Brachytherapy

Rectal morbidity after permanent interstitial brachytherapy for prostate cancer—Impact of Day 1 vs. Day 30 computed tomography–based postimplant dosimetry

2009-09-04

Abstract: Purpose: The aim of the study was to evaluate bowel quality-of-life changes after prostate brachytherapy and the impact of Day 1 vs. Day 30 postimplant dosimetry.Methods and Materials: In 61 patients, computed tomography (CT) scans were performed at Days 1 and 30 after 125I brachytherapy. The patients have been surveyed prospectively before (time A), 1 month (time B), and >1 year after treatment (time C) using a validated questionnaire (Expanded Prostate Cancer Index Composite). Different parameters were tested for their predictive value on bowel quality-of-life changes (bowel bother score decrease >20 points at time B=BB20; bowel bother score decrease >10 points at time C=BC10), including seed displacements.Results: Mean bowel function/bother score decreased 13/13 points at time B (p<0.01) and 1/4 points at time C (change not significant). BB20 and BC10 were found in 25% and 20% of patients, respectively. Bowel bother score declines at time B correlated well with declines at time C (r=0.53; p<0.01). Prostate volume before implantation and the number of seeds per cubic centimeters were found to be predictive for BB20 and BC10. Smaller rectal wall volumes covered by the 60–100% isodoses at Day 1 were (paradoxically) found to be significantly predictive for BC10. Larger posterior seed displacements between Days 1 and 30 were significantly associated with BB20.Conclusions: Quality-of-life scores have not been found to change significantly >1 year after brachytherapy. Larger rectal wall volumes within higher isodoses at Day 1 or 30 were not found to be predisposing for adverse quality-of-life changes.

Relationship between Day 0 dosimetric parameters and biochemical relapse-free survival in patients treated with transperineal permanent prostate interstitial brachytherapy with 125I seeds

2009-10-21

Abstract: Objectives: To determine the relationship between dosimetric parameters obtained on postimplantation Day 0 and biochemical relapse-free survival (bRFS) in patients treated with 125I transperineal interstitial permanent prostate brachytherapy (TIPPB).Methods: Two-hundred twenty men with low-risk (n=155, 70.4%), low-volume intermediate-risk (n=63, 28.7%), or high-risk (n=2, 0.9%) prostate cancer were treated with TIPPB between December 2000 and June 2006. Seventy-four (33.6%) patients received short-term (3–6 months) androgen suppression therapy before TIPPB. The median followup for patients free of biochemical failure was of 37.9 months (range, 24.0–84.5 months).Results: The receiver operating characteristic (ROC) analysis established a best-fit cutoff value for the quantifiers D90 and V100 of 147Gy and 92%, respectively. The Kaplan–Meier analysis of bRFS at the cutoff value of D90=147Gy using the ASTRO, nadir+2, and combined (ASTRO and nadir+2) definitions showed a trend toward statistical significance for the ASTRO (p=0.076) and nadir+2 (p=0.064) definitions and a statistically significant correlation for the combined definition (p=0.033). The corresponding 7-year bRFS for the D90 >147Gy and D90 ≤147Gy subsets using the ASTRO, nadir+2, and combined definitions were 96.5% vs. 89.7% (ASTRO, p=0.076); 93.7% vs. 70.5% (nadir+2, p=0.064); and 94.4 vs. 75.5% (combined, p=0.033). The V100 (%) cutoff value of 92% predicted by the ROC analysis was not significant. Among other cutoff values, only D90=140Gy (p=0.050) and D90=160Gy (p=0.098) showed a trend toward statistical significance when the nadir+2 and the ASTRO definitions were used. The rest of dosimetric, tumor, and patient parameters did not show statistical correlation with bRFS in the Kaplan–Meier analysis.Conclusions: The cutoff value of D90=147Gy obtained on postimplantation Day 0 showed a trend toward significant correlation with bRFS when the standard ASTRO and nadir+2 definitions were used and a weak but statistically significant correlation with bRFS as per the nonstandard combined definition in a series of patients with predominantly low-risk disease (70.4%) treated at high radiation doses (median D90=152.9Gy, median V100=92.5%).

External beam radiotherapy plus high-dose-rate brachytherapy for treatment of locally advanced prostate cancer: The initial experience of the Catalan Institute of Oncology

2009-09-07

Abstract: Purpose: The objective of this study was to report initial outcomes in patients with locally advanced prostate cancer (CaP) who underwent external beam radiation therapy (EBRT) treatment combined with high-dose-rate brachytherapy (HDR-BT) as a boost.Methods and Materials: From 2002 to 2007, 114 CaP patients underwent EBRT followed by 192I HDR-BT. The patients were classified into intermediate- (Group 1) or high- (Group 2) risk groups. The mean total EBRT dose was 60.0Gy (95% confidence interval [CI]: 59.9–60.1) at 2Gy per fraction. After a mean of 20.6 days (95% CI: 18.4–22.8), all the patients received a single-fraction 9-Gy dose of HDR-BT boost. Of the 114 patients in the study, 103 (90.4%) underwent up to 3 years of complete androgen deprivation therapy after diagnosis.Results: The mean followup for the entire group was 32.1 months (95% CI: 29.9–34.4). The 4-year biochemical failure-free survival rate was 97.4% and treatment was well-tolerated.Conclusions: Preliminary biochemical control rates after EBRT plus one fraction of 9-Gy HDR-BT are encouraging. This atypical fractionation schedule is cost-effective and reduces patient discomfort and treatment-related risks. More followup is required to confirm these findings.

AnchorSeed for the reduction of source movement in prostate brachytherapy with the Mick applicator implant technique

2009-09-18

Abstract: Purpose: The purpose of this study was to evaluate the influence of potential contributing factors to the incidence of seed slippage and quality of prostate brachytherapy dosimetry comparing “coated” vs. “bare” seeds with a Mick applicator.Methods and Materials: Two consecutive groups of 89 patients were treated with 125I prostate brachytherapy at a high treatment volume single institution. All the patients were evaluated with Day 0 plain films of the pelvis and CT-based dosimetry analysis. The incidence of seed slippage was quantified. The seed slippage outcome was evaluated with respect to source type (bare vs. coated). The Day 0 prostate V100, V150, D90%, rectal V100, and urethra D30 outcomes were evaluated with respect to source type.Results: A total of 13,512 seeds were placed in 178 patients. An average of 76 seeds and 16 needles were used for each patient. The bare seed group was significantly higher on fluoroscopy minutes (2.34 vs. 1.58min), seed slippage (5 vs. 1.5mm), volume of rectum receiving 100% of dose (0.05 vs. 0.0cc), dose percentage received by 30% of urethra (119% vs. 113.64%), and volume of prostate receiving 100% of prescription dose (95.21% vs. 92.8%). No significant differences in volume of prostate receiving 150% of prescription dose, dose percentage received by 90% of prostate, vascular seed migration, or operating room procedure time were seen. No seed drift greater than 10mm outside the “packet” of other seeds was seen in the AnchorSeed (BrachySciences, a division of Biocompatibles, Inc. Oxford, CT) cohort.Conclusion: The report is the first to show the unique “fixity” of AnchorSeed to remain in position after deployment from the Mick applicator. Minimizing seed drag can reduce dose to the penile bulb, and maximize radiation coverage to the apex of the gland.

High-dose-rate brachytherapy in combination with conformal external beam radiotherapy in the treatment of prostate cancer

2009-10-21

Abstract: Purpose: To report long-term outcomes for treatment of prostate cancer using dose escalation with high-dose-rate (HDR) brachytherapy and 3-dimensional conformal external beam radiotherapy (3DCRT), and compare them with outcomes for treatment of prostate cancer with 3DCRT alone at the same institution.Methods and Materials: From 1998 to 2003, 587 patients were treated for clinically localized prostate cancer. Patients received either 3DCRT (median, 46Gy) with a single HDR brachytherapy implant (196 patients) delivering a fractionated dose of 18Gy (combined group) or 3DCRT (median, 70Gy; 387 patients; “3DCRT alone”). There were 41.9% patients with intermediate-risk and 42.6% with high-risk disease. In all, 441 patients (75.1%) received neoadjuvant and 116 patients (19.8%) received adjuvant androgen deprivation therapy. The American Society of Therapeutic Radiology and Oncology Phoenix definition for biochemical failure was used.Results: The median followup was 5.5 years. The 5- and 7-year biochemical control (BC) rates were 82.5% and 80.3%, respectively, for the combined group and 81.3% and 71%, respectively, for 3DCRT alone; for overall survival, they were 91.9% and 89.5% vs. 88.7% and 86.2%, respectively, whereas for cause-specific survival, they were 96.9% and 96.1% vs. 97.6% and 96.2%, respectively. Cox proportional hazard regression analysis for BC revealed that low Gleason grade, HDR brachytherapy combined with 3DCRT, and adjuvant androgen deprivation therapy were significant in predicting BC. Radiation Therapy Oncology Group Grade 3 late urinary and rectal morbidity rates were 7.1% and 0%, respectively. No Grade ≥4 reactions were detected.Conclusions: HDR brachytherapy combined with 3DCRT was associated with improved BC and minimal toxicity in patients with unfavorable prostate cancer compared with conventional 3DCRT.

Needle applicator displacement during high-dose-rate interstitial brachytherapy for prostate cancer

2009-09-07

Abstract: Purpose: To introduce an effective ambulatory technique in high-dose-rate interstitial brachytherapy (HDR-ISBT) for prostate cancer, we investigated the displacement distance using our novel calculation method.Methods and Materials: Sixty-four patients treated with HDR-ISBT as monotherapy were examined. Of these, 4, 17, and 43 patients were administered treatment doses of 38Gy (3 days), 49Gy (4 days), and 54Gy (5 days), respectively. For dose administration, we used 776 flexible applicators with a removable template (ambulatory technique).Using CT images, we calculated the relative coordinates of the metal markers and applicators. From these coordinates, to analyze displacement during treatment, we measured the distance between the tip of the needle applicator and the center of gravity of the markers along the average applicator vector.Results: The median displacement distance for all applicators was 7mm (range, −14 to 24), and that of each treatment schedule was 4, 6, and 9mm for 38, 49, and 54Gy, respectively. Of the 776 applicators, displacement of >10mm was seen in 198 (26%) applicators and >15mm in 57 (7%) applicators.Body height (p<0.0001) and anticoagulant usage (p<0.0001) were significant factors influencing displacement.Conclusions: We investigated needle applicator displacement using our unique method. Additional cranial margins are necessary if there is no repositioning of the dwell position. CT scanning should be performed daily during treatment for checking the position of the applicator to detect and rectify the issue of displacement.

Factors impacting all-cause mortality in prostate cancer brachytherapy patients with or without androgen deprivation therapy

2009-10-30

Abstract: Purpose: Certain subsets of patients have an increased risk of all-cause mortality when androgen deprivation therapy (ADT) is used with definitive radiotherapy. We evaluated the relationship between pretreatment serum testosterone, age, and comorbidities on survival after prostate brachytherapy in men treated with and without ADT.Methods and Materials: From October 2001 to September 2005, 803 patients underwent brachytherapy and 720 had a pretreatment serum testosterone. Comorbidities were prospectively recorded for each patient (body mass index>30, hypertension, diabetes, current smoker). Median followup was 5.0 years. 34.2% of the patients received ADT. Focus was on subset of men who might be expected to have more significant side effects associated with ADT.Results: ADT did not significantly impact overall survival (OS) in men <65 years, >65 years, with one or no comorbidities, with more than one comorbidity, or with normal/high testosterone level. ADT use in men with low testosterone level was associated with decreased OS (83.6% vs. 93.1%, p=0.01). The adverse impact of ADT in men with low testosterone level was restricted to men with low testosterone level and more than one comorbidity (OS of 71.3% vs. 92.8%, p<0.01), with death from cardiovascular diseases accounting for almost all of the excess mortality. The subset of men with multiple comorbidities and normal/high testosterone level did not experience adverse OS with ADT.Conclusions: Low pretreatment testosterone level may be a marker for men at increased risk of premature death with ADT. The combination of low pretreatment serum testosterone level and multiple preexisting comorbidities is associated with decreased OS when ADT is incorporated into treatment.

Physical derivation of nomograms in permanent prostate brachytherapy

Texin Li, Betty L. Fountain, Edward W. Duffy — 2009-10-21

Abstract: Purpose: To demonstrate the physical origin of nomograms in permanent prostate brachytherapy, by using the correlation between fractional integral target dose (FITD) and target volume.Methods and Materials: The integral dose (ID) E delivered by unit activity is given by the integration of 4πr2D(r)/r2dr×1.44T1/2 using the point source model from AAPM TG43. If A is the total activity implanted, then total ID will be A×E. Integral target dose are obtained by multiplying the prostate volume V with mean dose Dmean by definition, assuming prostate gland has a unity density. The FITD the target receives is defined as FITD=DmeanV/AE by energy conservation in the target volume. From this equation, the total activity needed to achieve given dose for a target of volume V is obtained. Results are compared with existing nomograms for 125I and 103Pd, and available clinical data for 131Cs.Results: Agreement within 10.0% for 125I and 103Pd compared with existing nomograms for gland sizes from 18 to 80cc is observed. For 131Cs, the agreement is within 8.0% compared with available clinical data.Conclusions: It is shown that the correlation between the FITD and target volume can be used to obtain the total activity needed to achieve prescribed dose. This correlation is inherent rather than empirical. It suggests that the correlation between fraction of energy deposition in target and target volume is the underlying physical origin for nomograms used in permanent prostate brachytherapy.

3D CT-based volumetric dose assessment of 2D plans using GEC-ESTRO guidelines for cervical cancer brachytherapy

Mingcheng Gao, Kevin Albuquerque, Alex Chi, Iris Rusu — 2009-10-23

Abstract: Purpose: To investigate two-dimensional (2D) radiograph-based plans using three-dimensional (3D) dose–volume histogram (DVH) parameters following guidelines from Gynecologic GEC-ESTRO Working Group (GEC-ESTRO).Methods and Materials: Nineteen high-dose-rate (HDR) fractions from 8 patients were studied. Prescription was 45Gy from external beam radiation therapy plus 30Gy in five fractions from HDR using tandem and ring/ovoids. Both radiographs and CT scan were obtained. Treatment was planned using radiographs following American Brachytherapy Society (ABS) guidelines. Retrospective evaluation of above 2D plans on a 3D volumetric basis was achieved by generating CT image-based 3D plans using same dwell times.Results: In 2D plans, International Commission on Radiation Units and Measurement (ICRU) bladder and rectal point doses were 3.8±0.4 and 3.0±0.5Gy, respectively. In 3D plans, rectum D2cc is 4.0±1.0Gy and bladder D2cc is 5.4±0.9Gy. Position of actual hottest spot in 3D rectum volume was close to the position of ICRU rectal point. ICRU bladder point did not match with the actual hottest spot in 3D bladder volume. In 2D plans, H-point dose was 5.8±0.2Gy. In 3D plans, dose to CT-based cervix (D90) reduced from 7.1 to 4.2Gy as the cervical volume increased from 12 to 39cc. Average D2cc/ICRU dose ratio was calculated to be 1.36/1.01 for bladder/rectum, respectively.Conclusions: The DVH analysis of 2D plans revealed a suboptimal coverage of CT-based cervix and a negative correlation between coverage and cervical size. Rectum dose to 2cc weakly correlated with ICRU point dose. Currently published constraint for bladder in 3D planning is tighter than ABS guidelines in past 2D planning.

Intraperitoneal radioactive phosphorus (32P) and vaginal brachytherapy as adjuvant treatment for uterine papillary serous carcinoma and clear cell carcinoma: The Indiana University experience

2010-01-01

Abstract: Purpose: To evaluate the outcomes of surgically staged patients with Stage I–IIIA uterine papillary serous carcinoma (UPSC) and clear cell carcinoma (CCC) of the uterus treated at Indiana University with intraperitoneal 32P and vaginal brachytherapy.Methods: Between 1997 and 2004, a total of 28 patients with Stage I–IIIA UPSC and CCC were treated with a standardized adjuvant therapy. All patients underwent comprehensive surgical staging with negative pelvic and para-aortic lymph nodes and no gross residual disease. After a Technetium-99m distribution study, 32P was administered intraperitoneally. Subsequently, high dose rate (HDR) vaginal cuff brachytherapy was delivered to a total dose of 2100cGy in three fractions prescribed to 0.5cm depth. The records of these 28 patients were reviewed, including 18 patients who were treated on Hoosier Oncology Group 97-01 (Phase II trial), and whose followup was updated.Results: Intraperitoneal 32P was administered at a median of 4 weeks from surgery, followed by vaginal brachytherapy. One patient had no available followup information and is not included in the analysis. The median followup for the 27 evaluable patients was 40.9 months. No patients had Grade 2, 3, or 4 complications related to their adjuvant treatment. There were 4 patients with recurrent disease: 2 initially relapsed intraperitoneally, 1 in the distal vagina, and 1 had a scar recurrence. Three patients have died of the disease. For all 27 patients, the 3-year overall survival, cause-specific survival, and disease-free survival were 84.2%, 90.7%, and 74.4%, respectively.Conclusions: Adjuvant therapy for UPSC and CCC with intraperitoneal 32P and vaginal brachytherapy after adequate surgical staging and maximal cytoreduction is well tolerated and appears to be effective. Further study is warranted.

High-dose-rate afterloading intraluminal brachytherapy for advanced inoperable rectal carcinoma

Carie Corner, Linda Bryant, Caroline Chapman, Rob Glynne-Jones, Peter J. Hoskin — 2009-10-21

Abstract: Purpose: High-dose-rate (HDR) intraluminal brachytherapy for advanced or inoperable tumors of the rectum has been used both palliatively and to dose escalate after chemoradiation for curative treatment.Methods: Between 1993 and 2007, 79 patients were treated with HDR afterloading brachytherapy for rectal cancer; 70 patients had adenocarcinoma of the rectum; and 9 patients had squamous cell carcinoma of the anal canal. Fifty-two patients had localized disease but were unfit for major surgery and received radiotherapy with radical intent. Twenty-seven patients with advanced or metastatic disease received palliative treatment. The median age was 82 years (range, 33–97). Radical treatment comprised either chemoradiation followed by intraluminal brachytherapy delivering 12Gy at 1cm in two fractions or radical monotherapy delivering up to 36Gy at 1cm in six fractions two to three times weekly. Palliative HDR brachytherapy schedules were predominantly 10Gy at 1cm single dose.Results: Objective local tumor response was seen in 41 of 48 assessable patients (85%); of whom, 28 patients (58%) had a complete response and 13 (27%) had a partial response. The most common symptom was rectal bleeding, which was controlled with a complete response rate of 63%. The median duration of the symptom response was 3 months (range, 1–73), and the median survival of the palliative patients was 6 months (range, 1 week–37 months). The median survival for patients treated with radical intent was 18.5 months (range, 2–119). Six patients reported late toxicity with three cases of rectal ulcer, two strictures, and one fistula.Conclusions: Intraluminal HDR brachytherapy is effective as local treatment in both the radical and palliative setting, with high tumor and symptom response rates, and acceptable late toxicity.

Duodenal complications in radiotherapy for bile duct cancer: A dose–volume histogram analysis

Ryuji Nakamura, Kenichi Kato, Miyuki Sone, Hirobumi Oikawa, Shigeru Ehara — 2009-11-02

Abstract: Purpose: To establish a method of quantitative assessment of the duodenal exposure dose to avoid duodenal morbidity after radiotherapy for bile duct cancer.Methods and Materials: After external beam radiotherapy (ERTx) and intraluminal high-dose-rate brachytherapy (BRTx), 4 of 10 patients developed Grade 3 or 4 ulcers at the posterior wall of the duodenal bulb (PWDB) (compromised group); the remainder exhibited no duodenal complications (spared group) for 14 (range, 7–59) months after radiotherapy. The radiation exposure to the duodenal volume at risk (Vduod) in ERTx and BRTx was individually analyzed using dose–volume histograms in terms of the mean doses (the average dose of Vduod[Dave] and the median dose of Vduod [Dmedian]), dose covering 1% or 5% of Vduod (dose covering 1% of the Vduod [D1] and dose covering 5% of the Vduod [D5], respectively), and the Vduod receiving 100% or 150% of the prescribed radiation dose (V100 and V150, respectively) in ERTx (Dave, Dmedian, D5) and BRTx (Dave, D1, D5, V100, V150). Dave and D5 were converted to biologically effective doses (BEDs), and each corresponding values of ERTx and BRTx were summed presenting as BEDave_sum and BED5_sum.Results: The PWDB was consistently involved in 100% of the prescription dose area in ERTx. The compromised group had smaller exposure doses without significant difference (SD). In BRTx, the PWDB was exposed to higher doses. The compromised group had larger dose exposures without SD and larger volume exposures (V100, V150) with SD in BRTx. The BEDave_sum and BED5_sum showed no difference between the groups.Conclusions: Measuring the duodenal volume exposed to determine doses that exceed the prescription in BRTx may be useful for predicting intractable complications in the combined radiotherapy.

Intraoperative placement of MammoSite for breast brachytherapy treatment and seroma incidence

Akkamma Ravi, Susan Lee, Karen Karsif, Adrian Osian, Dattatreyudu Nori — 2009-10-23

Abstract: Purpose: To identify possible risk factors for development of clinically significant seroma (CSS) (seroma requiring intervention) and to report on incidence of infection after intraoperative placement of MammoSite for breast brachytherapy.Methods and Materials: Fifty-eight postmenopausal patients with early stage breast cancer and no nodal metastases, treated with partial breast irradiation using the MammoSite catheter from June 2003 to November 2007 were analyzed retrospectively for CSS predictive factors and incidence of infection. After a lumpectomy, a MammoSite catheter was placed by intraoperative open-cavity technique (OCT). All the patients received wound care and prophylactic antibiotics. A dose of 3400cGy was prescribed at 1cm from the surface of the balloon and was delivered at 340 cGy twice daily 6h apart for 5 days. The patients with seroma who underwent intervention were considered to have CSS. On the basis of the characteristics and symptoms associated with seroma, interventions, such as aspiration, core biopsy, or re-excision of the lumpectomy cavity were performed either to relieve symptoms or to rule out a local recurrence.Results: Fifty-seven of the 58 patients were eligible for analysis. One patient, who died 4 weeks after treatment from unrelated causes, was excluded from final analysis. All the patients were postmenopausal, with a median age of 71 years (range, 53–88 years). Eighteen of the 57 patients (31.5%) had CSS; 9 of them had re-excision of the lumpectomy cavity. Pathology in all revealed evidence of fat necrosis, chronic inflammatory cells, and fibrosis. There was no evidence of tumor recurrence in any of these patients. Technical and nontechnical parameters were analyzed to determine possible risk factors for CSS, and none were found to be statistically significant. No patient developed acute postprocedural infection.Conclusions: Meticulous wound care and postoperative antibiotics prevented acute infection. Infection was not a contributing factor for seroma formation in these patients. Placement of the MammoSite catheter by OCT did not increase the risk of CSS development, in postmenopausal breast cancer patients.

Modeling study for optimization of skin dose for partial breast irradiation using Xoft Axxent electronic brachytherapy applicator

Jaroslaw T. Hepel, Jessica R. Hiatt, Gene A. Cardarelli, David E. Wazer — 2009-10-22

Abstract: Purpose: Balloon brachytherapy with the MammoSite system (Hologic Inc., Bedford, MA) is a widely used approach for accelerated partial breast irradiation. Inherent to this approach, high skin doses can occur if the balloon to skin distance is small. This has been associated with late skin toxicity, particularly telangiectasia. The Xoft Axxent electronic brachytherapy balloon applicator (Xoft, Fremont, CA) is a novel device for accelerated partial breast irradiation. It is unique in that it uses an electronic 50-kV source. This source has a pronounced anisotropy with constriction of isodose distribution at the proximal end of the catheter. This anisotropy can be considered as an advantage to optimize skin dose when the cavity to skin distance is small. In this study, we simulated various balloon-insertion orientations to optimized skin surface dose.Methods: Breast phantoms were constructed of tissue-equivalent material. Xoft Axxent balloon catheters were inserted at a distance of 6mm from the surface. The catheter was placed at three different catheter to surface orientations: (1) perpendicular to the surface, (2) oblique to the surface (45°), and (3) parallel to the surface. Three-dimensional treatment planning was then performed using Nucletron's Plato planning system (Nucletron, Columbia, MD). Multiple dwell positions were used, and the dose was optimized to the target volume. The target volume was defined as volume from the balloon surface to 1-cm distance from the balloon surface or to the phantom surface (if less then 1cm from the balloon surface). Target volume coverage was compared between plans using dose–volume histograms. Surface doses were compared using isodose line distribution and surface point doses. Plato planned surface doses were then verified by direct measurement using Landauer Dot InLight dosimeters (Landauer, Glenwood, IL).Results: Excellent target coverage was obtained for all three catheter orientations with a D95 of ≥95%. Surface dose was lowest for the perpendicular orientation with a calculated dose of 99%. The parallel orientation had the highest surface dose of 164%. The oblique orientation showed intermediate results with a surface dose of 117%. Measured surface doses were reproducible and correlated well with calculated values.Conclusion: Optimized Xoft Axxent balloon catheter orientation using source anisotropy and multiple dwell positions can be used to minimize excessive skin dose and yet maintain optimal tumor cavity coverage when the cavity to skin distance is small. This has the potential to decrease skin late effects and improve cosmetic outcome. Further clinical study is warranted.

High-dose-rate surface brachytherapy to boost elongated, curvilinear incisional scars after extrapleural pneumonectomy for malignant pleural mesothelioma treated with adjuvant intensity-modulated radiation therapy

2009-10-21

Abstract: Purpose: Providing adequate dosimetric coverage of elongated, curvilinear incisions during adjuvant intensity-modulated radiation therapy (IMRT) after extrapleural pneumonectomy (EPP) for malignant pleural mesothelioma (MPM) creates technical challenges. We explored high-dose-rate (HDR) surface brachytherapy to supplement dose to multiple curvilinear incisions. This modality circumvents the technical limitations of relying on multiple en face electron fields while minimizing dose to adjacent normal tissues.Methods and Materials: A 59-year-old man presented with a left-sided, Stage III, T3N2M0, epithelioid MPM. After undergoing a left EPP, adjuvant IMRT was recommended to improve local control. An eight-field IMRT plan was designed to encompass the postoperative hemithorax. Incisional scars were lengthy and extended beyond the hemithoracic target volume. Both en face electron and surface HDR plans were prepared and evaluated based on dosimetric coverage of the incisional scars, dose to normal tissues, reliability of setup, and treatment delivery.Results: HDR was preferred. The patient was planned and treated in the right lateral decubitus position. HDR source catheters were placed along the incisions atop 5-mm bolus. A composite plan including IMRT and brachytherapy dose contributions was produced. Boosts of incisional scars were performed in six fractions (three fractions per week) of 3Gy prescribed to 12mm from the catheter. HDR brachytherapy was well tolerated.Conclusions: Surface HDR brachytherapy is a viable option for supplemental dose to incisional scars at risk of local recurrence after EPP for MPM. Advantages over electron beam therapy include avoidance of field abutments and feathering, less tissue–bone interface dose uncertainty and reproducibility of treatment delivery.

The role of dose escalation with intracavitary brachytherapy in the treatment of localized CNS malignancies: Outcomes and toxicities of a prospective study

2009-10-22

Abstract: Purpose: This single-institution prospective study was designed to investigate the feasibility and safety of dose escalation with GliaSite (Proxima Therapeutics Inc., Alpharetta, GA) brachytherapy for the treatment of patients with newly diagnosed and recurrent central nervous system (CNS) tumors after neurosurgical resection. We now report mature results of this trial, its outcomes, and a toxicity profile.Methods and Materials: Ten adult consecutive patients with recurrent and newly diagnosed CNS malignancies underwent GliaSite brachytherapy after maximally safe neurosurgical resection between 2004 and 2007. GliaSite balloon was placed intraoperatively, and the size was selected so as to conform to the surgical cavity. Low-dose-rate radiation was delivered with an aqueous solution of organically bound 125I (Iotrex: sodium 3-(125I)-iodo-4-hydroxybenzenesulfonate; Proxima Therapeutics Inc.), introduced into the balloon portion of the device via a subcutaneous port. Two to 3 weeks later, the device was filled with Iotrex for a median dwell time of 94.3 hours (range, 68.0–120.5 hours), after which the balloon was explanted. A commercial 3-D planning system was used for a detailed analysis of dosimetry. Median dose of 52.0Gy (range, 45.0–60.0Gy) was prescribed 0.5–1.0cm from the balloon surface. Radiation Therapy Oncology Group (RTOG) criteria were used to assess acute and long-term toxicities associated with this technique. Followup was assessed with MRI scans and was available on all enrolled patients.Results: Median followup for surviving patients was 38 months (range, 18–57 months). Mean size of GliaSite balloon was 3.4cm (range, 2.0–4.0cm). Mean volume of filling was 19.0cc (range, 4.0–35.0cc). Median activity of Iotrex was 301.6mCi (range, 95.0–515.4mCi). Median survival was 14.0 months for the entire cohort after the treatment with the GliaSite device. Of our cohort, 6/10 (60%) patients sustained recurrence (20% local and 40% distant). Median time to recurrence after treatment with GliaSite was 8.0 months, and median time to death after recurrence was 7.5 months. There were no RTOG Grade 3 or 4 acute or late toxicities. Followup MRI imaging did not identify any evidence of radiation necrosis.Conclusions: Our data indicate that treatment with GliaSite balloon brachytherapy is feasible and safe, while rendering acceptable local control and minimal acute and long-term toxicities for newly diagnosed and recurrent CNS malignancies. These encouraging results compel us to embark on testing larger numbers of patients with this treatment modality.

Masthead

2010-01-01

Editorial Board

2010-01-01

Guide for Authors

2010-01-01

Brachytherapy

Rectal morbidity after permanent interstitial brachytherapy for prostate cancer—Impact of Day 1 vs. Day 30 computed tomography–based postimplant dosimetry

Relationship between Day 0 dosimetric parameters and biochemical relapse-free survival in patients treated with transperineal permanent prostate interstitial brachytherapy with 125I seeds

External beam radiotherapy plus high-dose-rate brachytherapy for treatment of locally advanced prostate cancer: The initial experience of the Catalan Institute of Oncology

AnchorSeed for the reduction of source movement in prostate brachytherapy with the Mick applicator implant technique

High-dose-rate brachytherapy in combination with conformal external beam radiotherapy in the treatment of prostate cancer

Needle applicator displacement during high-dose-rate interstitial brachytherapy for prostate cancer

Factors impacting all-cause mortality in prostate cancer brachytherapy patients with or without androgen deprivation therapy

Physical derivation of nomograms in permanent prostate brachytherapy

3D CT-based volumetric dose assessment of 2D plans using GEC-ESTRO guidelines for cervical cancer brachytherapy

Intraperitoneal radioactive phosphorus (32P) and vaginal brachytherapy as adjuvant treatment for uterine papillary serous carcinoma and clear cell carcinoma: The Indiana University experience

High-dose-rate afterloading intraluminal brachytherapy for advanced inoperable rectal carcinoma

Duodenal complications in radiotherapy for bile duct cancer: A dose–volume histogram analysis

Intraoperative placement of MammoSite for breast brachytherapy treatment and seroma incidence

Modeling study for optimization of skin dose for partial breast irradiation using Xoft Axxent electronic brachytherapy applicator

High-dose-rate surface brachytherapy to boost elongated, curvilinear incisional scars after extrapleural pneumonectomy for malignant pleural mesothelioma treated with adjuvant intensity-modulated radiation therapy

The role of dose escalation with intracavitary brachytherapy in the treatment of localized CNS malignancies: Outcomes and toxicities of a prospective study

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Table of Contents

Editorial Board

Guide for Authors