The significance of local tumor hyperthermia/radiation on the production of disseminated disease

Studies were designed to evaluate the significance of local tumor hyperthermia (LTH) alone and/or radiation (RAD) on the production of disseminated disease. The Dunn Osteogenic sarcoma transplanted (day 0) to the footpad of C3H/HeJ male mice was treated with 3 or 4 fractions of non-curative RAD (200 rad/fraction) and/or LTH (water bath: 40.5 or 42.5±0.1°C for 15 min) on days, 7, R and 9 or on days 7, 10, 13 and 16. The treated primary was removed surgically by amputation on day 10 or 15 (3 Rx group) or on day 21 or 28 (4 Rx group). Survival to day 120, was the eidpoint for analysis. Under these experimental conditions, mild (40.5°C) or moderate (42.5°C) LTH alone or in combination with the RAD treated at the time when metastases has not occurred did not increase the metastatic spread of disease. In addition, combined therapy (RAD+LTH) was effective in preventing dissemination at the time when metastases normally occurs.