Precision Diffusion-Weighted Imaging of Head and Neck Squamous Cell Carcinoma

Area of Science:

• Radiology and Medical Imaging
• Oncology
• Biomarkers

Background:

• Head and neck squamous cell carcinoma (HNSCC) poses a significant global health challenge, with high annual incidence and mortality rates.
• Accurate quantification of apparent diffusion coefficient (ADC) using diffusion-weighted imaging (DWI) is crucial for HNSCC assessment, but requires optimized protocols for reproducibility.
• Existing quantitative imaging biomarkers (QIB) profiles show variability across different cancer types.

Purpose of the Study:

• To optimize diffusion-weighted imaging (DWI) sequences for head and neck region imaging.
• To establish reproducible apparent diffusion coefficient (ADC) metrics for head and neck squamous cell carcinoma (HNSCC).
• To enable clinicians to differentiate true physiological changes from measurement errors in HNSCC imaging.

Main Methods:

• An optimized head and neck DWI protocol was developed using Quantitative Imaging Biomarker Alliance (QIBA)-recommended parameters, a high b-value (2000), Zoom-IT technology, and phantom calibration.
• Twenty-six HNSCC patients underwent test-retest DWI scans. Apparent diffusion coefficient (ADC) values were extracted from 46 segmented tumor regions.
• Reproducibility was assessed using within-subject coefficient of variation (wCV), repeatability coefficient (RC), and intraclass correlation coefficient (ICC), with both manual and semi-automated segmentation.

Main Results:

• The optimized DWI protocol demonstrated good test-retest reliability, with an intraclass correlation coefficient (ICC) between 0.8-0.83.
• The within-subject coefficient of variation (wCV) was 5.2-5.4%, yielding a repeatability coefficient (RC) of 14.4%.
• Excellent agreement was observed between segmentations performed by two expert readers (DICE scores of 0.991 and 0.976).

Conclusions:

• The optimized DWI protocol provides accurate and reproducible ADC quantification for HNSCC, comparable to or exceeding metrics for other cancers like breast, liver, and prostate.
• The findings support the clinical utility of DWI for evaluating HNSCC tumor burden and treatment response.
• Further research is needed to refine parameters and establish DWI as a standard for HNSCC evaluation, particularly for tumor recurrence detection.