Carcinoma of the prostate irradiated by combined I125 and external irradiation. Analysis of failure and significance of positive biopsy one year or more after therapy

Sixty-three patients with cancer of the prostate T2 or T3 were evaluated. The protocol of treatment called for pelvic lymphadenectomy, 10,000 rad from I125 implant and 4000 rad in 20 fractions using a Cobalt60 machine. They were followed for 1 to 5 years with a plan to rebiopsy the prostate 1 to 2 years after therapy. Six of 59 evaluable patients (10%) showed progressive disease. Distinctive prognostic features in the failure group were younger age, larger prostate, more advanced stage, poorer differentiation, more possibility of positive pelvic lymph nodes, and if the nodes were positive, the involvement of more than two pelvic lymph nodes. On the other hand, the patients with controlled disease with or without positive prostatic biopsy on follow-up showed identical features regarding age, size of prostate, stage, differentiation, involvement of pelvic lymph nodes, and if the nodes were positive, only one or two nodes involved. Positive biopsy 1 to 2 years after radical irradiation in otherwise controlled disease is considered of no prognostic value.