[Basic and clinical study of high dose rate intracavitary radiotherapy of bladder tumor].

Since 1984, through 8 years, 29 cases of bladder tumor were treated with high dose rate intracavitary radiotherapy. All cases were transitional cell carcinoma in histology and consisted of 12 cases of CIS, 7 of Ta, 3 of T1, 1 of T2 and 6 of T3. At the intracavitary therapy, 3-way catheter made specially for high dose rate intracavitary radiotherapy was inserted into the bladder and the balloon of the catheter was inflated with air of 80 to 100 ml. A radioactive source of 60Co was remotely controlled and drove through the catheter into the bladder. The delivered dose was 5 Gy per fraction and total dose was 40 to 50 Gy in 8 to 10 fractions. Complete response (CR) rate was 7/12 (58.3%) in CIS, 4/6 in Ta, 1/3 in T1, 1/1 in T2 and 1/6 in T3. CR rate of CIS and superficial tumor (Ta, T1) was 57.1% (12/21), whereas that of invasive cancer was 2/7. Regarding complications, one case suffered severe cystitis as an acute reaction, however, the remaining cases only noted a mild or moderate acute reaction. It was concluded that high dose rate intracavitary radiotherapy was a useful treatment for CIS of the bladder and superficial bladder cancer.