Pulmonary function in survivors of Wilm's tumor. Patterns of impairment

Whole-lung irradiation in Wilms' Tumor patients has been given prophylactically and for treatment of metastasis. Thirty-three children with Wilm's tumor who have survived for 4 to 20 years from the time of diagnosis were avaiable for study. Whole-lung irradiation was given in doses from 1163 to 1370 rads (orthovoltage). Eighteen patients (Group N) received no irradiation to the lungs. The remaining 15 patients were divided according to whether pulmonary irradiation was given for metastatic disease (Group M--10 patients) or for prophylactic treatment (Group P--five patients). All but five patients in Group N received at least one course of actinomycin D. A routine set of pulmonary function tests was done to assess possible abnormalities of lung volume and the mechanics of breathing. Group N was normal. The findings in Group M suggested moderately reduced lung volumes and may have also reflected obstruction of the large airways and/or a limited expiratory effort. Group P had essentially normal lung volumes but also appeared to have obstruction of the larger airways. Abnormalities were generally not severe; only two patients, in Group M, were symptomatic. Excess irradiation, presence of metastatsis, additional lung irradiation, and pneumonitis may have contributed to morbidity.