Colorectal liver metastases: disappearing lesions in the era of Eovist hepatobiliary magnetic resonance imaging

A Systematic Review of Disappearing Colorectal Liver Metastases: Resection or No Resection?

Background: Colorectal cancer is the second most common type of cancer and a leading cause of cancer-related deaths worldwide. Approximately 15% of the patients with colorectal cancer will already have liver metastases (CRLMs) at diagnosis. Luckily, the advances in chemotherapy regimens during the past few decades have led to increased rates of disease regression that could even render an originally unresectable disease resectable. In certain patients with CRLMs, the hepatic lesions are missing on preoperative imaging after neoadjuvant chemotherapy. These patients can undergo surgery with or without resection of the sites of the disappearing liver metastases (DLMs). In this systematic review, we assess the recurrence rate of the DLMs that were left unresected as well as the complete pathologic response of those resected. Methods: A literature search was conducted in PubMed for studies including patients with CRLMs who received neoadjuvant chemotherapy and had DLMs in preoperative imaging. Two independent reviewers completed the search according to the PRISMA checklist. Results: Three hundred and twenty-six patients with 1134 DLMs were included in our review. A total of 47 out of 480 DLMs (72.29%) that were removed had viable tumor cells in postoperative histology. One hundred and forty-five tumors could not be identified intraoperatively and were removed based on previous imaging, with thirty (20.69%) of them presenting viable cancer cells. Four hundred and sixty-five lesions could not be identified and were left in place. Of them, 152 (32.69%) developed local recurrence within 5 years. Of note, 34 DLMs could not be categorized as viable or non-viable tumors. Finally, DLMs that were identifiable intraoperatively had a higher possibility of viable tumors compared to non-identifiable ones (72.29% vs. 20.69%, respectively). Conclusions: Disappearing liver metastases that are left unresected have an increased possibility of recurrence. Patients receiving neoadjuvant treatment for CRLMs may have better survival chances after resecting all the DLM sites, either identifiable intraoperatively or not.

A graph-theoretic approach for the analysis of lesion changes and lesions detection review in longitudinal oncological imaging

Radiological follow-up of oncology patients requires the detection of lesions and the quantitative analysis of lesion changes in longitudinal imaging studies of patients, which is time-consuming and requires expertise. We present here a new method and workflow for the analysis and review of lesions and volumetric lesion changes in longitudinal scans of a patient. The generic graph-based method consists of lesion matching, classification of changes in individual lesions, and detection of patterns of lesion changes computed from the properties of the graph and its connected components. The workflow guides clinicians in the detection of missed lesions and wrongly identified lesions in manual and computed lesion annotations using the analysis of lesion changes. It serves as a heuristic method for the automatic revision of ground truth lesion annotations in longitudinal scans. The methods were evaluated on longitudinal studies of patients with three or more examinations of metastatic lesions in the lung (19 patients, 83 CT scans, 1178 lesions), the liver (18 patients, 77 CECT scans, 800 lesions) and the brain (30 patients, 102 T1W-Gad MRI scans, 317 lesions) with ground-truth lesion annotations. Lesion matching yielded a precision of 0.92-1.0 and recall of 0.91-0.99. The classification of changes in individual lesions yielded an accuracy of 0.87-0.97. The classification of patterns of lesion changes yielded an accuracy of 0.80-0.94. The lesion detection review workflow applied to manual and computed lesion annotations yielded 120 and 55 missed lesions and 20 and 164 wrongly identified lesions for all longitudinal studies of patients, respectively. The automatic analysis of lesion changes and review of lesion detection in longitudinal studies of oncological patients helps detect missed lesions and wrongly identified lesions. This method may help improve the accuracy of radiological interpretation and the disease status evaluation.

New trends in surgery for colorectal liver metastasis

By presenting the most up-to-date findings and incorporating the latest evidence, this article seeks to present a comprehensive guide for navigating the complexities inherent in the management of colorectal liver metastasis. It aims to serve as a valuable resource offering clinicians and healthcare professionals an understanding of the diverse modalities and approaches available for treating this challenging and multifaceted disease. In an era of rapidly evolving medical knowledge, this article examines the latest insights to make informed decisions in the realm of colorectal liver metastasis management. The article does not only highlight the up-to-date knowledge but also provides the evidence for existing therapeutic strategies. This practical tool provides evidence-based recommendations to clinicians, thereby contributing to the ongoing advancement of effective treatment strategies for this challenging disease.

Contemporary Surgical Management of Colorectal Liver Metastases

Colorectal cancer is the third most common cancer in the United States and the second most common cause of cancer-related death. Approximately 20-30% of patients will develop hepatic metastasis in the form of synchronous or metachronous disease. The treatment of colorectal liver metastasis (CRLM) has evolved into a multidisciplinary approach, with chemotherapy and a variety of locoregional treatments, such as ablation and portal vein embolization, playing a crucial role. However, resection remains a core tenet of management, serving as the gold standard for a curative-intent therapy. As such, the input of a dedicated hepatobiliary surgeon is paramount for appropriate patient selection and choice of surgical approach, as significant advances in the field have made management decisions extremely nuanced and complex. We herein aim to review the contemporary surgical management of colorectal liver metastasis with respect to both perioperative and operative considerations.

Gadoxetic acid in hepatocellular carcinoma and liver metastases: pearls and pitfalls

Gadoxetic disodium (Primovist) is a hepatocyte-specific magnetic resonance imaging (MRI) contrast agent with increasing popularity with its unique dual dynamic and excretory properties in focal liver lesion detection and characterisation. In-depth knowledge of its diagnostic utility and pitfalls in hepatocellular carcinoma (HCC) and liver metastases is crucial in facilitating clinical management. The current article reviews the pearls and pitfalls in these aspects with highlights from the latest research evidence. Pearls for common usage of Primovist in HCC includes detection of precursor cancer lesions in cirrhotic patients. Hepatobiliary phase hypointensity precedes arterial phase hyperenhancement (APHE) in hepatocarcinogenesis. Hepatobiliary phase hypointense nodules without APHE can represent early or progressed hepatocellular carcinoma (HCC) and high-grade dysplastic nodules. In addition, Primovist is useful to differentiate HCC from pseudolesions. Pitfalls in diagnosing HCC include transient tachypnoea in the arterial phase, rare hepatobiliary phase hyperintense HCC, and decompensated liver cirrhosis compromising image quality. Primovist is currently the most sensitive technique in diagnosing liver metastases before curative hepatic resection. Other patterns of enhancement of liver metastases, "disappearing" liver metastases are important pitfalls. Radiologists should be aware of the diagnostic utility, limitations, and potential pitfalls for the common usage of hepatobiliary specific contrast agent in liver MRI.

Retrospective analysis of colorectal cancer patients with metachronous initially unresectable liver metastases (and no other) achieving no evidence of disease after first-line comprehensive therapy: a multicenter real-world study

PURPOSE

To explore the optimal timing of locoregional therapy in patients with colorectal cancer (CRC) recurrence after radical resection and initially unresectable liver metastases but no other metastases and whether maintenance therapy should be performed after achieving no evidence of disease (NED).

METHODS

This study was jointly carried out in six medical institutions in China to collect the clinical data of patients with primary CRC from January 2015 to December 2021. Research participants were identified according to the inclusion criteria of this study for statistical analysis of the clinical characteristics and recurrence time.

RESULTS

625 patients CRC with metachronous initially unresectable liver metastases but no other metastases were enrolled. Multivariate analysis showed that the number of metastases in the liver and the time from the start of first-line chemotherapy to locoregional therapy significantly affected the progression-free survival (PFS, P < 0.05) following the first-line treatment, and continued maintenance therapy reduced the risk of tumor progression in the patients (P < 0.05). Furthermore, stratified analysis showed that the median PFS of patients with 3-5 metastases in the liver was maximized when the time from the start of first-line chemotherapy to locoregional therapy was 3-4 months. Patients with > 6 metastases in the liver should extend the duration between the start of first-line chemotherapy and locoregional therapy to more than four months. Similarly, with the significant increase in the number of metastases in the liver, subsequent maintenance therapy significantly extended the PFS of the patients.

CONCLUSIONS

The overall therapeutic plan in patients with CRC recurrence after radical resection and initially unresectable liver metastases but no other metastases should consider the individual patients' situations, especially the number of metastases in the liver at initial recurrence.

Exploring the Outcome of Disappearance or Small Remnants of Colorectal Liver Metastases during First-Line Chemotherapy on Hepatobiliary Contrast-Enhanced and Diffusion-Weighted MR Imaging

We aimed to evaluate the outcome of the disappearance or small remnants of colorectal liver metastases during first-line chemotherapy assessed by hepatobiliary contrast-enhanced and diffusion-weighted MR imaging (DW-MRI). Consecutive patients with at least one disappearing liver metastasis (DLM) or small residual liver metastases (≤10 mm) assessed by hepatobiliary contrast-enhanced and DW-MRI during first-line chemotherapy were included. Liver lesions were categorized into three groups: DLM; residual tiny liver metastases (RTLM) when ≤5 mm; small residual liver metastases (SRLM) when >5mm and ≤10 mm. The outcome of resected liver metastases was assessed in terms of pathological response, whereas lesions left in situ were evaluated in terms of local relapse or progression. Fifty-two outpatients with 265 liver lesions were radiologically reviewed; 185 metastases fulfilled the inclusion criteria: 40 DLM, 82 RTLM and 60 SRLM. We observed a pCR rate of 75% (3/4) in resected DLM and 33% (12/36) of local relapse for DLM left in situ. We observed a risk of relapse of 29% and 57% for RTLM and SRLM left in situ, respectively, and a pCR rate of about 40% overall for resected lesions. DLM assessed via hepatobiliary contrast-enhanced and DW-MRI very probably indicates a complete response. The surgical removal of small remnants of liver metastases should always be advocated whenever technically possible.

Disappearing colorectal liver metastases in the era of state-of-the-art triple-modality diagnostic imaging

INTRODUCTION

Systemic therapy can result in disappearance of colorectal liver metastases in up to 40% of patients. This might be an overestimation caused by suboptimal imaging modalities. The aim of this study was to investigate the use of imaging modalities and the incidence, management and outcome of patients with disappearing liver metastases (DLMs).

METHODS

This was a retrospective study of consecutive patients treated for colorectal liver metastases at a high volume hepatobiliary centre between January 2013 and January 2015 after receiving induction or neoadjuvant systemic therapy. Main outcomes were use of imaging modalities, incidence, management and longterm outcome of patients with DLMs.

RESULTS

Of 158 patients included, 32 (20%) had 110 DLMs. Most patients (88%) had initial diagnostic imaging with contrast enhanced-CT, primovist-MR and FDG-PET and 94% of patients with DLMs were restaged using primovist-MR. Patients with DLMs had significantly smaller metastases and the median initial size of DLMs was 10 mm (range 5-61). In the per lesion analysis, recurrence after "watch & wait" for DLMs occurred in 36%, while in 19 of 20 resected DLMs no viable tumour cells were found. Median overall (51 vs. 28 months, p < 0.05) and progression free survival (10 vs. 3 months, p = 0.003) were significantly longer for patients with DLMs.

CONCLUSION

Even state-of-the-art imaging and restaging cannot solve problems associated with DLMs. Regrowth of these lesions occurs in approximately a third of the lesions. Patients with DLMs have better survival.

Disappearing Colorectal Liver Metastases: Do We Really Need a Ghostbuster?

The development of new systemic treatment strategies has resulted in a significant increase in the response rates of colorectal liver metastases (CRLM) in the last few years. Although the radiological response is a favorable prognostic factor, complete shrinkage of CRLM, known as disappearing liver metastases (DLM), presents a therapeutic dilemma, and proper management is still debated in the literature. In fact, DLM is not necessarily equal to cure, and when resected, pathological examination reveals in more than 80% of patients a variable percentage of the tumor as residual disease or early recurrence in situ. Moreover, while a higher incidence of intrahepatic recurrence is documented in small series when surgery is avoided, its clinical significance for long-term OS is still under investigation. In light of this, a multidisciplinary approach and, in particular, radiologists’ role is needed to assist the surgeon in the management of DLM, thanks to emerging technology and strategy. Therefore, the aim of this review is to provide an overview of the DLM phenomenon and current management.

The management of colorectal liver metastases amenable of surgical resection: How to shape treatment strategies according to clinical, radiological, pathological and molecular features

Metastatic colorectal cancer (mCRC) patients have poor chances of long term survival, being < 15% of them still alive after 5 years from diagnosis. Nonetheless, patients with colorectal liver metastases (CRLM) may be eligible for metastases resection thus being able to achieve long-term disease remission and survival. The likelihood for patients with CRLM of being or becoming eligible for liver metastasectomy is increasing, thanks to the evolution of surgical techniques, the availability of active systemic treatments and the widespread diffusion of experienced multidisciplinary boards to manage these patients. However, disease relapse after liver surgery is common and occurs in two-thirds of resected patients. Therefore, adequate radiological staging and risk stratification is crucial for the optimal selection of patients candidate to surgery in order to maximize the benefit-risk ratio of liver metastasectomy and to individualize the treatment strategy. Based on the multidimensional assessment, three possible approaches are available: upfront liver surgery followed by adjuvant chemotherapy, perioperative chemotherapy preceding and following liver surgery, and an upfront systemic treatment including chemotherapy plus a targeted agent, both chosen according to patients' and tumours' characteristics, then followed by liver surgery if indicated. In this review, we describe the most important factors impacting the therapeutic choices in patients with resectable and potentially resectable CRLM, and we discuss the most promising factors that may reshape the future decision-making process of these patients.

The Influence of Radiological “Disappearing Lesions” on the Efficacy and Prognosis of Patients with Colorectal Liver Metastases Undergoing Conversion Therapy

Purpose

The purpose of the current study was to analyze the influence of radiological “disappearing liver metastasis” (DLM) on the efficacy and prognosis of patients with colorectal liver metastases (CRLM) undergoing conversion therapy.

Methods

Patients with CRLM by the multidisciplinary team (MDT) of the First Affiliated Hospital of Chongqing Medical University were retrospectively enrolled from January 2014 to January 2021. The relationship between the occurrence and recurrence of DLM and different clinical factors was analyzed.

Results

Thirty-five of the 113 patients (31.0%) with initially unresectable CRLM developed DLM, and of the 361 lesions, 177 disappeared (49.0%). Within 6 months, 6-12 months, and 12-24 months groups, the recurrence rate was 3.4%, 16.8%, and 34.8%, but there is no recurrence in after 24 months group. There was a statistical difference between chemotherapy alone and chemotherapy combined with the targeted therapy group on the occurrence of DLM (58.3% vs. 37.1%, P < 0.001). There were significant differences between <5 mm group and >10 mm group on occurrence of DLM（76.7% vs. 30.4%, P < 0.001) and between 5-10 mm group and >10 mm group also (70.0% vs. 30.4%, P < 0.001). Through univariate and multivariate analyses, it was concluded that age (P = 0.026, 95%CI = 3.690) and treatment regimens (P = 0.033, 95%CI = 2.703) had a significant influence on the progression-free survival (PFS) time of DLM.

Conclusion

Younger patients, who use chemotherapy alone to achieve a therapeutic effect, might have better survival benefits when the lesions do not progress within 2 years after the appearance of DLMs.

Imaging of Colorectal Liver Metastasis

Colorectal cancer (CRC) is one of the most common cancers in the world. The most important determinant of survival and prognosis is the stage and presence of metastasis. The liver is the most common location for CRC metastasis. The only curative treatment for CRC liver metastasis (CRLM) is resection; however, many patients are ineligible for surgical resection of CRLM. Locoregional treatments such as ablation and intra-arterial therapy are also available for patients with CRLM. Assessment of response after chemotherapy is challenging due to anatomical and functional changes. Antiangiogenic agents such as bevacizumab that are used in the treatment of CRLM may show atypical patterns of response on imaging. It is vital to distinguish patterns of response in addition to toxicities to various treatments. Imaging plays a critical role in evaluating the characteristics of CRLM and the approach to treatment. CT is the modality of choice in the diagnosis and management of CRLM. MRI is best used for indeterminate lesions and to assess response to intra-arterial therapy. PET-CT is often utilized to detect extrahepatic metastasis. State-of-the-art imaging is critical to characterize patterns of response to various treatments. We herein review the imaging characteristics of CRLM with an emphasis on imaging changes following the most common CRLM treatments.

Missing colorectal liver metastases: the surgical challenge

BACKGROUND

New chemotherapy schemes have allowed for a better radiological response of unresectable colorectal liver metastases, leading to an interesting scenario known as a complete radiological response. The aim of this study was to review the current management of missing liver metastases (MLM) from the liver surgeon's point of view.

METHODS

A systematic search was conducted on all publications of PubMed and Embase between 2003 and 2018. Meta-analysis was performed on MLM resected/unresected. Residual tumor or regrowth and relapse-free survival were used as evaluation indices.

RESULTS

After literature search, 18 original articles were included for analysis. The predictive factors for MLM are type and duration of chemotherapy and size and number of lesions. Magnetic resonance is the most sensitive preoperative technique. Regarding clinical management, liver surgery is deemed the fundamental pillar in the therapeutic strategy of these patients. Meta-analysis due to data heterogeneity was inconclusive.

CONCLUSIONS

Depending on the clinical context, MLM monitoring appears to be a valid therapeutic alternative. Nevertheless, prospective randomized clinical studies are needed.

Long-term outcome for colorectal liver metastases: combining hepatectomy with intraoperative ultrasound guided open microwave ablation versus hepatectomy alone

OBJECTIVE

To compare the long-term outcome of combining hepatectomy with intraoperative ultrasound (IOUS)-guided open microwave ablation (MWA) versus hepatectomy alone in patients with colorectal cancer liver metastases (CRLM).

METHOD

A retrospective analysis of patients with CRLM who underwent hepatectomy alone (HT group; 380 patients) or hepatectomy combined with IOUS-guided open MWA (HT + MWA group; 57 patients) from April 2002 to September 2018 was conducted at our center. A propensity score-matched (PSM) analysis was used to reduce data bias between the two groups.

RESULTS

The overall survival (OS) and disease-free survival (DFS) were not significantly different between the two groups after matching. Although intrahepatic recurrence was more frequent in the HT + MWA group in both the whole and matched cohort, the two groups exhibited similar rates of extrahepatic recurrence as well as concomitant intra- and extrahepatic recurrence. A higher number of CRLM (>3), larger maximum-size and absence of response to induction chemotherapy were independent risk factors for OS.

CONCLUSION

The oncological outcomes of hepatectomy combined with intraoperative open ablation was not significantly different to hepatectomy alone and should be considered as a safe and fair option for patients with difficultly resectable CRLM.

Radiological assessment of secondary biliary tree lesions: an update

Objective

To conduct a systematic literature review of imaging techniques and findings in patients with peribiliary liver metastasis.

Methods

Several electronic datasets were searched from January 1990 to June 2017 to identify studies assessing the use of different imaging techniques for the detection and staging of peribiliary metastases.

Results

The search identified 44 studies, of which six met the inclusion criteria and were included in the systematic review. Multidetector computed tomography (MDCT) is the technique of choice in the preoperative setting and during the follow-up of patients with liver tumors. However, the diagnostic performance of MDCT for the assessment of biliary tree neoplasms was low compared with magnetic resonance imaging (MRI). Ultrasound (US), without and with contrast enhancement (CEUS), is commonly employed as a first-line tool for evaluating focal liver lesions; however, the sensitivity and specificity of US and CEUS for both the detection and characterization are related to operator expertise and patient suitability. MRI has thus become the gold standard technique because of its ability to provide morphologic and functional data. MRI showed the best diagnostic performance for the detection of peribiliary metastases.

Conclusions

MRI should be considered the gold standard technique for the radiological assessment of secondary biliary tree lesions.

Human Gut Microbiota-associated Gastrointestinal Malignancies: A Comprehensive Review

The human gastrointestinal tract houses trillions of microbes. The gut and various types of microorganisms, including bacteria, viruses, fungi, and archaea, form a complex ecosystem known as the gut microbiota, and the whole genome of the gut microbiota is referred to as the gut microbiome. The gut microbiota is essential for homeostasis and the overall well-being of a person and is increasingly considered an adjunct "virtual organ," with a complexity level comparable to that of the other organ systems. The gut microbiota plays an essential role in nutrition, local mucosal homeostasis, inflammation, and the mucosal immune system. An imbalanced state of the gut microbiota, known as dysbiosis, can predispose to development of various gastrointestinal malignancies through three speculated pathogenic mechanisms: (a) direct cytotoxic effects with damage to the host DNA, (b) disproportionate proinflammatory signaling inducing inflammation, and (c) activation of tumorigenic pathways or suppression of tumor-suppressing pathways. Several microorganisms, including Helicobacter pylori, Epstein-Barr virus, human papillomavirus, Mycoplasma species, Escherichia coli, and Streptococcus bovis, are associated with gastrointestinal malignancies such as esophageal adenocarcinoma, gastric adenocarcinoma, gastric mucosa-associated lymphoid tissue lymphoma, colorectal adenocarcinoma, and anal squamous cell carcinoma. Imaging plays a pivotal role in diagnosis and management of microbiota-associated gastrointestinal malignancies. Appropriate use of probiotics, fecal microbiota transplantation, and overall promotion of the healthy gut are ongoing areas of research for prevention and treatment of malignancies. Online supplemental material is available for this article. ^©RSNA, 2021.

When is a Ghost Really Gone? A Systematic Review and Meta-analysis of the Accuracy of Imaging Modalities to Predict Complete Pathological Response of Colorectal Cancer Liver Metastases After Chemotherapy

BACKGROUND

Administration of chemotherapy to patients with colorectal liver metastases may result in disappearing liver metastases (DLM). This poses a therapeutic dilemma due to the uncertainty of true complete (pathological) response.

OBJECTIVE

We aimed to examine the diagnostic performance of imaging modalities in detecting true complete response in patients with DLM after chemotherapy.

METHODS

We performed a systematic search for articles assessing the diagnostic performance of imaging modalities in evaluating DLM following chemotherapy. True complete response was defined as 1-year recurrence-free survival in non-resected patients or complete pathological response on histologic examination in resected patients. We calculated the negative predictive value (NPV) for detecting true complete response of each imaging modality using a random effects model.

RESULTS

Thirteen studies comprising 332 patients with at least one DLM were included. The number of DLMs after chemotherapy was 955 with computed tomography (CT), 104 with positron emission tomography (PET), 50 with intraoperative ultrasound (IOUS), 585 with magnetic resonance imaging (MRI), and 175 with contrast-enhanced IOUS (CEIOUS). Substantial variation in study design, patient characteristics, and imaging features was observed. Pooled NPV was 0.79 (95% confidence interval [CI] 0.53-0.96), 0.73 (95% CI 0.58-0.85), 0.54 (95% CI 0.37-0.7), 0.47 (95% CI 0.34-0.61), and 0.22 (95% CI 0.11-0.39) for CEIOUS, MRI, IOUS, CT, and PET, respectively.

CONCLUSION

After chemotherapy, MRI or CEIOUS are the most accurate imaging modalities for assessment of DLM and should be used routinely in this context. Given the high NPV of these two modalities, surgical resection of visible CRLM is warranted if technically possible, even if DLM remain.

Augmented Reality during Open Liver Surgery Using a Markerless Non-rigid Registration System

INTRODUCTION

Intraoperative navigation during liver resection remains difficult and requires high radiologic skills because liver anatomy is complex and patient-specific. Augmented reality (AR) during open liver surgery could be helpful to guide hepatectomies and optimize resection margins but faces many challenges when large parenchymal deformations take place. We aimed to experiment a new vision-based AR to assess its clinical feasibility and anatomical accuracy.

PATIENTS AND METHODS

Based on preoperative CT scan 3-D segmentations, we applied a non-rigid registration method, integrating a physics-based elastic model of the liver, computed in real time using an efficient finite element method. To fit the actual deformations, the model was driven by data provided by a single RGB-D camera. Five livers were considered in this experiment. In vivo AR was performed during hepatectomy (n = 4), with manual handling of the livers resulting in large realistic deformations. Ex vivo experiment (n = 1) consisted in repeated CT scans of explanted whole organ carrying internal metallic landmarks, in fixed deformations, and allowed us to analyze our estimated deformations and quantify spatial errors.

RESULTS

In vivo AR tests were successfully achieved in all patients with a fast and agile setup installation (< 10 min) and real-time overlay of the virtual anatomy onto the surgical field displayed on an external screen. In addition, an ex vivo quantification demonstrated a 7.9 mm root mean square error for the registration of internal landmarks.

CONCLUSION

These first experiments of a markerless AR provided promising results, requiring very little equipment and setup time, yet providing real-time AR with satisfactory 3D accuracy. These results must be confirmed in a larger prospective study to definitively assess the impact of such minimally invasive technology on pathological margins and oncological outcomes.

Consensus report from the 9th International Forum for Liver Magnetic Resonance Imaging: applications of gadoxetic acid-enhanced imaging

Objectives

The 9th International Forum for Liver Magnetic Resonance Imaging (MRI) was held in Singapore in September 2019, bringing together radiologists and allied specialists to discuss the latest developments in and formulate consensus statements for liver MRI, including the applications of gadoxetic acid–enhanced imaging.

Methods

As at previous Liver Forums, the meeting was held over 2 days. Presentations by the faculty on days 1 and 2 and breakout group discussions on day 1 were followed by delegate voting on consensus statements presented on day 2. Presentations and discussions centered on two main meeting themes relating to the use of gadoxetic acid–enhanced MRI in primary liver cancer and metastatic liver disease.

Results and conclusions

Gadoxetic acid–enhanced MRI offers the ability to monitor response to systemic therapy and to assist in pre-surgical/pre-interventional planning in liver metastases. In hepatocellular carcinoma, gadoxetic acid–enhanced MRI provides precise staging information for accurate treatment decision-making and follow-up post therapy. Gadoxetic acid–enhanced MRI also has potential, currently investigational, indications for the functional assessment of the liver and the biliary system. Additional voting sessions at the Liver Forum debated the role of multidisciplinary care in the management of patients with liver disease, evidence to support the use of abbreviated imaging protocols, and the importance of standardizing nomenclature in international guidelines in order to increase the sharing of scientific data and improve the communication between centers.

Key Points

• Gadoxetic acid–enhanced MRI is the preferred imaging method for pre-surgical or pre-interventional planning for liver metastases after systemic therapy.

• Gadoxetic acid–enhanced MRI provides accurate staging of HCC before and after treatment with locoregional/biologic therapies.

• Abbreviated protocols for gadoxetic acid–enhanced MRI offer potential time and cost savings, but more evidence is necessary. The use of gadoxetic acid–enhanced MRI for the assessment of liver and biliary function is under active investigation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-020-07637-4.

Colorectal liver metastases: Current management and future perspectives

The liver is the commonest site of metastatic disease for patients with colorectal cancer, with at least 25% developing colorectal liver metastases (CRLM) during the course of their illness. The management of CRLM has evolved into a complex field requiring input from experienced members of a multi-disciplinary team involving radiology (cross sectional, nuclear medicine and interventional), Oncology, Liver surgery, Colorectal surgery, and Histopathology. Patient management is based on assessment of sophisticated clinical, radiological and biomarker information. Despite incomplete evidence in this very heterogeneous patient group, maximising resection of CRLM using all available techniques remains a key objective and provides the best chance of long-term survival and cure. To this end, liver resection is maximised by the use of downsizing chemotherapy, optimisation of liver remnant by portal vein embolization, associating liver partition and portal vein ligation for staged hepatectomy, and combining resection with ablation, in the context of improvements in the functional assessment of the future remnant liver. Liver resection may safely be carried out laparoscopically or open, and synchronously with, or before, colorectal surgery in selected patients. For unresectable patients, treatment options including systemic chemotherapy, targeted biological agents, intra-arterial infusion or bead delivered chemotherapy, tumour ablation, stereotactic radiotherapy, and selective internal radiotherapy contribute to improve survival and may convert initially unresectable patients to operability. Currently evolving areas include biomarker characterisation of tumours, the development of novel systemic agents targeting specific oncogenic pathways, and the potential re-emergence of radical surgical options such as liver transplantation.

Imaging in disappearing colorectal liver metastases and their accuracy: a systematic review

Background

Approximately 30% of patients with colorectal cancer develop colorectal liver metastases (CRLM). CRLM that become undetectable by imaging after chemotherapy are called disappearing liver metastases (DLM). But a DLM is not necessarily equal to cure. An increasing incidence of patients with DLM provides surgeons with a difficult dilemma: to resect or to not resect the original sites of DLM? The aim of this review was to investigate to what extent a DLM equates a complete response (CR) and to compare outcomes.

Methods

This review was conducted in accordance with the PRISMA guidelines and registered in Prospero (registration number CRD42017070441). Literature search was made in the PubMed and Embase databases. During the process of writing, PubMed was repeatedly searched and reference lists of included studies were screened for additional studies of interest for this review. Results were independently screened by two authors with the Covidence platform. Studies eligible for inclusion were those reporting outcomes of DLM in adult patients undergoing surgery following chemotherapy.

Results

Fifteen studies were included with a total of 2955 patients with CRLM. They had 4742 CRLM altogether. Post-chemotherapy, patients presented with 1561 DLM. Patients with one or more DLM ranged from 7 to 48% (median 19%). Median DLM per patient was 3.4 (range 0.4–5.6). Patients were predominantly evaluated by contrast-enhanced computed tomography (CE-CT) before and after chemotherapy, with some exceptions and with addition of magnetic resonance imaging (MRI) in some studies. Intraoperative ultrasound (IOUS) was universally performed in all but two studies. If a DLM remained undetectable by IOUS, this DLM represented a CR in 24–96% (median 77.5%). Further, if a DLM on preoperative CE-CT remained undetectable by additional workup with MRI and CE-IOUS, this DLM was equal to a CR in 75–94% (median 89%). Patients with resected DLM had a longer disease-free survival compared to patients with DLM left in situ but statistically significant differences in overall survival could not be found.

Conclusion

Combination of CE-CT, MRI, and IOUS showed promising results in accurately identifying DLM with CR. This suggests that leaving DLM in situ could be an alternative to surgical resection when a DLM remains undetectable by MRI and IOUS.

Cleistanthin A induces apoptosis and suppresses motility of colorectal cancer cells

Colorectal cancer (CRC) is a leading cause of cancer-related deaths worldwide. Here, we investigated the molecular mechanisms that underpin the anticancer effects of cleistanthin A (CA) in two CRC cell lines, HCT 116, and SW480. At 48 h, CA exhibited apoptotic cytotoxic effects in both CRC cell lines, concomitant with reduction of an anti-apoptotic protein, survivin. Mechanistically, CA treatment significantly reduced the expression levels of β-catenin and active-β-catenin in a dose-dependent manner in both CRC cell lines. Moreover, CA suppressed the Wnt/β-catenin signaling pathway by decreasing β-catenin-mediated transcriptional activity and expression of β-catenin target genes, AXIN2, CCND1, and survivin. Furthermore, CA also inhibited transcriptional activity in cells overexpressing a constitutively active β-catenin S33Y, indicating a GSK-3β-independent mechanism underlying the observed CA effects on CRC cells. Although cytotoxic activity was not observed with CA treatment at 24 h, cell migration and invasion were significantly reduced. In addition, CA suppressed V-type ATPase activity and focal adhesion kinase (FAK) phosphorylation. Collectively, our study reveals that CA has time-dependent effects on CRC cell phenotypes. First, short-term CA treatment inhibited CRC cell migration and invasion partly through the suppression of V-type ATPase activity. This suppression resulted in reduced FAK activation. Second, longer-term CA treatment decreased cell viability which correlated with the suppression of Wnt/β-catenin signaling induced transcriptional activity. Altogether, our data suggest that CA has the potential to develop as an effective and novel therapeutic drug for CRC patients.

Tumour markers and their utility in imaging of abdominal and pelvic malignancies

The utility of tumour biomarkers has increased considerably in the era of personalised medicine and individualised therapy in oncology. Biomarkers may be prognostic or predictive, and only a handful of markers are currently US Food and Drug Administration (FDA)-approved for clinical use. Tumour markers have a wide array of uses such as screening, establishing a differential diagnosis, assessing risk, prognosis, and treatment response, as well as monitoring disease status. Major overlap exists between biomarkers and their associated pathologies; therefore, despite suggestive imaging features, establishing a differential diagnosis may be challenging for the radiologist. We review common biomarkers that are of interest to radiologists such as carcinoembryonic antigen (CEA), lactate dehydrogenase (LDH), prostate-specific antigen (PSA), beta human chorionic gonadotropin (β-hCG), carbohydrate antigen 19-9 (CA 19-9), alpha fetoprotein (AFP), and carbohydrate or cancer antigen 125 (CA 125), as well as their associated malignant and non-malignant pathologies. We also present relevant case examples from our practice.

Current state of the art imaging approaches for colorectal liver metastasis

One of the most common cancers worldwide, colorectal cancer (CRC) has been associated with significant morbidity and mortality and therefore represents an enormous burden to the health care system. Recent advances in CRC treatments have provided patients with primary and metastatic CRC a better long-term prognosis. The presence of synchronous or metachronous metastasis has been associated, however, with worse survival. The most common site of metastatic disease is the liver. A variety of treatment modalities aimed at targeting colorectal liver metastases (CRLM) has been demonstrated to improve the prognosis of these patients. Loco-regional approaches such as surgical resection and tumor ablation (operative and percutaneous) can provide patients with a chance at long-term disease control and even cure in select populations. Patient selection is important in defining the most suitable treatment option for CRLM in order to provide the best possible survival benefit while avoiding unnecessary interventions and adverse events. Medical imaging plays a crucial role in evaluating the characteristics of CRLMs and disease resectability. Size of tumors, proximity to adjacent anatomical structures, and volume of the unaffected liver are among the most important imaging parameters to determine the suitability of patients for surgical management or other appropriate treatment approaches. We herein provide a comprehensive overview of current-state-of-the-art imaging in the management of CRLM, including staging, treatment planning, response and survival assessment, and post-treatment surveillance. Computed tomography (CT) scan and magnetic resonance imaging (MRI) are two most commonly used techniques, which can be used solely or in combination with functional imaging modalities such as positron emission tomography (PET) and diffusion weighted imaging (DWI). Providing up-to-date evidence on advantages and disadvantages of imaging modalities and tumor assessment criteria, the current review offers a practice guide to assist providers in choosing the most suitable imaging approach for patients with CRLM.

Personalized 3D-Printed Transparent Liver Model Using the Hepatobiliary Phase MRI: Usefulness in the Lesion-by-Lesion Imaging-Pathologic Matching of Focal Liver Lesions-Preliminary Results

PURPOSE

The aim of this study was to investigate the usefulness of a personalized, 3-dimensional (3D)-printed, transparent liver model with focal liver lesions (FLLs) for lesion-by-lesion imaging-pathologic matching.

MATERIALS AND METHODS

This preliminary, prospective study was approved by our institutional review board, and written informed consent was obtained. Twenty patients (male-to-female ratio, 13:7; mean age, 56 years) with multiple FLLs, including at least one presumed malignant, or an indeterminate lesion 10 mm or less on the preoperative gadoxetic acid-enhanced magnetic resonance imaging (MRI), were included. After digital segmentation of hepatobiliary phase MRI, a transparent, 3D-printed liver model with colored anatomical structures and FLLs was produced. During the gross examination of the liver specimen, the per-lesion detection rates were compared between those without (routine protocol) and those with the aid of the 3D-printed liver model.

RESULTS

Among 98 MRI-detected FLLs (11.5 ± 12.5 mm), the per-lesion detection rate on gross examination using the 3D-printed liver model was 99.0% (97/98), which was significantly higher than that obtained on routine examination (82.7% [81/98]; P < 0.001). In the subgroup analysis, according to the tumor size, 23.9% (16/67) of FLLs 10 mm or less were additionally detected using the liver model, whereas none were additionally detected in greater than 10 mm. The additionally detected 16 FLLs in 12 patients included histologic diagnoses of viable metastases, pathologic complete response of metastases, hepatocellular carcinomas, focal nodular hyperplasia-like nodules, and hemangiomas.

CONCLUSIONS

A personalized, 3D-printed liver model with FLLs may improve the lesion-by-lesion imaging-pathologic matching for small FLLs, thus leading to accurate pathologic tumor staging and obtaining a reliable reference for imaging-detected FLLs.

Disappearing liver metastases: A systematic review of the current evidence

Advances in systemic chemotherapy have resulted in a significant increase in the reported response rates of colorectal liver metastases (CRLM) over time. Although radiologic response is usually prognostic of favorable outcomes, complete shrinkage of CRLM after chemotherapy, namely "disappearing liver metastases" (DLMs) poses significant therapeutic dilemmas. A systematic review of the literature was conducted to evaluate the existing evidence on the imaging and management of patients with DLMs using the PubMed (Medline), Embase and Cochrane library through December 21st, 2018. The following algorithm was used: "(disappearing OR vanishing OR missing OR (residual tiny)) AND ((liver OR hepatic) AND (metastasis OR metastases OR metastatic OR secondary))." From the 225 records retrieved, 15 studies were finally deemed eligible. A total of 479 patients with DLMs with a median age of 59.5 years (range, 30-83) were identified. Median number of DLM per patient ranged from 1 to 8.8. Median size of LMs prior to chemotherapy was 1.07 cm (range 0.3-3.5). The systemic treatment used to achieve DLMs included systemic chemotherapy alone (only 2 studies) or in combination with targeted agents (11 studies). The median number of chemotherapy cycles in the included studies was 7.8 (range 6-12). Identified factors predisposing to the development of DLM were small size (<2 cm), increased number of treatment cycles, oxaliplatin-based therapy, increased number of CRLM (≥3) and synchronous CRLM. Baseline and preoperative MRI with iv contrast showed the highest sensitivity for DLM detection. Fiducial placement facilitated pre- and intra-operative identification of DLM. Although resection of DLM decreased the local recurrence risk, there was no clearly demonstrated survival benefit after resecting all sites of disappearing lesions. Future randomized clinical trials are highly encouraged to provide strict, evidence-based recommendations for the treatment of patients with DLM.

Evaluation of a strategy using pretherapeutic fiducial marker placement to avoid missing liver metastases

Background

Hepatic surgery is appropriate for selected patients with colorectal liver metastases (CRLM). Advances in chemotherapy have led to modification of management, particularly when metastases disappear. Treatment should address all initial CRLM sites based on pretherapeutic cross-sectional imaging. This study aimed to evaluate pretherapeutic fiducial marker placement to optimize CRLM treatment.

Methods

This pilot investigation included patients with CRLM who were considered for potentially curative treatment between 2009 and 2016. According to a multidisciplinary team decision, lesions smaller than 25 mm in diameter that were more than 10 mm deep in the hepatic parenchyma and located outside the field of a planned resection were marked. Complication rates and clinicopathological data were analysed.

Results

Some 76 metastases were marked in 43 patients among 217 patients with CRLM treated with curative intent. Of these, 23 marked CRLM (30 per cent), with a mean(s.d.) size of 11·0(3·4) mm, disappeared with preoperative chemotherapy. There were four complications associated with marking: two intrahepatic haematomas, one fiducial migration and one misplacement. After a median follow-up of 47·7 (range 18·1-144·9) months, no needle-track seeding was noted. Of four disappearing CRLM that were marked and resected, two presented with persistent active disease. Other missing lesions were treated with thermoablation.

Conclusion

Pretherapeutic fiducial marker placement appears useful for the curative management of CRLM.

Clinical implications of disappearing colorectal liver metastases have changed in the era of hepatocyte-specific MRI and contrast-enhanced intraoperative ultrasonography

BACKGROUND

Clinical implication of disappearing liver metastases (DLMs) from colorectal cancer after chemotherapy needs to be reviewed in the era of modern imaging studies.

METHODS

Between 2010 and 2015, 184 patients underwent curative hepatectomy for colorectal liver metastases following preoperative chemotherapy. The sites of metastases detected on pre-chemotherapy CE-CT were examined post-chemotherapy using CE-CT, gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI), and contrast-enhanced intraoperative ultrasonography (CE-IOUS). DLMs were defined as tumors that disappeared on CE-CT post chemotherapy. The detection rate of DLMs with EOB-MRI and CE-IOUS were assessed, and the outcome of DLMs resected and those left in place were reviewed.

RESULTS

A total of 275 DLMs were noted in 59 patients. On EOB-MRI, 71 lesions (26%) were visible and were resected, 92% (65/71) of which contained viable disease. Using CE-IOUS, an additional 94 lesions were identified. A total of 165 DLMs (60%) were identified and resected by sequential use of EOB-MRI and CE-IOUS, 77% (127/165) of which contained viable disease. Of 110 DLMs not identified, 68 were resected, 4% (3/68) of which contained viable disease. Among 42 lesions left in place, 6 (14%) recurred during the median follow-up period of 27 (9-72) months.

DISCUSSION

EOB-MRI and CE-IOUS exploration identified clinically relevant DLMs containing viable disease with a high level of accuracy.

Management of disappearing lesions after chemotherapy for colorectal liver metastases: Relation between detectability and residual tumors

BACKGROUND AND OBJECTIVES

To clarify the detectability of gadolinium ethoxybenzyl diethylene-triamine pantaacetic acid enhanced magnetic resonance imaging (EOB-MRI) and contrast-enhanced intraoperative-ultrasonography (CE-IOUS) for residual disease in disappearing colorectal liver metastases (DLMs) and to seek a better management for DLMs.

METHODS

Eighty-two patients who underwent hepatectomy after chemotherapy for colorectal liver metastases were retrospectively reviewed. Lesions which disappear on post-chemotherapy contrast-enhance CT were defined as DLMs. All the patients underwent EOB-MRI and CE-IOUS. With pathologic evaluation for resected specimens and clinical observation of anatomically corresponding site for non-resected lesions, detectability of residual disease in DLMs were estimated between these two imaging modalities.

RESULTS

Twenty (18%) patients presented with 111 DLMs, and EOB-MRI and CE-IOUS identified 64 (57.6%) and 62 (55.9%), respectively. Residual disease was pathologically confirmed for 69.2% in resected specimens and clinically estimated in 33.3% for non-resected DLMs. EOB-MRI showed a higher accuracy of prediction of residual disease compared with CE-IOUS (0.90 vs 0.70). Of the 11 non-resected lesions which were undetected with CE-IOUS and regrew after surgery, 9 (81.8%) were detected on EOB-MRI.

CONCLUSIONS

EOB-MRI may be superior to CE-IOUS in detecting residual tumors for DLMs. Maximum attempt of resection would be needed for visualized lesions in EOB-MRI.

Hepatic Metastasis from Colorectal Cancer

The liver is the most common site of metastasis in patients with colorectal cancer due to its anatomical situation regarding its portal circulation. About 14 to 18% of patients with colorectal cancer present metastasis at the first medical consultation, and 10 to 25% at the time of the resection of the primary colorectal cancer. The incidence is higher (35%) when a computed tomography (CT) scan is used.

In the last decades, a significant increase in the life expectancy of patients with colorectal cancer has been achieved with different diagnostic and treatment programs. Despite these improvements, the presence of metastasis, disease recurrence, and advanced local tumors continue to remain poor prognostic factors.

Median survival without treatment is <8 months from the moment of its presentation, and a survival rate at 5 years of 11% is the best prognosis for those who present with local metastasis. Even in patients with limited metastatic disease, 5-year survival is exceptional. Patients with hepatic metastasis of colorectal cancer have a median survival of 5 to 20 months with no treatment. Approximately 20 to 30% of patients with colorectal metastasis have disease confined to the liver, and this can be managed with surgery. Modern surgical strategies at the main hepatobiliary centers have proved that hepatectomy of 70% of the liver can be performed, with a mortality rate of <5%.

It is very important to have knowledge of predisposing factors, diagnostic methods, and treatment of hepatic metastasis. However, the establishment of newer, efficient, preventive screening programs for early diagnosis and adequate treatment is vital.

How to cite this article: Valderrama-Treviño AI, Barrera-Mera B, Ceballos-Villalva JC, Montalvo-Javé EE. Hepatic Metastasis from Colorectal Cancer. Euroasian J Hepato-Gastroenterol 2017;7(2):166-175.