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In patients with head and neck cancer, a strategy to reduce the radiation dose to dysphagia-and aspiration-related structures improved swallowing and other functional outcomes compared with standard intensity-modulated radiotherapy (IMRT), according to results from the phase III DARS trial.

Patients treated with dysphagia-optimized (DO) IMRT had significantly higher patient-reported composite scores on the MD Anderson Dysphagia Inventory (MDADI) 12 months later (average score 77.7 vs 70.6, P=0.037), reported Christopher Nutting MD, PhD, of the Royal Marsden Hospital in London, and colleagues.

The difference in MDADI composite scores persisted after multivariable adjustment and at 24 months, the authors reported.

"This level 1 evidence supports a new gold standard for radiotherapy of patients with head and neck cancer," Nutting and his colleagues wrote in . "Future research should aim to further reduce the radiation dose to the dysphagia and aspiration risk structures to refine the DO-IMRT technique."

DO-IMRT is intended to reduce the radiation dose to the pharyngeal constrictor muscles, which are responsible for the initiation and completion of swallowing. Patients newly diagnosed with oropharyngeal and hypopharyngeal cancers receive chemoradiotherapy with curative intent, but most end up with swallowing problems after treatment, according to Nutting and his colleagues.

While the authors acknowledged the observed mean difference in the MDADI composite score was less than the predefined clinically meaningful score of 10 points at the time of study design, they pointed that the 9.8 difference in scores adjusted for tumor site, stage, and chemotherapy use, as well as the fact that several secondary endpoints favored DO-IMRT over standard IMRT, "is indicative of a meaningful benefit for patients."

In addition, University of Washington Quality of Life scores were statistically and clinically significantly improved with DO-IMRT compared with standard IMRT at 3 months and at 12 months and across all domains, including saliva, swallowing, and taste.

Sandra Nuyts, MD, of the Katholieke Universiteit Leuven in Belgium, agreed that the results of the study, as well as results from a and a , provide "compelling evidence that the risk of dysphagia after head and neck radiotherapy can be reduced with this technology, without increasing the risk of local recurrences."

In her , Nuyts noted that DO-IMRT is not available globally and suggested it should still be accompanied by supportive care measures -- such as prophylactic swallowing exercises prescribed by speech and language specialists -- that "should be implemented to manage and even prevent dysphagia."

In the , 112 patients with no pre-existing swallowing dysfunction were randomly assigned 1:1 to DO-IMRT or standard IMRT. Their median age was 57 years, 80% were men, and the median follow-up was 39.5 months.

The MDADI questionnaire has 20 questions, each with a 5-point Likert scale. The composite total score ranges from 20 (indication very low functioning) to 100 (extremely high functioning), and is the sum of the emotional, functional, and physical problems subscales.

Secondary endpoints favoring DO-IMRT included more participants reporting normalcy of diet (62% vs 45%) and eating in public (85% vs 75%) on the Performance Status Scale for Head and Neck at 12 months.

Four local recurrences were reported (two in each arm), with no regional recurrences. Three distant metastases were recorded in the DO-IMRT group versus two in the standard IMRT arm. Five and six deaths occurred in the two arms, respectively (none deemed treatment related), with no significant difference seen in overall survival.

Regarding safety, the most common grade 3/4 late adverse events were hearing impairment (16% in the DO-IMRT group vs 13% in the standard IMRT group), dry mouth (5% vs 15%), and dysphagia (5% vs 15%).

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