Maiko Kozumi, Presenter: Nothing to Disclose

Hideki Ota MD, PhD, Abstract Co-Author: Nothing to Disclose

Tomonori Matsuura, Abstract Co-Author: Nothing to Disclose

Kei Takase MD, PhD, Abstract Co-Author: Nothing to Disclose

Shoki Takahashi MD, Abstract Co-Author: Nothing to Disclose

Keiichi Jingu MD, Abstract Co-Author: Nothing to Disclose

To evaluate correlation between tumor response to chemoradiotherapy (CRT) in esophageal carcinoma and histogram-derived apparent diffusion coefficient (ADC) parameters obtained from volumetric assessment of the primary lesion on diffusion-weighted MR imaging.  

Consecutive 22 patients (20 men; mean age 70.0 years, range 51-88 years) with esophageal squamous cell carcinoma (clinical T3, 17, T4, 5) were included in this prospective study. All the patients underwent radiotherapy with a total dose of 59.6-62.4 Gy and concurrent chemotherapy (cisplatin and 5-fluorouracil [5-FU], 14, nedaplatin and 5-FU, 6, docetaxel, cisplatin and 5-FU, 2). MR examination at 3 Tesla was performed 1-3 days prior to CRT. Readout-segmented echo-planar diffusion imaging (RESOLVE, b=50, 800 s/mm2) was used to acquire ADC maps. Two radiologists evaluated MR images by consensus reading. Regions of interests were placed on all slices of the ADC maps where the tumor was visualized. Histogram parameters (the mean, 10th, 25th, 50th, 75th, 90th percentiles, skewness and kurtosis) of ADCs were compared with post-treatment disease status based on Response Evaluation Criteria In Solid Tumors criteria (complete response [CR], partial response [PR] or stable disease [SD]) and tumor regression ratio in diameter on pre- and post-treatment CT scans.

The mean of the largest tumor diameter on pretreatment CT was 33.5 ± 9.1 mm. Post-treatment status were CR in one, PR in nine and SD in 12, respectively. Mean tumor regression ratio was 33.1 ± 22.4%. The mean 50th percentile ADC values were (1.39 ± 0.27) ×10-3 mm2/s in patients with CR or PR and (1.35 ± 0.18) ×10-3 mm2/s in those with SD (P = 0.61). None of the  ADC parameters was significantly correlated with post-treatment status (Spearman's ρ = 0.09 - 0.26, P = 0.29 - 0.79) or tumor regression ratio (Pearson's r = -0.13 - 0.26, P = 0.25 - 0.99).

Histogram-derived pretreatment ADC parameter was not a predictive imaging biomarker for tumor response by CRT in esophageal squamous cell carcinoma. Further investigation that includes long-term follow-up is warranted to evaluate association between tumor characteristics determined by ADC and patients' prognoses. 

ADC parameters obtained from readout-segmented echo-planar diffusion imaging are not correlated with tumor response to CRT in esophageal squamous cell carcinoma and are not recommended for its prediction.

Kozumi, M, Ota, H, Matsuura, T, Takase, K, Takahashi, S, Jingu, K, Comparison between Histogram-derived Apparent Diffusion Coefficient Parameters of Esophageal Squamous Cell Carcinoma and Tumor Regression after Chemoradiotherapy..  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14013310.html