Rectal and bladder injuries in relation to radiation dosage in carcinoma of the cervix: A 5 year follow-up

Abstract

A survey was made of 500 patients with invasive carcinoma of the cervix treated at the Radiumhemmet, who were followed for more than 5 yr with particular attention to the development of radiation injuries. Increased dosage of radiotherapy used on an experimental basls during the time of this study appears to be responsible for improvement in survival rates but was accompanied by a higher rate of injuries. There is a direct correlation between dosage levels in bladder and rectum and injury rate. A dose of more than 5,000 gamma r or a total dose of more than 6,000 r to the rectal mucosa is accompanied by a very high injury rate as is a dose of more than 6,000 gamma r or more than 9,000 total r to the bladder. Because of these results, treatment of carcinoma of the cervix, beginning in 1956, was modified on the basis of direct dosage measurements in the bladder and rectum at the time of treatment. Currently, 4,000 gamma r to an area of more than 2 cm in diameter is considered the maximum permissible dose in the average patient. There is also a correlation between intensity of treatment and injury rate in bothmore » the bladder and rectum. A total of 2,400 gamma r to the rectum in 24 hr is the maximum intensity which is now permitted. Both rectum and bladder injuries are usually transient, with those in the rectum generally occurring sooner than those in the bladder. The incidence of permanent disability due to therapy in this series (1% of patients treated) is very low compared with the overall 5-yr survival rate of 54.5%. (H.H.D.)« less