Evaluation of radiation – Induced carotid artery stenosis after supraclavicular irradiation in patients with breast carcinoma

Abstract

Objective: To screen breast cancer patients for carotid artery stenosis (CAS) after supraclavicular irradiation and study its possible effect on the pathogenesis. Methods: The study included 114 patients who received supraclavicular irradiation. They were recruited from the follow up clinic at Minia University Hospital and Minia Oncology Center from January 2015 to December 2016. Evaluation was by Carotid duplex ultrasonography. Results: In 28% of patients, CAS was more on the irradiated side than the non-irradiated side in the same patient. The degree of stenosis was severe on the irradiated side in 81.2% versus only 9.4% on the non-irradiated side. There was no significant difference except for the presence of co-morbidity. In nine patients with no co-morbidity, supra-clavicular irradiation was considered to be the only possible factor responsible for stenosis. Conclusion: Supraclavicular irradiation may play a role in the pathogenesis of carotid stenosis in about 1/3 of breast carcinoma patients. The presence of co-morbidity has an additive role in radiation induced CAS. This stresses the importance of regular examination of the carotid artery by duplex ultrasonography. Every effort should be considered to minimize the dose to carotid artery within the clinical target volume by its proper delineation especially in high risk patients. Keywords: Breast cancer, Supraclavicular radiation, Carotid artery stenosis