Risk of Hypothyroidism in Women After Radiation Therapy for Breast Cancer

Purpose To study the hypothyroidism risk after adjuvant radiation therapy (RT) and the association of different RT targets with hypothyroidism risk. Methods We studied 4073 women treated with adjuvant RT for breast cancer from 2007 to 2016. The primary endpoint was hypothyroidism development after RT. Patients were divided and analyzed into 3 groups: whole breast (WB)–alone (n = 2468), regional node irradiation (RNI)–Lv.4 (n = 215; cranial...