Radiotherapy (RT) is essential for treating
cancer alongside chemotherapy and surgery, improving
survival rates, and lowering local recurrence risk in high-
risk breast cancer (BC) patients. However, it can lead to
thyroid complications like hypothyroidism (HT), especially
with higher radiation doses using traditional methods.
Higher radiation doses to the thyroid, especially with
conventional methods and exposure of the cervical region,
increase the risk of HT. External radiation, particularly in
the supraclavicular (SCV) and infra-clavicular nodal
levels, poses a significant risk to the thyroid, a radiation-
sensitive organ. Radiation's negative impact on the thyroid
includes late and irreversible effects like atrophy, follicle,
and vascular damage. Thyroid size, radiation dose,
technique, and clinical factors (age, stage) influence these
outcomes and toxicities. As a result, routine thyroid
function assessment should be performed for BC patients
after radiation. According to the reviewed articles, further
study is needed to pinpoint variables and create advanced
normal tissue complication probability (NTCP) models.
Intensity-modulated radiotherapy (IMRT) must limit the
dose to the thyroid to reduce the prevalence of HT. This
review aims to outline SCV radiation's impact on thyroid
function and factors related to radiation-induced
hypothyroidism in breast cancer patients.
Keywords : Radiotherapy; Breast Cancer; Supraclavicular; Hypothyroidism.