Document Type : Original Paper
Molecular Medicine Research Center, Institute of Bio-medicine, Tabriz University of Medical Sciences, Tabriz, Iran
Radiology and Radiotherapy Department, Medical School, Tabriz University of Medical Science, Tabriz, Iran
Radiation Oncology Department, Tabriz Vali-asr Hospital, Tabriz, Iran
Department of Statistics and Epidemiology, Faculty of Health, Tabriz University of Medical Sciences, Tabriz, Iran
Department of Medical Physics, Radiation Oncology Institute, Istanbul University, Istanbul, Turkey.
Tabriz University of Medical Sciences
Introduction: The current study aimed to compare the performance of radiobiological models in predicting acute esophagitis (AE) complications after three-dimensional conformal radiation therapy (3D-CRT).
Material and Methods: Out of a total of 100 patients, 50 patients with concurrent chemotherapy and 50 patients without such therapy were treated with different total doses and a daily dose range of 1.8-2.4 Gy on the basis of 5 days a week for 3 months. Predictions of AE were based on Lyman–Kutcher–Burman (LKB) and equivalent uniform dose (EUD)-based radiobiological models. Consequently, 3 months of follow-upwere performed to monitor the complication incidence among the studied patients. Receiver operating characteristic (ROC) and univariable logistic regression analyses were carried out to determine the effect of mean dose, volume percentage, and weight loss percentage on the probability of AE grade ³ 2.
Results: The EUD-basedmodel showed a better concordance with the clinical data for all patients (area under the curve [AUC]=0.919) and the concurrent chemoradiotherapy (CCRT) group (AUC=0.986). For the radiation therapy group, the LKB model had a better performance than the EUD-based model (AUC=0.921). Grade ³ 2 esophagitis occurred 37.94±4.0 and 68.39±7.1 days after the initiation of radiation therapy in the chemoradiation and radiation therapy groups, respectively.
Conclusion: The EUD-basedmodel showed a higher agreement with the follow-up data. The incidence time of grade ³ 2 AE in the CCRT was approximately two times shorter than that in the non-CCRT group.