Oscar Streeter

Initial clinical experience with the MammoSite breast brachytherapy applicator in women with early-stage breast cancer treated with breast-conserving therapy.

PURPOSE We present the results of the initial clinical testing of the MammoSite balloon breast brachytherapy applicator in women with early-stage breast cancer treated with breast-conserving therapy. METHODS AND MATERIALS Seventy patients were enrolled in a multicenter prospective trial testing the applicator for safety and performance. Fifty-four patients were implanted, and 43 patients were ultimately eligible for and received brachytherapy as the sole radiation modality after lumpectomy. Patients were staged T1N0M0 with negative pathologic margins and age >45 years. A dose of 34 Gy was delivered in 10 fractions over 5 days prescribed to 1 cm from the applicator surface using 192Ir high-dose-rate brachytherapy. A minimum skin-to-balloon surface distance of 5 mm was required for treatment. Device performance, complications, and cosmesis were assessed. RESULTS Computed tomography imaging post-balloon inflation showed 8, 14, and 21 patients with 5-6 mm, 7-9 mm, and >10 mm of skin spacing, respectively. Two patients were explanted because of inadequate skin spacing and 7 because of suboptimal conformance of the surgical cavity to the applicator balloon. One patient was explanted because of positive nodal status and another because of age. The most common side effects related to device placement included mild erythema, drainage, pain, and echymosis. No severe side effects related to implantation, brachytherapy, or explantation occurred. Side effects related to radiation therapy were generally mild with erythema, pain, and dry desquamation being the most common. At 1 month, 88% of patients were evaluated as having good-to-excellent cosmetic results. CONCLUSIONS The MammoSite balloon breast brachytherapy applicator performed well clinically. All eligible patients completed treatment. Side effects were mild to moderate and self-limiting. Skin-balloon surface distance and balloon-cavity conformance were the main factors limiting the initial use of the device.

Lay patient navigator program implementation for equal access to cancer care and clinical trials: essential steps and initial challenges.

Disparities in cancer detection, treatment, and outcomes among racial/ethnic minorities and low‐income patients are well documented. One way to reduce these disparities is to use patient navigators to address barriers to care. However, little information about optimal characteristics of navigator programs or considerations for those interested in setting up such programs is available.

Optimization of mammosite therapy

PURPOSE Radiation source anisotropy causes about 10% of a spherically shaped planning target volume surrounding a MammoSite balloon to receive less than the prescribed dose. The principal dose-limiting factor for MammoSite therapy is the dose to the overlying skin. Additional limiting factors potentially include the dose to portions of the heart and lung. The goal of optimization is to deliver the prescribed dose to as much of the planning target volume as possible while avoiding toxicity to adjacent organs. METHODS AND MATERIALS An experimental CT-based high-dose-rate brachytherapy treatment planning system was used to investigate optimization strategies for MammoSite treatment. This system implements a linear optimization of high-dose-rate dwell times on the basis of constraints assigned to points of interest and a set of potential dwell positions. RESULTS The cylindrical symmetry of the MammoSite catheter limits the optimization process to creating spherical, ellipsoidal, or egg-shaped isodose distributions whose major axis is oriented along the catheter axis. If the dose to a limiting structure, such as skin, is not an issue, the use of multiple dwell positions can compensate for source anisotropy and create a more spherical isodose surface enclosing the planning target volume compared with a single dwell position. When skin becomes a dose-limiting factor, the catheter axis orientation, source anisotropy, dwell position, and dwell weighting can be exploited to limit the skin dose while simultaneously preserving the prescribed dose to as much of the target volume as possible. CONCLUSION Optimization of MammoSite therapy using multiple dwell positions within the balloon is both possible and practical.

Postoperative radiotherapy in 423 patients with pT3N0 prostate cancer.

PURPOSE To evaluate the treatment outcome in pT3N0 patients with adenocarcinoma of the prostate treated with an elective course of postoperative irradiation (RT). METHODS AND MATERIALS During a 22-year period, a total of 423 pT3N0 prostate cancer patients were treated at a single medical center with prostatic fossa RT, which was the only adjuvant therapy given. The patient characteristics were as follows: median age 66 years; Stage pT3aN0 in 296 (70%) and pT3bN0 in 127 (30%); Gleason score 2-4 in 12 (2.8%), 5-6 in 157 (37.1%), 7 in 151 (35.7%), and 8-10 in 100 (23.6%); and the median and mean preoperative prostate-specific antigen (PSA) level was 10 and 15.9 ng/mL, respectively. Radiotherapy consisted of a median dose of 48 Gy delivered to the prostatic fossa and its immediate vicinity. The median follow-up was 7 years. RESULTS The 5- and 10-year actuarial survival rate was 92% and 73%, respectively, and the 5- and 10-year disease-free survival rate (PSA <0.05 ng/mL) was 69% and 51%, respectively. In multivariate analysis, the Gleason score was the most important predictor for survival (p = 0.00005), and pathologic stage and Gleason score were independently predictive of disease-free survival (p = 0.00007 and 0.0003, respectively). The worst prognostic category was represented by pT3bN0, Gleason score 7-10 patients who had a 5.3 times greater risk of tumor recurrence than those with pT3aN0, Gleason score 2-6. A high (>25 ng/mL) preoperative PSA level was also a predictor of tumor recurrence (p = 0.03). A total of 43 patients (10.2%) developed clinical recurrence. This included 30 patients (7%) with distant metastases alone and 13 (3%) with local recurrence, which included 2 patients who also had distant disease. An additional 88 patients (20%) had PSA elevation (>0.05 ng/mL). This treatment program was well tolerated, with acute toxicity common (62%) but of no clinical significance. No late or severe toxicity was recorded. CONCLUSION Adjuvant radiotherapy, as given in this study, appears to substantially reduce the expected incidence of local tumor recurrence in pT3N0 prostate cancer patients. The treatment outcome was poor in pT3bN0 and Gleason score 7-10 patients, with >80% showing evidence of clinical or PSA recurrence at 10 years after therapy. This group should be the target of a prospective trial of systemic therapy.

Use of brachytherapy in management of locally recurrent rectal cancer

PURPOSE: Locally recurrent rectal cancer is associated with poor quality of life and has justified aggressive surgical and adjuvant approaches to control the disease. This study was designed to evaluate if the use of brachytherapy in association with wide surgical excision (debulking operation) can offer reasonable palliation for patients with locally recurrent rectal cancer. MATERIALS AND METHODS: Patients with biopsy-proven locally recurrent rectal cancer who were not candidates for intraoperative radiation therapy and who were previously considered as having unresectable tumors were included in the study and were followed-up from May 1981 to November 1990. All of them had undergone laparotomy and had either radical or debulking surgical resection performed. At the same time, brachytherapy was used with temporary or permanent implant of seeds of iridium-192 or iodine-125. RESULTS: Thirty patients were included. Patients ranged in age from 28 to 74 years, and 16 patients were female. No mortality was observed, and morbidity was low (small-bowel obstruction (1 patient), intestinal fistula (1 patient), and urinary fistula (1 patient). Histologic examination of the specimen showed gross residual disease in 67 percent of patients and microscopic disease in 25 percent of patients. Long-term follow-up was possible in 28 patients. Mean follow-up and local control were, respectively, 26.5 months and 37.5 percent for gross residual disease and 34 months and 66 percent for microscopic residual disease. Eighteen patients (64 percent) had locally recurrent rectal cancer under control at the time of the last follow-up, with seven patients (25 percent) having no evidence of local or distant recurrence. CONCLUSION: This is the first report of brachytherapy for locally recurrent rectal cancer. This appears to offer a therapeutic alternative to patients who are not candidates for intraoperative radiation therapy. Surgical morbidity and mortality are acceptable. Local control in 18 patients (64 percent) is comparable with intraoperative radiation therapy or more morbid surgical alternatives. Cancer-related deaths are most often related to disseminated disease, which suggests the need for systemic therapy in addition to brachytherapy.

Breast-conserving therapy for ductal carcinoma in situ: a 20-year experience with excision plus radiation therapy

BACKGROUND Breast conservation therapy is a practical alternative to mastectomy for the treatment of ductal carcinoma in situ (DCIS). The role of radiation therapy after excision for DCIS has been debated, however, its value in reducing recurrence has been proven by multiple prospective randomized trials and is well accepted. METHODS We examined a prospective database of 260 patients treated for DCIS with excision and radiation from 1979 to 2002. Two different treatment regimens were examined for local recurrence-free survival. Patients treated with radiation therapy 4 days per week were compared with patients treated 5 days per week. The total doses were similar for both groups; boost types differed. Local recurrence as a function of other factors, including nuclear grade, comedonecrosis, and margin width was evaluated. RESULTS The median time to local recurrence was 61 months for patients treated 4 days per week compared with 52 months for patients treated 5 days per week (P = not significant). There was no statistical difference in the Kaplan-Meier detailing the probability of local recurrence-free survival for patients treated 4 days per week versus patients treated 5 days per week. Overall, cosmetic results between the two groups were equivalent. CONCLUSIONS The comparison of two different radiation treatment regimens shows no difference in local disease-free survival or cosmetic result.

MammoSite radiation therapy system.

Abstract The MammoSite ® Radiation Therapy System (RTS) has become the most widely used brachytherapy method used in the treatment of breast cancer, due to its ease of use, short learning curve, and requirement of only one interstitial path through the breast skin. The dosimetry is simple, one source position in the middle of the MammoSite ® balloon catheter. The data on long-term complications, however are not available, though developing. Trials for DCIS are being developed, as well as a comparison trial to standard external beam radiation as well as other forms of accelerated partial breast irradiation (APBI).

Adjuvant radiotherapy in patients with pathologic stage C (pT3N0) adenocarcinoma of the prostate

OBJECTIVES This report is an update on the outcomes in the management of pathologic Stage C (T3N0) prostate cancer (CaP) with postoperative irradiation. METHODS Between 1976 and 1994, 311 patients with pathologic Stage C CaP were treated with radical prostatectomy. Pathologic stage was as follows: C1, 60 patients (19%), C2, 146 patients (47%), and C3, 105 patients (34%). Gleason score was 2 to 4 in 10 patients (3.2%), 5 to 6 in 121 (39%), 7 in 101 (32%), and 8 to 10 in 76 (24%); median prostate-specific antigen (PSA) level was 11.9 ng/mL. Postoperative irradiation consisted of a median dose of 48 Gy. Follow-up was up to 18 years (median 5). RESULTS The 10-year actuarial survival was 81% and 10-year disease-free survival was 51%. Pathologic stage and Gleason score were independently predictive of recurrence, each with P >0.001 after controlling for the other. Patients with pathologic Stage C3 and Gleason score 7 to 10 were in the worst prognostic category and had 5.4 times the risk of recurrence compared with patients with pathologic Stage C1-C2, Gleason score 2 to 6. Preoperative PSA was a good (P = 0.02) predictor of disease-free survival. Clinical recurrence was seen in 28 patients (9%), including 10 (3.2%) with local recurrence. PSA recurrence (PSA greater than 0.05 ng/mL) developed in 68 patients (22%). CONCLUSIONS With the known limitations of a nonrandomized clinical trial, on the basis of the experience of this study we recommend the use of moderate dose, limited-field postoperative radiotherapy in patients with pathologic Stage C disease with Gleason score greater than 4.

Use of high-dose-rate brachytherapy in the management of locally recurrent rectal cancer.

AbstractINTRODUCTION: Locally recurrent rectal cancer is associated with poor quality of life and has justified aggressive surgical and adjuvant approaches to control the disease. This study was designed to evaluate the use of fractionated perioperative high-dose-rate brachytherapy in association with wide surgical excision (debulking). Our hypothesis is that this combined therapy can help control locally recurrent rectal cancer. METHODS: Patients with biopsy-proven locally recurrent rectal cancer that could not be completely removed surgically were considered candidates for this procedure. All patients had abdominal exploration, aggressive tumor debulking, and placement of afterloading brachytherapy catheters. Patients underwent simulation on postoperative Day 3 and received 1,200 to 2,500 (mean, 1,888) cGy of fractionated high-dose-rate brachytherapy between postoperative Days 3 and 5. All patients had involvement of the lateral pelvic sidewall and/or the sacrum. RESULTS: Twenty-seven patients (18 males) aged 32 to 79 years underwent therapy. Follow-up ranged from 18 to 93 (mean, 50) months and was available in 27 patients. Ten patients (37 percent) were alive at the time of this report. Nine patients are without evidence of disease. Five patients (18 percent) died of non–cancer-related causes without evidence of recurrent disease. Five complications potentially related to treatment (3 abscesses, 2 fistulas) occurred in five patients. CONCLUSION: High-dose radiation brachytherapy delivers high-dose, highly controlled, focused radiation to specific sites of disease, thereby minimizing injury to normal tissues. The results in this series suggest increased local control, better palliation, and increased salvage of patients.

Comparison of outcomes of radical prostatectomy with and without adjuvant pelvic irradiation in patients with pathologic stage C (T3N0) adenocarcinoma of the prostate

Patients with localized adenocarcinoma of the prostate gland (CaP) are frequently (approximately 50%) found at radical prostatectomy to have extracapsular disease or positive surgical margins. The management of these patients is a subject of controversy because some question the impact of this manifestation of CaP on patient survival or disease-free survival. Between 1976 and 1991, 241 patients with pathologic stage C (T3N0) were treated in this medical center. Of these 241 patients, 201 (83%) received a planned postoperative pelvic irradiation consisting of 48 Gy given to the prostatic fossa, whereas 40 (17%) patients were treated with radical prostatectomy alone. The two study urologists selected these patients not to receive postoperative irradiation based on intraoperative findings and important prognostic factors. Comparison of treatment outcomes in these two treatment groups is a subject of this report. The 201 patients treated with surgery-radiotherapy (S+RT) combination had a higher pathologic stage, greater incidence of seminal vesicle involvement, p = 0.002, and higher mean and median preoperative prostate-specific antigen level, p < 0.0001, than the 40 surgery (S) alone patients. There was no significant difference in the incidence of higher Gleasons score by the treatment group, p = 0.14. In univariate analysis, there was no significant difference in survival, disease-free survival, and time to failure between the two treatment groups. In multivariate analysis after controlling for pathologic stage and Gleasons score, the 201 adjuvant radiotherapy patients were predicted to have recurrence at 68% (95% confidence interval 39%-118%) the rate of the 40 surgery-alone patients. Local recurrence with or without metastatic disease was found in 10% of surgery-alone patients as compared to 5% in those also receiving postoperative irradiation. Treatment tolerance was very good with minor radiotherapy complications only. There was no significant difference in the incidence of incontinence between the two treatment arms. In summary: (a) The use of moderate-dose postoperative radiotherapy was of low toxicity and it did not increase the incidence of incontinence. (b) Local recurrence was 5% in S+RT and 10% in S-alone patients. (c) In multivariate analysis, S+RT patients had 68% rate of recurrence of S-alone patients. (d) Adjuvant RT probably reduces the risk of recurrence in patients with poor prognostic factors. (e) These data need to be interpreted with caution because of the nonrandomized nature of the study.