Pulmonary reaction to upper mantle radiation therapy for Hodgkin's disease.

To study the effects of upper mantle radiation therapy on pulmonary function, forced expiratory volume in one second (FEV 1 ), vital capacity (VC), inspiratory capacity (IC), diffusing capacity for CO (D l co) and diffusion per unit of alveolar volume (D ls / va were determined in 28 patients with Hodgkin's disease, stages 1–3, before therapy and at regular intervals thereafter. Within the first year of follow-up there were significant declines in D l co, VC, and IC, whereas there were no significant changes in FEV 1 or D L / va . D L co showed the greatest decline in the largest number of subjects (22/28). Eleven of the 22 had 20 to 60 percent decline of D l co from baseline. The maximum mean decline in D l co was −12.7 ± 3 percent at the 87th ± 3 days from initiation of therapy post-radiation sustained through the 150th day and improving to pre treatment value (± 5 percent) by the 8th to 12th month. The changes in D l co seemed to be independent of the radiation dose ranges evaluated, clinically apparent intrathoracic lymphoma, post-radiation radiographic abnormalities and respiratory symptoms. We concluded that impairment in diffusing capacity and loss of vital capacity will develop in most patients receiving upper mantle radiation therapy, indicating that pulmonary reaction occurs despite lung shielding. The functional losses were prolonged and occasionally severe, but were transient and subclinical in most but not all cases. A case of fatal radiation pneumonitis affecting the lung beyond the field of irradiation is reported.