title: Efficacy of continuous treatment with radiation in a rat brain-tumor model.
abstract: Rats bearing intracerebral 9L/Ro tumors were treated with 10 daily fractions of cesium-137 gamma-rays, BCNU, or combinations of these to agents beginning on either Day 10 or Day 12 after implantation. The treatments were administered either 5 days/week for 2 weeks, with the weekend off, or 10 consecutive days. The median day of death for untreated tumor-bearing rats was Day 15, so Day 12 tumors can be considered late tumors and Day 10 tumors can be considered moderately early. Although all single- and multiple-agent treatments significantly (p less than 0.05) increased the lifespan of tumor-bearing rats over that of the untreated controls, and all multiple-agent schedules significantly (p less than 0.05) increased the lifespan over that of the single-agent therapies, none of the 10 consecutive day schedules increased the lifespan of tumor-bearing rats significantly (p less than 0.2) over that obtained with the 5-day/week schedules. Thus, the evidence from this tumor model suggests that no significant improvement in lifespan would be expected if malignant brain tumors were treated with radiation 7 days a week, either alone or in combination with chemotherapeutic agents such as BCNU.
mesh_terms: D000818:Animals; D001932:Brain Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000532:radiotherapy*; D002330:Carmustine / Q000627:therapeutic use; D004195:Disease Models, Animal; D008297:Male; D009374:Neoplasms, Experimental / Q000188:drug therapy / Q000401:mortality / Q000532:radiotherapy; D011829:Radiation Dosage; D051381:Rats
chemical_list: D002330:Carmustine