[Exclusive intra-operative radiation therapy (IORT) for early stage breast cancer: pilot study of feasibility]

To evaluate feasibility, tolerability and cosmetic outcome of intra-operative radiation therapy (IORT) as an exclusive post-surgery treatment of early stage breast cancer.

From October 2008 to October 2009 30 patients underwent wide breast cancer excision or quadrantectomy followed by IORT on tumor bed with accelerated electrons at the dose of 21Gy. The characteristics of the patients were: ductal breast cancer or invasive lobular cT1, cT2 ≤ 2,5 cm, cN0, G1-2, age over 35 years, M0.

The average age was 51.7 (range 38 - 75) with an average follow up of 11.7 months (range 6 - 18). The pathologic stage of the lesions resulted pT1 in 29 cases (96,6%), in particular: one case pT1a (3,3%), 21 cases pT1b (70,0%) and 7 cases pT1c (23,3%). One case (3,3%) was pT2 with a diameter of 2.5 cm. The grading was G2 in 20 cases (66,6%) and G1 in 10 cases (33,3%). The toxicity, evaluated according to the EORTC-RTOG criteria, was G0 (33.3%) in 10 cases, G1 (63,3%) in 19 cases, G2 in one case (3,4%); there was no G3 toxicity. The time needed for a complete healing of the wound was less than 10 days in 96,7% of the cases, with one case of limphocele (3,3%). There were no infections of the surgical wound nor any mastitis, neither in the treated quadrant nor in the other ones. We observed a light fibrosis in 5 cases (16,6%), moderate in 2 cases (6,6%) but never severe. Cosmetics, evaluated in four levels, according to Danoff et al., was excellent in 3 cases (43,3%), good in 15 cases (50%), sufficient in 2 cases (6,7%), never insufficient. As regards local control, there was no local relapse. The global survival was 100%.

The IORT in early breast cancer, at the doses used in this study, proved itself as a secure technique, repeatable, with limited complications. The advantages of its use are the possibility of a direct control, by the surgeon and the radiotherapist, of the structures to treat and those to protect; the absence of time needed for cellular repopulation between surgery and radiotherapy; a good cosmetic outcome; and logistic advantages. It is necessary to have a long term follow up to evaluate the efficacy in terms of long term cosmetic and local control.