Preliminary report on phase III RTOG studies of extended-field irradiation in carcinoma of the prostate

Abstract

The Radiation Therapy Oncology Group (RTOG) has conducted 2 studies testing the value of extended- vs. limited-fields in carcinoma of the prostate. RTOG protocol 75-06 tests the value of paraaortic irradiation in patients with locally advanced tumors limited to the pelvis. RTOG protocol 77-06 tests the value of pelvic irradiation in patients with tumors limited to the prostate. Two hundred sixty-eigth evaluable patients have been entered on RTOG 75-06, and 219 on RTOG 77-06 prior to 1981. This is a preliminary report on treatment-related morbidity in patients followed for a minimum of 1 yr. Thirty-one percent of 268 patients on RTOG 75-06 and 34% of 219 patients on RTOG 77-06 had some form of treatment side effects. The majority (> 80%) of these were mild (grade 1 and 2) and by definition did not interfere with the patients'' performance (life style). Only 3 patients on RTOG 75-06 and 1 on RTOG 77-06 had grade 4 complications (by definition requiring a surgical intervention). No fatal (grade 5) complications have been recorded so far. The use of paraaortic fields in RTOG 75-06 and pelvic fields in RTOG 77-06 have not resulted in a significant increase of GI [gastrointestinal] or GU [genitourinary] morbidity at this time. The only statistically significant trend was the incidence of postirradiation genital and lower extremity edema which strongly correlated with the extent of staging lymphadenectomy.