GONADAL EXPOSURE IN THE RADIATION TREATMENT PART 2,MEASUREMENT OF GONAD DOSE IN RADIATION TREATMENT OF BENIGN DISEASES

The radiation treatment was given to 719 cases of a variety of benign diseases, which were equivalent to 4.1% of all out-patients, 17409 cases, visiting the Department of Radiology, Chiba University Hospital between August, 1954 and December 1968. The localizations of the radiation treatment were classified into the following four groups, head and neck, chest and upper abdomen, lower abdomen and thigh, and extremities. The group of head and neck occupied 74% of all treated cases and the others did 8 to 10% respectively. The annual number of cases of benign deseases have been decreasing in recent several years. The age distribution of the patients indicated the largest number in 16 to 25 years old. Gonadal exposure was measured on 74 cases using the pocket chamber placed ether on the genitals or at the vaginal fornix. The differences of the portions and conditions of the treatment made a variety of measured doses when the same dose was irradiated. The average dose per 100R exposure was 10mR with the conventional x-rays and 28mR with the tele-cobalt gamma-ray. The group of lower abdomen and upper thigh showed much higher gonadal exposures than the other groups, reaching up to 65mR per 100R of the conventional x-rays, though the lead rubber sheets were used to cover the out-side of the irradiated field for protection. The average accumulated dose during the full course of treatment ranged from 123 to 176mR with the conventional x-rays and from 632 to 775mR with the tele-cobalt gamma-ray, when the group of lower abdomen and upper thigh was excluded. The measurement was performed on a Mix-D phantom of the body-size, showing the relationship between the dose distribution of the scatter radiations inside of the body.