THE RESULT OF EXTERNAL RADIOTHERAPY AND SIDE EFFECT FOR PROSTATE CANCER

Radiotherapy for 67 cases with prostate cancer at the Cancer Institute Hospital during the period of January 1980 to December 1989 is reported. Mean age was 70 years (43-85), and clinical stages were classified as Stage A, 10; B, 24; C, 19; D, 11; not specified (NS), 3. Pathological classification showed well differentiated, 19; moderately differentiated, 20; poorly differentiated, 19; NS, 9. Treatment was performed as follows: radiotherapy (RT) only, 18; RT plus hormonal therapy, 34; RT plus transurethral resection of prostate (TURP), 13; RT plus chemotherapy, 2. Local irradiation to the prostate was conducted mainly by bilateral 120 degree arc rotation with 10 MV photons and a mean dose of 69±2 Gy (TDF = 118±10). Pelvic lymphnodes were treated by lymphadenectomy in 18 patients, or by whole pelvic radiotherapy in 6 cases. Overall survival (OS) and disease specific survival (DSS) at 5 year were 70% and 87%, and at 10 year 51% and 87%, respectively. According to the clinical staging, OS and DSS at 5 year were, respectively: Stage A, 100%, 100%; Stage B, 89%, 100%; Stage C, 63%, 81; Stage D, 37%, 65%. Pollakisuria (27%), urinary retention (19%), and bloody stool (8%) were temporally observed as acute radiation complications. Late radiation hazards manifested as rectal bleeding or tarry stool in 2 cases; one with overlapping field resulted in disseminated intravascular coagulation, and the other with mispositioning of the posterior margin of the radiation field, was finally salvaged by artificial anal replacement. Local radiotherapy by bilateral arc rotation method for prostate cancer would be warranted instead of radical prostatectomy.