Interobserver Reproducibility of Diffusion-Weighted MRI in Monitoring Tumor Response to Neoadjuvant Therapy in Esophageal Cancer

Abstract

ObjectiveTo investigate the reproducibility of diffusion-weighted magnetic resonance imaging (DW-MRI) in assessing tumor response early in the course of neoadjuvant chemoradiotherapy in patients with operable esophageal cancer.MethodsEleven male patients (mean age 54.8 years) with newly diagnosed esophageal cancer underwent DW-MRI before and 10 days after start of chemoradiotherapy. Reproducibility of apparent diffusion coefficient (ADC) measurements by manual (freehand) and semi-automated volumetric methods was assessed.ResultsInterobserver reproducibility for the assessment of mean tumor ADC by the manual measurement method was good, with an ICC of 0.69 (95% CI, 0.36 to 0.85; P = 0.001). Interobserver reproducibility for the assessment of mean tumor ADC by the semi-automated volumetric measurement method was very good, with an ICC of 0.96 (95% CI, 0.91 to 0.98; P<0.001).ConclusionSemi-automated volumetric ADC measurements have higher reproducibility than manual ADC measurements in assessing tumor response to chemoradiotherapy in patients with esophageal adenocarcinoma.

Diffusion-weighted magnetic resonance imaging for the prediction of pathologic response to neoadjuvant chemoradiotherapy in esophageal cancer

“…One study reported that esophageal squamous cell carcinoma patients with higher initial ADC showed a better response to chemoradiotherapy [31], whereas another study contrarily found significantly higher initial ADC values in non-responders [32]. Similar to our results, a third study found no significant association between initial ADC and response, regardless of a manual or semi-automated ADC measurement in that study [33]. However, our exploratory study suggests that there is some information to gain from the initial ADC value with regard to primary tumor characteristics.…”

“…This finding has also been recognized in FDG-PET studies for response assessment in esophageal cancer [11,24], and is supported by results from recent DW-MRI studies in rectal cancer [15,39]. In the first study that reported on MRI scanning before and during nCRT in 11 esophageal cancer patients, no correlation was found between change in mean tumor ADC and the histopathologic TRG [33]. However, that study differed from the current study as a smaller sample of patients was studied, a different MRI scan protocol with other b-values was used, other methods for VOI delineation were applied, and patients underwent a different nCRT regimen [33].…”

“…This suggests inability of pre-treatment MRI to accurately identify prognostic indicators of treatment response that would allow for guiding individualized treatment decisions from the start. Contradictory results on the value of initial ADC for predicting response have been published in three previous studies with substantial differences in terms of tumor histology, MRI scan protocol, and used reference standard [31][32][33]. One study reported that esophageal squamous cell carcinoma patients with higher initial ADC showed a better response to chemoradiotherapy [31], whereas another study contrarily found significantly higher initial ADC values in non-responders [32].…”

Personalized therapy based on image for esophageal or gastroesophageal junction adenocarcinoma

“…Because diffusion within tumor is interrupted by cellular membranes or macromolecular structures, presence or residual tumor cell can be detected as ADC decrease, conversely treatment response can be detected as ADC increase (49). So far, three studies evaluate the benefit of DW-MRI for predicting preoperative treatment (50)(51)(52). A prospective study found that change in ADC during preoperative chemoradiation was associated with pCR (50).…”

“…A prospective study found that change in ADC during preoperative chemoradiation was associated with pCR (50). One study reported similar result that change in ADC was associated with TRG (52), but another study did not (51). These studies were small, therefore a multi-center study assessing the value of MRI and PET-CT for predicting of preoperative treatment response (NCT02125448).…”