SYNERGISTIC EFFECTS OF HYPERTHERMIA IN PREOPERATIVE RADIOCHEMOTHERAPYFOR RECTAL-CARCINOMA

PURPOSE: We investigated the effectiveness of hyperthermia added to pr eoperative radiation and chemotherapy for the treatment of rectal carc inoma. METHODS: Forty-one patients receiving preoperative radiation we re divided into two groups, Group A (20 patients; receiving radiation, hy perthermia, and chemotherapy) and Group B (21 patients, receiving no hyperthermia). Total dose of radiation was 40.5 Gy. Hyperthermia wa s administered using 8 MHz of radiofrequency. Rectal temperature reach ed 42 degrees C. A total dose of 3,400 mg of fi-fluorouracil given by suppository was used as the chemotherapeutic agent. Effect of the preo perative treatment was assessed by tumor reduction on barium enema, hi stologic findings of the resected specimens, area measurement of the r esidual cancer tissue, and by silver-staining nucleolar organizer regi on (AgNOR) score. RESULTS: Tumor reduction on barium enema was signifi cantly greater in Group A than in Group B (P < 0.01). Excluding two ca ses of mucinous carcinoma because a large acellular mucinous accumulat ion added materially to the cancerous area, the ratio of residual canc er area to total lesion size in Group A was significantly smaller than in Group B (P < 0.05). AgNOR store of the resected tumor tended to be smaller in Group A than in Group B. CONCLUSION: Addition of hyperther mia resulted in a greater degree of tumor necrosis and was considered to be useful as a preoperative treatment for rectal carcinoma.