The value of intraoperative ultrasound and preoperative imaging, individually and in combination, in liver resection for metastatic colorectal cancer

Americas Hepato-Pancreato-Biliary Association HPB Ultrasound and Advanced Technology post-graduate course: Overview and review

Background

Americas Hepato-Pancreato-Biliary Association (AHPBA) established the Hepato-Pancreato-Biliary (HPB) ultrasound (US) and Advanced Technology Post-Graduate Course in 2012 in response to a perceived gap in training and practice.

Methods

The HPB US and Advanced Technology Post-Graduate Course consists of both didactic and hands-on skills sessions. The didactic sessions are divided into foundational, organ-focused, and application content. Hands-on sessions are constructed to immediately practice skills in the simulation setting which were taught during the didactic sessions. Course participant demographic data (practice location and practice type) and participant evaluations were reported.

Results

Since the first course in 2012, 298 participants have taken the post-graduate course. Most participants reported the content quality, delivery effectiveness, and practice relevance to be either excellent or above average (93.6 %, 91.1 %, 93.6 %, respectively). Participants' motivations to take the course included to enhance skills, knowledge, to incorporate US into practice, or to obtain formal training or qualification/certification, or to teach.

Conclusion

The HPB US and Advanced Technology Post-Graduate Course has filled a gap in HPB US training for practicing HPB surgeons. The annual course has been well-received by participants (Kirkpatrick Level 1 Program Evaluation) and will continue to fill the gap in training in operative US for the HPB surgeon.

Key message

Americas Hepato-Pancreato-Biliary Association established the HPB Ultrasound and Advanced Technology Post-Graduate Course in 2012. The Course has been well-received by participants and will continue to address a gap in surgical HPB training.

Routine Intraoperative Ultrasound for the Detection of Liver Metastases during Resection of Primary Colorectal Cancer - A Systematic Review

During the discovery of ColoRectal Cancer (CRC), 20% to 30% of patients have synchronous liver metastases. Ten to 30% of patients have non-evidence of Liver Metasteses (LM) following preoperative imaging such as Contrast-Enhanced Ultrasound (CE-US), multi-slice Contrast-Enhanced Computed Tomography (CE-CT), Contrast-Enhanced Magnetic Resonance Imaging (CE-MRI), and Positron Emission Tomography-Computed Tomography (PET-CT). Today, IntraOperative UltraSound (IOUS) in open surgery and Laparoscopic UltraSound (LUS) in laparoscopic or robotic surgery are considered the "gold standard" for detecting liver metastases. The object of this review is to demonstrate the higher sensitivity and specificity of IOUS and LUS in the detection rate of liver metastases.

Improved imaging of colorectal liver metastases using single-source, fast kVp-switching, dual-energy CT: preliminary results

Purpose

Computed tomography remains the first-choice modality for assessment of colorectal cancer liver metastases (CRLM). Dual-energy computed tomography (DECT) is a relatively new technique that is becoming increasingly available. One of the advantages of DECT is the ability to maximise iodine detection. Our aim was to test whether single-source, fast kVp-switching DECT can improve imaging quality of CRLM compared to conventional (polychromatic) CT.

Material and methods

Twenty consecutive patients were enrolled into a preliminary prospective study. The scanning protocol consisted of four phases: non-contrast with standard 120 kV tube voltage and three post-contrast phases with rapid voltage switching. As a result, three sets of images were reconstructed: pre- and postcontrast polychromatic (PR), monochromatic (MR), and iodine concentration map (IM). To compare the sensitivity of the tested reconstructions, the number of CRLMs and the maximum diameter of the largest lesion were calculated. Objective image quality was measured as signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). The radiation dose was expressed as CTDI_vol.

Results

Imaging was successfully performed in all patients. The number of detected lesions was significantly lower on PR images than on IM and MR 50-70 keV (mean number: 4.20 and 4.45, respectively). IM and MR at 70 keV presented the highest quality. SNR was significantly higher for IM and 70 keV images than for other reconstructions. The mean radiation dose was 14.61 mGy for non-contrast 120 kV scan and 17.89 mGy for single DECT scan (p < 0.05).

Conclusions

DECT is a promising tool for CRLM imaging. IM and low-photon energy MR present the highest differences in contrast between metastases and the normal liver parenchyma.

Case-controlled study comparing peri-operative and cancer-related outcomes after major hepatectomy and parenchymal sparing hepatectomy for metastatic colorectal cancer

INTRODUCTION

Liver resection is potentially curative in selected patients with colorectal liver metastases (CLM). There has been a trend towards parenchyma sparing hepatectomy (PSH) rather than major hepatectomy (MH) due to lower perioperative morbidity. Although data from retrospective series suggest that long-term survival after PSM are similar to MH, these reports may be subject to selection bias. The aim of this study was to compare outcomes of PSH and MH in a case-controlled study.

PATIENTS AND METHODS

917 consecutive patients who underwent liver resection for CLM during 2000-2010 were identified from a prospective database. 238 patients who underwent PSH were case-matched with 238 patients who had MH, for age, gender, tumour number, maximum tumour diameter, primary Dukes' stage, synchronicity and chemotherapy status using a propensity scoring system. Peri-operative outcomes, recurrence and long-term survival were compared.

RESULTS

Fewer PSH patients received peri-operative blood transfusions (p < 0.0001). MH patients had greater incidence of complications (p = 0.04), grade III/IV complications (p = 0.01) and 90-day mortality (p = 0.03). Hospital stay was greater in the MH group (p = 0.04). There was no difference in overall/disease-free survival.

CONCLUSION

Patients with resectable CLM should be offered PSH if technically feasible. PSH is safer than MH without compromising long-term survival.

An overview of imaging techniques for liver metastases management

Evaluation of liver metastases is one of the most common indications for liver imaging. Imaging plays a key role in the of assessment liver metastases. A variety of imaging techniques, including ultrasonography, computed tomography, MRI and PET combined with CT scan are available for diagnosis, planning treatment, and follow-up treatment response. In this paper, the authors present the role of imaging for the assessment of liver metastases and the contribution of each of the different imaging techniques for their evaluation and management. Following recent developments in the field of oncology, the authors also present the importance of imaging for the assessment of liver metastases response to therapy. Finally, future perspectives on imaging of liver metastases are presented.

[Liver transection: modern procedure: Technique, results and costs]

Liver resection has developed into the current standard procedure due to modern resection techniques, profound knowledge of the liver anatomy and optimized surgical and anesthesiological strategies to allow extended resections with both low morbidity and mortality. Initially major blood loss was the biggest concern with liver resection and a Pringle's manoeuvre was necessary. Nowadays, biliary leakage is the major problem after liver surgery. Besides the classical conventional clamp crushing technique for parenchymal transection, various devices including ultrasound, microwaves and staplers have been introduced. Minimally invasive techniques have become increasingly important for liver resection but are still applied in selected patients only. The selection of the resection technique and device mainly depends on the extent of the resection and also on the liver parenchyma, the liver disease, costs, personal experiences and preferences. This article presents a selection of techniques used in modern parenchymal transection during liver resection with special focus on transection time, blood loss, bile leakage and costs.

Is intraoperative ultrasound still useful for the detection of colorectal cancer liver metastases?

BACKGROUND

Debate on the optimal mode of preoperative imaging in the management of colorectal liver metastases (CRLM) is ongoing and, despite its longstanding use, the precise role of intraoperative ultrasonography (IOUS) is not well established. This study evaluates the impact of IOUS in the era of high-quality, cross-sectional imaging techniques.

METHODS

All patients who underwent liver resection for CRLM in a tertiary care referral centre from January 2006 to December 2013 were included. All patients were submitted to computed tomography (CT) and/or liver magnetic resonance imaging (MRI) before surgery. Intraoperative US was performed mainly to detect previously non-diagnosed tumours that would change the surgical strategy.

RESULTS

A total of 225 liver resections were performed. Liver MRI and CT scans were available for 202 patients (89.8%) and 225 patients (100%), respectively. Radiological reports recorded 632 liver tumours in 219 patients (i.e. 2.9 lesions per patient). The median time between preoperative liver MRI and surgical resection was 36 days. Intraoperative inspection, palpation and US found 20 additional lesions in 18 patients (8.0%), in three of whom lesions were diagnosed only on IOUS (1.4%). Overall, only 12 of the 20 lesions were malignant.

CONCLUSIONS

Although CT and liver MRI are commonly used, IOUS alone allows the discovery of a few additional lesions that result in a change of surgical strategy in 1.4% of cases.

Advances in understanding of colorectal liver metastasis and implications for the clinic

Colorectal cancer is one of the most common cancers in both the USA and Europe. Over the course of diagnosis, treatment and surveillance, up to 50% of these patients will develop metastases to their liver. In the past 20 years alone, there have been multiple advances in the management of these colorectal metastases to the liver. These advances have been made in characterization of these tumors, diagnosis and in treatment, both locally and systemically. Because of this progress, there are subsets of patients with this stage IV disease who are cured of their disease. While significant progress has been made, there still exist limitations in the management of metastatic colorectal cancer to the liver. This review outlines current strategies and highlights recent advances in the management of colorectal liver metastases.

Current status of imaging and emerging techniques to evaluate liver metastases from colorectal carcinoma

Colorectal cancer is the third most common cancer diagnosed in both men and women in the United States. Liver is a common site of tumor spread and in approximately 30% of the cases; synchronous liver disease is present at the time of diagnosis. Early detection of liver metastases is crucial to appropriately select patients who may benefit from hepatic resection among those needing chemotherapy, to improve 5-year survival. Advances in imaging techniques have contributed greatly to the management of these patients. Multidetector computed tomography is the most useful test for initial staging and in posttreatment surveillance settings. Magnetic resonance imaging is considered superior to multidetector computed tomography and positron emission tomography for the detection and characterization of small lesions and for liver evaluation in the presence of background fatty liver changes. Positron emission tomography-computed tomography has a problem-solving role in the detection of distant metastasis and in posttreatment evaluation. The advanced imaging methods also serve a role in selecting appropriate patients for radiologically targeted therapies and in monitoring response to conventional and novel therapies.

A comparison of diagnostic imaging modalities for colorectal liver metastases

AIMS

The aims of this study were to compare the diagnostic performance of CT scan, MR liver, PET-CT and intra-operative ultrasound (IOUS) for the detection of liver metastases against the histopathological findings, and to compare PET-CT with CT for the detection of distant disease in metastatic colorectal cancer patients eligible for surgical treatment.

METHODS

A prospective study was performed that measured concordance between the number and stage of metastatic lesions identified with various preoperative imaging modalities and histology of patients undergoing surgical treatment for CRLM.

RESULTS

Compared with histopathology, concordance for the number of metastatic liver lesions was moderate for CT scan (K = 0.477, 95% CI: 0.28-0.66), moderate for MR scan (K = 0.574, 95% CI: 0.39-0.75), good for FDG PET-CT (K = 0.703, 95% CI: 0.52-0.87) and very good for IOUS (K = 0.904, 95% CI: 0.81-0.99). Additional CRLM were identified intraoperatively in six patients (9.1%) with IOUS and in 7.5% of the cases surgical strategy was changed according to the new intraoperative findings. The diagnosis of intra abdominal lymph node metastatic disease was made with PET-CT only in nine patients (13.6%)

DISCUSSION

Our study supports the recent recommendations of the Oncosurg Multidisciplinary International Consensus regarding the importance of high quality CT and MR in the staging of CRLM but provides further evidence for the added value of PET-CT, especially in detecting extrahepatic intra-abdominal metastatic disease that may be amenable to potentially curative resection. Despite these advances in preoperative staging, there still remains a role for IOUS in detecting additional metastases at the time of surgery.

Laparoscopy with laparoscopic ultrasound for pretreatment staging of hepatic focal lesions: a prospective study

INTRODUCTION

The need for accurate intrahepatic staging is crucial for patients with primary or secondary hepatic malignancies. Currently available data indicate that laparoscopy with laparoscopic ultrasound provides information similar to that obtained by intraoperative ultrasound and that it is able to identify small intrahepatic lesions not diagnosed by preoperative conventional imaging techniques.

OBJECTIVE

To determine the role of preoperative laparoscopy and laparoscopic ultrasonography in patients with potentially resectable hepatic focal lesion or candidate for radiofrequency ablation based on preoperative imaging.

MATERIAL AND METHODS

From March 2004 to March 2007, 55 patients with potentially resectable hepatic focal lesions were candidates for exploratory laparotomy based on preoperative abdominal ultrasonography and triphasic spiral CT. All cases were then reevaluated prior to surgery using laparoscopy and laparoscopic ultrasound. All these procedures were performed within a time period of no more than 4 weeks. The data obtained were compared to those obtained by the preoperative conventional imaging studies as regards the presence of satellites, subcentimetric lesions, newly discovered deep parynchymatous lesions, liver condition, portal vein thrombosis, nodal metastases, ascites, peritoneal implants, size and site of the primary lesion.

RESULTS

After performing ultrasound-guided laparoscopy, fourteen patients proved to be unfit for surgical resection or ablation, seven patients showed newly discovered focal lesions, five patients proved to have satellites around the tumor and peritoneal deposits, one patient had ascites and one patient had been falsely diagnosed as HCC, proved to have had a liver abscess.

CONCLUSION

Preoperative laparoscopy and laparoscopic ultrasonography as an adjunct to preoperative imaging techniques provide more accurate staging for patients with potentially resectable hepatic focal lesions.