Squamous cell carcinoma of the head and neck: diffusion-weighted MR imaging for prediction and monitoring of treatment response

Abstract

Single ADC measurements pre- or intra-treatment did not predict response, but ADC post-treatment was a marker for LF. Serial change in ADC was an even stronger marker, when using an early or late treatment fall in ADC to identify LF.

Intravoxel incoherent motion diffusion‐weighted MRI during chemoradiation therapy to characterize and monitor treatment response in human papillomavirus head and neck squamous cell carcinoma

“…Also, King et al13 reported a significant correlation between local failure and post‐TX ADC, but not pre‐ or intra‐TX ADC values. Kim et al11 reported a significant increase in ADC values observed in the CR group within 1 week of treatment in HNSCC.…”

“…Several reports have suggested that the quantitative imaging metric apparent diffusion coefficient (ADC), derived from DW‐MRI data using a minimum of two b (b = diffusion‐weighted gradient factor) values, has shown promise in clinical applications ranging from tumor characterization to the evaluation of treatment response 10, 11, 12. It has been reported that hypercellular tissue is characterized by low ADC, whereas hypocellular tissue with necrosis, or apoptosis, is characterized by high ADC; the change in ADC (ΔADC) before, during, or after chemoradiation therapy in HNSCC is a surrogate biomarker of treatment response 13, 14…”

MRI Sequences in Head & Neck Radiology – State of the Art

“…For the evaluation of treatment response it has been shown that two-week intra-treatment ADCs are predictors of outcome, as a lower increase in the percentage change of the mean ADC, higher skewness, and higher kurtosis are significantly more likely to show local failure than local control [51]. A decrease in ADC during treatment is strongly indicative of a time point of tumor resistance and treatment failure [52]. DWI seems even superior to FDG PET/CT for post-treatment recurrence [53].…”

“…The advantages of suppressing the signal from fat is to suppress artifacts due to high fat signals, to improve T2 contrast between fatty and non-fatty tissue, to enable detection of enhancing tumors hidden in fatty tissue, and the proof of adipose tissue, such as in lipoma, or cholesterol granuloma. Reading T1w and T2w basic sequences and T2w fat sat images is important because the very high STIR/TIRM ▶ Table 1 (Continuation) MRI sequences main pathologies/field of application diagnostic clues paraganglioma high peak enhancement, SER, and short TME on DCE [37] schwannoma low peak enhancement and SER with a longer TME on DCE [37] diffusionweighted imaging primary tumors low ADC values (lymphoma, followed by carcinoma, benign tumor and cystic lesions) [47] lymph node staging low ADC values [49] residual cancer after chemoradiation therapy lower increase in the percentage change of the mean ADC or decrease in ADC during treatment [51,52] cholesteatoma high signal on DWI [60] Granulation tissue, fibrous tissue, cholesterol granuloma or serous fluid…”

Trends in head and neck radiology

“…King et al [3] and Vandecaveye et al [4] stressed the necessity of an early identification of non-responders to radiotherapy or chemoradiotherapy for modification or change of treatment regimens in patients with head and neck squamous cell carcinoma. In this early post-treatment phase previous radiological assessment has been described as suboptimal: Treatmentinduced inflammation may hamper the accuracy of PET-CT. Volumetric analysis with anatomical imaging (CT, MRI) has shown variable results.…”