Dose local x-irradiation of a tumor increase the incidence of metastases?
KHT sarcomas were implanted into the right rear legs of C3H mice. Animals receiving no treatment died at 32 days with a 67% incidence of metastatic tumors. A dose of 6000 rads in ten fractions over 12 days, starting ten days after implant, delivered to the primary tumor (with the remainder of the body shielded) produced 55% local tumor control. However, 83% of the mice with local tumor control, subsequently developed metastatic lesions. Amputation of the tumor-bearing leg either prior to the start of radiation treatment, at the end of treatment or at intervals during treatment or sham treatment, indicated that 1) metastases occurred predominantly during the initial three radiation fractions and 2) the increased incidence of metastases following irradiation was a result of the manipulations associated with the irradiation and not the irradiation per se. Irradiation did not change the distribution of organ sites involved with metastatic tumors compared to untreated or sham-treated tumors.
D000818:Animals; D005260:Female; D008175:Lung Neoplasms / Q000209:etiology*; D051379:Mice; D008809:Mice, Inbred C3H; D008954:Models, Biological; D009362:Neoplasm Metastasis; D009381:Neoplasms, Radiation-Induced; D011878:Radiotherapy / Q000009:adverse effects*; D011879:Radiotherapy Dosage; D012513:Sarcoma, Experimental / Q000532:radiotherapy*