Apparent diffusion coefficient (ADC) values from diffusion-weighted imaging (DWI) magnetic resonance imaging may help with the differential diagnoses of intrahepatic cholangiocarcinoma (IHCC) and gastrointestinal system (GIS)-derived adenocarcinoma liver metastases, according to a new study published in Radiology and Oncology.
The ADC values of patients with IHCC were significantly higher than those of patients with GIS adenocarcinoma liver metastases (P <.001), with median values of 1293.0 and 861.0, respectively.
The area under the receiver operating characteristic (ROC) curve (AUC) showed that the mean ADC value was significant in differentiating between IHCC and GIS adenocarcinoma liver metastases (AUC=0.879; P <.0001).
Using the ROC curve revealed that a cut-off value of <1178 x10-6 mm2/s for the mean ADC resulted in a sensitivity of 90.57% and a specificity of 70.0% when differentiating between the 2 tumor types. The model also yielded a positive predictive value of 94.1 and a negative predictive value of 58.3.
“Our study results suggest that ADC values have a potential role for differentiation between IHCC and GIS liver metastases which may be valuable for patient management,” the authors summarized.
Read more about cholangiocarcinoma differential diagnosis
The authors hypothesized that the higher ADC values in IHCC may be “due to decreased cellularity due to fibrotic changes,” whereas the lower ADC values in the metastases group may be due to hypercellularity and decreased intra- and extracellular space.
The mean ages of the patients in the IHCC and GIS metastases groups were not significantly different (62.50±13.49 years vs 61.15±9.18 years, respectively; P =.679).
“Further larger-scale studies are needed to establish the relationship between IHCC and different tumor origins in terms of ADC values,” the authors suggested.
In this study, 64 patients with liver metastases due to GIS adenocarcinoma and 13 patients with IHCC were initially recruited between January 2018 and January 2020. After exclusions for neoadjuvant therapy, lack of DWI, heavy image artefacts and technical issues, and small lesions causing difficulty reading ADC values, a final 53 patients with GIS adenocarcinoma with 53 liver lesions and 10 patients with IHCC were included in the study.
Yilmaz TF, Gultekin MA, Turk HM, et al. Diagnostic performance of apparent diffusion coefficient values for the differentiation of intrahepatic cholangiocarcinoma from gastrointestinal adenocarcinoma liver metastases. Radiol Oncol. Published online December 22, 2021. doi:10.2478/raon-2021-0052