Intraoperative radiation therapy: is it a standard now?

The question whether and for whom the gold standard of whole breast radiotherapy (WBRT) may be replaced by accelerated partial breast irradiation (APBI) is one of the most controversial issue in the adjuvant breast cancer setting. Among different APBI techniques, intraoperative radiation therapy (IORT) is particularly appealing to patients and physicians, because the procedure is fast, convenient, normal structures sparing and able to solve some clinical problems, like the integration with chemotherapy. Early findings from phase II and randomized phase III trials show the approach of APBI in selected patients at low risk for local recurrence is safe and well tolerated, but short follow-up creates some reservations. Since recurrences of breast cancer can occur after a considerably time delay, final assessment of APBI will only be valid after sufficient follow-up from prospective randomized trials with large patients number. Until then APBI should be considered experimental. Furthermore, many questions regarding the appropriate patient selection criteria, treatment volume and dose fractionation still exist. In the context of risk-adapted RT, the key to success is the proper selection of the patients. Both the American and European Society of Radiology and Oncology provided a consensus statement regarding patient selection criteria based on tumour and patient-related features. The 5-year results of the non-randomized ELIOT study from Milan, using 21 Gy-full dose, identified a group of patients who may be good candidates for the treatment. The stratification of patients according to clinical phenotype or by molecular class and a widespread use of preoperative breast magnetic resonance imaging might be better identify patients eligible for APBI.