The Impact of Intermediate Time between Chemotherapy and Hypofractionated Radiotherapy to the Radiation Induced Skin Toxicity for Breast Adjuvant Treatment

To evaluate the impact of intermediate time between chemotherapy and radiotherapy (ITCR) to skin toxicity for a hypofractionated irradiation schedule. Forty-four patients with stage I-II invasive breast cancer receiving postoperative radiotherapy (RT) after lumpectomy and axillary dissection were studied. All patients received RT with 6MV linear accelerator (LINAC) with a total tumor dose of 53Gy (Equivalent dose-EQD2- 60Gy), 2.65Gy per fraction, in 20 fractions. All patients received six cycles of cyclophosphamide methotrexate fluorouracil chemotherapy i.v. every 21days. Acute and late effects and cosmetic results were assessed using the European Organization for Research and Treatment of Cancer and Radiation Therapy Oncology Group (EORTC/RTOG) Rating System. The mean follow-up was 7years. The spearman rho test showed that there was a significant correlation between short ITCR and acute skin toxicity 3months post RT, by means of acute radiation induced morbidity. None of the related late-toxicity parameters was correlated with the ITCR. However, there was significantly higher acute toxicity when the ITCR was less than 20days (p<0.05). We may suggest that when a hypofractionated irradiation schedule is used for breast cancer patients, then the ITCR should be more than 20days from chemotherapy.