El-Shebiney Mohamed, El-Mashad Nehal, El-Mashad Wael, El-Ebiary Ahmed A, Kotkat Abdallah E
Clinical Oncology Department, Faculty of Medicine, Tanta University Hospital, Egypt.
Clinical Oncology Department, Faculty of Medicine, Tanta University Hospital, Egypt.
J Egypt Natl Canc Inst. 2018 Mar;30(1):33-38. doi: 10.1016/j.jnci.2018.01.004. Epub 2018 Feb 7.
The purpose of this study is to determine radiotherapy (RT) dose-volumetric threshold of radiation-induced hypothyroidism (HT) in head and neck squamous cell carcinoma (HNSCC) patients.
The diagnosis of HT in 78 HNSCC patients treated with RT was based on a thyroid stimulating hormone (TSH) level greater than the maximum value of laboratory range. In all patients, dose-volumetric parameters were analyzed according to their relation to development of HT, and thyroid volumes spared from doses ≥10, 20, 30, 40 and 50 Gy (V10, V20, V30, V40 and V50) were analyzed from the dose volume histograms (DVHs).
Median follow-up duration was 31 months. At the end of study, 33 patients (42.3%) developed HT and the cumulative incidence of HT was 24.6%, 36.5% and 42.3% at one, two and three years, respectively. V30 of 42.1% (P = 0.005) was defined as dose-volumetric threshold of radiation-induced HT in HNSCC patients. Our analysis showed that V30 separates patients into low- and high-risk groups; the incidence of radiation-induced HT in the group with V30 < 42.1% and V30 ≥ 42.1% was 29.4% and 71.4%, respectively (P = 0.002).
The V30 may predict risk of developing HT after RT for HNSCC patients. V30 of 42.1%, defined as dose-volumetric threshold of radiation-induced HT, can be useful in treatment planning of HNSCC patients.
本研究旨在确定头颈部鳞状细胞癌（HNSCC）患者放射性甲状腺功能减退（HT）的放疗（RT）剂量-体积阈值。
78例接受放疗的HNSCC患者中HT的诊断基于促甲状腺激素（TSH）水平高于实验室范围的最大值。在所有患者中，根据剂量-体积参数与HT发生的关系进行分析，并从剂量体积直方图（DVH）中分析甲状腺接受≥10、20、30、40和50 Gy剂量的体积（V10、V20、V30、V40和V50）。
中位随访时间为31个月。研究结束时，33例患者（42.3%）发生HT，HT的累积发生率在1年、2年和3年分别为24.6%、36.5%和42.3%。42.1%的V30被定义为HNSCC患者放射性HT的剂量-体积阈值（P = 0.005）。我们的分析表明，V30将患者分为低风险和高风险组；V30＜42.1%组和V30≥42.1%组放射性HT的发生率分别为29.4%和71.4%（P = 0.002）。
V30可能预测HNSCC患者放疗后发生HT的风险。42.1%的V30被定义为放射性HT的剂量-体积阈值，可用于HNSCC患者的治疗计划。
