Effect of dose constraint on the thyroid gland during locoregional intensity-modulated radiotherapy in breast cancer patients.

Effect of dose constraint on the thyroid gland during locoregional intensity-modulated radiotherapy in breast cancer patients. J Appl Clin Med Phys. 2019 Jun 24;: Authors: Haciislamoglu E, Canyilmaz E, Gedik S, Aynaci O, Serdar L, Yoney A Abstract The aim of the present study was to compare radiation dose received by thyroid gland using different radiotherapy (RT) techniques with or without thyroid dose constraint (DC) for breast cancer patients. Computerized tomography (CT) image sets for 10 patients with breast cancer were selected. All patients were treated originally with opposite tangential field-in field (FinF) for the chest wall and anteroposterior fields for the ipsilateral supraclavicular field. The thyroid gland was not contoured on the CT images at the time of the original scheduled treatment. Four new treatment plans were created for each patient, including intensity-modulated radiotherapy (IMRT) and helical tomotherapy (HT) plans with thyroid DC exclusion and inclusion (IMRTDC(-) , IMRTDC(+) , HTDC(-) , and HTDC(+) , respectively). Thyroid DCs were used to create acceptable dose limits to avoid hypothyroidism as follows: percentage of thyroid volume exceeding 30 Gy less than 50% (V30  < 50%) and mean dose of thyroid (TDmean ) ≤ 21 Gy. Dose-volume histograms (DVHs) for TDmean and percentages of thyroid volume exceeding 10, 20, 30, 40, and 50 Gy (V10 , V20 , V30 , V40 , and V50 , respectively) were also analyze...
Source: Clinical Genitourinary Cancer - Category: Cancer & Oncology Authors: Tags: J Appl Clin Med Phys Source Type: research