p.s A radiation oncologist would, of course, be the best source of information regarding this issue.
bb
In general, repeat radiation is consisered a rarely used treatment strategy that must be performed with caution.
However, there was a report in 2011 from a small research study that investigated the efficacy and toxicity of a second curative radiotherapy series in cases of recurrent breast cancer.
It concluded that "repeat radiotherapy for recurrent breast cancer with total radiation dose of 60 Gy and the addition of hyperthermia in the majority of patients was feasible, with acceptable late morbidity and improved prognosis, particularly in patients with previous resection of recurrent tumors."
Best wishes,
bluebutterfly