On the study of the interstitial reaction from the lineac irradiation therapy for gastric cancer and its complication

Histologically studied 42 cases of resected stomach and 10 cases of autopsied stomach were evaluated for the therapeutic efficacy of lineac radiation therapy (LRT). Complete disappearance of cancer cells or minimal residual cancer cells were found in 38.5% of the cases, and more than half of cancer cells disappeared in 30.8%, indicating that LRT was effective in 69.3%. Degeneration without disappearance of cancer cells was noticed in 11.5% which was classified as unresponded cases. Histological studies in the unresponded cases except one receiving merely 10 Gy suggested that 2 stages were involved in the degeneration process of cancer cells by LRT. Namely, the primary response was the direct effect of radiation to produce DNA degeneration and lysosomal enzyme liberation, and the second response, which followed the primary one, was macrophage-lymphocytic reaction. Complications of the LRT were acute myocardial infarction (1), hepatic veno-occlusive disease (1), and liver metastasis (1). (J.P.N.)