Acute toxicities associated with radiation in the second National Wilms' Tumor Study.

Twenty-three of 303 patients (7.6%) entered into National Wilms' Tumor Study Number 2 (NWTS-2) with groups II, III, and IV disease experienced 26 toxic events thought to be related to radiotherapy (RT). The randomization between vincristine (VCR) plus dactinomycin (AMD) and the same two drugs plus doxorubicin (ADR) had a minimal effect on RT toxicity. Five (1.6%) fatalities were recorded and the surviving 18 patients recovered without discernible residua. Sixteen patients had hepatic, four had pulmonary, and three had cardiac toxicity. Hepatic toxicity was significantly more common when the right side of the abdomen or the whole abdomen was irradiated than when the left side was treated (P = .01). We conclude that acute RT-related toxicity in NWTS-2 was very similar to that in NWTS-1, in which 26 (7.2%) of 359 randomized patients developed RT-related toxicity and three died. This acceptable rate was maintained despite more intensive chemotherapy (CT) in NWTS-2.