[Use of the TDF factor in soft roentgen radiotherapy]

In a prospective randomized study 164 patients with altogether 142 basal cell carcinomas and 24 squamous cell carcinomas were each irradiated with a single dose of 3 Gy daily on 20 consecutive days, giving a total dose of 60 Gy (TDF factor 123). In another group of 155 patients, with altogether 148 basal cell carcinomas and 20 squamous cell carcinomas, each patient received 4 Gy 3 times per week until 12 irradiations had been administered, giving a total dose of 48 Gy (TDF factor 103). The cure rates in patients with basal cell carcinomas did not differ between the two groups: 90% were cured by the higher total dose and 92%, by the lower dose. The high dose regimen brought about a cure in 96% of squamous cell carcinomas, in contrast to only 85% with the low dose regimen. Owing to the small number of patients the difference was not statistically significant. These data demonstrate that basal cell carcinomas can be controlled by low-dose irradiation regimens. Squamous cell carcinomas may have a lower radiosensitivity than basal cell carcinomas and may require higher doses.