Comparison of two-port and four-port irradiation in the bladder preservation therapy for locally invasive bladder cancer

Abstract

To ascertain therapeutic effectiveness and adverse reactions with radiochemotherapy for locally invasive bladder cancer, comparison was made between two-port and four-port irradiation with intravenous cisplatin administration. In 86 patients who were diagnosed with locally invasive bladder cancer on the basis of imaging and biopsy findings, transurethral tumor resection was carried out initially to minimize tumor volume, and then radiochemotherapy was done. From 1985 to 1997, bilateral two-port irradiation was carried out, and after 1998, four-port irradiation was done. In regards to chemotherapy, cisplatin was administered intravenously. Therapeutic effects were assessed 1 month after the end of therapy. Fifty-five patients underwent two-port irradiation; complete response (CR) was achieved in 26 and partial response (PR) in 29 patients. Thirty-one patients underwent four-port irradiation; CR was achieved in 20 patients and PR in 11 patients. The cause-specific 5-year survival rate did not differ significantly between two-port and four-port irradiation (74%vs 79%), but there was a significant difference of survival between CR and PR patients. In the two-port irradiation group, 5-year bladder preservation rate was 89% in CR patients and 52% in PR patients. In the four-port irradiation group, 5-year bladder preservation rate was 90% in CR patients and 46% in PR patients. Of the various adverse reactions, no significant differences in leukopenia, thrombocytopenia or bladder symptoms were observed between two-port and four-port irradiation, but the incidence and severity of loss of appetite, nausea and/or vomiting, diarrhea and dermatitis were significantly greater for two-port irradiation. Radiochemotherapy are considered to be modest effective in the bladder preservation therapy for locally invasive bladder cancer. The four-port irradiation shows less adverse reactions than two-port irradiation.