The use of electron beams in treating local recurrence of breast cancer in previously irradiated fields.
A retrospective study was performed to assess the efficacy of using electron beam therapy to treat locally recurrent breast cancer in previously-irradiated fields. In a group of patients who received postmastectomy nodal and chest wall megavoltage photon therapy to doses of 4000-5000 rads, an additional 4000-5000 rads were delivered to chest wall recurrences with 7-10 MeV electrons. Good tumor responses were obtained without unacceptable concomitant normal tissue damage. With a follow-up time of 9 months to 5 years, 62% (8 of 13) are alive and clinically free of disease in the irradiated volume. Two patients died at respective times of 5 and 6 months after retreatment, with only one showing evidence of chest wall recurrence. One patient showed no response to therapy and the remaining two patients recurred in the treated volume at 10 and 59 months. Morbidity was limited to dry and/or moist desquamation with no evidence of soft tissue necrosis. These results demonstrate that the first course of irradiation did not select for a subset of radioresistant tumor cells, and indicate that a second course of radiation therapy may have much to offer in controlling locally recurrent breast cancer.
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000532:radiotherapy*; D004583:Electrons / Q000627:therapeutic use; D005069:Evaluation Studies as Topic; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011879:Radiotherapy Dosage