A unique hypofractionated radiotherapy schedule with 51.3 Gy in 18 fractions three times per week for early breast cancer: outcomes including local control, acute and late skin toxicity.

Breast cancer (Tokyo, Japan)

PubMedID: 27093861

Vassilis K, Ioannis G, Anna Z, Christina A, Christos A, John K, Porfyrios K, Vassiliki G, John K. A unique hypofractionated radiotherapy schedule with 51.3 Gy in 18 fractions three times per week for early breast cancer: outcomes including local control, acute and late skin toxicity. Breast Cancer. 2016;.
AIM
Evaluation of local control and acute and late toxicity regarding a hypofractionated RT schedule for breast cancer patients.

METHODS AND MATERIALS
Between October 2007 and October 2009, 80 women with early breast cancer were treated by 42.75 Gy in 15 fractions over 5 weeks. This treatment involved three fractions per week (Monday-Wednesday-Friday). All patients received an additional boost dose to the tumor bed of 8.55 Gy in 3 fractions using 6 MV photons. The primary endpoint included any local recurrence in the treated breast. Secondary endpoint included acute and late radiation skin toxicity. The median follow-up time was 63 months (range 60-72). Radiation toxicity was graded according the RTOG/EORTC criteria.

RESULTS
Neither local nor distant recurrence was noted in any patient during this 3-year follow-up. Grade 0, 1, 2 acute skin toxicity was observed in 56/80 (70.0 %), in 19/80 (23.8 %) and in 5/80 (6.3 %), respectively. Three months post-RT, toxicity grades 0, 1, 2 skin toxicity were 64/80 (80 %), 14/80 (17.5 %) and 2/80 (2.5 %), respectively. Late toxicity as grade 0, 1 was observed in 72/80 (90.0 %) and in 8/80 (10.0 %), respectively, 6 months post-RT, whereas after 1 year they were 78/80 (97.5 %) and 2/80 (2.5 %), respectively.

CONCLUSIONS
Preliminary results regarding skin reactions, cosmetic appearance and local control are consistent with published data that support the use of shorter fractionation schedules in early breast cancer patients after breast conservative surgery. Longer follow-up and a randomized prospective study stand in need for the extraction of safe conclusions.