Pathological findings in the injury areas.

Notes) -: No abnormal changes, ±: Very slight, + : Slight, 2+: Moderate, 3+: Marked, NE: Not examined.Cellular infiltration was observed in the mucosa, submucosa, muscle layer, and adventitia in the 25 J/cm2 group. Cellular infiltration was observed within and outside of the adventitia in the 50 J/cm2 and 100 J/cm2 groups. Fibrosis and hemorrhage were observed in the submucosa, muscle layer, and adventitia in the 25 J/cm2 group, and fibrosis and hemorrhage were observed within and outside of the adventitia in the 50 J/cm2 and 100 J/cm2 groups. Necrosis was observed in the submucosa and muscle layer in the 25 J/cm2 group and within and outside of the adventitia in the 50 J/cm2 and 100 J/cm2 groups. These changes tended to become more severe as the irradiation dose increased.