A pilot randomized controlled trial of photobiomodulation therapy in head and neck cancer survivors with chronic lymphedema.

Abstract

e18068 Background: Chronic lymphedema is a common late effect after completion of head and neck cancer (HNC) treatment, contributing to substantial symptom burden and negatively impacting quality of life. To date, no evidence-based effective approaches are available to treat this progressive condition. Findings from a single-group, pre-post design study showed the feasibility, acceptability, and potential efficacy of photobiomodulation (PBM) for treatment of HNC-related chronic lymphedema. This study aimed to further evaluate preliminary efficacy of PBM therapy for chronic lymphedema in HNC survivors. Methods: This was a pilot, randomized, wait-list controlled trial conducted during the COVID pandemic. Eligible HNC survivors included those with chronic lymphedema after completion of initial lymphedema therapy. Participants were randomized to one of two arms: intervention arm or wait-list control arm. Study assessments were conducted at baseline (pre-intervention), end-of-intervention, 4-week, and 8-week post-intervention. Participants in the intervention arm received a total of 12 PBM therapy sessions (twice a week for 6 weeks). Participants in the wait-list control arm underwent the same study assessments and were then offered the same frequency and dose of PBM therapy as the intervention arm, after completion of the initial 8-week post-intervention assessment. Outcome measures included severity of external lymphedema and fibrosis (LEF), symptom burden, jaw range of motion, and neck range of motion. Of note, assessment of internal lymphedema was not feasible due to exam limitations associated with COVID. Linear mixed-effects models were used as statistical analysis methods. Results: Of the 25 eligible patients enrolled in the study, 12 patients were randomized to the intervention arm and 13 patients to the wait-list control arm. In the intervention arm, two patients withdrew from the study before attending the PBM therapy sessions due to disease progression and family obligation. Regarding the intervention completion, 110 of 120 (91.7%) planned treatments sessions (12 sessions per patient x 10 patients = 120 sessions) were completed. Reasons for missing the PBM therapy sessions included job conflict, family obligations, and COVID infection. No adverse events were reported. Compared to the wait-list control arm, the intervention arm demonstrated improvements at 8-week post-intervention in the severity of external LEF (p < 0.05), symptom burden (e.g., Soft Tissues and Neurologic Toxicity subscale, Cohen’s d = - 0.47), and neck range of motion (e.g., extension, Cohen’s d = 0.65). Conclusions: Our findings indicate that PBM therapy may improve chronic lymphedema associated outcomes. Future large RCTs are warranted to examine the efficacy of PBM therapy for HNC-related chronic lymphedema. Clinical trial information: NCT04482855 .