[Intraoperative radiotherapy (IORT) in early breast cancer]

BACKGROUND: Breast-conservation therapy is widely accepted as an effective treatment option for patients with early stage carcinoma of the breast. The proportion of patients with recurrence after receiving partial breast irradiation is the same as that seen in patients treated with whole breast irradiation. Therefore, the necessity of whole breast irradiation has been questioned, and partial breast irradiation has emerged as a reasonable alternative.

METHODS: Since 2006, 468 women with early breast cancer (age > 60 years, T1, infiltrative duct carcinoma and with no clinical or sonographic suspicion of involved axillary lymph nodes) were treated in the Carmel Medical Center with intraoperative radiotherapy, using the INTRABEAM System giving 20 Gy at the tumor bed. We report the cohort of the first 100 patients who have had a follow up period of more than 3 years.

RESULTS: The median age was 70 years (range 56-87 years). Twenty four patients had mild to moderate local complications, while nine patients experienced major local complications. Eighteen patients had metastatic involvement of the axillary lymph nodes, and in 16 of them, only one node was involved. Five patients had additional local therapy (one patient underwent mastectomy and four patients received whole breast irradiation). During the follow up period, four ipsilateral breast failures were observed: two new primary tumors (by location and histology) and two local recurrences.

CONCLUSIONS: Intraoperative radiotherapy using the INTRABEAM system is feasible and may offer an alternative to whole breast radiotherapy, in low risk early breast cancer patients with a low rate of local recurrence and morbidity. Longer follow up is required in order to evaluate long term results and late toxicity.