In the phase III DARS study reported in The Lancet Oncology, Nutting et al found that dysphagia-optimized intensity-modulated radiotherapy (DO-IMRT) was associated with improved patient-reported swallowing function vs standard IMRT in newly diagnosed patients with head and neck cancer.
In the multicenter trial, 112 patients with T1–4, N0–3, M0 oropharyngeal or hypopharyngeal cancer and no preexisting swallowing dysfunction were randomly assigned between June 2016 and April 2018 to receive DO-IMRT (n = 66) or standard IMRT (n = 66). Patients and speech language therapists were blinded to treatment allocation. Radiotherapy was given in 30 fractions over 6 weeks; doses were 65 Gy to the primary and nodal tumor and 54 Gy to the remaining pharyngeal subsite and nodal areas at risk of microscopic disease. In DO-IMRT, the volume of the superior and middle pharyngeal constrictor muscle or inferior pharyngeal constrictor muscle lying outside the high-dose target volume had a mandatory 50-Gy mean dose constraint. The primary endpoint was MD Anderson Dysphagia Inventory (MDADI) composite score at 12 months after radiotherapy in the modified intention-to-treat population, including only patients who completed the 12-month assessment.
A total of 52 patients in the DO-IMRT group and 45 patients in the standard IMRT group were evaluable for the endpoint.
Patients in the DO-IMRT group had a significantly higher MDADI composite score— better swallowing function—at 12 months vs those in the standard IMRT group (mean score = 77.7 [standard deviation = 16.1] vs 70.6 [standard deviation = 17.3]; mean difference = 7.2, 95% confidence interval = 0.4–13.9, P = .037).
Median follow-up was 39.5 months. During radiotherapy, grade ≥ 3 adverse events occurred in 75% of those in the DO-IMRT group vs 87% of those in the standard IMRT group. The most common (reported by > 25% of all patients) were dysphagia (48% vs 58%), oral mucositis (38% vs 56%), anorexia (29% vs 47%), pharyngeal mucositis (25% vs 38%), and dry mouth (20% vs 33%). The most common grade 3 or 4 late adverse events were hearing impairment (16% vs 13%), dry mouth (5% vs 15%), and dysphagia (5% vs 15%). No treatment-related deaths were observed.
The investigators concluded, “Our findings suggest that DO-IMRT improves patient-reported swallowing function compared with standard IMRT. DO-IMRT should be considered a new standard of care for patients receiving radiotherapy for pharyngeal cancers.”
Christopher Nutting, FRCR, of the Head and Neck Unit, The Royal Marsden Hospital, London, is the corresponding author for The Lancet Oncology article.
Disclosure: The study was funded by Cancer Research UK. For full disclosures of the study authors, visit thelancet.com.