Comparative Study of Dysphagia-optimized Intensity Modulated Radiotherapy (Do-IMRT) and Standard Intensity Modulated Radiotherapy (S-IMRT) and Its Clinical Correlation in Head and Neck Cancer Patients.

Objective: Dosimetric sparing of critical swallowing structures like constrictor muscles and larynx can lead to improved functional outcomes in head and neck cancer patients treated by chemoradiation.

Methods: A total of 50 Patients with newly diagnosed, biopsy proven AJCC stage II-IV head and neck squamous cell cancers (HNSCC) were prospectively studied. 25 patients were randomized in each arm of Dysphagia-optimized Intensity Modulated Radiotherapy (Do-IMRT) arm and Standard Intensity Modulated Radiotherapy (SIMRT) arm. Additional dose constraints were applied to the dysphagia/aspiration at risk structures (DARS) in Do-IMRT arm. The impact of using Do-IMRT was assessed by the difference in mean scores of MD Anderson Dysphagia Inventory (MDADI), University of Washington-Quality of Life (UW-QOL), and 100 ml Water Swallow Test (WST).

Results: Patients in both arms showed significant (P <0.01 or P < 0.001) improvement in MDADI (global and composite), UW-QOL and Water Swallow Test scores. However, the improvements were found significantly higher in Do-IMRT as compared to S-IMRT. Significant improvements i.e. mean change from baseline to 12 months (P <0.05 or P <0.01 or P <0.001) were 19. 2, 8.6, 14.3, 7.4, 18.6 and 22.0%  higher respectively in Do-IMRT as compared to S-IMRT  in MDADI global and composite scores, UW-QOL swallowing scores, and 100 ml Water Swallow  (swallowing volume, swallowing capacity and swallowing speed)  test scores.

Conclusion: The Do-IMRT improves swallowing functions compared to S-IMRT in HNSCC patients treated with radical chemoradiation.