Carcinoma of the urinary bladder. Influence of dose and volume irradiated on survival.

Two groups with comparable bladder carcinoma were selected from 249 patients treated with telecobalt therapy from 1955 through 1971. Group I received a mean isocentric dose of 6,060 rads in six weeks to an average volume of about 1,050 cm3 within the 90% isodose lines; Group II received a mean isocentric dose of 6,542 rads in six and one-half weeks to a volume of approximately 1,700 cm3. Overall five-year survival rates were 12.6% (+/- 5.4) in Group I and 25.5% (+/- 4) in Group II, with improvement being most marked in patients with advanced stages of disease. Results show that when the dose was increased and a larger volume of pelvic tissue was irradiated, the five-year survival rate improved.