors predicting IPSS at 3 months included radiation dose (D90) (p-value=0.01) and number of needles used (p-value=0.01).Conclusion: Prostatic length is a useful tool for determining urinary toxicity after brachytherapy for prostate cancer and should be included in the pretreatment assessment.

Accelerated partial breast irradiation using the strut-adjusted volume implant single-entry hybrid catheter in brachytherapy for breast cancer in the setting of breast augmentation - Corrected Proof

2010-08-19

Abstract: Purpose: Accelerated partial breast irradiation (APBI) has gained popularity as an alternative to adjuvant whole breast irradiation; however, owing to limitations of delivery devices for brachytherapy, APBI has not been a suitable option for all the patients. This report evaluates APBI using the strut-adjusted volume implant (SAVI) single-entry catheter to deliver brachytherapy for breast cancer in the setting of an augmented breast.Methods and Materials: The patient previously had placed bilateral subpectoral saline implants; stereotactic core biopsy revealed estrogen receptor- and progesterone receptor-positive ductal carcinoma in situ of intermediate nuclear grade. The patient underwent needle-localized segmental mastectomy of her left breast; pathologic specimen revealed no residual malignancy. An SAVI 8-1 device was placed within the segmental resection cavity. Treatment consisted of 3.4Gy delivered twice a day for 5 days for a total dose of 34Gy. Treatments were delivered with a high-dose-rate 192Ir remote afterloader.Results: Conformance of the device to the lumpectomy cavity was excellent at 99.2%. Dosimetric values of percentage of the planning target volume for evaluation receiving 90% of the prescribed dose, percentage of the planning target volume for evaluation receiving 95% of the prescribed dose, volume receiving 150% of the prescribed dose, and volume receiving 200% of the prescribed dose were 97.1%, 94.6%, 22.7cc, and 11.6cc, respectively. Maximum skin dose was 115% of the prescribed dose. The patient tolerated treatment well with excellent cosmetic results, and limited acute and late toxicity at 8 weeks and 6 months, respectively.Conclusions: Breast augmentation should not be an exclusion criterion for the option of APBI. The SAVI single-entry catheter is another option to successfully complete APBI using brachytherapy for breast cancer in the setting of an augmented breast.

Reirradiation of head and neck cancer with high-dose-rate brachytherapy: A customizable intraluminal solution for postoperative treatment of tracheal mucosa recurrence - Corrected Proof

2010-08-19

Abstract: Purpose: Delivering adequate dose to tracheal mucosa recurrence after multiple prior courses of surgery and radiation presented a challenge for radiation delivery. Tumor bed location and size, combined with previous doses to surrounding areas, complicated the use of external beam therapy with either photons or electrons. High-dose-rate (HDR) brachytherapy was explored to provide sufficient dose coverage.Methods and materials: A 45-year-old gentleman presented with recurrent head and neck cancer. After undergoing additional excision of gross tumor in the tracheal region, radiation was recommended to improve local control. The region of residual tumor was confined to a small superficial lesion at the posterior–superior aspect of the trachea, involving mucosa located along the bend of the trachea, immediately deep to the stoma. External beam treatment was discussed but was not recommended based on recurrence location in the prior radiation field and patient’s flexed chin position. HDR technique with a custom applicator was preferred.Results: A three-dimensional HDR plan based on computed tomography used a single catheter optimized to cover gross tumor volume as delineated by physician. Prescribed dose was 5Gy/fraction for six fractions (two fractions/wk). The applicator position was verified daily with computed tomography and physician setup approval before treatment. The patient was positioned on a wing board to allow access to the stoma. HDR brachytherapy was well tolerated.Conclusions: Intraluminal HDR brachytherapy is a viable option for providing dose to region inside tracheal stoma. Advantages over photon and electron beam therapy include reduced dose to surrounding tissues previously irradiated, skin dose, and reproducibility of treatment delivery.

Localized prostate cancer with intermediate- or high-risk features treated with combined external beam radiotherapy and iodine-125 seed brachytherapy - Corrected Proof

2010-08-16

Abstract: Objective: The aim of the study is to compare the results of the combined external beam radiotherapy (EBRT) with iodine-125 seed brachytherapy vs. brachytherapy alone for prostate cancer treatment in patients with intermediate and high risk of disease recurrence.Methods and Materials: Ninety-six patients were treated from January 1998 to December 2006. Twenty-four patients received combined treatment and 72 patients received brachytherapy alone. Patients were classified into intermediate or high risk of recurrence according to the D’Amico’s classification. The prescribed dose for brachytherapy was 145Gy as monotherapy and 110Gy for combined treatment. The dose of EBRT was 45Gy over 5 weeks, with 1.8Gy daily fractions. Results were analyzed based on Phoenix definition of biochemical recurrence, that is, nadir plus 2ng/mL.Results: Biochemical control was achieved by 96% (23 of 24) of patients receiving combined treatment and by 72% (52 of 72) in the group treated by brachytherapy alone (p<0.015). The addition of EBRT resulted in a 94% biochemical disease-free survival at 5 years; and in brachytherapy alone group, the rate was 54% (p<0.011). Mean followup was 96 months (24–132 months; confidence interval 95%: 90–102).Conclusion: This study shows that in patients with localized prostate cancer, with intermediate and high risk of biochemical recurrence, the addition of EBRT can confer a significant biochemical control advantage when added to brachytherapy.

Variations in health-related quality of life in Japanese men who underwent iodine-125 permanent brachytherapy for localized prostate cancer - Corrected Proof

2010-08-16

Abstract: Purpose: The purpose of this study was to prospectively assess the variations in health-related quality of life (HR-QoL) in patients who underwent low–dose rate prostate brachytherapy using iodine-125 seed source during the first year after seed implantation.Methods and Materials: Between July 2004 and December 2006, 109 patients underwent low–dose rate brachytherapy. The Medical Outcomes study 36-Item Short Form; the University of California, Los Angeles-Prostate Cancer Index; and the International Index of Erectile Function-5 were evaluated before and at 1, 3, 6, and 12 months after seed implantation.Results: In Medical Outcomes study 36-Item Short Form analyses and the HR-QoL scores were well preserved during the first year after seed implantation. In the University of California, Los Angeles-Prostate Cancer Index analyses, the urinary function and bother scores showed significant decrease during 6 months after seed implantation. The bowel function and bother scores showed significant decrease at 3 months after seed implantation. The sexual function score showed significant decrease at 3, 6, and 12 months after seed implantation, whereas the sexual bother score showed no change during the first year. The International Index of Erectile Function-5 score dramatically decreased at 1, 3, 6, and 12 months after seed implantation.Conclusions: The general HR-QoL in the patients who underwent seed implantation was well preserved during the first year after seed implantation, whereas the urinary, bowel, and sexual function and bother scores showed transient deterioration during the first year after seed implantation. Especially, sexual function showed significant deterioration in Japanese men after seed implantation.

A novel ytterbium-169 brachytherapy source and delivery system for use in conjunction with minimally invasive wedge resection of early-stage lung cancer - Corrected Proof

Kara Lynne Leonard, Thomas A. DiPetrillo, John J. Munro, David E. Wazer — 2010-08-13

Abstract: Purpose: To describe a novel source–delivery system for intraoperative brachytherapy in patients with early-stage lung cancer that is readily adaptable to a video-assisted thoracoscopic surgery approach and can be precisely delivered to achieve optimal dose distribution.Methods and Materials: Radioactive ytterbium-169 (169Yb) was sealed within a titanium tube 0.28mm in diameter and then capped and resealed by titanium wires laser welded to the tube to serve as the legs of a tissue-fastening system. Dose simulations were performed using Monte Carlo computer code (Los Alamos National Laboratory, Los Alamos, NM) to mimic the geometric and elemental compositions of the source, fastening apparatus, and surroundings.Results: Five test source capsules were subjected to a tensile load to failure. Failure in each capsule occurred in the wire of the fastener leg; there were no weld failures. Monte Carlo simulations and subsequent dose measurement showed the perturbation by the source legs in the deployed (bent over) position to be small (4–5%) for 169Yb and much less than that for iodine-125 (32%).Conclusion: We have developed a 169Yb brachytherapy source–delivery system that can be used in conjunction with commercially available surgical stapling instruments, facilitates the precise placement of brachytherapy sources relative to the surgical margin, assures the seeds remain fixed in their precise position for the duration of the treatment, overcomes the technical difficulties of manipulating the seeds through the narrow surgical incision associated with video-assisted thoracoscopic surgery, and reduces the radiation dose to the clinicians.

High–dose rate brachytherapy in the treatment of penile carcinoma—First experience - Corrected Proof

2010-08-12

Abstract: Purpose: Interstitial low–dose rate brachytherapy (BRT) allows a conservative treatment of T1–T2 penile carcinoma. High–dose rate (HDR) BRT is often considered as a dangerous method for interstitial implants because of higher risk of complications. However, numerous reports suggest that results of HDR-BRT may be comparable to low–dose rate BRT. There are no data available in the literature regarding HDR interstitial BRT for carcinoma of the penis.Methods and Materials: Ten patients with early penile carcinoma were treated by interstitial hyperfractionated HDR-BRT at the dose of 18 times 3Gy twice daily between years 2002 and 2009. Breast interstitial BRT template was used for fixation and precise geometry reconstruction of stainless hollow needles.Results: Median followup was 20 months. Our BRT technique and fractionation schedule was well tolerated by all patients. Acute reaction consisted predominantly of penis edema and Grade 2 radiation mucositis that dissolved during 8 weeks after the treatment. We neither observed any postradiation necrosis nor urethral stenosis. The worst late side effects recorded were mild telanagiectasias in the treatment region. At the last followup, all patients were alive without evidence of the tumor and with fully functional organ.Conclusions: Hyperfractionated interstitial HDR-BRT with 18 times 3Gy per fraction twice daily is a promising method in selected patients of penile carcinoma and deserves further evaluation in a larger prospective study.

Minimizing the number of implantation needles for prostate 125I brachytherapy: An investigation of possibilities and implications - Corrected Proof

Marcel J. Steggerda, Henk G. van der Poel, Luc M.F. Moonen — 2010-08-09

Abstract: Purpose: Reduction of the number of implantation needles for prostate brachytherapy will shorten the duration of implantation procedures and possibly reduce trauma-related morbidity. The purpose of this study was to investigate possibilities for the minimization of the number of needles and to investigate the consequences for the dose distribution.Methods and Materials: A planning study for six different prostate volumes was performed. The number of needles was minimized by changing fixed 1cm interseed spacing to free interseed spacing within the needles and by increasing the seed activity. Dose–volume parameters of prostate and organs at risk (OAR) bladder, rectum, and urethra were determined. For plans with different needle and seed configurations, the sensitivity for random seed placement inaccuracies was tested. Dose distributions of realized implants based on fixed (n=21) and free interseed spacing (n=21) were compared.Results: The average number of needles (±1 standard deviation) could be reduced from 18.8±3.6 to 12.7±2.9 (−33%) when changing from fixed interseed spacing to free interseed spacing and subsequently to 7.3±1.0 (−42%) by increasing the seed strength from 0.57U to 1.14U. These needle reductions resulted in increased dose inhomogeneity within the prostate and increased sensitivity of dose–volume parameters of the OAR for random geometrical inaccuracies. Introduction of free interseed spacing in our clinic resulted in very satisfactory dose coverage of the prostate (D90=172±17Gy), while the average number of needles was reduced by 30%.Conclusions: Substantial reduction of the number of implantation needles is possible without compromising adequate dose coverage of the prostate. However, the chance of an unpredicted high dose to the OAR increases as fewer needles are used.

Dynamic intraoperative dosimetry for prostate brachytherapy using a nonisocentric C-arm - Corrected Proof

2010-08-09

Abstract: Purpose: To evaluate a prototypical system of dynamic intraoperative dosimetry for prostate brachytherapy using registered ultrasound and fluoroscopy (RUF) with a nonisocentric C-arm (GE OEC, Salt Lake City, UT) and to compare intraoperative dosimetry of RUF as well as ultrasound-based seed localization (USD) with Day 0 CT dosimetry.Methods: Seed positions were independently determined using RUF and USD. RUF uses a radio-opaque fiducial for registration to ultrasound and 3-dimensional reconstruction of seeds relative to prostate using nonisocentric C-arm fluoroscopy. Postimplant CT was performed on Day 0. Squared differences between dosimetric measures for RUF vs. CT and USD vs. CT were calculated and mean squared differences evaluated. Paired t test was used to evaluate which method was more closely aligned with CT. Accuracies of USD and RUF compared with CT were estimated using a nonparametric approach.Results: Six patients were treated and compared with USD. RUF identified areas of underdosage intraoperatively in all patients and median 5 additional seeds were placed. In 40 of 42 measures, RUF was equally or more closely correlated with CT than USD. USD showed statistically significant variation from CT for 6 of 7 parameters compared with 1 of 7 parameters for RUF. Mean squared differences from CT were significantly smaller for RUF in 4 of 7 parameters compared with USD.Conclusions: Dynamic intraoperative dosimetry is possible with a conventional nonisocentric C-arm. Compared with an USD method, RUF-based intraoperative dosimetry was more closely aligned with immediate postimplant CT. RUF identified areas of underdosage, which were not detected using USD.

Quadrant dosimetry as a predictor of biochemical relapse in 125I prostate brachytherapy - Corrected Proof

2010-08-09

Abstract: Purpose: To evaluate region-specific dose metrics as predictors of biochemical relapse in prostate brachytherapy patients.Methods and Materials: In a cohort of 1006 low-risk and “low-tier” intermediate-risk prostate brachytherapy patients treated to a planned dose of 144Gy mPD (minimal peripheral dose), 30 of 32 with biochemical relapse (nadir+2ng/mL definition) had postimplant CT scans available for retrospective analysis. These were matched to nonrelapsing controls from the same era. Three copies of each CT were created and, after randomization and deletion of identifiers and original contours, were re-contoured by three radiation oncologists. Prostate contours were then divided into quadrants: Anterior-Superior (ASQ), Posterior-Superior (PSQ), Anterior-Inferior (AIQ), and Posterior-Inferior (PIQ), and dosimetric parameters calculated. Results were analyzed using mixed-effects linear regression and multivariate logistic regression.Results: Whole prostate volume of the prostate receiving at least 100% of the prescribed dose (V100) and minimum dose, as a percentage of the prescribed dose, received by 90% of the prostate volume (D90) were similar for relapses and controls (p=0.40 and 0.48, respectively). Among the quadrants, the largest differences between relapses and controls were seen for the AIQ. Mean AIQ V100s were 91.2% (relapses) and 95.5% (controls) (p=0.096), and D90s were 112.8% (relapses) and 119.3% (controls) (p=0.145). Overall, the lowest doses were in the ASQ, but were not very different for relapses and controls (V100=76.5% and 78.5%, respectively) (p=0.54). On multivariate analysis along with various clinical parameters, AIQ metrics approached significance at the p ≤0.05 level in models that also included initial prostate-specific antigen, androgen suppression, and risk group.Conclusions: Although whole prostate dose metrics did not predict for biochemical relapse in our data set, dose to the AIQ was predictive in multivariate analysis.

High–dose rate brachytherapy alone in postoperative soft tissue sarcomas with close or positive margins - Corrected Proof

2010-08-09

Abstract: Purpose: In the management of soft tissue sarcomas, perioperative radiation therapy has been used to reduce the risk of local recurrence after resection. However, a significance of postoperative high–dose rate brachytherapy (HDRBT) remains to be studied. Retrospective analysis was performed to elucidate the role of postoperative HDRBT.Methods and Materials: Twenty-five patients with 26 soft tissue sarcoma lesions underwent postoperative HDRBT using 192Ir remote afterloader without external beam radiation therapy. Ninety-two percent of the lesions were Grade 2 or 3 malignancies, and 50% were resected with positive surgical margins. The remaining 50% had very close margins. Fourteen lesions were treated for local recurrences after previous resections. Applicators of HDRBT were placed during the operation to include only the tumor bed excluding surgical scars. Applied dose was mainly 36Gy/6 fractions/3 d b.i.d.Results: Five-year local recurrence-free survival was 78.2% in all the 26 lesions. Recurrences were not seen within the treated volume of HDRBT. Two groups were defined according to the marginal status and number of previous operations. Group 1 was the lesions with a positive margin and foregoing resections. The remaining lesions were classified as Group 2. Five-year local recurrence-free survival was 43.8% and 93.3% in Group 1 and Group 2, respectively with a statistically significant difference (p=0.004).Conclusions: Postoperative HDRBT was effective in controlling local lesions; but in Group 1 lesions, addition of a wide field external beam radiation therapy seems to be necessary to improve the local control rate.

Definitive 125I prostate brachytherapy implant for low-risk prostate cancer in a patient with an ileal pouch–anal anastomosis: A case report - Corrected Proof

Edward F. Miles, John W. Nelson — 2010-08-06

Abstract: Purpose: To report on the safe and effective use of a prostate brachytherapy implant for clinically low-risk prostate cancer in a patient with previous ileal pouch–anal anastomosis.Methods and Materials: A patient with a previous history of total proctocolectomy with ileal pouch–anal anastomosis was diagnosed with low-risk prostate cancer. He underwent prostate brachytherapy implant and his urinary, bowel, and sexual function were monitored preoperatively and regularly after his implant.Results: Approximately 1-year postimplant, the patient’s serum prostate-specific antigen continued to decrease and urinary obstructive symptoms measured via a standardized patient-reported instrument increased transiently but returned to baseline. His sexual function remains slightly diminished. His self-reported bowel function has been essentially unchanged, and he specifically denies increased stool frequency, urgency, incontinence, tenesmus, or hematochezia.Conclusions: Prostate brachytherapy appears to be both safe and effective for treating low-risk prostate cancer in patients with a pre-existing ileal pouch–anal anastomosis. Although there is a potential for significant late injury to the neorectum, a previous small series indicated that this had not been seen. Models currently used to predict normal tissue complication probabilities do not seem well applied to this case. The developments of algorithms that more correctly model this condition are encouraged.

Comparison of PSA relapse-free survival in patients treated with ultra-high-dose IMRT versus combination HDR brachytherapy and IMRT - Corrected Proof

2010-08-05

Abstract: Purpose: We report on a retrospective comparison of biochemical outcomes using an ultra-high dose of conventionally fractionated intensity-modulated radiation therapy (IMRT) vs. a lower dose of IMRT combined with high-dose-rate (HDR) brachytherapy to increase the biologically effective dose of IMRT.Methods: Patients received IMRT of 86.4Gy (n=470) or HDR brachytherapy (21Gy in three fractions) followed by IMRT of 50.4Gy (n=160). Prostate-specific antigen (PSA) relapse was defined as PSA nadir+2. Median followup was 53 months for IMRT alone and 47 months for HDR.Results: The 5-year actuarial PSA relapse-free survival (PRFS) for HDR plus IMRT vs. ultra-high-dose IMRT were 100% vs. 98%, 98% vs. 84%, and 93% vs. 71%, for National Comprehensive Cancer Network low- (p=0.71), intermediate- (p<0.001), and high-risk (p=0.23) groups, respectively. Treatment (p=0.0006), T stage (p<0.0001), Gleason score (p<0.0001), pretreatment PSA (p=0.0037), risk group (p<0.0001), and lack of androgen-deprivation therapy (p=0.0005) were significantly associated with improved PRFS on univariate analysis. HDR plus IMRT vs. ultra-high-dose IMRT (p=0.0012, hazard ratio [HR]=0.184); age (p=0.0222, HR=0.965); and risk group (p<0.0001, HR=2.683) were associated with improved PRFS on multivariate analysis.Conclusion: Dose escalation of IMRT by adding HDR brachytherapy provided improved PRFS in the treatment of prostate cancer compared with ultra-high-dose IMRT, independent of risk group on multivariate analysis, with the most significant benefit for intermediate-risk patients.

Effects of ellipsoid prostate deformation on dose delivery during permanent interstitial brachytherapy - Corrected Proof

2010-08-05

Abstract: Purpose: To elucidate the potential effects of prostate deformation on dose distribution during Iodine-125 (125I) seed implantation brachytherapy for prostate cancer.Methods and Materials: A retrospective analysis of 245 patients who underwent only transperineal brachytherapy for low-risk prostate adenocarcinoma was performed. The maximum diameters of the prostate were measured before treatment by transrectal ultrasound volumetry along right to left (RL), anterior to posterior (AP), and apex to base (Length) directions. The seeds were inserted by the modified peripheral loading method using real-time ultrasound-guided seed placement. The ellipsoid deformation rates in the axial plane (Eax) and in the sagittal plane (Esag) were defined as [RL−AP]/RL and [Length−AP]/Length, respectively. The correlation between them and the dose–volume histogram parameters at 30 days after the operation was evaluated. A simulation test was additionally performed to ascertain the change in dose distribution among virtual volumes built in a radiotherapy planning device that corresponds to prostates with increased Eax or Esag.Results: The mean Esag and Eax of patients were 0.313 (range, −0.28 to 0.844) and 0.261 (range, −0.02 to 0.54), respectively. Esag showed a positive correlation with dose (Gy) covering 90% of the prostate volume (pD90), prostate volume (%) covered by 100% of the prescribed dose (pV100), the rectal volume (cc) irradiated by 100% of the prescribed dose (rV100), and the rectal volume (cc) irradiated by 150% of the prescribed dose (rV150), whereas Eax showed a positive correlation with prostate volume (%) covered by 150% of the prescribed dose (pV150) and the urethral dose (Gy) delivered to 5% of its volume (uD5). The simulation test suggested that the prescribed dose resulted in the best coverage in patients with increased Esag, and that patients with increased Eax exhibited poor urethral sparing from overdosage.Conclusion: In the seed implantation method, ellipsoid deformation of the prostate causes higher rectal dose exposure or dose delivery to the urethra.

Subacute penile numbness after brachytherapy for prostate cancer - Corrected Proof

2010-08-05

Abstract: PURPOSE: Penile numbness is a rare complication of permanent prostate brachytherapy, and optimal clinical management remains unclear. We present such a case and discuss pathophysiology and clinical management strategies.Methods and Materials: A 68-year-old male presented with a serum prostate-specific antigen level of 6.9 ng/mL, Gleason score of 7 (3+4), and clinical T1c adenocarcinoma of the prostate. After a permanent prostate brachytherapy implant with 125I monotherapy to a dose of 145Gy, the patient developed complete penile numbness postoperatively on the third day.Results: The patient experienced complete restoration of penile sensation and function by postoperative day 9 with conservative management.Conclusions: Subacute penile shaft numbness after brachytherapy is rare and is caused by dorsal penile nerve compression. Over the course of a week, the restoration of penile sensation is likely to occur with conservative management.

Comparison of conservative management techniques in the re-treatment of ipsilateral breast tumor recurrence - Corrected Proof

2010-08-05

Abstract: Purpose: To compare brachytherapy and three-dimensional (3-D) conformal external beam radiotherapy for breast cancer presenting in the previously irradiated breast.Methods and Materials: Thirty-six patients with TIS–T2 breast carcinomas received brachytherapy or 3-D conformal radiotherapy (3-D CRT) after lumpectomy in a previously irradiated breast as an alternative to salvage mastectomy. Brachytherapy consisted of low-dose-rate (LDR) interstitial technique in 21 patients, whereas 11 patients were treated using high-dose-rate (HDR) balloon technique. Four patients received 3-D CRT. Cosmesis was graded according to the Harvard criteria and the Allegheny General Modification of the Harvard criteria. Acute sequelae were graded according to the Common Terminology Criteria for Adverse Events (version 3.0).Results: Thirty-five of 36 patients remained free of local failure, with a mean followup of 37 months. Five patients treated with LDR developed Grade II and two developed Grade III acute side effects. No patient treated with balloon brachytherapy or 3-D CRT developed a Grade II or higher acute effect. Cosmetically, 12 LDR interstitial patients were scored as Grade I, six as Grade II, and three as Grade III. Nine of the HDR patients were scored as Grade I, one as Grade II, and one as Grade III. Two 3-D CRT patients were scored as Grade II and two as Grade III. The Allegheny Modification of the Harvard criteria more accurately reflected the cosmetic effects of re-treatment.Conclusion: Brachytherapy is feasible for patients who desire breast preservation in a previously irradiated breast. All techniques demonstrated similar local control rates. Acute side effects were less, and cosmesis was superior in HDR balloon brachytherapy.

Quantitative estimation of doses to salivary glands from using brachytherapy in head and neck cancers - Corrected Proof

2010-08-05

Abstract: Purpose: To quantify the percentage doses received by salivary glands (SGDs) in head and neck interstitial brachytherapy (BT).Methods and Materials: The study included 43 patients who underwent high–dose rate iridium-192 implant for oral cavity and oropharyngeal lesions treated with BT as a boost. BT dose varied with disease stage and external radiation dose, with the total mean dose of 66±4Gy. Patients were divided into two groups, midline and lateralized, based on anatomic implant location. Different dose parameters such as Dmax, Dmean, DV30% of individual glands were derived from dose volume histogram representing the percentage maximum dose, mean dose, and dose received by 30% volume of individual SGDs, respectively. For better perception of the impact of BT on individual SGDs, the doses received are extrapolated to radical BT dose of 60Gy.Results: For lateralized implants, the highest dose received by ipsilateral parotid (PTD) was 12.3% seen in tonsillar implants. The contralateral PTD receives minimal doses. As expected, the ipsilateral submandibular gland (SMG) received high doses in the range of 80% of the total prescribed dose, whereas contralateral SMG received 10% of ipsilateral dose. For the midline implants, the mean dose range for PTD was 7–11% of the total prescribed dose and for SMG between 17% and 56%, depending on the location.Conclusions: The study quantifies the percentage doses received by the individual SGDs in interstitial head and neck BT for use in future planning of the BT procedures and for salivary functional studies, prediction of damage, and quality-of-life parameters.

Optimization of high–dose-rate intracavitary brachytherapy schedule in the treatment of carcinoma cervix - Corrected Proof

2010-08-05

Abstract: Purpose: At our institute, we use high–dose-rate (HDR) intracavitary brachytherapy (ICBT) schedule of 9Gy per fraction for two fractions after external beam radiotherapy (EBRT) in advanced stage carcinoma cervix patients. But American Brachytherapy Society recommends that individual fraction size should be less than 7Gy per fraction in such patients. We present the results of comparison of our institution standard schedule with biologically equivalent dose of 6.8Gy per fraction for three fractions in terms of local control, disease-free survival, and late toxicity.Methods and materials: Between October 2003 and August 2007, 104 patients with carcinoma of the uterine cervix (Stages IIB and IIIB) were treated with EBRT and HDR ICBT. After EBRT, patients were randomized to one of the treatment arms. ICBT dose in Control Arm A (n=52) was 9Gy per fraction in two fractions, 1 week apart, and in Study Arm B (n=52), it was 6.8Gy per fraction in 3 fractions, 1 week apart.Results: The median followup was 31.48 months. The 3-year actuarial local control was 81.35% in Arm A and 65.18% in Arm B (p=0.0423), and the 3-year actuarial disease-free survival was 64.97% in Arm A and 49.47% in Arm B (p=0.0393). The 3-year actuarial risk of developing any Grade 3 or worse late toxicity was 7.47% in Arm A and 3.57% in Arm B (p=0.2907).Conclusion: In our setup, HDR brachytherapy at 9Gy per fraction in two fractions is safe and effective with good local control, survival, and manageable normal tissue toxicity.

Second conservative treatment for ipsilateral breast cancer recurrence using high-dose rate interstitial brachytherapy: Preliminary clinical results and evaluation of patient satisfaction - Corrected Proof

2010-08-05

Abstract: Purpose: To assess early clinical results and evaluate patient satisfaction in case of second conservative treatment (2nd CT) combining lumpectomy plus high-dose rate (HDR) interstitial brachytherapy for patients (pts) presenting with ipsilateral breast cancer recurrence (IBCR).Methods and Materials: From June 2005 to July 2009, 42 pts presenting with an IBCR underwent a second lumpectomy with intraoperative implantation of plastic tubes in the tumor bed. After performing the dose distribution analysis on the postimplant CT scan, a total dose of 34Gy in 10 fractions over 5 consecutive days was delivered. Toxicity evaluation was based on the Common Terminology Criteria for Adverse Events v3.0 criteria. Applying a visual analogic scale (VAS) analysis, patient satisfaction regarding cosmetic result and 2nd CT possibility was performed after the end of brachytherapy.Results: Median followup was 21 months (range, 6–50 months) and median age at the time of local recurrence was 65 years (range, 30–85 years). Median delay between primary and recurrence was 11 years (range, 1–35 years). Median recurrence tumor size was 12mm (range, 2–30mm). Median number of plastic tubes and planes were nine (range, 5–12) and two (range, 1–3), respectively. Median clinical target volume was 68cc (range, 31.2–146cc). Second local control rate was 97%. Twenty-two pts (60%) developed complications. Cutaneous and subcutaneous fibrosis was the most frequent side effect. Median VAS satisfaction score regarding cosmetic result was 7 of 10 (range, 4–9), whereas median VAS satisfaction score for 2nd CT was 10 of 10 (range, 8–10).Conclusion: A 2nd CT for IBCR using high-dose rate brachytherapy seems feasible with encouraging results in terms of second local control with an acceptable toxicity. Patient satisfaction regarding the possibility of second breast preservation should be considered.

Intra-articular chromic phosphate (32P) in the treatment of diffuse pigmented villonodular synovitis - Corrected Proof

Jennifer E. Zook, Daniel L. Wurtz, Judd E. Cummings, Higinia R. Cárdenes — 2010-08-05

Abstract: Purpose: Pigmented villonodular synovitis (PVNS) is an uncommon proliferative lesion of synovial tissue. In diffuse PVNS, recurrence rates are high after resection alone. Adjuvant external beam radiation therapy contributes to improved local control. Limited data exist for intra-articular radioisotope therapy after surgical resection. We report institutional experience with intra-articular chromic phosphate (32P).Methods and Materials: Records were reviewed from the Department of Radiation Oncology at Indiana University. Nine cases of PVNS treated with 32P were identified (mean age=40). Seven patients were treated at time of recurrence and 2 patients were treated prophylactically. Intra-articular injections were performed by accessing the joint space, aspirating joint fluid, reinjecting 1–2mCi of 32P, and barbitaging to ensure good distribution in the joint space. No external beam radiation therapy was delivered. One patient was lost to followup. Mean followup of remaining patients was 20 months (range, 2–48).Results: Eleven injections were performed in 9 patients. Eight had PVNS in the knee(s) and 1 patient had involvement of the hip. Two patients were treated more than once, one for a recurrence in the same joint at 13 months and another for PVNS of a contralateral joint. Three clinical recurrences (2, 13, and 28 months) were noted. Two of three recurrences were in patients who had bulky diffuse PVNS at the time of injection. Overall local control was 70%. In patients without bulky diffuse PVNS at the time of injection, local control was 88%.Conclusion: We report success using intra-articular injections of 32P after synovectomy in patients with PVNS.

The use of adjuvant high-dose-rate breast brachytherapy in patients with collagen vascular disease: A collaborative experience - Corrected Proof

2010-08-02

Abstract: Purpose: To analyze toxicity and cosmesis in patients with collagen vascular disease (CVD) treated with accelerated partial breast irradiation (APBI) via high-dose-rate (HDR) brachytherapy.Methods and Materials: This is a pooled analysis of patients with early stage and in situ breast cancer with CVD treated with adjuvant multicatheter or balloon brachytherapy. Physicians at multiple institutions were asked to review their experience and report data regarding toxicity and cosmesis in patients with CVD. All patients fit American Society of Breast Surgeons recommendations for APBI and were treated with HDR brachytherapy with ≥3 months followup.Results: Nine cases from five institutions are the subject of this analysis. The median patient age was 54 years and median followup was 31 months. All patients had documented history and active signs/symptoms of rheumatoid arthritis, systemic lupus erythematosis, psoriatic arthritis, or scleroderma. All patients had received medical therapy for CVD in the past, and 78% were under active treatment at the time of brachytherapy. All the patients were treated with multicatheter or balloon (MammoSite [Hologic, Inc., Marlboro, MA], MammoSite ML [Hologic, Inc., Marlboro, MA], or Contura [Senorx, Irvine, CA]) brachytherapy with a median volume of 45.5cc and a median skin distance of 7.5mm. Acute toxicity included Grade 1 skin erythema (5) and catheter-site wound dehiscence (1). Late toxicity included seroma (5), induration (5), pain (2), telangectasia (2), and superficial infection (1). Cosmesis was excellent or good for all the patients.Conclusions: Women with CVD have a toxicity and cosmesis profile consistent with other APBI series. Although confirmatory data is needed, it may not be necessary to exclude these patients from clinical trials of APBI.

Cross-linked hyaluronan gel improves the quality of life of prostate cancer patients undergoing radiotherapy - Corrected Proof

2010-07-01

Abstract: Purpose: To test the hypothesis that cross-linked hyaluronan gel (Hylaform) does not affect the quality of life (QOL) of prostate cancer patients undergoing radiotherapy.Methods and Materials: Thirty-five patients with early stage prostate cancer underwent high-dose-rate brachytherapy to 2200cGy and intensity modulated radiation therapy to 5040cGy on a prospective study. Thirty patients received a single transperineal injection of 9-mL Hylaform between the prostate and rectum under transrectal ultrasound guidance immediately before the start of radiotherapy. Hylaform increased the separation between the prostate and rectum by 6–19mm (median, 13mm) at the start of radiotherapy. Five patients did not receive Hylaform and served as controls. We assessed gastrointestinal-related QOL using Expanded Prostate Cancer Index Composite Bowel Bother scores immediately before the start of and during the last week of radiotherapy.Results: At the beginning of intensity modulated radiation therapy, daily mean rectal doses were 74±8cGy (mean±standard deviation) and 105±25cGy (mean±standard deviation) with vs. without Hylaform, respectively (p=0.01). Expanded Prostate Cancer Index Composite Bowel Bother scores decreased by 0±3 (mean±standard deviation) and 11±14 (mean±standard deviation) in patients who did and did not receive Hylaform, respectively (p=0.03).Conclusions: Hylaform increased the separation between the prostate and rectum and decreased the mean rectal dose, thereby improving the gastrointestinal-related acute QOL of prostate cancer patients undergoing radiotherapy. Patients will be followed up long term to determine if the improvement in acute QOL also translates into an improvement in late QOL.

Apples to apples - Corrected Proof

Louis Potters — 2010-06-07

The lack of Level I evidence comparing various treatments for localized prostate cancer allows one to profess or proclaim a bias for almost any modality they choose. The lack of “good” evidence has confounded the issue by allowing those with favoritism toward any one modality with less robust data, such as proton beam therapy, stereotactic body radiation, or high intensity frequency ultrasound to have a voice in the chorus of identical outcomes. In the end, either side can state their case at a tumor board or with patients with impunity. The patient's confusion in selecting appropriate therapy is further complicated by the physician's bias that may be linked to ego or the pocketbook.

Comparative 5-year outcomes of brachytherapy and surgery for prostate cancer - Corrected Proof

Tom Pickles, W. James Morris, Michael W. Kattan, Changhong Yu, Mira Keyes — 2010-06-07

Abstract: Purpose: To compare the predicted outcome by radical retropubic prostatectomy (RRP) of patients actually treated with prostate brachytherapy (PB) for low- and intermediate-risk prostate cancer, using a surgical nomogram.Methods and Materials: Data of consecutive patients treated with PB from the start of our program in 1998 to February 1, 2005 were extracted from a prospectively maintained database that records patient, tumor, and outcomes information. Prognostic features of each patient and brachytherapist experience were entered into a nomogram of surgical outcomes that incorporates surgeon experience. The definition of failure was a rising prostate specific antigen (PSA) >0.4ng/mL or secondary intervention. Comparisons of actual PB outcome vs. predicted surgical outcome were compared using the log-rank test.Results: One thousand two hundred fifty-four patients were treated in this era, and all are included for analysis. The median followup is 56 months. Forty-six percent have stage T1, and 54% have stage T2 cancer. Twenty-five percent have Gleason 7 disease, and the median PSA is 6.3ng/mL (range, 0.3–19.6ng/mL). Fifty-eight percent have low-risk disease, and 41% have intermediate-risk disease. Androgen deprivation therapy was used for 6 months in 92% of intermediate-risk and 46% of low-risk cases. The median PSA at last followup is 0.06ng/mL. Five-year biochemical no evidence of disease rate with PB is 90.6%, and that predicted with RRP is 86.8%, p=0.003.Conclusions: Excellent PB outcomes are observed that exceed that predicted from the use of RRP.

A comparison of preplan transrectal ultrasound with preplan-CT in assessing volume and number of seeds needed for real-time ultrasound-based intra-operative planning in prostate 125I seed implantation - Corrected Proof

2010-03-12

Abstract: PURPOSE: Intra-operative (real-time) treatment planning has been adapted by many institutions for low–dose rate prostate brachytherapy. Although this allows dosimetric planning to be done during the procedure, preplan imaging to obtain a prostate volume is essential to identify the number of seeds to ensure adequate volume coverage. Currently, there is no consensus regarding the most appropriate imaging to obtain this information. We conducted a retrospective study to compare how volumes obtained from preplan CT (p-CT) scans or preplan transrectal ultrasound (p-TRUS) correlated with real-time ultrasound and postimplant CT volumes and the difference in accuracy of seed estimation between these techniques.Methods and Materials: Ninety-two patients underwent 125I permanent seed implants at Thomas Jefferson University Hospital between February 2002 and August 2008. Fifty-one patients underwent p-TRUS before intra-operative planning and 41 patients were evaluated by p-CT.Results: The median difference in volume between preimplant imaging and the intra-operative planning ultrasound was 3.59 and 5.2cc for patients who underwent p-TRUS and p-CT, respectively. p-TRUS volumes more closely correlated with real-time intra-operative volumes (R=0.84 in all patients and R=0.91 in hormone-naïve patients) vs. p-CT (R=0.82). The median number of seeds wasted using p-CT was 18 vs. 7 using volumes derived from p-TRUS.Conclusions: The number of seeds ordered could be more accurately obtained from p-TRUS volumes, and this translated into less seed wastage. Our findings indicate that p-TRUS is a more accurate and an economically superior alternative to p-CT imaging in the era of real-time ultrasound planning.

Postimplant rectal dosimetry is not dependent on 103Pd or 125I seed activity - Corrected Proof

2010-02-12

Abstract: Purpose: In this study, the effect of prostate brachytherapy seed activity on postimplant rectal dosimetry was evaluated in Pro-Qura (Prostate Brachytherapy Quality Assurance; Seattle, WA) proctored, community-based programs.Methods and Materials: Twenty-three hundred patients (1563 iodine-125 [125I] and 737 palladium-103 [103Pd]) from 78 brachytherapists with postimplant rectal dosimetry were identified. Seed activity was stratified into three tertiles for each isotope (≤0.300, 0.301–0.326, and >0.326mCi/seed for 125I and ≤1.330, 1.331–1.547, and >1.547mCi/seed for 103Pd). Postimplant dosimetry was performed in a standardized fashion. The rectum was contoured by outlining the outer rectal wall. The volume of the rectum receiving 100% of the prescription dose (R100) was calculated in cubic centimeters. The prostate V100 and D90 volumes were also calculated.Results: The mean prostate volume was 35.8 and 32.3cm3 for 125I and 103Pd. The median time to postimplant CT was 30 days. For 125I, the V100 increased from 91.0% to 93.7% (p=0.012) and the D90 increased from 105.9% to 108.7% (p<0.001) for the lowest to the highest 125I seed activities. In contrast, no significant changes in V100 (p=0.751) or D90 (p=0.200) were discerned when stratified by seed activity. For both isotopes, there was no correlation between seed activity and R100, and R100 was highest for the intermediate seed activities. Overall, the R100 was lower for 103Pd vs. 125I (0.63 vs. 0.82cm3, p<0.001).Conclusions: Within the confines of seed activities used in this study, higher activity seeds did not result in a deleterious effect on rectal dose. Higher activity seeds were associated with improved prostate dosimetry for 125I, whereas 103Pd dosimetry was not dependent on seed activity.

Evaluation of radiobiologic biochemical control in a large permanent prostate brachytherapy population from a single institution using AAPM TG-137 parameters - Corrected Proof

Wayne M. Butler, Renee R. Stewart, Gregory S. Merrick — 2010-02-12

Abstract: Purpose: To re-evaluate prostate implant dosimetry using American Association of Physicists in Medicine Task Group 43 parameters and the radiobiologic approach of American Association of Physicists in Medicine Task Group 137.Methods and Materials: Among 1473 consecutive patients implanted with iodine-125 or palladium-103 sources before March 2006, there have been 55 biochemical failures. The dosimetric quality parameter, D90, was updated according to the radionuclide and dosimetric era of the implant. For each patient, biologically equivalent dose (BED) and tumor control probability (TCP) were calculated from the updated implant D90 plus any external beam dose using recommended indices and equations.Results: There was no significant difference in BED between biochemical failures and nonfailures, 148±27Gy and 145±24Gy, respectively (p=0.352). TCP was 0.90±0.26 for biochemical failures and 0.93±0.21 for nonfailures (p=0.414). Cox regression analysis found that neither BED nor TCP predicted for biochemical control either for the entire population or within each radionuclide-dependent dosimetric era. The only overall predictors of biochemical control were dosimetric era, Gleason score, and percent positive biopsies. Improvements in dosimetric quality over the first 300 patients were evident, but dosimetric era remained a better predictor of biochemical outcome than implant sequence number.Conclusion: In a large prostate implant population, dosimetric and derived radiobiologic parameters did not predict for failure. Apparently, too few patients had total BEDs below the level necessary for optimum biochemical control. A learning curve extended over hundreds of patients before plateauing but changes in seed characterization parameters also had a pronounced effect.

A comprehensive dosimetric comparison between 131Cs and 125I brachytherapy sources for COMS eye plaque implant - Corrected Proof

2010-01-29

Abstract: Purpose: To verify the dosimetric characteristics of 131Cs source in the Collaborative Ocular Melanoma Study (COMS) eye plaque brachytherapy, to compare 131Cs with 125I in a sample implant, and to examine the accuracy of treatment planning system in dose calculation.Methods and Materials: Monte Carlo (MC) technique was used to generate three-dimensional dose distributions of a 16-mm COMS eye plaque loaded with 131Cs and 125I brachytherapy sources separately. A spherical eyeball, 24.6mm in diameter, and an ellipsoidal tumor, 6mm in height and 12mm in diameter, were used to evaluate the doses delivered. The simulations were carried out both with and without the gold and gold alloy plaque. A water-equivalent seed carrier was used instead of the silastic insert designed for the traditional COMS eye plaque. The 13 sources involved were also individually simulated to evaluate the intersource effect. In addition, a treatment planning system was used to calculate the doses at the central axis for comparison with MC data.Results: The gold plaque had significantly reduced the dose in the tumor volume; at the prescription point of this study, that is, 6mm from the edge of inner sclera, the gold plaque reduced the dose by about 7% for both types of 131Cs and 125I sources, but the gold alloy plaque reduced the dose only by 4% for both types of sources. The intersource effect reduced the dose by 2% for both types of sources. At the same prescription dose, the treatment with the gold plaque applicator tended to create more hot regions for either type of sources than were seen with the homogeneous water phantom. The doses of TPS agree with the MC.Conclusion: The 131Cs source is comparable to the 125I source in the eye plaque brachytherapy. The TPS can provide accurate dose calculations for eye plaque implants with either type of sources.

Clinical and dosimetric factors associated with acute rectal toxicity in patients treated with 131Cs brachytherapy for prostate cancer - Corrected Proof

Abhay S. Gokhale, Sushil Beriwal, Ryan P. Smith, Xiang Li, Ronald Benoit — 2010-01-29

Abstract: Purpose: 131Cs has been recently introduced for use in prostate brachytherapy. We wished to identify clinical and dosimetric factors associated with acute bowel/rectal toxicity in patients treated with 131Cs.Methods and Materials: Patients treated with 131Cs prostate brachytherapy at the University of Pittsburgh were asked to complete expanded prostate cancer index composite surveys preoperatively and at 2–4 weeks and 3 months postimplant. We identified patients who experienced acute and persistent acute bowel toxicity to determine if any factors could correlate with either situation.Results: One hundred six patients were treated with 131Cs from September 2006 to May 2008. Thirty-eight percent of patients met our criteria for patient-appreciated acute bowel symptoms. On multivariate analysis, the volume of rectum receiving 50% of the prescribed dose (R-V50; 4.1 vs. 2.6cc, p=0.01), R-V75 (1.3 vs. 0.62cc, p=0.01), the percentage of the prescribed dose received by 1cc of the rectum (R-D-1cc; 75% vs. 64%, p=0.02), and R-D-2cc (63% vs. 54%, p=0.003) were found to be factors associated with a greater risk of severe acute bowel toxicity. At 3-month followup, 28% of patients had persistent acute bowel toxicity. On multivariate analysis, no factors were identified that correlated with persistent acute bowel toxicity.Conclusions: This study identifies R-V50, R-V75, R-D-1cc, and R-D-2cc as factors associated with patient-appreciated acute rectal toxicity. We are performing dosimetric analysis to determine the optimal distance for the posterior needles from the prostate–rectal interface to decrease rectal dose while still maintaining adequate coverage of prostate.

Time course of prostatic edema post permanent seed implant determined by magnetic resonance imaging - Corrected Proof

2010-01-29

Abstract: Purpose: To quantify the time course of postimplant prostatic edema magnitude and spatial isotropy using serial magnetic resonance imaging (MRI).Methods and Materials: Forty patients with histologic diagnosis of prostate cancer received an iodine-125 seed implant (Day 0) and consented to 1.5-T MRI on Days −1, 0, 14, and 28. Seeds of strength 0.39mCi were placed in a modified peripheral loading pattern to deliver 145Gy to the target volume. MR images consisted of 3–4mm thick axial slices with no gap. The image sets were anonymized and randomized to minimize contouring bias, then contoured by a single radiation oncologist. Contours were reoriented about their center of mass to align the prostate long axis with the superior–inferior (S−I) direction; prostate volumes and dimensions in the left–right (L−R), anterior–posterior (A−P), and S−I directions through the center of mass were calculated.Results: The average relative edema volume was 1.18±0.14 (1standard deviation) on Day 0 and 1.01±0.15 on Day 30. Between Days 0 and 30, the edema resolved linearly with time on average. Average relative edema dimensions on Day 0 in the L−R, A−P, and S−I directions were 1.01±0.07, 1.11±0.09, and 1.08±0.13, respectively.Conclusions: As measured using MRI, the average edema magnitude for our study population was ∼20% on Day 0 and resolved linearly with time to ∼0% on Day 30. The edema exhibited spatial anisotropy, the prostate expanding on Day 0 by ∼10% in each of the A−P and S−I directions and by ∼0% in the L−R direction.

Preliminary results in prostate cancer patients treated with high-dose-rate brachytherapy and intensity modulated radiation therapy (IMRT) vs. IMRT alone - Corrected Proof

2009-10-23

Abstract: Purpose: To analyze results with high-dose-rate (HDR) brachytherapy and intensity modulated radiation therapy (IMRT) vs. IMRT alone for prostate cancer.Methods and Materials: Between October 2003 and August 2008, 284 patients with early stage prostate cancer underwent HDR brachytherapy to 2200cGy and IMRT to 5040cGy (n=240) or IMRT alone to 7920–8100cGy (n=44).Results: The median followup was 2.2 years. There was no significant difference in terms of the proportions of patients who had diabetes mellitus (p=0.07) or who received hormonal therapy (p=0.75) by radiotherapy technique.The 3-year biochemical disease-free survival rates in low-risk, intermediate-risk, and high-risk patients treated with HDR brachytherapy and IMRT are 100%, 98%, and 93%, respectively. The 3-year biochemical disease-free survival rates in low-risk, intermediate-risk, and high-risk patients treated with IMRT alone are 100%, 100%, and 67%, respectively. There was no significant difference in biochemical disease-free survival or toxicity between treatment groups. The similarity in outcomes between treatment groups remained unchanged when we examined only hormone-naive patients.Conclusions: The HDR brachytherapy and IMRT yielded similar biochemical disease-free survival and toxicity to IMRT alone. As a result, we continue to base treatment on physician and patient preference. Longer followup will help to determine the role of HDR brachytherapy and IMRT in the treatment of early stage prostate cancer, particularly because a number of patients received androgen deprivation therapy and we delivered a higher biologically effective dose with combined modality therapy.