The pilot trial on intraoperative radiotherapy with electrons (ELIOT): update on the results

Background: Intraoperative radiotherapy with electrons (ELIOT) is under evaluation in the conservative treatment of breast carcinoma. At the European Institute of Oncology we started our study on ELIOT in 1999; the first step has been a phase I-II trial to test feasibility and tolerance of ELIOT in patients candidate to breast conserving surgery. Patients and methods. From July 1999 to September 2000, 101 patients affected by unifocal breast carcinoma up to a diameter of 2.5 cm received wide resection of the breast followed by ELIOT. The trial was based on a dose-escalation starting from 10 Gy: we tested the dose-levels of 10, 15, 17, 19 and 21 Gy. The dose-levels of 10 and 15 Gy were followed by a reduced course of external fractionated radiotherapy. Most patients received 21 Gy intraoperatively. Patients were evaluated 1, 3, 6 and 12 months after surgery, and thereafter every 6 months, to look for early, intermediate, late complications, and other events. Results. After a mean follow-up of 42 months, 16 patients (16%) developed breast fibrosis, mild in 15, severe in one, which resolved within 24 months. Two patients suffered of postoperative infection, and four developed a lyponecrosis in the treated area. Conclusion. The first group of patients treated with ELIOT in the phase I-II trial are confirming the good impact of the procedure in terms of tolerance and quality of life.