Dose reduction of postmastectomy radiation in the management of local breast cancer

Purpose. To assess the comparative effectiveness of traditional (normal-dose) and reductional (low-dose) variants of postmastectomy chest-wall irradiation with the criteria of local control, overall and relapse-free survival rates, frequency of postradiation cardiac complications. Material and methods. Two groups of patients with breast cancer IIB - IIIB stages were studied: the 1st group - variant of normal-dose (50 Gy to chest wall in 25 fractions) radiation therapy with/without chemotherapy (129 patients), the 2nd group - variant of low-dose (40 Gy to chest wall in 20 fractions) radiation therapy with/without chemotherapy (82 patients). In all cases radiation therapy followed Madden mastectomy. Dose to regional areas (46-50 Gy according to the number of metastatic lymphatic nodes) as well as neoadjuvant and adjuvant chemotherapy regimes was similar in both groups. The median follow-up was 111 and 95 months for the 1st and 2nd group respectively. Results. Frequency of 5-year actuarial loco-regional progression in case of normal-dose and low-dose variants was estimated as 6,2±2,1% and 3,7±2,1% respectively (p=0,4). Metastases developed in 34,6±4,2% and 19,5±4,4% of patients in the 1st and 2nd group (p