Percutaneous Transperineal Placement of Radioactive Gold Seeds for Treatment of Localized Prostatic Carcinoma

Gold seed implantation in prostate brachytherapy

Interstitial brachytherapy for treatment of prostate cancer with radioactive gold--initially with liquid gold and later with seed technique--is based on an experience of more than four decades. With biopsy results approaching a 80% negative rate, and, at 5 years, a cancer specific survival of 100% for Stages A and B1, 90% for Stage B2, and 76% for Stage C, this form of treatment offers an effective and well-tolerated alternative mode of therapy for patients with localized prostate cancer.

Survival of patients with localized prostate cancer treated with percutaneous transperineal placement of radioactive gold seeds: stages A2, B, and C

Between 1984 and 1991, a total of 177 patients with adenocarcinoma of the prostate were treated with transcutaneous, transperineal radioactive gold seeds. Of these 177 patients, 20 were determined to have pelvic lymph node involvement and were excluded from this review. The remaining 157 patients received a median radioactivity dose of 164 mCi with a median follow-up of 48 months. Cancer-specific survival at 5 years was 100% for stage A2 and B1, 90% for stage B2, and 76% for stage C cancer. Covariates of grade, total radioactivity administered, age of the patient, and number of seeds implanted did not influence disease-free survival in a statistically significant manner. Significant complications were observed in two patients. The survival rates of patients treated with 198Au seed implantation for localized cancer are equivalent or better when compared to historical data of patients treated with 125I implantation, external beam radiotherapy, combination radioactive gold seed implantation and external irradiation, and radical prostatectomy. In addition, these comparable survival rates using interstitial 198Au seeds may be achieved with less morbidity.

Use of percutaneous transperineal 198Au seeds to treat recurrent prostate adenocarcinoma after failure of definitive radiotherapy

Patients who fail external radiation therapy for prostatic cancer pose a therapeutic challenge. No further external radiation treatment can be delivered safely to the local lesion, although some patients are candidates for salvage surgery. In this study, 31 patients who failed prior external beam radiotherapy received percutaneous transperineal placement of gold seeds (198Au). Initial prostate volume was 17.7 cc and decreased to 10 cc 24 months after 198Au implantation. Of 15 patients biopsied at 12 months after treatment, 4 (27%) were positive, 6 (40%) were negative, and 5 (33%) showed prostate cancer with radiation changes. Two of three patients have died of prostate cancer, with an overall 5-year estimated survival of 67%. Interstitial brachytherapy was found to be an additional well-tolerated treatment modality in this group of 31 patients.

Management of stage C adenocarcinoma of the prostate

A review of numerous clinical series dealing with the treatment of patients with clinical stage C prostate cancer failed to find the treatment or a combination of treatments that is superior to any other. Accurate staging, which was difficult in older studies, and stage migration, which complicates the comparison of recent to older studies, may contribute to this lack of identification. The majority of patients ultimately experience disease progression and are therefore treated with hormonal therapy, the use of which obscures survival data for initial modes of treatment. These observations point to the need for control of randomised clinical trials to identify effective treatments in the future.