Radical external radiotherapy for prostatic carcinoma

From 1965 through 1974, 88 patients with Stage B or C prostatic carcinoma were treated with radical megavoltage therapy. Treatment technique was small field arc alone for Stage B and 4 field box whole pelvis irradiation to 4400 or 5000 rad with small field rotational boost for Stage C. All were at risk for 5 years and 30 for 10 years or more. None of the 14 Stage B patients have died of cancer, although one is living with metastases. In Stage C (74 patients) uncorrected actuarial survival was 55% ± 5.8 (5 year) and 28% ± 6.5 (10 year). When corrected for intercurrent deaths, survival was 65 % ± 5.8 (5 year) and 37 % ± 8.1. Survival curves for those patients receiving 6000–6900 rad were not significantly different from those receiving 7000 rad or more. Local control may be better in the latter group, 82.7% (43/52) versus 71.4% (20/28), although this is, not significant. Thirty-one percent of local failures appeared after 5 years. Whole pelvis dose of 5000 rad was associated with a higher 5 and 10 year survival than 4400 rad but the difference was not statistically significant. Comparison between groups treated with radiation alone, versus radiation plus a simultaneous hormonal therapy showed no significant differences in survival, local control or complications. A group of 20 patients who failed hormonal therapy and were then irradiated did less well. Complications were generally mild, but early in the series 2 patients receiving 7500 rad developed ano-rectal necrosis; one of these patients died. More common problems were urethral stricture (12 % ) and ano-rectal stenosis (10%). Changes in technique in 1971 drastically reduced the subsequent complications. The failure of whole pelvic irradiation to improve on the 10 year results of local treatment is discussed.