Exploring Quantitative MRI Biomarkers of Head and Neck Post-Radiation Lymphedema and Fibrosis: Post Hoc Analysis of a Prospective Trial

Background: Quantifying head and neck lymphedema and fibrosis (HN-LEF) is crucial in the investigation and management of treatment sequelae in head and neck cancer (HNC). Methods: The T1- and T2-weighted MRI signal intensity (SI) was examined in relation to HN-LEF categories per physical/tactile examination (No-LEF, A-B = edema, C = edema + fibrosis, D = fibrosis), and MRI structural volumes were examined in relation to a novel 10-point HN-LEF score in the intraoral and submental regions. Results: We identified differences in ranks among HN-LEF categories in relation to the MRI SI (A-B and C are higher than D and No-LEF for T2 SI, and A-B is the highest for T1). Furthermore, six pairs of FOM volumes on MRI demonstrated a strong negative correlation (p < 0.05) with the HN-LEF score at adjacent palpable sites. Conclusion: Both MRI SI and structural volumes can potentially be imaging biomarkers of edematous soft tissue states in HNC patients.