The dosimetric impact of supraclavicular nodal irradiation on the thyroid gland in patients with breast cancer

Abstract

Purpose: The thyroid is not routinely considered an organ at risk in supraclavicular (SC) nodal radiation therapy (RT) for breast cancer. We compared the dosimetric impact of the following 2 RT planning techniques on the thyroid: (1) conventional single anterior field to encompass the SC nodal volume defined clinically; and (2) 3-dimensional conformal radiation therapy (3DCRT) planning to encompass the computed tomography (CT)-contoured SC nodal volume. Methods and Materials: The thyroid, SC nodal volumes, and organs at risk were contoured on the planning CT of 20 patients who received 50 Gy in 2-Gy daily fractions to the breast or chest wall, and SC nodes. Comparisons of dosimetric paramete..