Normal tissue complication probability modeling of radiation-induced sensorineural hearing loss after head-and-neck radiation therapy

Abstract

Purpose: The aim of this study was to generate the dose–response curves by six normal tissue complication probability (NTCP) models and ranking the models for prediction of radiation induced sensorineural hearing loss (SNHL) caused by head and neck radiation therapy (RT).

Materials and methods: Pure tone audiometry (PTA) was performed on 70 ears of patients for 12 months after the completion of RT. The SNHL was defined as a threshold shift ≤15 dB at two contiguous frequencies according to the common toxicity criteria for adverse events scoring system. The models evaluated were: Lyman and Logit; Mean Dose; relative seriality (RS); Individual critical volume (CV); and population CV models. Maximum likelihood analysis was used to fit the models to experimental data. The appropriateness of the fit was determined by the two-sample Kolmogorov–Smirnov test. Ranking of the models was made according to Akaike’s information criterion.

Results: The dose of 50% complication rate (D₅₀) was 51–60 Gy. Three of the examined models fitted well with clinical data in a 95% confidence interval. The RS model was ranked as the best model of prediction for radiation induced SNHL.

Conclusions: Cochlea shows a different behavior against different NTCP models; it may be due to its small size.

Keywords:

• Head and neck
• sensorineural hearing loss
• radiotherapy
• normal tissue complication probability

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Notes on contributors

Susan Cheraghi is a PhD of Medical Physics in the Iran University of Medical Sciences. She is working as a Lecturer and Researcher at Department of Radiation Sciences and Radiation Biology Research Center.

Alireza Nikoofar is a Professor of Radiation Oncology and head of Radiation Oncology Department in the Iran University of Medical Sciences. He is working on different aspects of Radiation Biology and Physics of Therapeutic Oncology.

Mohsen Bakhshandeh is a PhD of Medical Physics in the Shahid Beheshti University of Medical Sciences. He is a Qualified Therapeutic Medical Physicist and is working on Radiobiological Modelling in Radiation Oncology.

Samideh Khoei is a Professor of Biophysics at Department of Medical Physics in the Iran University of Medical Sciences. She is head of Medical Physics Department and also working on Therapeutic, Diagnostic and Theranostic Nanoparticles in Radiation Oncology.

Saeid Farahani is an Audiologist in the Tehran University of Medical Sciences. He has many collaborations with Radiation Oncology Department.

Hamid Abdollahi is a PhD Candidate of Medical Physics in the Iran University of Medical Sciences. He is currently working on Radiomics and Radiogenomics in Radiation Oncology.

Seied Rabi Mahdavi is an Assistant Professor of Medical Physics in the Iran University of Medical Sciences. He is head of Iranian Association of Medical Physics (IAMP) and also working as a Qualified Therapeutic Medical Physicist in Radiation Oncology Centers.

Additional information

Funding

This study was supported financially by Grant No. 92-03-30-240-71 from the Research Chancellor of Iran University of Medical Sciences.