Clinical Course after External Beam Radiation Therapy for Localized Prostate Cancer

Kim, Gi Young; Kim, Sun Il; Woo, Young Nam

Abstract

PURPOSE: External beam radiation therapy (EBRT) is a standard treatment modality for localized prostate cancer (PC), and its efficacy compares favorably to radical prostatectomy. We evaluated the outcomes of conventional EBRT for the clinically localized PC performed on patients during the last 9 years.
MATERIALS AND METHODS
We retrospectively reviewed the data from 28 men who were treated with external beam radiation with curative intent at our institution from 1995 and 2002. The histologic diagnosis was established by transurethral resection or transrectal ultrasonography guided biopsy. There was no evidence of lymph node invasion or metastasis in all the patients. None of the patients were treated with hormonal therapy until they exhibited a clinical recurrence of their condition. The 4 field pelvic brick technique was used for a dose of 45 Gy or 50.4 Gy at 1.8 Gy per day during 5 to 6 weeks of treatment; after this, a small boost field was delivered (2.9 Gy per day) for a total dose of 66 to 70 Gy. PSA failure was defined according to the consensus guidelines of the American Society for Therapeutic Radiation Oncology. The mean follow- up was 31 months.
RESULTS
The mean patient age at treatment was 70 years. The mean time to PSA nadir and the mean PSA at nadir were 13 months and 0.88 ng/ml, respectively. There were 8 (28.6%) biochemical failures and 1 clinical recurrence. The 36 and 60 months biochemical disease-free survival rates were 89% and 43%, respectively. Mild to moderate complications were observed in 25% of patients, but severe complications requiring intensive or surgical procedures were not observed.
CONCLUSIONS
EBRT for localized PC is effective and safe. A greater number of cases and longer follow-up are required to provide more accurate baseline data on the PSA kinetics following EBRT in the Korean population.