The following is a summary of “Randomized Phase II Study of Physiologic MRI-Directed Adaptive Radiation Boost in Poor Prognosis Head and Neck Cancer” published in the December 2022 issue of Oncology by Mierzwa et al.

To determine if increasing the radiation therapy (RT) dose based on magnetic resonance imaging(MRI) of the patient’s physiological characteristics improves the result for patients with advanced, poor-prognosis head and neck cancer, researchers conducted a randomized, phase II, multicenter clinical trial. Low blood volume/apparent diffusion coefficient maps were generated from MRI scans taken before RT and after RT portion 10 to define RT boost subvolumes in the gross tumor volume. Patients were randomly assigned to receive either 70 Gy (normal RT) or 80 Gy to the boost subvolume (RT boost) with concomitant weekly platinum. 

Disease-free survival (DFS) was the primary goal, with significance determined at the one-sided 0.1 level; locoregional failure (LRF), overall survival (OS), comparison of adverse events, and patient-reported outcomes (PRO) were secondary endpoints. No significant improvement in DFS (HR=0.849, P=0.31) or OS (HR=1.19, P=0.66) was seen in the RT boost arm of the study, which included 81 patients. The addition of the RT increases significantly reduced the occurrence of LRF (HR=0.43, P=0.047). The cumulative incidence of LRF was estimated to be 40% (27%-53%) in the regular RT arm and 18% (10%-31%) in the RT boost arm after 2 years of treatment [90% CI]. 

DFS was estimated to be 48% (34%-60%) in the regular RT arm and 57% (43%-69%) in the RT boost arm after 2 years (90% CI). In linear mixed-effects models, there were no statistically significant differences between treatment groups about toxicity or longitudinal alterations in the EORTC QLQ30/HN35 subscales. The LRF was reduced using a physiologic MRI-based RT boost, but there was no significant improvement in DFS or OS and no increase in grade 3+ toxicity or longitudinal PRO differences. Better DFS and OS will require more work to be done on systemic treatment.

Source; text