Advanced carcinoma of the stomach treated with definitive proton therapy

We report the case of a 72-yr-old man who suffered from severe chronic emphysema with poor pulmonary function, and who had advanced cancer of the stomach. Proton beam radiotherapy was applied to the lesion, since surgery was contraindicated. The total dose to the stomach lesion was 61 Gy in 7 wk. The tumor on the stomach regressed, with flattening of the round wall of the lesion. The reactive changes of the proton beam radiotherapy, based on the histopathological examination, revealed extensive tumor necrosis and sparing of vital architecture of normal tissue around the irradiated tumor tissue. Only small clusters of vital or devitalized tumor cells with less than approximately 5% of the whole tumor tissue remained after treatment. We suggest that a high dose of radiation delivered by well-defined proton field could result in an improved therapeutic outcome without undue risk of injury to normal tissue.