A comparison between conventionally fractionated irradiation and low dose radiotherapy in treatment of large tumors of the breast

44 patients with large tumors of the breast were treated with primary irradiation followed by various therapeutic modalities. Twenty-one patients received conventionally fractionated irradiation (CF) at 45 Gy and 23 low-dose rate radiotherapy (LDR), 12 patients at 45 Gy and 11 at 35 Gy. Tumor regression was estimated 3 months after beginning radiotherapy, whereas reactions in healthy tissue were observed at 6 months. In the CF group, tumor regression was complete in 19%, partial in 19% and poor in 62% of cases and the corresponding findings in the LD group were respectively 70, 30 and 0%. During the same follow-up period the pathological specimens obtained by incision biopsy were negative in 25% and positive in 75% of cases, whereas the corresponding results for LDR were respectively 64 and 36%. Cosmetic results in the CF group were good in almost all cases and no poor cases were found. In the LDR group, cosmetic results at 45 Gy were mediocre or poor in the majority of cases but good in all cases at 35 Gy. It is concluded that irradiation permits conservative treatment of large tumors of the breast in almost all cases. 35 Gy appears to be the optimal dose to obtain high tumor control with good cosmetic results