Brachytherapy - Articles in Press

Three-dimensional image-based planning for cervix brachytherapy with bilateral hip prostheses: A solution using MVCT with helical tomotherapy - Corrected Proof

2010-03-02

Abstract: Purpose: We present a method of three-dimensional image-based planning for cervix high-dose-rate (HDR) brachytherapy for patients with bilateral metal hip prostheses using megavoltage computed tomography (MVCT) imaging.Methods and Materials: Two patients with bilateral metal hip prostheses were treated with our standard HDR brachytherapy fractionation and critical structure tolerance limits for cervical cancer. MVCT imaging was used for treatment planning because of artifacts present in kilovoltage computed tomography (kVCT), which did not allow visualization of the organs of interest.Results: The MVCT images provided adequate contrast to allow the contouring of organs at risk and the digitization of HDR applicators. HDR brachytherapy treatment planning was successfully accomplished based on MVCT images for 2 patients with bilateral metal hip prostheses.Conclusions: Using MVCT imaging eliminated streak artifacts, which improved the image quality for treatment planning. MVCT offers an option for three-dimensional planning for cervix brachytherapy in patients with bilateral hip prostheses.

Technical aspects and perspectives of the vaginal mold applicator for brachytherapy of gynecologic malignancies - Corrected Proof

2010-02-15

Abstract: Purpose: The importance of the quality of cervical cancer brachytherapy applicators has been reported, suggesting a direct influence of competent technical implant performance on outcome. In our institute, an original brachytherapy technique based on the use of a molded applicator for genital tract brachytherapy has been applied routinely in clinical practice. Here, we report the technical aspects of this customized applicator and perspectives on its use.Technical Aspects: The first step consists of a vaginal impression that accurately shows the topography and extension of the tumor as well as the anatomy of the vagina and cervix. From this impression, an acrylic applicator is made. Then, the intended positions of the vaginal catheters are drawn on the surface of the mold by the radiation oncologist. Two plastic vaginal catheters are introduced and fixed on the internal surface of the molded applicator. A hole for the cervical os is made through which the uterine probe will be positioned.Perspectives: This method allows for high specificity within the framework of a modern brachytherapy procedure, integrating the tumor topography, anatomy of the patient, and internal movements of target and critical volumes. This technique has been successfully extended to other tumor locations, such as genital tract rhabdomyosarcoma in children and postoperative endocavitary brachytherapy in patients with endometrial cancer.Conclusion: Customization of a vaginal brachytherapy applicator allows for the maintenance of morphologic optimization throughout the treatment course, which better takes into account a fourth dimension: internal organ motion during the course of brachytherapy.

Partial vs. whole breast irradiation in a community hospital: A retrospective cohort analysis of 200 patients - Corrected Proof

2010-02-15

Abstract: Purpose: We compared patients undergoing partial breast irradiation (PBI) with the MammoSite applicator (Cytyc Corp., Marlborough, MA) to a similar group of patients who underwent whole breast irradiation with external beam radiotherapy.Methods and Materials: Stage 0–IIA breast cancer patients satisfying American Brachytherapy Society selection criteria and receiving accelerated PBI with the MammoSite system (n=100) were compared for toxicities with similarly staged patients receiving whole breast irradiation using tangential portals (n=100). The MammoSite applicator treatment was prescribed to a total dose of 34Gy. External beam doses generally ranged from 60 to 66Gy.Results: Based on common toxicity criteria scores for acute toxicities, MammoSite patients experienced less cutaneous toxicity, fatigue, and breast pain and had higher Karnofsky performance status scores during the acute period than external beam patients but experienced more seroma pain during followup. These results were both statistically significant and clinically meaningful.Conclusions: In our institutional experience, PBI using the MammoSite applicator produces less acute toxicity than external beam radiotherapy of the whole breast but is associated with an increased incidence of seroma pain. The rate of disease recurrence in both cohorts was low.

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.

Prostate gland edema after single-fraction high-dose rate brachytherapy before external beam radiation therapy - Corrected Proof

Fabio L. Cury, Marie Duclos, Armen Aprikian, Horacio Patrocinio, Luis Souhami — 2010-02-10

Abstract: Purpose: High–dose rate brachytherapy (HDRB) is frequently used as a boost to external beam radiation therapy (EBRT) in prostate cancer patients. With the increasing use of small planning target volume margins in EBRT, prostatic edema induced by HDRB can be a contributing factor to geometric miss when HDRB is performed before or during EBRT. We assessed prostate gland volumetric change after single-fraction HDRB and its impact on definition of treatment volume for EBRT.Methods and materials: Thirty-one consecutive patients with intermediate-risk prostate cancer treated with single-fraction HDRB (10Gy) combined with hypofractionated EBRT were analyzed. A second CT scan was performed 7 days after HDRB, and images were coregistered with the planning CT scan that contained the original clinical target volume (CTV). The post-HDRB prostate CTV volume was compared with the original CTV by a single observer.Results: All patients presented volumetric variation. In most cases (68%), the prostate increased in volume, whereas it decreased in 32%. The mean prostatic volume was 42.2cc before HDRB and 43.6cc after HDRB, representing a mean volume difference of 3.4%, ranging from −14.2% to 23.8% (p=0.756). This difference is the result of mean changes of 0.6mm (−6.1 to 6.6) in the anterior–posterior, 0.5mm (−5.5 to 3.0) in the lateral, and 0.2mm (−5.0 to 5.0) in the superior–inferior axes.Conclusions: Although a nonsignificant volumetric change occurs after single-fraction HDRB, individual variations on specific axis could lead to important uncertainties during EBRT.

Investigation of geometric distortions on magnetic resonance and cone beam computed tomography images used for planning and verification of high–dose rate brachytherapy cervical cancer treatment - Corrected Proof

2010-02-10

Abstract: Purpose: To measure the amount of geometric distortions present in the three-dimensional imaging modalities—cone beam computed tomography (CBCT) and magnetic resonance imaging (MRI)—used at University of California, San Francisco, CA, for gynecologic high dose rate brachytherapy.Methods and materials: An MRI- and CT–compatible water phantom with two different sets of support structures was designed and built for this study. The support structures were used to precisely position catheters that were filled with either an MRI contrast agent or a string of radio-opaque markers. The first support structure without anatomy was built to test system-based distortions. A second structure included two types of gynecologic applicators as well as several anatomical structures, including bones and rectum to test object-induced distortions. Images were acquired with CT (for reference), kilovoltage CBCT, and MRI (1.5T with T1- and T2-weighted images). The difference in catheter positions between the images and the CT images was analyzed.Results: For CBCT, the mean of the absolute deviations was below 1mm in all directions. The inherent uncertainty in the measurement of distortion was less than 0.5mm. MRI presented mean absolute system-based distortions between 0.6 and 1.1mm in the central region of the image and between 0.7 and 2.3mm in the outer region. Images with the applicator and anatomy in place created mean absolute distortions of 0.4, 0.8, and 0.8mm or less for CBCT, MR-T1, and MR-T2 images, respectively.Conclusions: The distortions measured in the presence of applicators are small enough to validate the use of CBCT and 1.5T MRI for GYN brachytherapy treatment planning and verification.

Definitive radiation therapy for endometrial cancer in medically inoperable elderly patients - Corrected Proof

2010-02-01

Abstract: Purpose: With the increasing elderly population, more women with newly diagnosed endometrial cancer may not be surgical candidates due to medical comorbidities. Definitive radiation therapy with external beam radiation (EBRT) and/or brachytherapy is a reasonable primary treatment for endometrial cancer in patients who cannot undergo surgery.Methods: A retrospective review identified 26 women 75 years and older with endometrial cancer who were not operative candidates due to comorbidities and received definitive radiation.Results: The median age of the treated patients was 83, all of whom had significant medical comorbidities precluding surgical treatment. Seventy-three percent of the patients had stage T1 disease, 19% were stage T2, and 8% were stage T3. Seventy-three percent of patients received EBRT before brachytherapy (median dose: 45 Gy). The median brachytherapy dose was 20 Gy in 5 fractions. The types of brachytherapy used were Rotte Y applicator (42%), tandem and cylinder (42%), and ring and tandem (16%). Median followup was 12 months (1–60 months). No treatment breaks were required for the entire group and only 2 patients (8%) developed late toxicity. The overall survival for all patients was 89% and 28% at 1 and 2 years, respectively. Disease-specific survival for all patients was 93% at 1 year and 73% at 3 years.Conclusions: The results in this study indicate that definitive radiation with EBRT and/or brachytherapy for endometrial cancer is feasible and well tolerated in an elderly population.

Differences between intraoperative ultrasound-based dosimetry and postoperative computed tomography-based dosimetry for permanent interstitial prostate brachytherapy - Corrected Proof

2010-02-01

Abstract: Purpose: To compare the results of intraoperative ultrasound (US)-based dosimetry with those of postimplant computed tomography (CT)-based dosimetry after 125I prostate brachytherapy.Methods and Materials: Subjects comprised 160 patients who underwent prostate brachytherapy using 125I seed implants. Prescribed dose was set as 145Gy to the periphery of the prostate. Implantation was performed using an intraoperative interactive technique. Postimplant dosimetry was performed on Days 1 and 30 after implantation using CT. Dosimetric results for the prostate, urethra, and rectum were compared among intraoperative US and CT on Day 1 (CT1) and Day 30 (CT30).Results: Mean minimal dose received by 90% of prostate volume was 133.7%, 115.6%, and 125.8% of the prescribed dose on US, CT1, and CT30, respectively: This value temporarily decreased on Day 1 and increased on Day 30. Other parameters for the prostate and urethra showed similar trends. Conversely, mean rectal volume receiving 100% of the prescribed dose was 0.69, 0.46, and 1.02mL on US, CT1, and CT30, respectively. Rectal parameters tended to be underestimated on US relative to CT30-based dosimetry. A positive linear relationship was identified between US and CT observations for every prostate parameter and the dose covering 30% of the urethra.Conclusions: Our results demonstrate significant differences between dosimetric parameters obtained by US, CT1, and CT30. However, significant correlations also exist between US and CT, at least in prostate and urethral parameters. Clarification of the degrees of difference might make US planning more feasible.

Retrospective study of 81 patients treated with brachytherapy for endobronchial primary tumor or metastasis - Corrected Proof

Anne Dagnault, Annie Ébacher, Éric Vigneault, Serge Boucher — 2010-02-01

Abstract: Purpose: The purpose of this retrospective study is to evaluate the role of endobronchial brachytherapy in the palliation of lung cancer (or metastasis) symptoms and its potential impact on overall survival.Methods and Materials: Eighty-one patients were included in this study. Endobronchial brachytherapy catheter was placed under conscious sedation. The projection of the tumor was drawn by the bronchoscopist to help the radiation oncology team to perform the dosimetry. Patients were treated with iridium-192 high-dose rate afterloading unit. Patients were planned to receive 5Gy in four fractions weekly for a total of 20Gy.Results: Seventy-three percent of the patients were treated for primary lung cancer. The remaining patients were treated for lung metastasis of other primary. Most patients presented dyspnea, cough, or hemoptysis. These three main symptoms were relieved in 85%, 77%, and 100%, respectively. The median survival was 14.7 months and local progression-free survival at 12 months was 77% and at 24 months 64%, respectively.Conclusion: Endobronchial brachytherapy is a very effective palliative treatment for endobronchial lesions.

Acquisition of equal or better planning results with interstitial brachytherapy when compared with intensity-modulated radiotherapy in tongue cancers - Corrected Proof

2010-01-29

Abstract: Purpose: Intensity-modulated radiotherapy (IMRT) technique in external beam radiotherapy and interstitial implant brachytherapy (ISBT) play important role in the treatment of head and neck cancers. Both are proved to be highly conformal techniques of radiotherapy. In this study, we investigated whether ISBT can give treatment planning results similar to those of IMRT.Methods and Materials: Fifteen patients with tongue cancer treated with interstitial high-dose-rate brachytherapy were replanned. They were evaluated with the IMRT planning system. Contouring of target volume, including all critical structures was done on the IMRT treatment planning system to closely match implant brachytherapy planning system. Treatment plans were generated after specifying the goals in the prescription. Conformity index and dose to critical organ were calculated and compared between IMRT and ISBT. Planning time was also recorded for both the techniques in all the cases.Results: Very good dose conformity was observed in ISBT, which was almost the same as that in IMRT. Dose to the critical structure was lower in ISBT in all the cases. Planner time was also less in ISBT for more number of cases.Conclusions: Results show that ISBT treatment modality produces equal or superior planning results when compared with IMRT with our optimization techniques. These results encourage us to continue ISBT practice.

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.

Prostate brachytherapy seed migration to the left testicular vein - Corrected Proof

Ba D. Nguyen, Genevieve L. Egnatios — 2010-01-29

Abstract: Purpose: Prostate brachytherapy seeds may detach from their initial insertion sites and migrate to lungs, heart, coronary artery, liver, kidney, and vertebral venous plexus. The authors present the left testicular vein as additional site of seed embolization.Methods and Materials: The authors report a 68-year-old man with seed migration to the left testicular vein shortly after brachytherapeutic procedure. All imaging procedures obtained after the transperineal seed implant insertion are retrospectively analyzed in correlation with the patient's clinical course.Results: The retrospective imaging review shows a left lower abdominal seed anterior to the left psoas muscle. CT re-evaluation localizes the seed in the left testicular vein. This embolized seed was not initially identified on any imaging modality. Although there is no solid cause–effect proof in this case, the fully potent embolized seed may be contributory to the patient's testicular symptomatology.Conclusion: The uncommon seed relocation to the left testicular vein is probably because of periprostatic–pampiniform venous communication.

Efficacy of high-dose-rate interstitial brachytherapy in patients with oral tongue carcinoma - Corrected Proof

2010-01-29

Abstract: Purpose: To evaluate the results of high-dose-rate (HDR)-interstitial brachytherapy (ISBT) in oral tongue carcinomas.Methods and Materials: Between September 1999 and August 2007, 50 patients were treated for oral tongue carcinoma with HDR-ISBT. The patient's mean age was 58 years. Forty-two patients were in T1–2 stage and 8 patients were in T3 stage; 16 patients were in N+ stage and 34 patients in N0 stage. Exclusive ISBT was given to 17 patients (34%) in T1–2 N0 stage and complementary to external beam radiotherapy (EBRT) to 33 patients (66%). A perioperative technique was performed on 14 patients. The median total dose was 44Gy when HDR was used alone (4Gy per fraction) and 18Gy when complementary to 50Gy EBRT (3Gy per fraction).Results: The median followup was 44 months. Actuarial disease-free survival rates at 3 and 5 years were 81% and 74%, respectively. Local failure developed in 7 patients. Actuarial local control (LC) rates were 87% and 79% at 3 and 5 years in T1–2 stage 94.5% and 91% and T3 stage 43% and 43% (with salvage surgery). Exclusive HDR cases showed LC in 100% of the cases, and the combined group (EBRT+HDR) showed LC in 80% and 69% of the cases at 3 and 5 years (p=0.044). Soft-tissue necrosis developed in 16% and bone necrosis in 4% of the cases.Conclusions: HDR brachytherapy is an effective method for the treatment of oral tongue carcinoma in low-risk cases. Doses per fraction between 3 and 4Gy yield LC and complication rates similar to low-dose rate. The perioperative technique promises encouraging results.

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.

Howard Kelly establishes gynecologic brachytherapy in the United States - Corrected Proof

Jesse N. Aronowitz, Roger F. Robison — 2009-12-21

Abstract: Purpose: Exploration of Howard Atwood Kelly's contributions to gynecologic brachytherapy.Methods and Materials: Review of contemporary journals, texts, newspaper accounts, and the memoirs of Kelly's associates. Information from unpublished material, including Kelly's handwritten notes and diaries, was culled from the Alan Mason Chesney Archives of the Johns Hopkins Medical Institutions.Results: Despite European reports of radium's efficacy, gynecologists on both sides of the Atlantic resisted its adoption. The endorsement of radium therapy by America's foremost gynecologist, Howard Kelly, was instrumental in its acceptance. His consummate skill as clinician, investigator, publicist, and entrepreneur established brachytherapy as the primary treatment modality for carcinoma of the cervix and vagina. The technique he pioneered in the second decade of the 20th century, a combination of brachytherapy and megavoltage-equivalent teletherapy, presaged modern practice.Conclusion: Principles for the management of female genital neoplasia, outlined by Howard Kelly nine decades ago, remain relevant today.

The impact of perineural invasion on biochemical outcome after permanent prostate iodine-125 brachytherapy - Corrected Proof

2009-12-21

Abstract: Purpose: Perineural invasion (PNI) in prostate biopsies is associated with increased risk of higher Gleason score and worse pathologic stage. We report the influence of PNI in biochemical no evidence of disease (bNED) survival after 125I prostate brachytherapy (BT).Methods and Materials: Pathology reports of 700 men with localized prostate cancer who underwent 125I prostate BT in 1999–2008 were reviewed. The presence or absence of PNI in the biopsy was documented in 339 men. Clinical, treatment, and dosimetric parameters, along with PNI status, were evaluated for bNED survival, defined by “nadir+2” definition.Results: Of the 339 patients, 87% had favorable risk and 13% intermediate risk. PNI was present in 89 patients (26%). After a median followup of 32 months, there were five biochemical failures (4: +PNI and 1: −PNI), of which one was local failure (+PNI). Actuarial 5-year bNED survival for the entire group was 97.0% (92.9% for +PNI; 99.2% for −PNI). In univariate analysis age, pretreatment prostate-specific antigen, Gleason score 7, and intermediate risk group predicted for worse biochemical outcome, whereas the presence of PNI showed a trend toward significance (p=0.06). Some of the regression algorithms failed to converge because of low event rates.Conclusions: We report excellent biochemical control in 339 men treated with 125I prostate BT. The presence of PNI showed a trend toward significance in predicting 5-year bNED survival but did not impact on local control and should not influence the decision to recommend BT for localized prostate cancer.

Do high radiation doses in locally advanced prostate cancer patients treated with 103Pd implant plus external beam irradiation cause increased urinary, rectal, and sexual morbidity? - Corrected Proof

Nelson N. Stone, Jamie A. Cesaretti, Barry Rosenstein, Richard G. Stock — 2009-11-02

Abstract: Purpose: To investigate the morbidity of higher radiation doses in prostate cancer patients.Methods and Materials: Five hundred eighty-five men treated with seed implantation and external beam irradiation were followed a median of 5 years (range, 2–11). Hormonal therapy (HT) of 9 months duration was used in 504 (86.2%) patients. The biologic effective dose (BED) was calculated using an α/β of 2. Urinary incontinence (UI) and symptoms (IPSS) were prospectively collected. Rectal morbidity was scored according to the Radiation Therapy Oncology Group (RTOG) scale. Two BED dose groups of ≤220Gy (n=449) and >220Gy (n=136) were used. Comparisons of means were made by Student's t test, and the associations were tested by chi-square analysis (Pearson).Results: Urinary retention developed in 36 (6.2%) and was not associated with BED or IPSS. Retention occurred more often with prostate volume >50cc (17%, p=0.001). The median change in urinary symptoms (IPSS) was 1. Sixty-one percent with high BED were more likely to have increased postimplant symptoms compared with 39% with lower BED (p=0.025; odds ratio [OR], 1.107; 95% confidence interval [CI], 1.10–1.21). UI occurred in 25 patients (4.3%) and was only associated with a postimplant transurethral resection of the prostate (TURP) (n=25), 16% vs. 2.3% for no TURP (p=0.001; OR, 8; 95% CI, 2.4–27). Of the 373 patients initially potent, 204 (54.7%) maintained potency. Impotence was only associated with age at implant (p=0.001) and HT (p=0.004). Sixty-two (10.6%) patients had Grade 1–2 and 4 patients had Grade 3–4 (0.7%, 2 ulcers and 2 fistulas) rectal complications. Three of the Grade 3/4 complications occurred with a dose ≤220Gy.Conclusion: A BED >220Gy does not seem to increase morbidity.

Values of biologically equivalent doses in healthy tissues: Comparison of PDR and HDR brachytherapy techniques - Corrected Proof

Janusz Skowronek, Julian Malicki, Tomasz Piotrowski — 2009-11-02

Abstract: Purpose: The aim of this work was to compare the values of doses measured in healthy tissues in chosen pulsed-dose-rate (PDR) brachytherapy (PDRBT) and high-dose-rate (HDR) brachytherapy (HDRBT) fractionation schemas.Methods and Materials: Fifty-one patients treated with PDRBT were qualified for calculations. This group included patients with head and neck cancer, brain tumor, breast cancer, sarcoma, penile cancer, and rectal cancer. The doses were calculated in chosen points in surrounded organs at risk (OaR). The biologically equivalent dose (BED) formula was used to compare doses in PDRBT and HDRBT.Results: One ascertained that in biologically equivalent (to PDR) HDRBT, the increase of fractional dose from 4 to 10Gy caused the necessity to decrease the total dose in treatment target (p<0.001). The use of HDR instead of PDR essentially caused lower physical and biologic doses in examined OaR. In many examined critical points in OaR where BED in the treatment area was the same, one ascertained the decrease of total physical HDR dose according to the growth of the fractional dose. Similar dependences were observed for BED.Conclusions: The use of biologically equivalent HDRBT instead of PDRBT caused the decrease of physical doses in the treatment target and the decrease of physical doses and BEDs in OaR. Prolongation of intervals between pulses in PDRBT was connected with lower values of BED doses in healthy tissues.

A single-institutional brachytherapy experience in the management of esophageal cancer - Corrected Proof

2009-10-30

Abstract: Purpose: The aim of this work was to analyze the efficacy of high-dose-rate brachytherapy in the management of patients with esophageal cancer.Methods and Materials: Between 2001 and 2008, 104 patients (88 males and 16 females) received a brachytherapy treatment as a part of a personalized multimodal approach. The median age was 72 years, and the median Karnofsky performance status was 60. Brachytherapy was used in different situations: to complete a primary treatment with radical intent in patients not suitable for surgery; to control local recurrences; or to obtain a rapid and durable palliation of dysphagia in patients with metastases or in poor general condition. In selected cases, endoscopic ultrasound images were integrated in treatment planning procedure to obtain a more accurate volume definition. Efficacy in controlling dysphagia was assessed 1 month after brachytherapy.Results: Fifty-one patients received a radical treatment, and 53 patients were treated to relieve the symptoms. The median overall survival was 20.8 months. Lymph node involvement was found to be a significant prognostic factor for overall survival and dysphagia. Dysphagia was controlled in 88 patients (84.6%), and the median dysphagia-free interval was 17.5 months. Early and late adverse events were generally mild to moderate. The most severe effects were esophagotracheal fistulas, observed in 3 patients.Conclusions: Brachytherapy has an important role in the management of esophageal cancer with a low rate of complications. endoscopic ultrasound–assisted treatment planning can be useful for a better individualization of curative treatments.

Less-restrictive, patient-specific radiation safety precautions can be safely prescribed after permanent seed implantation - Corrected Proof

2009-10-26

Abstract: Purpose: To use radiation exposure rate measurements to determine patient-specific radiation safety instructions with the aim of reducing unnecessary precaution times and to evaluate potential doses to members of the public.Methods and Materials: Radiation exposure rate measurements were obtained from 1279 patients with Stage T1-2 prostate cancer who underwent transperineal 125I or 103Pd seed implantation from January 1995 through July 2008. An algorithm was developed from these measurements to determine the required precaution times to maintain public effective doses below 50% of the limits for specific exposure situations.Results: The median air kerma rates at 30cm from the anterior skin surface were 4.9μGy/h (range: 0.1–31.5) for 125I and 1.5μGy/h (range: 0.02–14.9) for 103Pd. The derived algorithms depended primarily on the half-life Tp, the measured exposure rate at 30cm, and specific exposure situation factors. For the typical 103Pd patient, no radiation safety precautions are required. For the typical 125I patient, no precautions are required for coworkers, nonpregnant adults who do not sleep with the patient, or nonpregnant adults who sleep with the patient. Typical 125I patients should only avoid sleeping in the “spoon” position (i.e., in contact) with pregnant adults and avoid holding a child for long periods of time in the lap for about 2 months.Conclusions: The large number of cases available for this study permitted the development of an algorithm to simply determine patient-specific radiation safety instructions. The resulting precaution times are significantly less restrictive than those generally prescribed currently.

Penile brachytherapy: Technical aspects and postimplant issues - Corrected Proof

Juanita Crook, John Jezioranski, Joanna E. Cygler — 2009-10-26

Abstract: PURPOSE: Squamous carcinoma (SCC) of the penis affects about 1 in 100,000 men in western societies. Interstitial brachytherapy can be an effective penis-conserving modality for T1, T2, and selected T3 tumors. Unfortunately, few radiation oncology trainees have the opportunity to treat a case of penile cancer during their residency, and few centers have brachytherapy expertise for this tumor site. We report our technique that has been developed and refined over the past 20 years.Materials and Methods: From 1989 to 2009, we have been using brachytherapy to treat penile SCC and have experience with 75 cases. From 1989 to 1998, manual afterloading was used with 192Ir wire or seeds, and from 1999 to the present, pulse dose rate automated afterloading. Sixty Gray is delivered over a period of 4–5 days.Results: Patient selection for penile brachytherapy and the technical and dosimetric aspects of the procedure will be discussed along with posttreatment care and followup.Conclusions: Brachytherapy is an effective treatment for T1, T2, and selected T3 SCC of the penis. Efficacy depends on careful planning and appreciation of dosimetry.

Preliminary results with accelerated partial breast irradiation in high-risk breast cancer patients - Corrected Proof

2009-10-26

Abstract: Purpose: To analyze prognostic factors in adequately staged breast cancer patients who were treated with accelerated partial breast irradiation (APBI).Methods and Materials: Axillary staging was required for invasive carcinomas. Between February 2003 and June 2009, 204 women with early stage breast carcinomas were treated with APBI using multicatheter, MammoSite, or Contura brachytherapy to 34Gy in 10 fractions 2 times per day. Six patient characteristics were examined for prognostic significance: (1) N stage, (2) estrogen receptor (ER) status, (3) histologic subtype, (4) margin status, (5) age, and (6) tumor size. The median followup was 22 months.Results: There were three failures in the ipsilateral breast (all were elsewhere failures), one relapse in the axilla, and seven relapses at any site. The presence of positive axillary node(s) had a significant adverse effect on ipsilateral breast tumor control (p=0.045) and locoregional control (p=0.001). The presence of an ER (−) tumor had a significant adverse effect on relapse-free survival (p=0.04).Conclusions: The patients with positive axillary node(s) were at increased risk for failure elsewhere in the ipsilateral breast or axilla, and the patients with ER (−) tumors were at increased risk for relapse at any site. However, it is unclear whether the pN1 and ER (−) patients would have faired any better if they had received whole breast irradiation rather than APBI. We believe that the patients with positive axillary node(s) or ER (−) tumors should be treated on clinical trials to better define the role of APBI.

Practical considerations for prostate HDR brachytherapy - Corrected Proof

Eric D. Slessinger — 2009-10-23

Abstract: Purpose: A process for prostate high-dose-rate (HDR) brachytherapy was developed and implemented successfully in the community hospital setting. The practical aspects of the program are reviewed and may serve as a foundation for clinics interested in offering this clinical service.Methods and Materials: A generic needle distribution geometry was established to accommodate target volumes of variable size. A system to identify and assign treatment channels to each implant needle was devised. The computerized tomography (CT)–based treatment planning was used with dose constraints defined for sensitive structures and target uniformity. Implant needle stability was promoted by supporting the patient on a CT compatible padded sliding board. A process that aligns dwell position to CT imaging without the use of radiographic markers was followed. Graphical optimization of dwell times was used to generate the treatment dose distributions.Results: Prostate HDR brachytherapy as a boost or as monotherapy has been offered in a program that has evolved over the past 8 years. Practical aspects of the program promote its feasibility and precision. Collaboration with commercial entities has also led to the development of products that support the technique.Conclusions: Prostate HDR brachytherapy offers a relatively high degree of dose distribution control in comparison with other prostate radiotherapy modalities. The practical aspects described offer assurance to achieve that goal.

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.

Effect of planning margin on dosimetric quality in 131Cs permanent prostate brachytherapy - Corrected Proof

Texin Li, Betty L. Fountain, Edward W. Duffy — 2009-10-23

Abstract: Purpose: To investigate the dosimetric effect of planning margin in 131Cs prostate seed implants.Methods and Materials: The transrectal ultrasonography images are obtained intraoperatively in 5-mm steps from base to apex. The prostate is contoured as clinical target volume (CTV). The CTV is enlarged with 3mm expansion except the posterior. The CTV and planning target volume (PTV) are then used as planning target for treatment planning, respectively. Dose calculations are performed using VariSeed treatment planning system using AAPM TG-43 formalism. The total activity implanted, target coverage (the percent of the prostate volume covered by the prescription dose, V100; the dose that covers 90% of the prostate volume, D90) for CTV and PTV, dose inhomogeneity (the percentage volume of the prostate receiving 150% of the prescription dose [V150]), and the critical organ dose (the dose that covers 10% of the urethra volume [UD10] for urethra and the dose that covers 50% of the rectum volume [RD50] for rectum) are compared.Results: When CTV is used as target for planning, compared with PTV as planning target, the total activity implanted is decreased by 5.6%. Integral dose is thus lower by 5.6%. Coverage for CTV (CTV100) is increased by 0.3%. Coverage for PTV (PTV100) is lower by 2.1%. CTV150 is increased by 13.6%. PTV150 is higher by 2.5% with a standard deviation of 10.2%. Rectum dose (RD50) is lower by 4.5%. Urethra dose (UD10) is higher by 10.0%.Conclusion: It is shown that the planning margin has minimal effect on dosimetric quality because of 131Cs's gradual dose fall-off. Thus, it is possible to reduce or even eliminate planning margin using 131Cs. The modest benefits in reducing the planning margin, such as lower total activity (lower integral dose), dose reduction to surrounding healthy tissues and reduced likelihood of seeds migration, can be achieved while adequate coverage is maintained.

Periauricular mold brachytherapy - Corrected Proof

Bahadir Ersu, Ibrahim Tulunoglu, Mustafa Cengiz — 2009-10-23

Abstract: Purpose: We present a patient with recurrent basal cell carcinoma (BCCA) who was treated with custom-made mold brachytherapy.Methods and Materials: The patient was admitted to the hospital with the complaint of recurrent BCCA of the auditory canal. He has previously treated by surgery and external beam radiotherapy. We decided to continue with reirradiation to tumor bed after surgical excision. A total of 25Gy to 5mm depth of surgical bed was delivered by mold brachytherapy.Results: The patient did well during the treatment without any acute toxicity. He was lost to followup after 2 years of treatment without any obvious late morbidity.Conclusion: Custom-made mold brachytherapy is an alternative treatment modality, for reirradiation of selected group of patients, with minimal morbidity and good disease control.

Late rectal toxicity after prostate brachytherapy: Influence of supplemental external beam radiation on dose–volume histogram analysis - Corrected Proof

2009-10-23

Abstract: Purpose: To describe the rate of gastrointestinal (GI) toxicity after prostate brachytherapy and describe how external beam radiation therapy (EBRT) may influence the association of rectal dose–volume histogram (DVH) parameters with rectal toxicity.Methods and Materials: One hundred ten patients with prostate cancer were treated with I-125 brachytherapy alone (n=62, 144Gy) or as a boost (n=48, 108Gy) after 45-Gy EBRT. CT-based dosimetry was performed a median of 29 days after implantation. GI toxicity was evaluated by Radiation Therapy Oncology Group criteria. Median followup was 41 months.Results: Eleven patients developed Grade 2+GI toxicity. Men treated with EBRT had an increased risk of GI toxicity, with freedom from Grade 2+ toxicity of 82% vs. 91% for implant alone, but this difference was not statistically significant (p=0.3044). Of the DVH parameters analyzed, only the rectal volume receiving the prescription dose (rV100%) was associated with late Grade 2+GI toxicity. Men with rV100%≥0.05cc had a 4-year freedom from Grade 2+ toxicity of 77% vs. 100% for those with an rV100%<0.05cc (p=0.0248). However, this relationship was only significant for the subset of patients treated with EBRT, where men with rV100%≥0.05cc had a 26% risk of Grade 2+ toxicity compared with 0% for rV100%<0.05cc. Additional DVH parameters, including dose to the hottest 0.1cc (p=0.0199), 1% (p=0.0086), and 3% (p=0.0043), were also associated with GI toxicity but only in men treated with EBRT.Conclusions: Supplemental EBRT may lower the threshold for rectal toxicity after prostate brachytherapy. Morbidity can be minimized by observing rectal constraints.

PSA bounce after prostate brachytherapy with or without neoadjuvant androgen deprivation - Corrected Proof

2009-10-22

Abstract: Purpose: To assess the impact of PSA bounce (PB) on biochemical failure (BF) and clinical failure (CF) in brachytherapy patients treated with or without neoadjuvant androgen deprivation (AD).Methods and Materials: From 1987 to 2003, 691 patients with clinical stage T1–T3N0M0 prostate cancer were treated with external beam radiotherapy (EBRT) and high-dose-rate (HDR) brachytherapy boost (n=407), HDR brachytherapy alone (n=93), or permanent seed implant (n=191). Three hundred seventeen patients (46%) received neoadjuvant/adjuvant AD with RT. BF was scored using 3 definitions (ASTRO—3 rises, nadir+2ng/ml, and threshold 3ng/ml) based on current and absolute nadir (AN) methodologies. PB was defined as any increase in PSA followed by a decrease to the prior baseline or lower. The median followup was 4.0 years.Results: Forty-six patients (7%) experienced CF at 5 years. PB of ≥0.1, ≥1.0, and ≥2.0ng/ml at any time after RT occurred in 330 (48%), 60 (9%), and 22 patients (3%) respectively. The use of an AN definition reduced the likelihood of scoring PB as BF across all levels. The patients receiving AD experienced significantly longer bounce duration. Bounce <1.0ng/ml showed no association with CF. For bounce ≥1.0ng/ml, 10% demonstrated CF vs. 6% without bounce of this amplitude (p=0.27). Bounces ≥1.0ng/ml were more likely to be scored as BFs for definitions based on current nadir (3 rises: 20% vs. 13%, nadir+2: 43% vs. 11%, 3 at/after nadir: 57% vs. 12%) than those based on AN (3 rises: 8% vs. 10%, nadir+2: 18% vs. 11%, 3 at/after nadir: 13% vs. 11%).Conclusions: Bounces ≥1.0ng/ml are rare after brachytherapy with or without neoadjuvant AD, occurring in less than 10% of patients. Low PBs have little impact on BF, but as PB amplitude increases, the BF rate increases. BF definitions based on AN are less sensitive to PB after brachytherapy.

Treatment outcome and toxicity after salvage 125-I implantation for prostate cancer recurrences after primary 125-I implantation and external beam radiotherapy - Corrected Proof

2009-10-22

Abstract: Purpose: To evaluate the outcome and toxicity after salvage iodine-125 (125-I) implantation in patients with locally recurrent prostate cancer after primary 125-I implantation and external beam radiotherapy.Methods and Materials: Retrospectively, 31 patients were analyzed with pathology-proven local recurrent prostate cancer after primary external beam radiotherapy (n=20) or 125-I implantation (n=11), and who had undergone salvage 125-I implantation between 1994 and 2009. For recording biochemical failure rates, the Phoenix definition and the American Society for Therapeutic Radiology and Oncology definition were applied. Toxicity was scored according to the Common Terminology Criteria for Adverse Events version 3.0 (CTCAE v3.0) (Cancer Therapy Evaluation Program, National Cancer Institute, National Institutes of Health, Bethesda, MD).Results: The mean (±standard deviation [SD]) followup was 9 years (±4). The freedom from biochemical failure after 1 and 5 years' followup were 51% and 20%, respectively. Fourteen (45%) patients died of prostate cancer after a mean (±SD) followup of 73 (±39) months. Grade 1, 2, or 3 toxicity of the genitourinary tract was reported in 29%, 58% and 3% of the patients, respectively, in the acute phase, and in 16%, 39%, and 19%, respectively, in the late phase. Grade 1, 2, or 3 toxicity of the gastrointestinal tract was reported in 45%, 10%, and 0% of the patients, respectively, in the acute phase, and in 48%, 3%, and 6%, respectively, in the late phase. Grade 4 toxicity of any tract occurred in none of the patients in the acute or the late phase.Conclusions: Freedom from biochemical failure after salvage 125-I implantation for locally recurrent prostate cancer after radiotherapy is limited, and both genitourinary and gastrointestinal toxicity occur frequently.

An intraoperative real-time sleeved seed technique for permanent prostate brachytherapy - Corrected Proof

2009-10-22

Abstract: Purpose: To describe a novel technique that integrates customized sleeved seed production to reduce seed migration using preloaded needles with real-time intraoperative dosimetric planning for patients treated with iodine-125 (I-125) permanent prostate seed implants.Methods and Materials: Customized seed-spacer sequences were calculated for patients in real time based on an intraoperative transrectal ultrasound-guided volume study. Using a Fox Chase Cancer Center modified Best Iodine-125 seed loader (Best Medical, Springfield, VA), the seeds and spacers were inserted into a hollow suture material (sleeve) and then loaded into the implant needles. Needles were placed sequentially under transrectal ultrasound guidance with sagittal plane visualization of the dropped sleeved seeds.Results: This technique was successfully implemented allowing intraoperative planning to be combined with real-time sleeved seed production.Conclusions: The use of sleeves for seeds combined with real-time intraoperative planning allowed for the intraoperative customization of implants with the practical advantages of linked seeds.