# Mapping fibrosis in colorectal liver metastases (CRLM) with gadobenate dimeglumine-enhanced MRI: prognostic implications and imaging biomarkers

## TL;DR

This study shows that MRI can detect fibrosis in liver tumors after chemotherapy, and higher fibrosis is linked to worse survival in colorectal cancer patients.

## Contribution

The study introduces MRI-based biomarkers (SICP and TLEI) to non-invasively assess fibrosis in CRLM and links them to prognosis.

## Key findings

- High SICP in the 60-min delayed phase was associated with significantly lower overall survival.
- TLEI was significantly elevated in non-survivors, indicating a potential prognostic role.
- Fibrosis-associated enhancement was higher in patients treated with aflibercept and FOLFOX-4.

## Abstract

Development of fibrosis in treated colorectal liver metastases (CRLM) could be supposedly used for the estimation of both treatment response and prognosis. This study aimed to investigate the association between post-chemotherapy, fibrosis-related progressive gadolinium enhancement of CRLM on MRI and overall survival.

A retrospective study of 97 CRLM patients (68 M, mean age 62.3 ± 10.71 years) who underwent between 2017 and 2022 preoperative gadobenate dimeglumine (Gd-BOPTA) – enhanced MRI after chemotherapy. Tumor and liver enhancement were quantified using Signal Intensity Change Percentages (SICP) across 5-min and 60-min delay phases, along with the Tumor-to-Liver Enhancement Index (TLEI) to estimate fibrosis within CRLM. A subset of 18 patients was evaluated for radiologic-pathologic correlation. Cox regression, Kaplan–Meier analysis, and multivariate models were used to assess overall survival (OS).

High SICP (≥ 90.3%) in the 60-min delayed phase was associated with significantly lower OS (median: 37 vs. 66 months; p = 0.023). TLEI was significantly elevated in non-survivors (1.25 vs. 1.10; p = 0.007). Histopathologic correlation, available in 18 patients, confirmed fibrosis in lesions with elevated SICP, though limited sample size precluded statistical validation. In multivariate analysis, both high TLEI and elevated SICP were independent predictors of reduced OS (HR 1.38 [1.05–1.82], p = 0.023; HR 1.01 [1.00–1.01], p = 0.043, respectively). Notably, aflibercept- and FOLFOX-4-treated patients showed higher fibrosis-associated enhancement.

Gd-BOPTA-enhanced MRI, specifically SICP and TLEI in the delayed phase, may serve as non-invasive imaging biomarkers of fibrosis in CRLM. Contrary to prior assumptions, increased fibrosis was associated with worse prognosis, suggesting fibrosis-mediated tumor microenvironment alterations. Prospective studies with robust radiologic-pathologic validation are needed to clarify the mechanistic and prognostic implications.

The online version contains supplementary material available at 10.1007/s00384-026-05108-8.