Oesophageal squamous cell carcinoma: histogram-derived ADC parameters are not predictive of tumour response to chemoradiotherapy

Abstract

Objectives

To evaluate correlations between tumour response to definitive chemoradiotherapy (CRT) in oesophageal squamous cell carcinoma (SCC) and histogram-derived apparent diffusion coefficient (ADC) parameters on diffusion-weighted MR images.

Methods

Forty patients with clinical T3–4 oesophageal SCC underwent concurrent CRT. MR examination at 3 T was performed 1–3 days prior to CRT. Readout-segmented echo-planar diffusion imaging was used to acquire ADC maps. Pre- and post-treatment CT examinations were performed. Histogram parameters (mean, 10th, 25th, 50th, 75th, 90th percentiles, skewness and kurtosis) of the ADC values were compared with post-treatment disease status based on RECIST and the tumour regression ratio.

Results

None of the ADC parameters showed significant correlation with post-treatment status (range of Spearman's ρ values − 0.19 to 0.14, range of p values 0.22–0.47) or tumour regression ratio (range of Spearman's ρ values − 0.045 to 0.18, range of p values 0.26–0.96). Neither progression-free survival (PFS) (p = 0.17) nor overall survival (OS) (p = 0.15) was significantly different between the two groups corresponding to the lower (< median) and upper arms (≥ median) of the mean ADC values.

Conclusions

Histogram-derived pretreatment ADC parameters were not predictive imaging biomarkers for tumour response to CRT in patients with oesophageal SCC.

Key Points

• Apparent diffusion coefficient (ADC) values are derived from diffusion-weighted MR imaging.

• High-resolution diffusion-weighted images are generated by readout-segmented echo-planar diffusion imaging.

• Readout-segmented echo-planar diffusion-weighted imaging enabled evaluation of ADC parameters.

• Pretreatment ADC parameters do not predict chemoradiotherapy response in patients with oesophageal carcinoma.