Brachytherapy radiation doses to the neurovascular bundles.

PURPOSE: To investigate the role of radiation dose to the neurovascular bundles (NVB) in brachytherapy-related impotence. METHODS AND MATERIALS: Fourteen Pd-103 or I-125 implant patients were studied. For patients treated with implant alone, the prostate and margin (clinical target volume [CTV]) received a prescription dose of 144 Gy for I-125 or 115 Gy for Pd-103. Two patients received Pd-103 (90 Gy) with 46 Gy supplemental external beam radiation (EBRT). Axial CT images were acquired 2 to 4 hours postoperatively for postimplant dosimetry. Because the NVBs cannot be visualized on CT, NVB calculation points were determined according to previously published anatomic descriptions. Bilateral NVB points were considered to lie posterior-laterally, approximately 2 mm from the prostatic capsule. NVB doses were recorded bilaterally, at 0.5-cm intervals from the prostatic base. RESULTS: For Pd-103, the average NVB doses ranged from 150 Gy to 260 Gy, or 130% to 226% of the prescription dose. For I-125, the average NVB dose ranged from 200 Gy to 325 Gy, or 140% to 225% of the prescription dose. These was no consistent relationship between the NVB dose and the distance from the prostatic base. To examine the possible effect of minor deviations of our calculation points from the true NVB location, we performed NVB calculations at points 2 mm medial or lateral from the NVB calculation point in 8 patients. Doses at these alternate calculation points were comparable, although there was greater variability with small changes in the calculation point if sources were located outside the capsule, near the NVB calculation point. Three patients who developed early postimplant impotence had maximal NVB doses that far exceeded the average values. CONCLUSIONS: In the next few years, we hope to clarify the role of high NVB radiation doses on potency, by correlating NVB dose calculations with a large number of patients enrolled in an ongoing I-125 versus Pd-103 trial for early-stage patients, for whom detailed dosimetric and potency data are being collected prospectively. In the future, we anticipate that NVB doses may be incorporated into dosimetry guidelines to maximize tumor control and minimize treatment-related morbidity.

Follow-up costs after external radiation for low risk prostate cancer.

PURPOSE: Some routine follow-up costs for external radiation for prostate cancer might not be justifiable. To study this possibility, we reviewed the follow-up costs and clinical course of 36 consecutive, unselected patients treated with external beam radiation (EBRT) for low-risk prostate cancer at the University of Washington. METHODS AND MATERIALS: Thirty-six consecutive patients with Stage T1/T2 prostate cancer and pretreatment prostate specific antigen (PSA) < 10 ng/ml were treated with EBRT with curative intent at the University of Washington from 1990 through 1996. All follow-up visits with each patient's urologist and radiation oncologist, and all laboratory tests were tabulated. Charges quoted in this report are based on University of Washington billing. RESULTS: A total of 8 patients demonstrated biochemical evidence of tumor progression/persistence, none of whom has had any therapeutic intervention for progressive cancer. No patient had local disease progression by physical examination. One patient experienced a Radiation Therapy Oncology Group (RTOG) grade 3 bowel complication (obstruction), not detected on routine follow-up. The average combined PSA and physician follow-up charges for the first 2 years after therapy was $1,013. CONCLUSION: The data presented here suggests that for low-risk prostate cancer (PSA < 10 ng/ml), frequent follow-up by physical examinations and PSAs during the first 2 years after therapy is not warranted.

Adenocarcinoma of the fallopian tube: results of a multi-institutional retrospective analysis of 72 patients.

PURPOSE/OBJECTIVE: To determine the prognostic factors for predicting outcome of patients with adenocarcinoma of the fallopian tube and to evaluate the impact of treatment modalities in managing this uncommon disease. MATERIALS AND METHODS: A retrospective analysis of the tumor registries from 6 major medical centers from January 1, 1960 up to March 31, 1995 yielded 72 patients with primary adenocarcinoma of the fallopian tube. The Dodson modification of the FIGO surgical staging as it applies to carcinoma of the fallopian tube was utilized. Endpoints for outcome included overall and disease-free survival. Univariate analysis of host, tumor, and treatment factors was performed to determine prognostic significance, and patterns of failure were reviewed. RESULTS: The median age of the study cohort was 61 years (range 30-79 years). Stage distribution was 24 (33%) Stage I; 20 (28%) Stage II; 24 (33%) Stage III; and 4 (6%) Stage IV. Adjuvant chemotherapy was administered to 54 (75%) patients, and postoperative radiotherapy was employed in 22 (31%). In the latter treatment group, 14 (64%) had whole pelvic external beam irradiation, 5 (23%) whole abdominal radiotherapy, 2 (9%) P-32 instillation, and 1 (4%) vaginal brachytherapy alone. Chemotherapy was used in 67% of Stage I and in 79% of Stages II/III/IV disease (not significant); radiotherapy was more commonly employed in Stage I than in Stages II/III/IV (46% vs. 23%, p = 0.05). The 5-, 8-, 15-year overall and disease-free survival for the study patients were 44.7%, 23.8%, 18.8% and 27.3%, 17%, 14%, respectively. Significant prognostic factors of overall survival included Stage I vs. II/III/IV (p = 0.04) and age < or = 60 years vs. > 60 years at diagnosis (p = 0.03). Only Stage I vs. II/III/IV (p = 0.05) was predictive of disease-free survival. Patterns of failure included 18% pelvic, 36% upper abdominal, and 19% distant. For all patients, upper abdominal failures were more frequently found in Stages II/III/IV (29%) than in Stage I (7%) (p = 0.03). Relapses solely outside of what would be included in standard whole abdominal radiotherapy portals occurred for only 15% of patients (6 of 40) with failures. Furthermore, patients having any recurrence, including the upper abdomen, were more likely (p = 0.001) to die (45%) than those without any type of relapse (18%). CONCLUSION: This retrospective, multi-institutional study demonstrated the importance of FIGO stage in predicting the overall and disease-free survival of patients with carcinoma of the fallopian tube. Future investigations should consider exploring whole abdominal irradiation as adjunctive therapy, particularly in Stage II and higher.