MRI Findings of Liver Parenchyma Peripheral to Colorectal Liver Metastasis: A Potential Predictor of Long-term Prognosis
Authors: Nakai Y, Gonoi W, Kurokawa R, Nishioka Y, Abe H, Arita J, Ushiku T, Hasegawa K, Abe O.
Journal: Radiology. 2020 Dec;297(3):584-594.
doi: 10.1148/radiol.2020202367.
Epub 2020 Oct 6. PMID: 33021892.
Curative liver resection is recommended as the most effective therapy for colorectal liver metastasis (CRLM). Histopathological analysis of resected CRLM usually aims to confirm malignancy or evaluate surgical margins, but other aspects such as vascular or bile duct invasion have been proposed as poor prognostic factors after resection of CRLM (1,2).
For an accurate surgical planning, gadoxetic acid (Gd-EOB-DTPA)-enhanced MRI is usually performed. Some authors have tried to predict long-term prognosis after hepatectomy based on some MRI findings, such as delayed tumor enhancement (3), but there have been no reports of prediction of microscopic vascular invasion of CRLM based on Gd-EOB-DTPA–enhanced MRI.
The authors aim to investigate whether EOB-DTPA–enhanced MRI findings peripheral to the CRLM could be used to predict pathologic vessel invasion, overall survival (OS) and recurrence-free survival (RFS) after curative surgery in patients without neoadjuvant chemotherapy. Their retrospective study included 148 metastases in 106 patients, excluding patients with five or more metastases, CRLM of <10 mm and portal vein embolization before surgery. Some clinical and analytical variables were recorded, such as the primary site of the tumor, primary tumor nodal status, history of extrahepatic disease, history of synchronous liver metastasis, number of hepatectomies, history of adjuvant chemotherapy, and preoperative serum carcinoembryonic antigen (CEA) level.
Imaging follow-up was performed every three months for the first two years, and then every six months. The MRI dynamic study involving liver acquisition included double arterial and portal venous phase or arterial, portal venous, and delayed phase images. Hepatobiliary phase images were obtained.
The MRI images were examined by three independent abdominal radiologists who were blinded to the clinical and pathologic findings, and they evaluated for number and diameter of CRLMs, presence or absence of early enhancement of liver parenchyma, reduced Gd-EOB-DTPA uptake area and bile duct dilatation peripheral to the tumor.
Histologic specimens were reevaluated and analyzed by a board-certified pathologist also blinded to the clinical and imaging findings, to assess surgical margin status and the presence or absence of portal vein, hepatic vein and bile duct invasion.
Authors developed two multivariable analysis model. In the first, they analyzed separately three findings: the presence or absence of early enhancement, reduced Gd-EOB-DTPA uptake and bile duct dilatation. In the second model, they included the integrated MRI finding of CRLM positive for one or more of the three findings.
Bile duct dilatation peripheral to the tumor was associated with pathologic portal vein invasion (sensitivity, 12 of 50 [24%]; specificity, 89 of 98 [91%]; P = .02), bile duct invasion (sensitivity, 8 of 19 [42%]; specificity, 116 of 129 [90%]; P = .001), poor RFS (P = .03; hazard ratio [HR] = 2.4 [95% confidence interval {CI}: 1.3, 4.2]), and poor OS (P = .01; HR = 2.4 [95% CI: 1.2, 4.9]).
Early enhancement and reduced Gd-EOB-DTPA uptake peripheral to the CRLM were not associated with pathologic vessel invasion or RFS and were associated with OS only in univariable analysis. However, a combination of early enhancement and reduced Gd-EOB-DTPA uptake peripheral to the CRLM with bile duct dilatation at MRI was predictive of poor OS (P = .001, HR = 3.3).
The main weakness of this study is its retrospective design, and some limitations in the patient’s selection and evaluation. In patients who had undergone multiple hepatectomies, imaging findings at the time of the other hepatectomies were not reviewed. Besides, they did not evaluate tumors smaller than 10 mm and patients with neoadjuvant chemotherapy were not included. Furthermore, different patterns of recurrence were not evaluated. Future studies should investigate the tumor recurrence pattern and whether neoadjuvant chemotherapy improves prognosis in patients with tumors showing abnormal peritumoral imaging findings.
Previously other authors studied peritumoral MRI changes to evaluate microvascular invasion in hepatocellular carcinoma (4) and reported a clinical-pathological-radiomic model to predict early recurrence of hepatocellular carcinoma (5). Thus, this study could provide a background for elaborating a radiomic model of CRLM.
In conclusion, it is important for radiologists to bear in mind the importance the assessment of peritumoral imaging findings, as it adds clinical value to preoperative routine MRI and may help planning a wide surgical margin, facilitating the treatment of patients with a high preoperative probability of recurrence or poor estimates of overall survival.
References:
- Knijn N, de Ridder JA, Punt CJ, de Wilt JH, Nagtegaal ID. Histopathological evaluation of resected colorectal cancer liver metastases: what should be done? Histopathology 2013;63(2):149–156.
- Reijonen P, Österlund P, Isoniemi H, Arola J, Nordin A. Histologically Verified Biliary Invasion was Associated with Impaired Liver Recurrence-Free Survival in Resected Colorectal Cancer Liver Metastases. Scand J Surg 2019;108(3):201–209.
- Cheung HMC, Karanicolas PJ, Coburn N, Seth V, Law C, Milot L. Delayed tumour enhancement on gadoxetate-enhanced MRI is associated with overall survival in patients with colorectal liver metastases. Eur Radiol 2019;29(2):1032–1038.
- Kim H, Park MS, Choi JY, et al. Can microvessel invasion of hepatocellular carcinoma be predicted by pre-operative MRI? Eur Radiol 2009;19(7):1744–1751.
- Kim S, Shin J, Kim DY, Choi GH, Kim MJ, Choi JY. Radiomics on Gadoxetic Acid-Enhanced Magnetic Resonance Imaging for Prediction of Postoperative Early and Late Recurrence of Single Hepatocellular Carcinoma. Clin Cancer Res 2019;25(13):3847–385
Diana Veiga-Canuto is a fourth-year radiology resident at Hospital Universitari i Politècnic La Fe (València, Spain). She started her residency after completing her medical studies in Universitat de València, where she is currently a PhD student in Medicine. Diana has a broad range of interests in diagnostic imaging, especially abdominal adult and pediatric imaging. She is an ESGAR member and has attended some ESGAR/ESOR biomarkers workshops and courses. She has been actively involved in clinical imaging research and has participated as an author or co-author in different national and international publications.
Comments may be sent to