EXPERIMENTAL AND CLINICAL-STUDIES WITH INTRAOPERATIVE RADIOTHERAPY

Abstract

Studies of normal tissue tolerance to intraoperative radiotherapy were done on 65 dogs subjected to laparotomy and 11 million electron volt electron irradiation in doses ranging from 0 to 5000 rads. Evidently, intact aorta and vena cava can tolerate up to 5000 rads without loss of structural integrity. Ureteral fibrosis and stenosis developed at doses of 3000 rads or more. Arterial anastomoses healed after doses of 4500 rads, but fibrosis could lead to occlusion. Intestinal suture lines heal after doses of 4500 rads. Bile duct fibrosis and stenosis develop at doses of .gtoreq. 2000. Biliary-enteric anastomoses fail to heal at any dose level. A clinical trial of intraoperative radiotherapy combined with radical surgery was performed on 20 patients with advanced malignant tumors which were considered unlikely to be cured by conventional therapies and which included carcinomas of the stomach, carcinomas of the pancreas, carcinomas involving the hilus of the liver, retroperitoneal sarcomas and osteosarcomas of the pelvis. All patients underwent resection of gross tumor, followed by intraoperative irradiation of the tumor bed and regional nodal basins. Some patients received additional post-operative external beam radiotherapy. Treatment mortality for combined operation and radiotherapy occurred in 4 of 20 patients. Postoperative complications occurred in 4 of the 16 surviving patients. Local tumor control was achieved in 11 of the 16 surviving patients, with an over-all median follow-up period of 18 mo. The clinical trial suggested that intraoperative radiotherapy is a feasible adjunct to resection in locally advanced tumors, that the resulting mortality and morbidity is similar to that expected from operation alone and that local tumor control may be improved.