PURPOSE: To establish a multivariate normal tissue complication probability (NTCP) model for radiation-induced hypothyroidism. METHODS AND MATERIALS: The thyroid-stimulating hormone (TSH) level of 105 patients treated with (chemo-) radiation therapy for head-and-neck cancer was prospectively measured during a median follow-up of 2.5 years. Hypothyroidism was defined as elevated serum TSH with decreased or normal free thyroxin (T4). A multivariate logistic regression model with bootstrapping was used to determine the most important prognostic variables for radiation-induced hypothyroidism. RESULTS: Thirty-five patients (33%) developed primary hypothyroidism within 2 years after radiation therapy. An NTCP model based on 2 variables, including the mean thyroid gland dose and the thyroid gland volume, was most predictive for radiation-induced hypothyroidism. NTCP values increased with higher mean thyroid gland dose (odds ratio [OR]: 1.064/Gy) and decreased with higher thyroid gland volume (OR: 0.826/cm(3)). Model performance was good with an area under the curve (AUC) of 0.85. CONCLUSIONS: This is the first prospective study resulting in an NTCP model for radiation-induced hypothyroidism. The probability of hypothyroidism rises with increasing dose to the thyroid gland, whereas it reduces with increasing thyroid gland volume.
PURPOSE: To establish a multivariate normal tissue complication probability (NTCP) model for radiation-induced hypothyroidism. METHODS AND MATERIALS: The thyroid-stimulating hormone (TSH) level of 105 patients treated with (chemo-) radiation therapy for head-and-neck cancer was prospectively measured during a median follow-up of 2.5 years. Hypothyroidism was defined as elevated serum TSH with decreased or normal free thyroxin (T4). A multivariate logistic regression model with bootstrapping was used to determine the most important prognostic variables for radiation-induced hypothyroidism. RESULTS: Thirty-five patients (33%) developed primary hypothyroidism within 2 years after radiation therapy. An NTCP model based on 2 variables, including the mean thyroid gland dose and the thyroid gland volume, was most predictive for radiation-induced hypothyroidism. NTCP values increased with higher mean thyroid gland dose (odds ratio [OR]: 1.064/Gy) and decreased with higher thyroid gland volume (OR: 0.826/cm(3)). Model performance was good with an area under the curve (AUC) of 0.85. CONCLUSIONS: This is the first prospective study resulting in an NTCP model for radiation-induced hypothyroidism. The probability of hypothyroidism rises with increasing dose to the thyroid gland, whereas it reduces with increasing thyroid gland volume.
Authors: N Patrik Brodin; Rafi Kabarriti; Mark Pankuch; Clyde B Schechter; Vinai Gondi; Shalom Kalnicki; Chandan Guha; Madhur K Garg; Wolfgang A Tomé Journal: Int J Radiat Oncol Biol Phys Date: 2018-11-26 Impact factor: 7.038
Authors: Pierre Blanchard; Andrew J Wong; G Brandon Gunn; Adam S Garden; Abdallah S R Mohamed; David I Rosenthal; Joseph Crutison; Richard Wu; Xiaodong Zhang; X Ronald Zhu; Radhe Mohan; Mayankkumar V Amin; C David Fuller; Steven J Frank Journal: Radiother Oncol Date: 2016-09-15 Impact factor: 6.280