Ivana Kinclová1, Eva Hajtmanová2, Pavol Matula3, Soňa Balentová4, Peter Muríň2, Marián Ďuroška2, Katarína Kozlíková5. 1. Oncology Centre of Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava and Martin University Hospital, Kollárova 2, 03659, Martin, Slovakia. kinclova@unm.sk. 2. Oncology Centre of Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava and Martin University Hospital, Kollárova 2, 03659, Martin, Slovakia. 3. East Slovak Oncology Institute, Inc., Rastislavova 43, 04191, Košice, Slovakia. 4. Institute of Histology and Embryology, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Malá Hora 4, 03601, Martin, Slovakia. 5. Institute of Medical Physics, Biophysics, Informatics and Telemedicine, Faculty of Medicine, Comenius University in Bratislava, Sasinkova 2, 81372, Bratislava, Slovakia.
Abstract
AIM: Primary hypothyroidism is one of the late complications that can occur after radiation therapy for malignant tumors in the head and neck region. The aim of this retrospective study was to show the validity of the Lyman-Kutcher-Burman (LKB) normal tissue complication model for thyroid gland based on clinical results. METHODS: Thyroid function was evaluated by measuring thyroid-stimulating hormone and free thyroxine serum levels before radiation therapy, 3 months after the beginning of radiation therapy, and afterwards at each follow-up visit. Cumulative incidence was calculated using the Kaplan-Meier method. Dose-volume histogram, total dose, fractionation schedule, total duration of the treatment, and other parameters were used for normal tissue complication probability calculation based on the LKB model. The model was evaluated after fitting with the three sets of parameters for grade 2 hypothyroidism: 1) "Emami," where n = 0.22; m = 0.26, and D50 = 80 Gy; 2) "mean dose," where n = 1; m = 0.27, and D50 = 60 Gy; and 3) "Lyman EUD," where n = 0.49; m = 0.24, and D50 = 60 Gy. A value 3.0 Gy was used for α/β ratio RESULTS: Eighty-three patients treated with volumetric modulated arc therapy for head and neck cancers at the University Hospital Martin, Slovakia, from January 2014 to July 2017, were included in the retrospective study. Median follow-up was 1.2 years. Cumulative incidence of hypothyroidism grade 2 or higher after 12 and 24 months was 9.6 and 22.0%, respectively. Normal tissue complication probability values calculated with mean dose and Lyman EUD parameters showed the best correlation with our clinical findings. CONCLUSION: Empirically based modelling of normal tissue complication probability was valid for our cohort of patients. With carefully chosen parameters, the LKB model can be used for predicting the normal tissue complication probability value.
AIM: Primary hypothyroidism is one of the late complications that can occur after radiation therapy for malignant tumors in the head and neck region. The aim of this retrospective study was to show the validity of the Lyman-Kutcher-Burman (LKB) normal tissue complication model for thyroid gland based on clinical results. METHODS: Thyroid function was evaluated by measuring thyroid-stimulating hormone and free thyroxine serum levels before radiation therapy, 3 months after the beginning of radiation therapy, and afterwards at each follow-up visit. Cumulative incidence was calculated using the Kaplan-Meier method. Dose-volume histogram, total dose, fractionation schedule, total duration of the treatment, and other parameters were used for normal tissue complication probability calculation based on the LKB model. The model was evaluated after fitting with the three sets of parameters for grade 2 hypothyroidism: 1) "Emami," where n = 0.22; m = 0.26, and D50 = 80 Gy; 2) "mean dose," where n = 1; m = 0.27, and D50 = 60 Gy; and 3) "Lyman EUD," where n = 0.49; m = 0.24, and D50 = 60 Gy. A value 3.0 Gy was used for α/β ratio RESULTS: Eighty-three patients treated with volumetric modulated arc therapy for head and neck cancers at the University Hospital Martin, Slovakia, from January 2014 to July 2017, were included in the retrospective study. Median follow-up was 1.2 years. Cumulative incidence of hypothyroidism grade 2 or higher after 12 and 24 months was 9.6 and 22.0%, respectively. Normal tissue complication probability values calculated with mean dose and Lyman EUD parameters showed the best correlation with our clinical findings. CONCLUSION: Empirically based modelling of normal tissue complication probability was valid for our cohort of patients. With carefully chosen parameters, the LKB model can be used for predicting the normal tissue complication probability value.
Entities:
Keywords:
Head and neck cancer; Hypothyroidism; Lyman–Kutcher–Burman model; Normal tissue complication probability; Volumetric modulated arc therapy
Authors: Tim Cardilin; Joachim Almquist; Mats Jirstrand; Astrid Zimmermann; Floriane Lignet; Samer El Bawab; Johan Gabrielsson Journal: J Pharmacokinet Pharmacodyn Date: 2021-10-08 Impact factor: 2.745
Authors: Anastassia Löser; Kerstin Ramke; Maximilian Grohmann; Linda Krause; Pia Roser; Franziska Greinert; Anna Finger; Margaret Sommer; Eva Culmann; Tessa Lorenz; Saskia Becker; Marvin Henze; Daniel Schodrok; Julia von Grundherr; Silke Tribius; Andreas Krüll; Cordula Petersen Journal: Strahlenther Onkol Date: 2021-11-01 Impact factor: 3.621