Optimal imaging sequence for staging in colorectal liver metastases: Analysis of three hypothetical imaging strategies

Does 18F-FDG PET/CT change the surgical management of potentially resectable colorectal liver metastases?

PURPOSE

Resectability assessment of patients with colorectal liver metastases is based on computed tomography and liver magnetic resonance imaging. Addition of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography has been recommended, but the impact of the added information remains unclear. The primary aim of this study was to determine how preoperative positron emission tomography/computed tomography changed management in patients with potentially resectable colorectal liver metastases. The secondary aim was to investigate whether findings on positron emission tomography/computed tomography correlated to metastatic disease in cases with extended surgery and influenced oncological outcomes.

METHODS

A retrospective observational study of the impact of adding positron emission tomography/computed tomography to conventional imaging in the surgical decision-making of colorectal liver metastases. All patients with colorectal liver metastases diagnosed by conventional imaging were included and assessed by a multidisciplinary team conference at Umeå University Hospital between June 2013 and December 2017. Eligibility criteria were all patients with potentially resectable colorectal liver metastases. Patients who underwent preoperative positron emission tomography/computed tomography in addition to conventional radiology were compared with those who underwent conventional imaging only.

RESULTS

151/220 patients underwent preoperative positron emission tomography/computed tomography. Findings on positron emission tomography/computed tomography changed the management in 10.6% of the patients. Eight patients were excluded from surgery after detection by positron emission tomography/computed tomography of extrahepatic disease. Eight patients underwent more extended surgery than initially planned due to positron emission tomography/computed tomography. Five of these positron emission tomography-positive resected sites were verified by pathology as metastatic disease. No difference in overall survival was seen following surgical resection in patients with and without a preoperative positron emission tomography/computed tomography.

CONCLUSIONS

Preoperative positron emission tomography/computed tomography resulted in a changed surgical management in 10.6% of cases in a selected cohort.

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.

Whole-body MRI added to gadoxetic acid-enhanced liver MRI for detection of extrahepatic disease in patients considered eligible for hepatic resection and/or local ablation of colorectal cancer liver metastases

Background

Fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) can detect extrahepatic disease before local treatment of colorectal liver metastases.

Purpose

To investigate if whole-body magnetic resonance imaging (MRI) added to gadoxetic acid liver MRI could replace FDG-PET/CT for detection of extrahepatic disease in patients with colorectal liver metastases eligible for hepatic local treatment.

Material and Methods

This health-research-ethics-committee-approved prospective consecutive diagnostic accuracy study with written informed consent analyzed 79 cases included between 29 June 2015 and 7 February 2017. Whole-body MRI covering the thorax, abdomen, and pelvis and FDG-PET/CT including contrast-enhanced CT was performed 0–3 days before local treatment of liver metastases. Whole-body MR images were read independently by two readers. FDG-PET/CT images were read independently by two pairs of readers. Histopathology and follow-up imaging were used as reference standard. Sensitivities and specificities were calculated and compared including noninferiority analysis.

Results

Seventy-five malignant lesions and 419 benign lesions were confirmed. Sensitivities of both PET/CT reader pairs 1 and 2 (56.7 and 67.9%) and MRI reader 2 (63.0%) were significantly higher than that of MRI reader 1 (42.7) (P<0.04). Specificities of both PET/CT reader pairs 1 and 2 (92.5 and 92.4%) and MRI reader 1 (91.1%) were significantly higher than that of MRI reader 2 (86.3%) ( P < 0.02). Sensitivity of MRI reader 2 was non-inferior compared to PET/CT reader pair 1. Specificities of both MRI readers were non-inferior to both PET/CT reader pairs.

Conclusion

For detection of extrahepatic disease in patients with colorectal liver metastases, whole-body MRI was non-inferior to FDG-PET/CT for some reader combinations. However, reader-independent non-inferiority could not be demonstrated.

Outcome of indeterminate liver lesions on computed tomography in patients with colorectal cancer

Introduction The aim of this study was to determinate the outcome of indeterminate liver lesions on computed tomography (CT) in patients with a background history of colorectal cancer (CRC) and to identify clinicopathological variables associated with malignancy in these lesions. A secondary aim was to devise a management algorithm for such patients. Methods Patients referred to our institution with indeterminate liver lesions on CT with a background history of CRC between January 2012 and December 2014 were included in the study. Clinicopathological factors, surveillance period and histological findings were analysed. Results Fifty-six patients with indeterminate liver lesions were identified. Fifty-three (94.6%) of these required further imaging (magnetic resonance imaging [MRI; n=50] and positron emission tomography combined with CT [n=3]). For the patients who had MRI, the underlying diagnosis was benign in 19 and colorectal liver metastasis (CRLM) in 8 while 23 patients and an indeterminate lesion. In cases that remained indeterminate following MRI, liver resection was performed in 2 patients for a high suspicion of CRLM while the 21 remaining patients underwent interval surveillance (median: 9 months, range: 3-52 months). Of these 21 patients, 14 had benign lesions while CRLM was noted in 6 patients and an incidental hepatocellular carcinoma in a single patient. Age ≥65 years was the only statistically significant clinicopathological factor in predicting an underlying malignancy in patients with indeterminate liver lesions on CT. Conclusions Over a third of the patients diagnosed with indeterminate liver lesions on CT subsequently showed evidence of CRLM. These indeterminate lesions are more likely to be malignant in patients aged ≥65 years.

Cost-effective imaging for resectability of liver lesions in colorectal cancer: an economic decision model

BACKGROUND

This study aimed to determine the cost-effectiveness of contrast-enhanced magnetic resonance imaging (CE-MRI) compared with multiphase CE computed tomography (CE-CT) scan to characterize suspected liver lesions in patients with known colorectal carcinoma.

METHODS

A decision analytic model linking diagnostic accuracy to health outcomes in patients with colorectal carcinoma was constructed. The model assumed that CE-MRI has superior sensitivity and equivalent specificity to CE-CT, and patients with a colorectal liver metastasis could be eligible for curative surgery or chemotherapy and palliation. Delayed diagnosis or misdiagnosis was associated with worse health outcomes (disutility). Cost-effectiveness was calculated as the incremental cost relative to the incremental benefit, the benefit was estimated using quality-adjusted life years. Sensitivity analyses were conducted to test the robustness of the results.

RESULTS

The clinical evidence supports increased sensitivity of CE-MRI compared with CE-CT (0.943 versus 0.768). CE-MRI was more effective and more costly than CE-CT. The incremental cost-effectiveness ratio was estimated to be $40 548 per quality-adjusted life year gained. The model is most sensitive to the cost of MRI, cost of palliative treatment and the disutility associated with delayed palliative care. The results were also sensitive to the assumptions made about the clinical algorithm.

CONCLUSION

The results provide evidence of the potential cost-effectiveness associated with CE-MRI for the diagnosis of liver metastases in patients with identified colorectal carcinoma. CE-MRI can be recommended as cost-effective provided it replaces CE-CT and that improved diagnostic accuracy results in earlier, curative, disease management.

Current use of MRI in patients with liver metastatic colorectal cancer: a population-based study

BACKGROUND

Liver MRI is recommended as the preoperative imaging strategy in liver metastatic colorectal cancers.

OBJECTIVE

The aim of the study was to assess for the first time the use of liver MRI in a French population-based cancer registry.

PATIENTS AND METHODS

All liver-only metastatic colorectal cancers resected for their primary tumour diagnosed between 2009 and 2013 were included. Nonconditional logistic regression was used to search for associations between the MRI order and the characteristics of patients and tumours.

RESULTS

The primary tumour and liver metastases were resected for cure in 30% (69/233) of cases, and in 72% of these liver MRI was performed before resection of the liver metastases. Preoperative MRI ordering was not significantly higher in patients younger than 70 years when compared with that in older patients. Among patients who did not undergo resection of their liver metastasis, 22% had undergone a liver MRI. After adjustment for comorbidities, the probability of having undergone an MRI was higher for patients managed in the university hospital (P=0.004) and lower in those managed in nonuniversity hospitals (P=0.002) compared with the mean of odds for all facilities. Patients more than or equal to 70 years were 2.4 times less likely than younger patients to undergo an MRI (P=0.043).

CONCLUSION

Liver MRI was underused in patients with colorectal liver-only synchronous metastasis undergoing curative resection for metastases and in elderly patients.

Effects of multidisciplinary team on emergency care for colorectal cancer patients: A nationwide-matched cohort study

The literature describing the effectiveness of multidisciplinary team (MDT) for the care of colorectal cancer remains unclear. We investigated the effects of MDT care on the quality of colorectal cancer treatment, and the emergency department visit number was used as an indicator. In total, 45,418 patients newly diagnosed with colorectal cancer from the Taiwan National Health Insurance Research Database (2005-2009) were included. Propensity score matching with a ratio of 1:3 was adopted to reduce differences in characteristics between MDT care participants and non-MDT care participants. After matching, 3039 participation MDT care groups and 9117 nonparticipation groups were included and analyzed with χ and t tests, determine the distribution was similar. Without the control of variables, the percentage difference between participation and nonparticipation MDT care groups in utilization of emergency care was 0.03% (P > .05). The logistic regression model involving controlled variables demonstrated that odds ratio (OR) by probability of emergency care used for participation MDT care groups within a year of cancer diagnosis was less than that for nonparticipation (OR = 0.87, 95% confidence interval: 0.78-0.96). Large amount data were used and confirmed significant benefits of MDT in colorectal cancer care.

Synchronous Resectable Metastatic Colorectal Cancer: Lymph Node Involvement Predicts Poor Outcome

To evaluate the value of lymph node status of primary tumors in predicting the prognosis of synchronous resectable metastatic colorectal cancer (mCRC).The characteristics of resectable mCRC are substantially different from other cancers, and the prognostic factors of resectable mCRC are still controversial.The data of 2007 patients with mCRC who received resection of the primary tumors and metastatic lesions synchronously were reviewed from the Surveillance, Epidemiology and End-Result database. The Kaplan-Meier method was used to evaluate the capacity of different prognostic factors. Univariate and multivariate logistic regression models were used to evaluate the relationship between the lymph node status and other factors. The mRNA profiles of primary resectable mCRC tumors were obtained by microarray at our center.The median survival times were 50, 36, 32, 27, and 19 months in the N0-stage, N1a-stage, N1b-stage, N2a-stage, and N2b-stage subgroups according to the 7th American Joint Committee on Cancer (AJCC) Tumor Lymph Node Metastasis (TNM) N-classification (P = 0.000), and 40, 29, 22, and 15 months in patients with metastatic lymph node ratio (LNR) <0.25, 0.25-0.49, 0.5-0.74, and ≥0.75 subgroups (P = 0.000). In the COX model, the 7th AJCC TNM N-stage and LNR were independent prognostic factors. The mRNA profile was not associated with lymph node involvement.Both the N-stage according to the 7th AJCC TNM staging system and LNR had the capacity to subclassify synchronous resectable mCRC with different prognoses. The lymph node might be integrated into the AJCC staging system as a diagnose-delay prognostic factor for stage IV disease.

Guidelines for diagnosis, staging and treatment of metastatic colorectal cancer by Grupo Español Multidisciplinar en Cancer Digestivo (GEMCAD)

Abstract 

Advances in the care of patients with metastatic colorectal cancer arise from well-designed clinical trials. In the present document we address specific challenges in the design of clinical trials for metastatic colorectal cancer regarding staging and standard of care according to prognosis, as well as some relevant methodological issues.

Improved long-term survival after resection of colorectal liver metastases following staging with FDG positron emission tomography

BACKGROUND AND OBJECTIVES

Actual long-term survival of patients with colorectal liver metastases staged by PET CT has not been reported. Objectives were to investigate whether PET CT staging results in actual improved long-term survival, to examine outcome in patients with 'equivocal' PET CT scans, and those excluded from hepatectomy by PET CT.

METHODS

A retrospective analysis of patients undergoing hepatectomy for colorectal liver metastases between March 1998 and September 2008.

RESULTS

Overall 5- and 10-year survival was 44.8% and 23.9%. PET CT staging resulted in management changes in 23% of patients. PET CT staged patients showed significantly better survival than those staged by CT alone at 3 years (79.8% vs. 54.1%) and at 5 years (54.1% vs. 37.3%) with median survivals of 6.4 years versus 3.9 years (log rank P = 0.018). Patients with equivocal PET CT scans showed worse median survival than those with favourable PET CT (log rank P = 0.002), but may include a subpopulation whose prognosis trends towards a more favourable outcome than those excluded from liver resection by PET CT, whose median survival remains limited to 21 months.

CONCLUSIONS

Staging of patients with colorectal liver metastases by PET CT is associated with significantly improved actual long-term survival, and provides valuable prognostic information which guides surgical and oncological treatments.