Feasibility of Tomotherapy-Based Image-Guided Radiotherapy to Reduce Aspiration Risk in Patients with Non-Laryngeal and Non-Pharyngeal Head and Neck Cancer

Nam P Nguyen,Rick Davis,Michelle Stevie,Beng-Hoey Jo,Dave Abraham,Misty Ceizyk,Thomas Sroka,Paul Vos,Homayoun Modarresifar,Shane P Krafft,Vincent Vinh-Hung,Anand Desai,Lexie Smith-Raymond,Chin-Tu Chen

doi:10.1371/journal.pone.0056290

Abstract

PurposeThe study aims to assess the feasibility of Tomotherapy-based image-guided radiotherapy (IGRT) to reduce the aspiration risk in patients with non-laryngeal and non-hypopharyngeal cancer. A retrospective review of 48 patients undergoing radiation for non-laryngeal and non-hypopharyngeal head and neck cancers was conducted. All patients had a modified barium swallow (MBS) prior to treatment, which was repeated one month following radiotherapy. Mean middle and inferior pharyngeal dose was recorded and correlated with the MBS results to determine aspiration risk.ResultsMean pharyngeal dose was 23.2 Gy for the whole group. Two patients (4.2%) developed trace aspiration following radiotherapy which resolved with swallowing therapy. At a median follow-up of 19 months (1–48 months), all patients were able to resume normal oral feeding without aspiration.Conclusion and Clinical RelevanceIGRT may reduce the aspiration risk by decreasing the mean pharyngeal dose in the presence of large cervical lymph nodes. Further prospective studies with IGRT should be performed in patients with non-laryngeal and non-hypopharyngeal head and neck cancers to verify this hypothesis.

Highlights

Dysphagia and aspiration are common following radiotherapy for head and neck cancer [1]
Further prospective studies with image-guided radiotherapy (IGRT) should be performed in patients with nonlaryngeal and non-hypopharyngeal head and neck cancers to verify this hypothesis
In a previous dosimetric study comparing WF-intensity-modulated radiotherapy (IMRT) to Tomotherapy-based image-guided radiotherapy (IGRT), we had demonstrated that IGRT may significantly reduce the larynx, middle and inferior pharyngeal doses in non-laryngeal and non-hypopharyngeal cancer without compromising target coverage [7]

Summary

Introduction

Dysphagia and aspiration are common following radiotherapy for head and neck cancer [1]. Recent studies suggest a correlation between radiation dose to the pharyngeal constrictor muscles and the risk of tube feeding dependence following head and neck radiotherapy [2,3]. New radiotherapy techniques such as intensity-modulated radiotherapy (IMRT) may decrease dysphagia severity and the need for gastrostomy tubes because of decreased radiation dose to critical structures for swallowing. In a previous dosimetric study comparing WF-IMRT to Tomotherapy-based image-guided radiotherapy (IGRT), we had demonstrated that IGRT may significantly reduce the larynx, middle and inferior pharyngeal doses in non-laryngeal and non-hypopharyngeal cancer without compromising target coverage [7]. The current retrospective study was performed to determine if low radiation doses to these swallowing structures could decrease the aspiration rate in this subset of head and neck cancer patients as well

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Discussion

Conclusion