# Feasibility Study of Multiorgan Dosiomics for Evaluating Radiation-Induced Xerostomia and Dysphagia in Head and Neck Cancer Radiotherapy

## TL;DR

This study explores using multiorgan dosiomics to predict radiation-induced side effects in head and neck cancer radiotherapy, aiming to improve patient quality of life.

## Contribution

The study demonstrates the feasibility of multiorgan dosiomics for predicting radiation-induced xerostomia and dysphagia in head and neck cancer patients.

## Key findings

- A dosiomic model using all organs at risk achieved an AUC of 0.843 for predicting xerostomia.
- The model using the middle pharyngeal constrictor muscle achieved an AUC of 0.878 for predicting dysphagia.
- Multiorgan dosiomics showed potential for predicting radiation-induced toxicities in head and neck cancer radiotherapy.

## Abstract

Radiation-induced toxicity is a serious concern in head and neck cancer (HNC) radiotherapy because multiple organs related to the quality of life (QOL) of patients are located in that region. Hence, toxicities must be assessed to manage the QOL during and after HNC radiotherapy. Dosiomics is a novel dosimetric analysis method for evaluating toxicity. In this study, we conducted a dosiomic analysis of HNC radiotherapy to comprehensively investigate the relation between the severity of toxicities and dosimetric features, including dose textures, in multiple organs at risk (OARs). We considered xerostomia and dysphagia as common toxicities in HNC radiotherapy. A dosiomic prediction model was built and validated for each OAR. The intra- and inter-OAR model performances were compared, demonstrating the feasibility of multi-OAR dosiomics for predicting radiation-induced toxicities in HNC radiotherapy. Our findings can provide a basis for future multiorgan dosiomic studies on toxicities in HNC radiotherapy.

Background/Objectives: The severity of radiation-induced toxicity in head and neck cancer (HNC) radiotherapy should be predicted for the prognosis of the patient’s quality of life. Multiple organs at risk (OARs) are susceptible to toxicity in the head and neck. Hence, we aimed to investigate the feasibility of evaluating radiation-induced xerostomia and dysphagia based on multi-OAR dosiomics in HNC radiotherapy. Methods: We used radiotherapy treatment planning and toxicity data collected from 44 patients with HNC. High- and low-toxicity grades were classified using dosiomic models derived from multiple OARs. Dosiomic features were computed from the planned dose distribution per OAR. A prediction model was derived using selected dosiomic features and toxicity grades based on extreme gradient boosting for every OAR and all OARs. The model performance was evaluated in terms of the area under the curve (AUC) from leave-one-out cross-validation. Models based on dose volume histogram features and combining these with dosiomic features were derived to compare the prediction performance per OAR. Performance comparisons across OARs were also conducted. Results: The prediction models with the highest AUCs for xerostomia and dysphagia were the dosiomic model using all OARs, with an AUC of 0.843 (95% confidence interval—CI, 0.725–0.961), and that using the middle pharyngeal constrictor muscle, with an AUC of 0.878 (95% CI, 0.772–0.984). Conclusions: The evaluation results demonstrated the feasibility and potential of predicting radiation-induced toxicities based on multi-OAR dosiomics in HNC radiotherapy. Further investigations are required to determine the generalizability of our findings.