Imaging in resectable colorectal liver metastasis patients with or without preoperative chemotherapy: results of the PROMETEO-01 study

Efficacy of first-line radiofrequency ablation combined with systemic chemotherapy plus targeted therapy for initially unresectable colorectal liver metastases

BACKGROUND/OBJECTIVE

The optimal strategy for patients with colorectal liver metastases is still controversially discussed. This study aimed to evaluate the efficacy of radiofrequency ablation (RFA) combined with systemic chemotherapy plus targeted therapy as first-line treatment in patients with initially unresectable colorectal liver metastases (CRLM), to identify prognostic factors and construct nomograms predicting survival.

METHODS

This retrospective study included patients with initially unresectable CRLM treated with (study group n = 74) or without (control group n = 83) RFA at the National Cancer Center from January 2018 to January 2021. Survival curves were assessed using the Kaplan-Meier method and log-rank test. Univariate and multivariate Cox regression analyses were used to determine prognostic factors and include these factors in the nomograms to predict progression-free survival (PFS) and overall survival (OS).

RESULTS

The study group had significantly better median PFS (17.16 months vs. 8.35 months, p < 0.01) and OS (34.9 months vs. 21.1 months, p < 0.01) than the control group after propensity score matching. Cox regression analyses identified RFA treatment and clinical risk score (CRS) as independent prognostic factors for PFS. The largest diameter of liver metastases, RFA treatment, and CRS were independent prognostic factors for OS. Based on this finding, nomograms with good discrimination and calibration were constructed.

CONCLUSION

RFA combined with systemic chemotherapy plus targeted therapy as first-line treatment could significantly prolong PFS and OS in patients with initially unresectable CRLM compared with systemic chemotherapy plus targeted therapy. The nomograms predicting PFS and OS might help clinicians select personalized treatment.

EORTC consensus recommendations on the optimal management of colorectal cancer liver metastases

Patients with colorectal cancer liver metastases have long represented a unique and thoroughly investigated population. Nevertheless, the optimal management of these is still controversial with a number of open questions which are only partially addressed by available studies and existing guidelines. The European Organisation for Research and Treatment of Cancer (EORTC) Gastrointestinal Tract Cancer Group (GITCG) sought to fill this knowledge gap and promoted the development of a European consensus on this subject. By using the Delphi methodology and leveraging a multidisciplinary team of 43 international experts, including gastrointestinal oncologists, hepatobiliary surgeons, interventional radiologists, radiation oncologists, radiologists, nuclear medicine physicians and pathologists from 12 European countries, 34 practical recommendations and two consensus statements were proposed. These cover varying aspects of the optimal management of colorectal cancer liver metastases such as baseline imaging, selection criteria for liver-directed therapies, treatment strategies, assessment of treatment response, follow-up, care delivery, clinical research and future perspectives. This roadmap document is intended to complement national and international guidelines, and to provide practical guidance for clinicians and multidisciplinary teams, ultimately promoting practice standardisation, optimal management and better patient outcomes across Europe. Also, it provides a unique opportunity to highlight grey areas and unmet needs, and to give a strategic direction to future research in the field by identifying topics where there is no consensus among experts.

Early Recurrence of Colorectal Liver Metastasis (Number ≤ 5 and Largest Diameter ≤ 3 cm) after Resection or Thermal Ablation: a Multi-center Study of Patterns, Safety, Survival and Risk Factors

OBJECTIVE

To compare early recurrence patterns, safety, survival and investigate the clinical risk factors of early recurrence (ER) after liver resection or thermal ablation (TA) for patients with colorectal liver metastases (CRLM) with number ≤ 5 and largest diameter ≤ 3 cm.

MATERIALS AND METHODS

This retrospective study included patients with CRLM who underwent liver resection or TA between January 2016 and December 2021 at two hospitals in China. The Kaplan-Meier method and log-rank test were used to assess recurrence-free survival (RFS) and overall survival (OS). Risk factors for ER were analysed using univariate and multivariate Cox regression analyses.

RESULTS

303 patients with 632 liver metastases were enrolled. The most common early recurrence pattern was intrahepatic recurrence (IHR) in resection group and TA group. There was no significant difference in 6-month RFS rate (65.81% vs 66.23%) and median OS (P = 0.10) between two groups. Patients without ER had better OS than those with ER (P < 0.05). The incidence of serious complications (P = 0.013), length of hospitalization (P < 0.01), and albumin-bilirubin (ALBI) score (P = 0.038) in TA group were significantly better than resection group. The diameter of liver metastases (HR: 4.89, 95% CI: 1.16-20.60; P = 0.031) and clinical risk score (CRS) (HR: 1.86, 95% CI: 1.06-3.25; P = 0.029) were independent risk factors for ER.

CONCLUSION

For CRLM with largest diameter ≤ 3 cm and number ≤ 5, the efficacy of receiving resection or TA is comparable, and the safety of TA is better. TA may be considered as the first-line local treatment option for patients with CRLM.

Resection of colorectal carcinoma liver metastases: A population-based study in outcomes and factors associated with recurrent disease

OBJECTIVE

To assess the hepatic disease-free survival (HDFS) and overall survival (OS) of patients who underwent resection of colorectal cancer liver metastases (CRCLM) in our population, and evaluate what factors are associated with these outcomes.

METHODS

Patients with resected non-mucinous CRCLM between January 2013-February 2020 were retrospectively identified. Dates of diagnosis, surgery, and, if applicable, death were recorded. HDFS and OS were calculated using a census date of 24 September 2022. Separate Cox multivariate regression analyses were performed to evaluate for association between HDFS and OS and the following factors: pre-operative imaging interval (<4 weeks vs. ≥4 weeks); pre-operative imaging modality (CT only vs. MRI+CT); extrahepatic disease at time of hepatectomy (yes vs. no); tumor burden score (TBS, where TBS2 = (largest axial dimension of CRCLM)2 + (number of CRCLM)2); pT and pN; and neoadjuvant chemotherapy.

RESULTS

137 subjects (mean age, 61 ± 11 years, 86 males) were included. Associations with recurrent hepatic disease were found with chemotherapy (HR 2.11[95 % CI = 1.13-3.92]), TBS (HR 1.30[95 % CI = 1.17-1.45]), MRI+CT (HR 2.12[95 % CI = 1.29-3.48]), and extrahepatic disease at hepatectomy (HR 2.16[95 % CI = 1.08-4.35]). For mortality, associations were found with TBS (HR 1.22[95 % CI = 1.09-1.37]), pT (HR 1.45[95 % CI = 1.05-2.00]), and extrahepatic disease at hepatectomy (HR 2.10[95 % CI = 1.31-3.36]).

CONCLUSION

In our population, non-imaging related factors TBS, neoadjuvant chemotherapy, pT and presence of extrahepatic disease at time of hepatectomy were associated with HDFS and/or OS. The preoperative imaging interval and use of preoperative MRI were not associated with improved patient outcomes.

Imaging Considerations before and after Liver-Directed Locoregional Treatments for Metastatic Colorectal Cancer

Colorectal cancer is a leading cause of cancer-related death. Liver metastases will develop in over one-third of patients with colorectal cancer and are a major cause of morbidity and mortality. Even though surgical resection has been considered the mainstay of treatment, only approximately 20% of the patients are surgical candidates. Liver-directed locoregional therapies such as thermal ablation, Yttrium-90 transarterial radioembolization, and stereotactic body radiation therapy are pivotal in managing colorectal liver metastatic disease. Comprehensive pre- and post-intervention imaging, encompassing both anatomic and metabolic assessments, is invaluable for precise treatment planning, staging, treatment response assessment, and the prompt identification of local or distant tumor progression. This review outlines the value of imaging for colorectal liver metastatic disease and offers insights into imaging follow-up after locoregional liver-directed therapy.

Colon cancer: the 2023 Korean clinical practice guidelines for diagnosis and treatment

Colorectal cancer is the third most common cancer in Korea and the third leading cause of death from cancer. Treatment outcomes for colon cancer are steadily improving due to national health screening programs with advances in diagnostic methods, surgical techniques, and therapeutic agents.. The Korea Colon Cancer Multidisciplinary (KCCM) Committee intends to provide professionals who treat colon cancer with the most up-to-date, evidence-based practice guidelines to improve outcomes and help them make decisions that reflect their patients' values and preferences. These guidelines have been established by consensus reached by the KCCM Guideline Committee based on a systematic literature review and evidence synthesis and by considering the national health insurance system in real clinical practice settings. Each recommendation is presented with a recommendation strength and level of evidence based on the consensus of the committee.

Added Value of Liver MRI in Patients Eligible for Surgical Resection or Ablation of Colorectal Liver Metastases Based on CT: A Systematic Review and Meta-Analysis

Background

Abdominal computed tomography (CT) is the standard imaging modality for detection and staging in patients with colorectal liver metastases (CRLM). Although liver magnetic resonance imaging (MRI) is superior to CT in detecting small lesions, guidelines are ambiguous regarding the added value of an additional liver MRI in the surgical workup of patients with CRLM. Therefore, this systematic review and meta-analysis aimed to evaluate the clinical added value of liver MRI in patients eligible for resection or ablation of CRLM based on CT.

Methods

A systematic search was performed in the PubMed, Embase, and Cochrane Library databases through June 23, 2023. Studies investigating the impact of additional MRI on local treatment plan following CT in patients with CRLM were included. Risk of bias was assessed using the QUADAS-2 tool. The pooled weighted proportions for the primary outcome were calculated using random effect meta-analysis.

Results

Overall, 11 studies with 1440 patients were included, of whom 468 patients (32.5%) were assessed for change in local treatment plan. Contrast-enhanced liver MRI was used in 10 studies, including gadoxetic acid in 9 studies. Liver MRI with diffusion-weighted imaging was used in 8 studies. Pooling of data found a 24.12% (95% confidence interval, 15.58%-32.65%) change in the local treatment plan based on the added findings of liver MRI following CT. Sensitivity analysis including 5 studies (268 patients) focusing on monophasic portal venous CT followed by gadoxetic acid-enhanced liver MRI with diffusion-weighted imaging showed a change of local treatment plan of 17.88% (95% confidence interval, 5.14%-30.62%).

Conclusions

This systematic review and meta-analysis found that liver MRI changed the preinterventional local treatment plan in approximately one-fifth of patients eligible for surgical resection or ablation of CRLM based on CT. These findings suggest a clinically relevant added value of routine liver MRI in the preinterventional workup of CRLM, which should be confirmed by large prospective studies.

MRI in addition to CT in patients scheduled for local therapy of colorectal liver metastases (CAMINO): an international, multicentre, prospective, diagnostic accuracy trial

BACKGROUND

Guidelines are inconclusive on whether contrast-enhanced MRI using gadoxetic acid and diffusion-weighted imaging should be added routinely to CT in the investigation of patients with colorectal liver metastases who are scheduled for curative liver resection or thermal ablation, or both. Although contrast-enhanced MRI is reportedly superior than contrast-enhanced CT in the detection and characterisation of colorectal liver metastases, its effect on clinical patient management is unknown. We aimed to assess the clinical effect of an additional liver contrast-enhanced MRI on local treatment plan in patients with colorectal liver metastases amenable to local treatment, based on contrast-enhanced CT.

METHODS

We did an international, multicentre, prospective, incremental diagnostic accuracy trial in 14 liver surgery centres in the Netherlands, Belgium, Norway, and Italy. Participants were aged 18 years or older with histological proof of colorectal cancer, a WHO performance status score of 0-4, and primary or recurrent colorectal liver metastases, who were scheduled for local therapy based on contrast-enhanced CT. All patients had contrast-enhanced CT and liver contrast-enhanced MRI including diffusion-weighted imaging and gadoxetic acid as a contrast agent before undergoing local therapy. The primary outcome was change in the local clinical treatment plan (decided by the individual clinics) on the basis of liver contrast-enhanced MRI findings, analysed in the intention-to-image population. The minimal clinically important difference in the proportion of patients who would have change in their local treatment plan due to an additional liver contrast-enhanced MRI was 10%. This study is closed and registered in the Netherlands Trial Register, NL8039.

FINDINGS

Between Dec 17, 2019, and July 31, 2021, 325 patients with colorectal liver metastases were assessed for eligibility. 298 patients were enrolled and included in the intention-to-treat population, including 177 males (59%) and 121 females (41%) with planned local therapy based on contrast-enhanced CT. A change in the local treatment plan based on liver contrast-enhanced MRI findings was observed in 92 (31%; 95% CI 26-36) of 298 patients. Changes were made for 40 patients (13%) requiring more extensive local therapy, 11 patients (4%) requiring less extensive local therapy, and 34 patients (11%) in whom the indication for curative-intent local therapy was revoked, including 26 patients (9%) with too extensive disease and eight patients (3%) with benign lesions on liver contrast-enhanced MRI (confirmed by a median follow-up of 21·0 months [IQR 17·5-24·0]).

INTERPRETATION

Liver contrast-enhanced MRI should be considered in all patients scheduled for local treatment for colorectal liver metastases on the basis of contrast-enhanced CT imaging.

FUNDING

The Dutch Cancer Society and Bayer AG - Pharmaceuticals.

Artificial Intelligence to Early Predict Liver Metastases in Patients with Colorectal Cancer: Current Status and Future Prospectives

BACKGROUND

Artificial Intelligence (AI)-based analysis represents an evolving medical field. In the last few decades, several studies have reported the diagnostic efficiency of AI applied to Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) to early detect liver metastases (LM), mainly from colorectal cancer. Despite the increase in information and the development of different procedures in several radiological fields, an accurate method of predicting LM has not yet been found. This review aims to compare the diagnostic efficiency of different AI methods in the literature according to accuracy, sensibility, precision, and recall to identify early LM.

METHODS

A narrative review of the literature was conducted on PubMed. A total of 336 studies were screened.

RESULTS

We selected 17 studies from 2012 to 2022. In total, 14,475 patients were included, and more than 95% were affected by colorectal cancer. The most frequently used imaging tool to early detect LM was found to be CT (58%), while MRI was used in three cases. Four different AI analyses were used: deep learning, radiomics, machine learning, and fuzzy systems in seven (41.18%), five (29.41%), four (23.53%), and one (5.88%) cases, respectively. Four studies achieved an accuracy of more than 90% after MRI and CT scan acquisition, while just two reported a recall rate ≥90% (one method using MRI and CT and one CT).

CONCLUSIONS

Routinely acquired radiological images could be used for AI-based analysis to early detect LM. Simultaneous use of radiomics and machine learning analysis applied to MRI or CT images should be an effective method considering the better results achieved in the clinical scenario.

Liver transplantation for isolated unresectable colorectal liver metastases - Protocol for a service evaluation in the United Kingdom - UKCoMET study

BACKGROUND

Liver transplantation (LT) for unresectable colorectal liver metastases (CRCLM) demonstrates good overall survival for selected patients in contemporary studies, with 5-year survival of 80%. A Fixed Term Working Group (FTWG), set up by NHS Blood and Transplant (NHSBT) Liver Advisory Group (LAG), advised whether CRCLM should be considered for LT in United Kingdom. Their recommendation was that LT may be undertaken for isolated and unresectable CRCLM using strict selection criteria as a national clinical service evaluation.

METHODS

Opinions were sought from colorectal cancer/LT patient representatives, experts in colorectal cancer surgery/oncology, LT surgery, hepatology, hepatobiliary radiology, pathology, and nuclear medicine, and appropriate patient selection criteria, referral and transplant listing pathways were identified.

RESULTS

This paper summarises selection criteria for LT in United Kingdom for isolated and unresectable CRCLM patients, and highlights referral framework and pre-transplant assessment criteria. Finally, oncology-specific outcome measures to be utilised for assessing applicability of LT are described.

CONCLUSION

This service evaluation represents a significant development for colorectal cancer patients in United Kingdom and a meaningful step forward in the field of transplant oncology. This paper details the protocol for the pilot study, scheduled to begin in the fourth quarter of 2022 in United Kingdom.

Oxaliplatin-Induced Sinusoidal Obstruction Syndrome Masquerading as Colorectal Liver Metastasis: A Case Report

INTRODUCTION

Oxaliplatin-based chemotherapy is commonly used in adjuvant treatment of colon cancer as well as in neoadjuvant setting in patients with liver metastases. However oxaliplatin can cause damage to non-tumor bearing liver which presents as sinusoidal obstructive syndrome (SOS). These changes are difficult to differentiate from metastasis clinic-radiologically and manifests as sinusoidal dilatation, peliosis and nodular regenerative hyperplasia.

CASE

The present study reports the case of a patient with oxaliplatin-induced SOS which mimicked colo-rectal liver metastasis on follow up imaging studies after receiving neoadjuvant oxaliplatin based chemotherapy. After multidisciplinary discussion, patient was planned for simultaneous resection of rectal primary and right hepatectomy for metastasis. Final histopathology revealed no tumour in liver but the liver lesions seen radiologically were actually changes of oxaliplatin induced focal SOS and mimicked metastatic nodules.

CONCLUSION

In patients with colo-rectal cancer having received oxaliplatin-based chemotherapy, SOS may be considered as one of the causes of newly developed liver lesions, and should be subjected to additional radio-pathologic evaluation to prevent overtreatment and avoiding potentially morbid surgeries.

[18F]FDG PET/CT versus [18F]FDG PET/MRI for the diagnosis of colorectal liver metastasis: A systematic review and meta-analysis

Purpose

The purpose of our meta-analysis and systematic review was to compare the diagnostic performance of [18F]FDG PET/CT and [18F]FDG PET/MRI in colorectal liver metastasis.

Methods

We searched PubMed, Embase, and Web of Science for eligible articles until November 2022. Studies focusing on the diagnostic value of [18F]FDG PET/CT or PET/MRI for colorectal liver metastasis were included. Using a bivariate random-effect model, the pooled sensitivity and specificity for [18F]FDG PET/CT and [18F]FDG PET/MRI were reported as estimates with 95% confidence intervals (CIs). Heterogeneity among pooled studies was assessed using the I² statistic. The Quality Assessment of Diagnostic Performance Studies (QUADAS-2) method was used to evaluate the quality of the studies that were included.

Results

There were a total of 2743 publications identified in the initial search, finally, a total of 21 studies comprising 1036 patients were included. The pooled sensitivity, specificity, and AUC of [18F]FDG PET/CT in were 0.86 (95% CI: 0.76-0.92), 0.89 (95% CI: 0.83-0.94), and 0.92(95% CI: 0.90-0.94). [18F]FDG PET/MRI were 0.84 (95% CI: 0.77-0.89), 1.00 (95% CI: 0.32-1.00), and 0.89(95% CI: 0.86-0.92), respectively.

Conclusion

[18F]FDG PET/CT shows similar performance compared to [18F]FDG PET/MRI in detecting colorectal liver metastasis. However, pathological results were not obtained for all patients in the included studies and PET/MRI results were derived from studies with small sample sizes. There is a need for additional, larger prospective studies on this issue.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier (CRD42023390949).

Clinical value of fluorine-18-fluorodeoxyglucose PET/MRI for liver metastasis in colorectal cancer: a prospective study

PURPOSE

To evaluate the diagnostic performance of liver 18F-FDG PET/MRI in addition to whole-body PET/CT and to compare it with MRI in the detection and clinical management of liver metastasis in patients with colorectal cancer (CRC).

MATERIAL AND METHODS

Seventy-eight patients with CRC who underwent whole-body 18F-FDG PET/CT followed by liver PET/MRI were prospectively included. Histopathological confirmation and/or at least 3 months of clinical follow-up after PET/MRI were accepted as gold standard. Lesion and patient-based analyses were performed to evaluate the diagnostics performances of PET/CT, PET/MRI and MRI. In addition, changes of clinical management were evaluated.

RESULTS

On lesion-based analysis, for PET/CT, PET/MRI and MRI; sensitivity (Se): 55.6%, 97.2% and 100%; specificity (Sp): 98.5%, 100% and 80.5%; and accuracy (Acc): 70.7%, 98.2% and 93.1% were calculated, respectively. Se and Acc of PET/MRI and MRI were significantly superior than PET/CT (P < 0.001). Se and Acc of PET/MRI and MRI were comparable; however, Sp of PET/MRI was significantly better than MRI (P < 0.001). On patient-based analysis, Se: 75.6%, 100% and 100%; Sp: 97.3%, 100% and 86.5%; and Acc: 85.9%, 100% and 93.5% were calculated, respectively. Se and Acc of PET/MRI were significantly superior than PET/CT (P < 0.001). Also, Se of MRI was significantly superior than PET/CT (P < 0.001). Se of PET/MRI and MRI were comparable, but Sp and Acc of PET/MRI were significantly better than MRI. The additional information obtained from liver PET/MRI changed treatment strategy in 14/78 (18%) patients compared to PET/CT or alone liver MRI.

CONCLUSION

Diagnostic performances of PET/MRI and MRI for detection of CRC liver metastasis is superior to PET/CT. PET/MRI especially helps in the accurate detection of liver metastases that are suspicious on MRI and has the potential to change the clinical management of especially oligometastatic patients by identifying uncertain liver lesions.

Contrast-Enhanced Ultrasound With SonoVue and Sonazoid for the Diagnosis of Colorectal Liver Metastasis After Chemotherapy

PURPOSE

To compare the diagnostic efficacy of SonoVue and Sonazoid contrast-enhanced ultrasound (CEUS) in correctly detecting and characterizing colorectal liver metastasis (CRLM) after chemotherapy.

MATERIALS AND METHODS

Patients with CRLMs treated with chemotherapy and subsequently scheduled for hepatic resection were prospectively enrolled from April 2020 to January 2021. Lesions detected by SonoVue or Sonazoid CEUS were recorded as and characterized as metastases or non-metastatic lesions respectively. Histopathology or intraoperative ultrasound with MRI were the reference standard.

RESULTS

A total of 348 focal liver lesions in 42 patients were investigated, including 297 CRLMs and 51 non-metastatic lesions. SonoVue showed significantly higher diagnostic accuracy (64.7% versus 54.0%; P < .001) and sensitivity (63.3% versus 50.5%; P < .001) in the diagnosis of CRLMs than Sonazoid, both methods presented with similar specificity (72.5% versus 74.5%; P = 1.0). Forty metastases appeared non-hypoenhancing (hyperenhancing or isoenhancing) in the late phase and postvascular phase of Sonazoid CEUS and were mischaracterized as benign lesions.

CONCLUSION

SonoVue performed significantly better than Sonazoid in the diagnosis of CRLMs after chemotherapy.

Utility and specificity of plasma heat shock protein 90 alpha, CEA, and CA199 as the diagnostic test in colorectal cancer liver metastasis

BACKGROUND

Plasma heat shock protein 90 alpha (Hsp90α) has been suggested as a novel biomarker for the diagnosis and prognosis of cancer. Carcinoembryonic antigen (CEA) and carbohydrate antigen199 (CA199) are traditional tumor biomarkers for colorectal cancer (CRC). Previous studies have shown that Hsp90α and the combination of Hsp90α and CEA are optimal biomarkers for CRC at an early stage. However, research on the use of Hsp90α alone or in combination with CEA and/or CA199 in diagnosing CRC development, particularly liver metastasis, is limited. This study sought to investigate the value of Hsp90α alone or in combination with CEA/CA199 in diagnosing CRC liver metastasis.

METHODS

The clinical data of 472 CRC patients were retrospectively analyzed, which were confirmed by clinical manifestations and a histopathological examination associated with an imaging diagnosis. The levels of Hsp90α, and CEA, and CA199 were assessed by enzyme-linked immunoassays and electrochemiluminescence immunoassays. Liver metastasis was diagnosed by imaging or pathology of the liver. Logistic regression models were used to analyze associations between Hsp90α, CEA, and CA199, and liver metastasis in CRC. The areas under the curves (AUCs) were used to compare the utility of Hsp90α, CEA, and CA199 in the diagnosis of CRC liver metastasis (CRLM). Additionally, we compared the diagnostic utility of the models, including the Hsp90α plus 1 of the other serum markers, and a combination of the 3 serum makers.

RESULTS

The plasma levels of Hsp90α, CEA, and CA199 were positively associated with a higher risk of CRLM [odds ratios (OR) ranging from 1.36-2.72]. The AUCs of CEA, CA199, and Hsp90α for CRLM were 0.80, 0.69, and 0.55, respectively. The AUCs for the combination of Hsp90α and CEA, combination of Hsp90α and CA199, combinations of Hsp90α, CEA, and CA199 were 0.75, 0.66, 0.76, respectively. The combination of Hsp90α, CEA, and CA199 did not improve the diagnostic utility for liver metastasis in CRC.

CONCLUSIONS

The level of Hsp90α was elevated in CRC and was associated with CRLM. Thus, the Hsp90α is a potential biomarker for CRLM. CEA has the largest diagnostic utility for CRLM. Adding Hsp90α to CEA/CA199 did not improve their diagnostic utility for CRLM.

Impact of baseline gadoxetic acid-enhanced liver magnetic resonance and diffusion-weighted imaging in resectable colorectal liver metastases: A prospective, monocentric study

BACKGROUND

Liver magnetic resonance imaging (MRI) utilizing hepatocyte-specific contrast agent and diffusion-weighted imaging (DWI) is currently used to properly stage colorectal liver metastases (CRLM) in patients candidate to liver surgery. However, the added value of liver MRI in choosing the treatment strategy in resectable CRLM over computed tomography (CT)-scan is not clear.

PATIENTS AND METHODS

This is a prospective monocentric collection of consecutive cases of patients with CRLM conceived with the aim to assess the added value of liver MRI in changing the initial treatment strategy planned according to CT-scan. Potential changes in the initially planned strategy were defined as: - from upfront surgery to perioperative chemotherapy (fluoropyrimidine and oxaliplatin) - from upfront surgery to first-line systemic therapy (doublet or triplet plus a biological agent) - from perioperative chemotherapy to first-line systemic therapy. Hypothesising that MRI may induce a change in the choice of the treatment strategy in the 20% of cases (alternative hypothesis), against a null hypothesis of 5%, with one-tailed alpha and beta errors of 0.05 and 0.20 respectively, 27 patients were needed. The added value of liver MRI would have been considered clinically meaningful if at least 4 changes in the treatment strategy were observed.

RESULTS

Among 27 enrolled patients, upfront surgery and perioperative chemotherapy strategies were chosen in 17 (63%) and 10 (37%) cases, respectively, based on CT-scan. After liver MRI, additional liver lesions were found in 8 patients (30%) and the initial strategy was changed in 7 patients (26%) (4 initially deemed candidate to upfront surgery and 3 initially sent to perioperative chemotherapy) that were treated with first-line systemic therapy.

CONCLUSIONS

Our results support the indication of the current guidelines on the routine use of liver MRI in the initial workup of patients with resectable CRLM with an MRI-driven changes of initial treatment plan in a relevant percentage of cases.

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.

Early Diagnosis of Liver Metastases from Colorectal Cancer through CT Radiomics and Formal Methods: A Pilot Study

BACKGROUND

Liver metastases are a leading cause of cancer-associated deaths in patients affected by colorectal cancer (CRC). The multidisciplinary strategy to treat CRC is more effective when the radiological diagnosis is accurate and early. Despite the evolving technologies in radiological accuracy, the radiological diagnosis of Colorectal Cancer Liver Metastases (CRCLM) is still a key point. The aim of our study was to define a new patient representation different by Artificial Intelligence models, using Formal Methods (FMs), to help clinicians to predict the presence of liver metastasis when still undetectable using the standard protocols.

METHODS

We retrospectively reviewed from 2013 to 2020 the CT scan of nine patients affected by CRC who would develop liver lesions within 4 months and 8 years. Seven patients developed liver metastases after primary staging before any liver surgery, and two patients were enrolled after R0 liver resection. Twenty-one patients were enrolled as the case control group (CCG). Regions of Interest (ROIs) were identified through manual segmentation on the medical images including only liver parenchyma and eventual benign lesions, avoiding major vessels and biliary ducts. Our predictive model was built based on formally verified radiomic features.

RESULTS

The precision of our methods is 100%, scheduling patients as positive only if they will be affected by CRCLM, showing a 93.3% overall accuracy. Recall was 77.8%.

CONCLUSION

FMs can provide an effective early detection of CRCLM before clinical diagnosis only through non-invasive radiomic features even in very heterogeneous and small clinical samples.

Intraoperative (Contrast-Enhanced) Ultrasound Has the Highest Diagnostic Accuracy of Any Imaging Modality in Resection of Colorectal Liver Metastases

AIM

Defining sensitivity, specificity, diagnostic accuracy for detection of colorectal liver metastases in imaging compared to intraoperative assessment. Defining a cutoff, where accuracy of detection is impaired.

METHODS

Prospective single-institution clinical trial (clinicaltrials.gov: NCT01522209). Patients underwent CEUS, MDCT, and 3 Tesla EOB-MRI within 2 weeks preoperatively. Intraoperative palpation, IOUS, and CEIOUS were performed. A patient and lesion-based database was analyzed for accuracy of detection of CEUS, CT, MRI, and Palp/IOUS/CEIOUS combined read. Histology was standard of reference.

RESULTS

Forty-seven high tumor load (mean 5, 4 lesions) patients were analyzed. Histopathology confirmed 264 lesions (245 malignant: 19 benign). Accuracy for detection of all lesions: CEUS 63%, CT 71%, MRI 92%, and PALP/IOUS/CEIOUS 98%. ROC analysis for lesion size showed severe impairment of accuracy in lesion detection smaller than 5mm. Intraoperative imaging was not impaired by lesion size. Patient-based analysis revealed a change of resection plan after IOUS/CEIOUS in 35% of patients.

CONCLUSION

At 5-mm lesion size, preoperative imaging shows a drop in accuracy of detection. In patients with multiple lesions, addition of MRI to MDCT seems useful. Accuracy of intraoperative ultrasound is not impacted by lesion size and should be mandatory. CEIOUS can improve intraoperative decision-making.

TRIAL REGISTRATION

Study registered with clinicaltrials.gov : NCT01522209.

Long Term Survival Analysis in a Cohort of 125 Patients with Hepatocellular Carcinoma Treated with Transarterial Chemoembolization Using Small Drug Eluting Beads

PURPOSE

Different types of drug-eluting beads have been proposed for hepatocellular carcinoma (HCC) treatment, but long-term results are not well known. We report safety, efficacy and long-term overall survival of HCC patients not amenable of curative therapies treated with transcatheter arterial chemoembolization (TACE) using drug-eluting beads sized 70-150 micron.

MATERIALS AND METHODS

This single-center retrospective study included 125 patients with Barcelona Clinic Liver Cancer stage A (80), B (45) and compensated cirrhosis. TACE was executed injecting drug-elutings microparticles loaded with 75 mg of Doxorubicine and was repeated in patients with partial response or stable disease after one month. Adverse events, response according to modified Response Evaluation Criteria in Solid Tumors and overall survival were assessed.

RESULTS

Chemoembolization with 70-150 micron beads revealed an objective response rate of 88% according to mRECIST criteria and complete response was 60%. After a median follow-up of 53.3 months, overall survival was 36.6 months. Data were censored at the date of liver transplantation in 35 patients. 33 on 125 patients (26,4%) experienced at least one adverse event. We recorded a total of 102 adverse events and 18 were of a high grade (G3-G4). 30 day mortality was 0%.

CONCLUSION

Chemoembolization with very small particles (70-150 µm) is an effective and safe treatment in unresectable HCC both as a primary therapy or as bridge to transplantation.

Liver transplantation for non-resectable colorectal liver metastases: the International Hepato-Pancreato-Biliary Association consensus guidelines

Colorectal cancer is a prevalent disease worldwide, with more than 50% of patients developing metastases to the liver. Despite advances in improving resectability, most patients present with non-resectable colorectal liver metastases requiring palliative systemic therapy and locoregional disease control strategies. There is a growing interest in the use of liver transplantation to treat non-resectable colorectal liver metastases in well selected patients, leading to a surge in the number of studies and prospective trials worldwide, thereby fuelling the emerging field of transplant oncology. The interdisciplinary nature of this field requires domain-specific evidence and expertise to be drawn from multiple clinical specialities and the basic sciences. Importantly, the wider societal implication of liver transplantation for non-resectable colorectal liver metastases, such as the effect on the allocation of resources and national transplant waitlists, should be considered. To address the urgent need for a consensus approach, the International Hepato-Pancreato-Biliary Association commissioned the Liver Transplantation for Colorectal liver Metastases 2021 working group, consisting of international leaders in the areas of hepatobiliary surgery, colorectal oncology, liver transplantation, hepatology, and bioethics. The aim of this study was to standardise nomenclature and define management principles in five key domains: patient selection, evaluation of biological behaviour, graft selection, recipient considerations, and outcomes. An extensive literature review was done within the five domains identified. Between November, 2020, and January, 2021, a three-step modified Delphi consensus process was undertaken by the workgroup, who were further subgrouped into the Scientific Committee, Expert Panel, and Transplant Centre Representatives. A final consensus of 44 statements, standardised nomenclature, and a practical management algorithm is presented. Specific criteria for clinico-patho-radiological assessments with molecular profiling is crucial in this setting. After this, the careful evaluation of biological behaviour with bridging therapy to transplantation with an appropriate assessment of the response is required. The sequencing of treatment in synchronous metastatic disease requires special consideration and is highlighted here. Some ethical dilemmas within organ allocation for malignant indications are discussed and the role for extended criteria grafts, living donor transplantation, and machine perfusion technologies for non-resectable colorectal liver metastases are reviewed. Appropriate immunosuppressive regimens and strategies for the follow-up and treatment of recurrent disease are proposed. This consensus guideline provides a framework by which liver transplantation for non-resectable colorectal liver metastases might be safely instituted and is a meaningful step towards future evidenced-based practice for better patient selection and organ allocation to improve the survival for patients with this disease.

Microenvironment-triggered multimodal precision diagnostics

Therapeutic outcomes in oncology may be aided by precision diagnostics that offer early detection, localization and the opportunity to monitor response to therapy. Here, we report a multimodal nanosensor engineered to target tumours through acidosis, respond to proteases in the microenvironment to release urinary reporters and (optionally) carry positron emission tomography probes to enable localization of primary and metastatic cancers in mouse models of colorectal cancer. We present a paradigm wherein this multimodal sensor can be employed longitudinally to assess burden of disease non-invasively, including tumour progression and response to chemotherapy. Specifically, we showed that acidosis-mediated tumour insertion enhanced on-target release of matrix metalloproteinase-responsive reporters in urine. Subsequent on-demand loading of the radiotracer ⁶⁴Cu allowed pH-dependent tumour visualization, enabling enriched microenvironmental characterization when compared with the conventional metabolic tracer ¹⁸F-fluorodeoxyglucose. Through tailored target specificities, this modular platform has the capacity to be engineered as a pan-cancer test that may guide treatment decisions for numerous tumour types.

Neoadjuvant chemotherapy for colorectal liver metastases: A contemporary review of the literature

Colorectal carcinoma (CRC) is one of the leading causes of cancer-related deaths worldwide, and up to 50% of patients with CRC develop colorectal liver metastases (CRLM). For these patients, surgical resection remains the only opportunity for cure and long-term survival. Over the past few decades, outcomes of patients with metastatic CRC have improved significantly due to advances in systemic therapy, as well as improvements in operative technique and perioperative care. Chemotherapy in the modern era of oxaliplatin- and irinotecan-containing regimens has been augmented by the introduction of targeted biologics and immunotherapeutic agents. The increasing efficacy of contemporary systemic therapies has led to an expansion in the proportion of patients eligible for curative-intent surgery. Consequently, the use of neoadjuvant strategies is becoming progressively more established. For patients with CRLM, the primary advantage of neoadjuvant chemotherapy (NCT) is the potential to down-stage metastatic disease in order to facilitate hepatic resection. On the other hand, the routine use of NCT for patients with resectable metastases remains controversial, especially given the potential risk of inducing chemotherapy-associated liver injury prior to hepatectomy. Current guidelines recommend upfront surgery in patients with initially resectable disease and low operative risk, reserving NCT for patients with borderline resectable or unresectable disease and high operative risk. Patients undergoing NCT require close monitoring for tumor response and conversion of CRLM to resectability. In light of the growing number of treatment options available to patients with metastatic CRC, it is generally agreed that these patients are best served at tertiary centers with an expert multidisciplinary team.

Contrast-Enhanced Intraoperative Ultrasonography with Kupffer Phase May Change Treatment Strategy of Metastatic Liver Tumors - A Single-Centre Prospective Study

Aim

To compare the diagnostic performance of contrast-enhanced intraoperative ultrasonography (CE-IOUS) with Kupffer phase in metastatic liver tumours.

Methods

Twenty-seven consecutive patients with liver metastasis were prospectively recruited from November 2019 to July 2020 in the Department of HPB, Beijing Hospital. MRI and Contrast Enhanced Ultrasonography (CEUS) were obtained preoperatively, and the diagnosis was made by radiologists independently and blindly. Intraoperative ultrasonography (IOUS) and CE-IOUS with Sonazoid were done by the same sophisticated surgeon and sonographer and Kupffer phase was used to detect lesions. The sensitivity and specificity to detect lesions were compared between different radiologic methods. Then, the changes in treatment strategy due to CE-IOUS with Sonazoid were analysed.

Results

Twenty-seven patients were included. In MRI, 91 lesions were detected with sensitivity 93.3% (70/75) and specificity 68.8% (11/16). In CEUS, it was 97.1% (68/70) and 86.7% (13/15) in 85 lesions. Meanwhile, in the Kupffer phase in CE-IOUS, 99 lesions were found and 8 new lesions were discovered in 7 cases, with sensitivity 97.5% (80/82) and specificity 94.1% (16/17). The four imaging methods showed no statistic significance in sensitivity and specificity in detecting lesions (Cochran’s Q 10.825, P=0.055). Treatment strategies were altered in 7 patients, 6 achieved R0 resection or ablation, and 1 patient changed from planned R0 resection to palliative surgery.

Conclusion

CE-IOUS may play a similar or even better role than other radiological methods in diagnosing liver metastasis. The CE-IOUS using Sonazoid demonstrated a high sensitivity and specificity for finding occult metastases intraoperatively and changing the treatment strategy.

Plasma Levels of Heat Shock Protein 90 Alpha Associated With Colorectal Cancer Development

Aim: The role of plasma heat shock protein 90 alpha (HSP90α) in colorectal cancer patients remains unclear. This study aimed to evaluate the relationship between HSP90α and the occurrence and development of colorectal cancer through diagnosis and prognosis value. Methods: 635 colorectal cancer patients and 295 healthy controls were recruited. The HSP90α was measured by using the ELISA kit in all objects and the immune cells and common biomarkers as CEA, AFP, CA125, CA153 and CA199 were measured in all colorectal cancer patients. The relationship between plasma HSP90α with clinical features, common tumor markers and immune cells were also conducted. The survival analysis endpoint was progression-free survival (PFS). Results: The levels of plasma HSP90α were significantly higher in colorectal cancer patients compared to healthy controls [51.4 (ng/ml) vs. 43.7 (ng/ml), p < 0.001]. In additional, the levels of plasma HSP90α were associated with gender and disease progress as stage, lymphatic and distant metastasis. Furthermore, plasma HSP90α was closed correlation with CEA, CA125, CA199 and percentage of B cells. However, the initial expression level of plasma HSP90α failed to show a prognostic value for progression-free survival in colorectal cancer. Conclusion: The plasma Hsp90α was remarkable higher in colorectal cancer and correlated with common tumor biomarkers and immune cells. Plasma Hsp90α levels were associated with disease progress but a poor diagnosis performance and also failed to show a prognostic value in colorectal cancer.

Radiomics analysis of contrast-enhanced CT for classification of hepatic focal lesions in colorectal cancer patients: its limitations compared to radiologists

OBJECTIVE

To evaluate diagnostic performance of a radiomics model for classifying hepatic cyst, hemangioma, and metastasis in patients with colorectal cancer (CRC) from portal-phase abdominopelvic CT images.

METHODS

This retrospective study included 502 CRC patients who underwent contrast-enhanced CT and contrast-enhanced liver MRI between January 2005 and December 2010. Portal-phase CT images of training (n = 386) and validation (n = 116) cohorts were used to develop a radiomics model for differentiating three classes of liver lesions. Among multiple handcrafted features, the feature selection was performed using ReliefF method, and random forest classifiers were used to train the selected features. Diagnostic performance of the developed model was compared with that of four radiologists. A subgroup analysis was conducted based on lesion size.

RESULTS

The radiomics model demonstrated significantly lower overall and hemangioma- and metastasis-specific polytomous discrimination index (PDI) (overall, 0.8037; hemangioma-specific, 0.6653; metastasis-specific, 0.8027) than the radiologists (overall, 0.9622-0.9680; hemangioma-specific, 0.9452-0.9630; metastasis-specific, 0.9511-0.9869). For subgroup analysis, the PDI of the radiomics model was different according to the lesion size (< 10 mm, 0.6486; ≥ 10 mm, 0.8264) while that of the radiologists was relatively maintained. For classifying metastasis from benign lesions, the radiomics model showed excellent diagnostic performance, with an accuracy of 84.36% and an AUC of 0.9426.

CONCLUSION

Albeit inferior to the radiologists, the radiomics model achieved substantial diagnostic performance when differentiating hepatic lesions from portal-phase CT images of CRC patients. This model was limited particularly to classifying hemangiomas and subcentimeter lesions.

KEY POINTS

• Albeit inferior to the radiologists, the radiomics model could differentiate cyst, hemangioma, and metastasis with substantial diagnostic performance using portal-phase CT images of colorectal cancer patients. • The radiomics model demonstrated limitations especially in classifying hemangiomas and subcentimeter liver lesions.

Diagnostic and procedural intraoperative ultrasound: technique, tips and tricks for optimizing results

Intraoperative ultrasound (IOUS) is a valuable adjunctive tool that can provide real-time diagnostic information in surgery that has the potential to alter patient management and decrease complications. Lesion localization, characterization and staging can be performed, as well as surveying for additional lesions and metastatic disease. IOUS is commonly used in the liver for hepatic metastatic disease and hepatocellular carcinoma, in the pancreas for neuroendocrine tumors, and in the kidney for renal cell carcinoma. IOUS allows real-time evaluation of vascular patency and perfusion in organ transplantation and allows for early intervention for anastomotic complications. It can also be used to guide intraoperative procedures such as biopsy, fiducial placement, radiation, or ablation. A variety of adjuncts including microbubble contrast and elastography may provide additional information at IOUS. It is important for the radiologist to be familiar with the available equipment, common clinical indications, technique, relevant anatomy and intraoperative imaging appearance to optimize performance of this valuable imaging modality.

Clinical practice guidelines for the management of liver metastases from extrahepatic primary cancers 2021

BACKGROUND

Hepatectomy is standard treatment for colorectal liver metastases; however, it is unclear whether liver metastases from other primary cancers should be resected or not. The Japanese Society of Hepato-Biliary-Pancreatic Surgery therefore created clinical practice guidelines for the management of metastatic liver tumors.

METHODS

Eight primary diseases were selected based on the number of hepatectomies performed for each malignancy per year. Clinical questions were structured in the population, intervention, comparison, and outcomes (PICO) format. Systematic reviews were performed, and the strength of recommendations and the level of quality of evidence for each clinical question were discussed and determined. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations.

RESULTS

The eight primary sites were grouped into five categories based on suggested indications for hepatectomy and consensus of the guidelines committee. Fourteen clinical questions were devised, covering five topics: (1) diagnosis, (2) operative treatment, (3) ablation therapy, (4) the eight primary diseases, and (5) systemic therapies. The grade of recommendation was strong for one clinical question and weak for the other 13 clinical questions. The quality of the evidence was moderate for two questions, low for 10, and very low for two. A flowchart was made to summarize the outcomes of the guidelines for the indications of hepatectomy and systemic therapy.

CONCLUSIONS

These guidelines were developed to provide useful information based on evidence in the published literature for the clinical management of liver metastases, and they could be helpful for conducting future clinical trials to provide higher-quality evidence.

Contrast-Enhanced Ultrasound Imaging Features of Focal Chemotherapy-Induced Sinusoidal Injury in Patients With Colorectal Cancer: Initial Experience

OBJECTIVES

Increasing studies have reported focal chemotherapy-induced sinusoidal injury (CSI) mimicking colorectal liver metastasis (CRLM) on imaging studies, resulting in unnecessary lobectomy. This study aimed to investigate the contrast-enhanced ultrasound (CEUS) imaging features of focal CSI.

METHODS

We retrospectively evaluated 16 patients who had a pathologic diagnosis of focal CSI and underwent CEUS between January 2013 and January 2019. The images were compared with those obtained from 27 patients with CRLM.

RESULTS

On CEUS, 14 (87.5%) focal CSIs showed heterogeneous isoenhancement, 1 (6.3%) peripheral hyperenhancement, and 1 (6.3%) homogeneous hyperenhancement during the arterial phase. Compared with the adjacent liver parenchyma, the initial enhancement time of focal CSI was earlier in 2 (12.5%), simultaneous in 9 (56.3%), and later in 5 (31.3%) patients. In the portal and late phases, all of the focal CSI cases showed hypoenhancement compared with the adjacent liver parenchyma. Focal CSI had the following CEUS findings, which were different from those of CRLM: (1) heterogeneous isoenhancement in the arterial phase (87.5% versus 0%; P < .001); (2) an initial enhancement time later than that of the liver parenchyma (mean ± SD, 0.5 ± 1.5 versus -1.5 ± 1.9; P < .001); (3) a longer time to peak (30.5 ± 5.6 versus 22.5 ± 4.4 seconds; P < .001); and (4) a later time to wash-out (51.0 ± 12.5 versus 35.0 ± 6.2 seconds; P = .002).

CONCLUSIONS

Focal CSI usually shows heterogeneous isoenhancement in arterial phase and hypoenhancement in portal and late phases on CEUS, with slow contrast wash-in and wash-out, which can be helpful in the differential diagnosis with CRLM.

Search of low-contrast liver lesions in abdominal CT: the importance of scrolling behavior

Purpose: Visual search using volumetric images is becoming the standard in medical imaging. However, we do not fully understand how eye movement strategies mediate diagnostic performance. A recent study on computed tomography (CT) images showed that the search strategies of radiologists could be classified based on saccade amplitudes and cross-quadrant eye movements [eye movement index (EMI)] into two categories: drillers and scanners. Approach: We investigate how the number of times a radiologist scrolls in a given direction during analysis of the images (number of courses) could add a supplementary variable to use to characterize search strategies. We used a set of 15 normal liver CT images in which we inserted 1 to 5 hypodense metastases of two different signal contrast amplitudes. Twenty radiologists were asked to search for the metastases while their eye-gaze was recorded by an eye-tracker device (EyeLink1000, SR Research Ltd., Mississauga, Ontario, Canada). Results: We found that categorizing radiologists based on the number of courses (rather than EMI) could better predict differences in decision times, percentage of image covered, and search error rates. Radiologists with a larger number of courses covered more volume in more time, found more metastases, and made fewer search errors than those with a lower number of courses. Our results suggest that the traditional definition of drillers and scanners could be expanded to include scrolling behavior. Drillers could be defined as scrolling back and forth through the image stack, each time exploring a different area on each image (low EMI and high number of courses). Scanners could be defined as scrolling progressively through the stack of images and focusing on different areas within each image slice (high EMI and low number of courses). Conclusions: Together, our results further enhance the understanding of how radiologists investigate three-dimensional volumes and may improve how to teach effective reading strategies to radiology residents.

Preoperative imaging for colorectal liver metastases: a nationwide population-based study

Background

In patients with colorectal liver metastases (CRLM) preoperative imaging may include contrast‐enhanced (ce) MRI and [¹⁸F]fluorodeoxyglucose (¹⁸F‐FDG) PET–CT. This study assessed trends and variation between hospitals and oncological networks in the use of preoperative imaging in the Netherlands.

Methods

Data for all patients who underwent liver resection for CRLM in the Netherlands between 2014 and 2018 were retrieved from a nationwide auditing database. Multivariable logistic regression analysis was used to assess use of ceMRI, ¹⁸F‐FDG PET–CT and combined ceMRI and ¹⁸F‐FDG PET–CT, and trends in preoperative imaging and hospital and oncological network variation.

Results

A total of 4510 patients were included, of whom 1562 had ceMRI, 872 had ¹⁸F‐FDG PET–CT, and 1293 had combined ceMRI and ¹⁸F‐FDG PET–CT. Use of ceMRI increased over time (from 9·6 to 26·2 per cent; P < 0·001), use of ¹⁸F‐FDG PET–CT decreased (from 28·6 to 6·0 per cent; P < 0·001), and use of both ceMRI and ¹⁸F‐FDG PET–CT 16·9 per cent) remained stable. Unadjusted variation in the use of ceMRI, ¹⁸F‐FDG PET–CT, and combined ceMRI and ¹⁸F‐FDG PET–CT ranged from 5·6 to 100 per cent between hospitals. After case‐mix correction, hospital and oncological network variation was found for all imaging modalities.

Discussion

Significant variation exists concerning the use of preoperative imaging for CRLM between hospitals and oncological networks in the Netherlands. The use of MRI is increasing, whereas that of ¹⁸F‐FDG PET–CT is decreasing.

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.

Diagnostic performance of magnetic resonance imaging for colorectal liver metastasis: A systematic review and meta-analysis

The prognosis of colorectal cancer (CRC) is largely dependent on the early detection of hepatic metastases. With the advantages of nonradioactivity and the availability of multiple scanning sequences, the efficacy of magnetic resonance imaging (MRI) in the detection of colorectal liver metastases (CRLM) is not yet clear. We performed this meta-analysis to address this issue. PubMed, Embase, and the Cochrane Library were searched for studies reporting diagnostic performance of MRI for CRLM. Descriptive and quantitative data were extracted. The study quality was evaluated for the identified studies and a random effects model was used to determine the integrated diagnosis estimation. Meta-regression and subgroup analyses were implemented to investigate the potential contributors to heterogeneity. As a result, seventeen studies were included for analysis (from the year 1996 to 2018), comprising 1121 patients with a total of 3279 liver lesions. The pooled sensitivity, specificity, and diagnostic odds ratio were 0.90 (95% confidence intervals (CI): 0.81-0.95), 0.88 (0.80-0.92), and 62.19 (23.71-163.13), respectively. The overall weighted area under the curve was 0.94 (0.92-0.96). Using two or more imaging planes and a quantitative/semiquantitative interpretation method showed higher diagnostic performance, although only the latter demonstrated statistical significance (P < 0.05). Advanced scanning sequences with DWI and liver-specific contrast media tended to increase the sensitivity for CRLM detection. We therefore concluded that contemporary MRI has high sensitivity and specificity for screening CRLM, especially for those with advanced scanning sequences. Using two or more imaging planes and adopting a quantitative/semiquantitative imaging interpretation may further improve diagnosis. However, the MRI results should be interpreted with caution because of substantial heterogeneity among studies.

Colorectal liver metastases: An update on multidisciplinary approach

Liver metastasis is the commonest form of distant metastasis in colorectal cancer. Selection criteria for surgery and liver-directed therapies have recently been extended. However, resectability remains poorly defined. Tumour biology is increasingly recognized as an important prognostic factor; hence molecular profiling has a growing role in risk stratification and management planning. Surgical resection is the only treatment modality for curative intent. The most appropriate surgical approach is yet to be established. The primary cancer and the hepatic metastasis can be removed simultaneously or in a two-step approach; these two strategies have comparable long-term outcomes. For patients with a limited future liver remnant, portal vein embolization, combined ablation and resection, and associating liver partition and portal vein ligation for staged hepatectomy have been advocated, and each has their pros and cons. The role of neoadjuvant and adjuvant chemotherapy is still debated. Targeted biological agents and loco-regional therapies (thermal ablation, intra-arterial chemo- or radio-embolization, and stereotactic radiotherapy) further improve the already favourable results. The recent debate about offering liver transplantation to highly selected patients needs validation from large clinical trials. Evidence-based protocols are missing, and therefore optimal management of hepatic metastasis should be personalized and determined by a multi-disciplinary team.

Diagnostic performance of CT, gadoxetate disodium-enhanced MRI, and PET/CT for the diagnosis of colorectal liver metastasis: Systematic review and meta-analysis

BACKGROUND

Imaging studies, including computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET), have an essential role in the detection and localization of colorectal liver metastasis (CRLM).

PURPOSE

To systematically determine the diagnostic accuracy of multidetector row CT (MDCT), gadoxetate disodium-enhanced MRI, and PET/CT for diagnosing CRLM and the sources of heterogeneity between the reported results.

STUDY TYPE

Systematic review and meta-analysis.

SUBJECTS

In all, 2151 lesions in CT studies, 2301 lesions in MRI studies, 1846 lesions in PET/CT studies, FIELD STRENGTH: 1.5T and 3.0T.

ASSESSMENT

We identified research studies that investigated MDCT, gadoxetate disodium-enhanced MRI, and PET/CT to diagnose CRLM by performing a systematic search of PubMed MEDLINE and EMBASE. Study quality was assessed using Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2).

STATISTICAL TESTS

According to the types of imaging tests, study heterogeneity and the threshold effect were analyzed and the meta-analytic summary of sensitivity and specificity were estimated. Meta-regression analysis was performed to further investigate study heterogeneity.

RESULTS

Of the 860 articles screened, we found 36 studies from 24 articles reporting a diagnosis of CRLM (11 CT studies, 12 MRI studies, and 13 PET/CT studies). The meta-analytic summary sensitivity for CT, MRI, and PET/CT were 82.1% (95% confidence interval [CI], 74.0-88.1%), 93.1% (95% CI, 88.4-96.0%), and 74.1% (95% CI, 62.1-83.3%), respectively. The meta-analytic summary specificity for CT, MRI, and PET/CT were 73.5% (95% CI, 53.7-86.9%), 87.3% (95% CI, 77.5-93.2%), and 93.9% (95% CI, 83.9-97.8%), respectively. There was no threshold effect in any of the imaging tests. Neoadjuvant chemotherapy significantly decreased the sensitivity of CT and MRI (P < 0.01), although it did not significantly affect the sensitivity of PET/CT. The study design, type of reference standard, and study quality also affected the diagnostic performances of imaging studies.

DATA CONCLUSION

Despite the heterogeneous accuracy between studies, gadoxetate disodium-enhanced MRI showed the highest sensitivity, and gadoxetate disodium-enhanced MRI and PET/CT had similar specificities for diagnosing CRLM.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1237-1250.

Integrated analysis of genes associated with poor prognosis of patients with colorectal cancer liver metastasis

Colorectal cancer (CRC) is one of the most common malignances in the gut. Liver is the most common metastasis site of CRC. This study focuses on the primary CRC and its liver metastasis, aiming to discover several liver metastasis related genes and provide therapeutic candidates. We compared gene expression patterns among the groups of normal colorectal mucosa, primary tumor and the liver metastasis using a CRC gene expression dataset. 84 genes were found to be upregulated in both primary tumor and liver metastases. Function enrichment analysis indicated that these genes are enriched in pathways such as chemotaxis, coagulation and lipid metabolism which are crucial in multi-step cancer metastasis. Gene network analysis identified several important hub genes that may be involved in carcinogenesis and liver metastasis. Then we used a validation dataset containing 562 CRC samples with detailed clinical information, to screen prognostic biomarkers for overall survival (OS) and relapse free survival (RFS). Finally, overexpression of THBS2 (thrombospondin 2), INHBB (inhibin, beta B) and BGN (biglycan) were proved to be correlated with poor OS and RFS. In conclusion, this study indicated that chemotaxis, coagulation and lipid metabolism might play critical roles in the processes of carcinogenesis and liver metastasis. THBS2, INHBB and BGN are prognostic markers and potential therapeutic targets for CRC.

[Evaluation of Efficiencies on the Gadoxetic Acid-enhanced MRI for Preoperative Assessment of Liver Metastases from Colorectal Carcinoma]

THE AIMS OF OUR STUDY WERE

1) to evaluate efficiencies of gadoxetic acid-enhanced magnetic resonance imaging (Gd-EOB-MRI) for preoperative assessment of liver metastases from colorectal carcinoma, and 2) to compare them with other diagnostic imaging modalities. The subjects of the analysis were outpatients with advanced colorectal cancer who are at risk of developing liver metastases (initial setting: pre-test probability=20%). At initial setting, we performed a decision analysis to calculate numbers of true positive (TP), false negative (FN), false positive (FP) and true negative (TN) test results per 1000 patients of Gd-EOB-MRI and other imaging modalities (conventional contrast agent-enhanced MRI, contrast-enhanced CT and ¹⁸F-FDG PET/CT). From the result of decision analysis, we calculated the cost of detection per one patient with liver metastases (detection cost). Also, we calculated positive predictive value (PPV) and negative predictive value (NPV). Moreover, these values were defined as efficiencies in this study. In the initial setting, number of TP, FN, FP TN results and detection cost of Gd-EOB-MRI were 197, 3, 40, 760, and 224,032.8 Japanese Yen, respectively. Also, PPV and NPV were 83.1% and 99.7%, respectively. In comparison with other imaging modalities, efficiencies of Gd-EOB-MRI were superior to them, except detection cost. We consider that the efficiencies of Gd-EOB-MRI, which we had assessed are easy to understand and useful when they are used for explanation to patients.

Clinical Application of Contrast-Enhanced Ultrasound Using High-Frequency Linear Probe in the Detection of Small Colorectal Liver Metastases

To compare the performance of contrast-enhanced ultrasound (CEUS) using high-frequency linear and convex probes in the detection of small colorectal liver metastases (CRLMs). A total of 85 patients with 143 small CRLMs were evaluated. High-frequency ultrasound (US) and CEUS detected significantly more superficial lesions within 60 mm below the skin than a convex probe (p <0.05). The detection rate decreased in the chemotherapy group, especially when using a convex probe for US (p <0.05). By combining convex and linear probes, detection rates of US and CEUS were significantly higher than that of a convex or a linear probe alone (p <0.05). High-frequency US and CEUS helped to improve detection of small CRLMs and reduce the influence of chemotherapy. For patients with a high risk of CRLMs and those after chemotherapy, we recommend first scanning the liver by using a convex probe and subsequently screening the surface area of the liver and suspicious small lesions by using a linear probe.

Centralization of Liver Cancer Surgery and Impact on Multidisciplinary Teams Working on Stage IV Colorectal Cancer

Surgical resection is the most effective treatment approach for colorectal liver metastases but only a minority of patients is suitable for upfront surgery. The treatment strategies of stage IV colorectal cancer have shifted towards a continuum of care in which medical and surgical treatment combinations are tailored to the clinical setting of the individual patient. The optimization of treatment through appropriate decision-making and multimodal therapy for stage IV colorectal cancer require a joint multidisciplinary meeting in a centralized liver cancer unit.

Dynamic Contrast-Enhanced Ultrasound of Colorectal Liver Metastases as an Imaging Modality for Early Response Prediction to Chemotherapy

Our aim was to investigate whether dynamic contrast-enhanced ultrasound (DCE-US) can detect early changes in perfusion of colorectal liver metastases after initiation of chemotherapy. Newly diagnosed patients with colorectal cancer with liver metastases were enrolled in this explorative prospective study. Patients were treated with capecitabine or 5-fluorouracil-based chemotherapy with or without bevacizumab. DCE-US was performed before therapy (baseline) and again 10 days after initiation of treatment. Change in contrast-enhancement in one liver metastasis (indicator lesion) was measured. Treatment response was evaluated with a computed tomography (CT) scan after three cycles of treatment and the initially observed DCE-US change of the indicator lesion was related to the observed CT response. Eighteen patients were included. Six did not complete three series of chemotherapy and the evaluation CT scan, leaving twelve patients for analysis. Early changes in perfusion parameters using DCE-US did not correlate well with subsequent CT changes. A subgroup analysis of eight patients receiving bevacizumab, however, demonstrated a statistically significant correlation (p = 0.045) between early changes in perfusion measures of peak enhancement at DCE-US and tumor shrinkage at CT scan. The study indicates that early changes in DCE-US perfusion measures may predict subsequent treatment response of colorectal liver metastases in patients receiving bevacizumab.

Predictive and prognostic biomarkers in colorectal cancer: A systematic review of recent advances and challenges

BACKGROUND

Colorectal cancer (CRC) is one of the leading cause of cancer deaths worldwide. Since CRC is largely asymptomatic until alarm features develop to advanced stages, the implementation of the screening programme is very much essential to reduce cancer incidence and mortality rates. CRC occurs predominantly from accumulation of genetic and epigenetic changes in colon epithelial cells, which later gets transformed into adenocarcinomas.

SCOPE OF REVIEW

The current challenges of screening paradigm and diagnostic ranges are from semi-invasive methods like colonoscopy to non-invasive stool-based test, have resulted in over-diagnosis and over-treatment of CRC. Hence, new screening initiatives and deep studies are required for early diagnosis of CRC. In this regard, we not only summarise current predictive and prognostic biomarkers with their potential for diagnostic and therapeutic applications, but also describe current limitations, future perspectives and challenges associated with the progression of CRC.

MAJOR CONCLUSIONS

Currently many potential biomarkers have already been successfully translated into clinical practice eg. Fecal haemoglobin, Carcinoembryonic antigen (CEA) and CA19.9, although these are not highly promising diagnostic target for personalized medicine. So there is a critical need for reliable, minimally invasive, highly sensitive and specific genetic markers of an individualised and optimised patient treatment at the earliest disease stage possible.

GENERAL SIGNIFICANCE

Identification of a new biomarker, or a set of biomarkers to the development of a valid, and clinical sensible assay that can be served as an alternative tool for early diagnosis of CRC and open up promising new targets in therapeutic intervention strategies.

Computed Tomography Imaging of Solid Tumors Using a Liposomal-Iodine Contrast Agent in Companion Dogs with Naturally Occurring Cancer

OBJECTIVES

Companion dogs with naturally occurring cancer serve as an important large animal model in translational research because they share strong similarities with human cancers. In this study, we investigated a long circulating liposomal-iodine contrast agent (Liposomal-I) for computed tomography (CT) imaging of solid tumors in companion dogs with naturally occurring cancer.

MATERIALS AND METHODS

The institutional animal ethics committees approved the study and written informed consent was obtained from all owners. Thirteen dogs (mean age 10.1 years) with a variety of masses including primary and metastatic liver tumors, sarcomas, mammary carcinoma and lung tumors, were enrolled in the study. CT imaging was performed pre-contrast and at 15 minutes and 24 hours after intravenous administration of Liposomal-I (275 mg/kg iodine dose). Conventional contrast-enhanced CT imaging was performed in a subset of dogs, 90 minutes prior to administration of Liposomal-I. Histologic or cytologic diagnosis was obtained for each dog prior to admission into the study.

RESULTS

Liposomal-I resulted in significant (p < 0.05) enhancement and uniform opacification of the vascular compartment. Non-renal, reticulo-endothelial systemic clearance of the contrast agent was demonstrated. Liposomal-I enabled visualization of primary and metastatic liver tumors. Sub-cm sized liver lesions grossly appeared as hypo-enhanced compared to the surrounding normal parenchyma with improved lesion conspicuity in the post-24 hour scan. Large liver tumors (> 1 cm) demonstrated a heterogeneous pattern of intra-tumoral signal with visibly higher signal enhancement at the post-24 hour time point. Extra-hepatic, extra-splenic tumors, including histiocytic sarcoma, anaplastic sarcoma, mammary carcinoma and lung tumors, were visualized with a heterogeneous enhancement pattern in the post-24 hour scan.

CONCLUSIONS

The long circulating liposomal-iodine contrast agent enabled prolonged visualization of small and large tumors in companion dogs with naturally occurring cancer. The study warrants future work to assess the sensitivity and specificity of the Liposomal-I agent in various types of naturally occurring canine tumors.

A meta-analysis of diffusion-weighted and gadoxetic acid-enhanced MR imaging for the detection of liver metastases

OBJECTIVES

To obtain the diagnostic performance of diffusion-weighted (DW) and gadoxetic-enhanced magnetic resonance (MR) imaging in the detection of liver metastases.

METHODS

A comprehensive search (EMBASE, PubMed, Cochrane) was performed to identify relevant articles up to June 2015. Inclusion criteria were: liver metastases, DW-MR imaging and/or gadoxetic acid-enhanced MR imaging, and per-lesion statistics. The reference standard was histopathology, intraoperative observation and/or follow-up. Sources of bias were assessed using the QUADAS-2 tool. A linear mixed-effect regression model was used to obtain sensitivity estimates.

RESULTS

Thirty-nine articles were included (1,989 patients, 3,854 metastases). Sensitivity estimates for DW-MR imaging, gadoxetic acid-enhanced MR imaging and the combined sequence for detecting liver metastases on a per-lesion basis was 87.1 %, 90.6 % and 95.5 %, respectively. Sensitivity estimates by gadoxetic acid-enhanced MR imaging and the combined sequence were significantly better than DW-MR imaging (p = 0.0001 and p < 0.0001, respectively), and the combined MR sequence was significantly more sensitive than gadoxetic acid-enhanced MR imaging (p < 0.0001). Similar results were observed in articles that compared the three techniques simultaneously, with only colorectal liver metastases and in liver metastases smaller than 1 cm.

CONCLUSIONS

In patients with liver metastases, combined DW-MR and gadoxetic acid-enhanced MR imaging has the highest sensitivity for detecting liver metastases on a per-lesion basis.

KEY POINTS

• DW-MRI is less sensitive than gadoxetic acid-enhanced MRI for detecting liver metastases • DW-MRI and gadoxetic acid-enhanced MRI is the best combination • Same results are observed in colorectal liver metastases • Same results are observed in liver metastases smaller than 1 cm • Same results are observed when histopathology alone is the reference standard.

Managing synchronous liver metastases from colorectal cancer: a multidisciplinary international consensus

An international panel of multidisciplinary experts convened to develop recommendations for managing patients with colorectal cancer (CRC) and synchronous liver metastases (CRCLM). A modified Delphi method was used. CRCLM is defined as liver metastases detected at or before diagnosis of the primary CRC. Early and late metachronous metastases are defined as those detected ⩽12months and >12months after surgery, respectively. To provide information on potential curability, use of high-quality contrast-enhanced computed tomography (CT) before chemotherapy is recommended. Magnetic resonance imaging is increasingly being used preoperatively to aid detection of subcentimetric metastases, and alongside CT in difficult situations. To evaluate operability, radiology should provide information on: nodule size and number, segmental localization and relationship with major vessels, response after neoadjuvant chemotherapy, non-tumoral liver condition and anticipated remnant liver volume. Pathological evaluation should assess response to preoperative chemotherapy for both the primary tumour and metastases, and provide information on the tumour, margin size and micrometastases. Although the treatment strategy depends on the clinical scenario, the consensus was for chemotherapy before surgery in most cases. When the primary CRC is asymptomatic, liver surgery may be performed first (reverse approach). When CRCLM are unresectable, the goal of preoperative chemotherapy is to downsize tumours to allow resection. Hepatic resection should not be denied to patients with stable disease after optimal chemotherapy, provided an adequate liver remnant with inflow and outflow preservation remains. All patients with synchronous CRCLM should be evaluated by a hepatobiliary multidisciplinary team.

Non-invasive diagnostic imaging of colorectal liver metastases

Colorectal cancer is one of the few malignant tumors in which synchronous or metachronous liver metastases [colorectal liver metastases (CRLMs)] may be treated with surgery. It has been demonstrated that resection of CRLMs improves the long-term prognosis. On the other hand, patients with un-resectable CRLMs may benefit from chemotherapy alone or in addition to liver-directed therapies. The choice of the most appropriate therapeutic management of CRLMs depends mostly on the diagnostic imaging. Nowadays, multiple non-invasive imaging modalities are available and those have a pivotal role in the workup of patients with CRLMs. Although extensive research has been performed with regards to the diagnostic performance of ultrasonography, computed tomography, positron emission tomography and magnetic resonance for the detection of CRLMs, the optimal imaging strategies for staging and follow up are still to be established. This largely due to the progressive technological and pharmacological advances which are constantly improving the accuracy of each imaging modality. This review describes the non-invasive imaging approaches of CRLMs reporting the technical features, the clinical indications, the advantages and the potential limitations of each modality, as well as including some information on the development of new imaging modalities, the role of new contrast media and the feasibility of using parametric image analysis as diagnostic marker of presence of CRLMs.