Featuring study published by CAR members: Dr. Helen Cheung, Dr. Laurent Milot and Dr. Tishan Maraj
Delayed tumour enhancement of colorectal liver metastases (CRLM) on gadoxetate-enhanced MRI is associated with survival post-hepatectomy, according to results reported by researchers from Sunnybrook Health Sciences Centre1.
This report follows up on similar results published by the same group earlier in 2018 with the extracellular MRI contrast agent gadobutrol (Gadovist®, Bayer Inc.)2. In that work, Cheung et al. demonstrated that late gadolinium enhancement of CRLM on gadobutrol-enhanced MRI is associated with tumour fibrosis and overall survival after liver resection. The association between late gadolinium enhancement and fibrosis may be due to leakage of contrast into the tumour. It has already been well established in the literature that tumour fibrosis is associated with survival post-hepatectomy.
The group’s aim in this most recent study was to confirm whether the same association of delayed enhancement with long-term survival could be observed using the hepatobilary contrast agent gadoxetate (Primovist®, Bayer Inc.). Sixty-five patients who received preoperative chemotherapy and had a gadoxetate-enhanced MRI prior to surgery were included in this retrospective study. Delayed tumour enhancement was measured by calculating the increase in signal-to-noise ratio (SNR) between the non-contrast images and the 10-minute and 20-minute delayed phases. The mean tumour enhancement was calculated in the case of multiple lesions and per patient tumour enhancement was then divided into those with weak or strong enhancement based on the Youden Index for 3-year survival.
The study found that the proportion of patients with strong tumour enhancement surviving at 3 years was 85.1%, compared with 56.5% for those with weak enhancement at the 10-minute delayed phase. Using the 20-minute delayed phase, the proportion surviving at 3 years was 79.4% for patients who had strong tumour enhancement, compared to 58.7% for those who had weak tumour enhancement.
While further studies will be needed to assess the clinical impact of these findings, key advantages of imaging biomarkers over pathology and molecular biomarkers may include the ability to assess multiple tumours and even evaluate heterogeneity within the same tumour. Commenting on this work, principal investigator Dr. Laurent Milot is excited about the possibility of using this information as a prognostic tool. “Right now, all patients are getting treated the same, but with this data we could know up front what the best treatment regimen would be for each patient”.
- Cheung et al. Eur Radiol 2018 Jul 10 [Epub Ahead of Print]
- Cheung et al. Eur Radiol 2018; 28:3505-3512
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