Early and late effects of mitomycin C and continuous low-dose-rate irradiation on the mouse skin and soft tissues of the leg.

Abstract

The early and late effects of combined mitomycin C and continuous low-dose-rate irradiation (CLDRI) on the skin and soft tissues were studied in the C3Hf/SED mice. Localized CLDRI of the hind leg at 0.028 Gy/min with and without mitomycin C was delivered using a 137Cs laboratory irradiator. Mitomycin C at 6 mg/kg was given by continuous infusion through intraperitoneally implanted osmotic mini-pumps during CLDRI. Acute skin reaction was scored from days 13 to 30 and late skin contraction and leg contracture were measured at days 90, 180, 270, and 360 after treatment. Mitomycin C increased the early skin reaction following CLDRI; at a dose of 60 Gy, the dose effect factor was approximately 1.1. However, there was no significant enhancement of late skin contraction or leg contracture by mitomycin C. Our results suggest that mitomycin C can be combined with low-dose-rate brachytherapy without a significant increase in early or late damage to the skin and soft tissues.