Results of Biopsy After Early Stage Prostatic Cancer Treatment by Implantation of ¹²⁵ I Seeds

Abstract

We have treated 77 patients for clinically early stage carcinoma of the prostate, 9 stage A2, 63 stage B and 5 stage C, with direct implantation of 125I seeds into the prostate and pelvic lymphadenectomy. It is estimated that a minimum dose of 15,000 rad but a maximum dose of 35,000 rad is delivered to the prostate over several months. Of the 77 patients 14 (18 per cent) had metastatic disease in the pelvic lymph nodes. In 22 cases perineal needle biopsy was done 12 to 18 months after treatment and in 3 cases a second biopsy was performed after 2 to 3 years. Persistent tumor was present in 11 biopsies. Cytological changes were observed in 8 of these, primarily cytoplasmic vacuolation and nuclear pyknosis. There seemed to be no relationship between grade and stage of disease and histological evidence of persistence of tumor after radiation. One patient with persistent tumor in the postoperative biopsy has shown progression of disease after 2 years and another with a negative biopsy has a bony metastasis. The remaining 10 patients with persistent tumor have shown no sign of progression of disease during a 2 to 4-year interval.