Data Support Contrast-Enhanced MRI/CT for Colorectal Liver Metastases

“Our findings suggest that liver contrast-enhanced MRI should be considered in the routine diagnostic investigation of patients with primary and recurrent colorectal liver metastases amenable for local therapy based on contrast-enhanced CT," according to the study authors.

The addition of liver contrast-enhanced MRI imaging should be considered in the treatment of patients scheduled to undergo local therapy for colorectal liver metastases, according to findings from the CAMINO study (NL8039) published in Lancet Oncology.

Implementing liver contrast-enhanced MRI led to a change in local treatment plans for 31% (95% CI, 26%-36%) of patients, with 13% requiring more extensive local therapy, 4% needing less extensive local therapy, and 11% no longer requiring curative intent local treatment. Anywhere from 14% (95% CI, 3%-35%) to 57% (95% CI, 18%-90%; P = .24) had a change in local treatment plans following contrast-enhanced MRI, according to results from a post-hoc analysis.

A review from a central blinded expert panel highlighted that 34% (95% CI, 29%-40%) of patients needed a change in local treatment plans following contrast-enhanced MRI. Additionally, the expert panel and multidisciplinary team agreed that a change in local treatment plan was warranted for 22% of patients based on contrast-enhanced MRI. Overall, 252 of 261 patients who were indicated to undergo local treatment proceeded with therapy, which included resection for 163, thermal ablation for 34, and a combination of resection and intraoperative thermal ablation for 55.

Of the 252 patients who proceeded with local treatment, intraoperative changes were implemented for 68 based on contrast-enhanced MRI. In a post-hoc sub-analysis, investigators identified a significant increase in procedural changes for those treated with pre-interventional systemic therapy (33.3%; n = 39/117) vs those who were not (21.6%; n = 38/176; P = .049).

“The strength of this study lies mostly in its pragmatic prospective, multi-center design, including patients from 4 countries, with standardized use of contrast-enhanced MRI and an expert panel review of all patients to validate the findings of the individual centers,” the study authors wrote. “Our findings suggest that liver contrast-enhanced MRI should be considered in the routine diagnostic investigation of patients with primary and recurrent colorectal liver metastases amenable for local therapy based on contrast-enhanced CT.”

Investigators conducted this international, prospective, incremental diagnostic accuracy trial across 14 liver surgery centers in the Netherlands, Belgium, Norway, and Italy. The contrast-enhanced CT scans included a portal venous phase, and the liver contrast-enhanced MRI scans consisted of a T2-weighted sequence, diffusion-weighted imaging, and a T1-weighted sequence using a gadoxetic acid across multiple phases. There was a maximum interval of 10 weeks between the time of contrast-enhanced CT and administration of local therapy.

The study’s primary outcome was the extent to which liver contrast-enhanced MRI findings led to changes in local therapy plans. Secondary outcomes included changes in local therapy plans as determined by central blinded independent expert panel, the use of contrast-enhanced ultrasound, and colorectal liver metastasis recurrence during follow-up.

Patients 18 years and older with histologically confirmed colorectal cancer (CRC), a World Health Organization (WHO) performance status of 0 to 4, and primary or recurrent colorectal liver metastases were able to enroll on the study. Those with a contraindication for liver surgery or local thermal ablation were ineligible for enrollment.

Of 298 patients included in the intention-to-image analysis, most were male (59%), had a WHO performance status of 0 (63%), and disease primarily of the rectum (33%). Additionally, most patients had primary colorectal liver metastases (84%) and received pre-interventional systemic therapy (40%).

Of 223 patients who underwent surgery, 204 received intraoperative ultrasound, which revealed additional lesions in 9. Moreover, 6 patients who had additional lesions proceeded with surgical resection.

A multivariate regression analysis accounting for factors such as age, WHO performance status, site of primary colorectal carcinoma, and size of largest lesion on contrast-enhanced CT indicated a probability of no higher than 5% for local treatment plan changes based on contrast-enhanced MRI for a small patient subgroup.

Reference

Görgec B, Hansen IS, Kemmerich G, et al. MRI in addition to CT in patients scheduled for local therapy of colorectal liver metastases (CAMINO): an international, multicentre, prospective, diagnostic accuracy trial. Lancet Oncol. 2024;25:137-146. doi:10.1016/S1470-2045(23)00572-7