[A study on the effects of preoperative radiotherapy for lymph node metastases in rectal cancer]

Twenty-nine patients with rectal carcinoma who were treated by surgery only and 27 patients who received adjuvant preoperative radiation (42.6 Gy) were subjects of the present study. The entire pelvis was radiated with the dose of 30.6 Gy, and the rest 12 Gy was delivered to the primary tumor. By injecting micro activated carbon into the submucosa of the rectum near the tumor, the number of the defection of removed lymph nodes in non-radiation as well as radiation group was markedly improved, 48.6 and 54.2 respectively. The rates of distal lymph nodes metastases in irradiated patients were 25.9% (n0 74.1%, n1 14.8%, n2 11.1%, n3 0%), whereas it was 51.7% in patients who had surgical resection only (n0 48.3%, n1 20.7%, n2 17.2%, n3 13.8%). The number of metastatic lymph nodes were fewer in irradiated patients. Histopathological study indicated that preoperative irradiation was effective on decreasing the quantity of metastatic lymph nodes.