Intraoperative detection of disappearing colorectal liver metastases as a predictor of residual disease

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

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

Contemporary Surgical Management of Colorectal Liver Metastases

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

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Missing colorectal liver metastases: the surgical challenge

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Management of disappearing colorectal liver metastases: an international survey

BACKGROUND

Improved chemotherapy response rates have lead to "disappearing" colorectal liver metastases (dCRLM). We aim to assess management patterns of dCRLM from an international body of hepatobiliary surgeons.

METHODS

A survey was designed, tested for item relevance, readability and content validity, and distributed to the AHPBA, IHPBA and ANZHPBA.

RESULTS

The majority of 226 respondents were <15 years from training (69%), practiced in academia (82%) and devoted >50% of their practice to hepatobiliary (75%). Surgeons utilize CT(45%) or MRI(47%) for preoperative planning with a preferred imaging interval of <6 weeks. Nearly all have experienced dCRLM (99%) and 63% of surgeons have waited a few months to assess for durability of response prior to definitive surgical/ablative therapy. Only 24% place fiducial markers for lesions <1-cm prior to neoadjuvant chemotherapy. Intra-operatively, 97% of surgeons perform ultrasound, and 71% ablation. When a tumor has "disappeared," 49% elect for observation and 31% resect if the dCRLM is superficial. Of those electing observation, 87% believe there is effective treatment with progression on surveillance imaging.

CONCLUSIONS

Nearly all surgeons have experienced dCRLM with half choosing observation over intervention due to the belief that these lesions may be re-addressed in the future.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Current role of intraoperative ultrasonography in hepatectomy

Hepatectomy had a high mortality rate in the previous decade because of inadequate techniques, intraoperative blood loss, liver function reserve misdiagnoses, and accompanying postoperative complications. However, the development of several modalities, including intraoperative ultrasonography (IOUS), has made hepatectomy safer. IOUS can provide real-time information regarding the tumor position and vascular anatomy of the portal and hepatic veins. Systematic subsegmentectomy, which leads to improved patient outcomes, can be performed by IOUS in open and laparoscopic hepatectomy. Although three-dimensional (3D) computed tomography and gadoxetic acid-enhanced magnetic resonance imaging have been widely used, IOUS and contrast-enhanced IOUS are important modalities for risk analyses and making decisions regarding resectability and operative procedures because of the vital anatomical information provided and high sensitivity for liver tumors, including "disappearing" liver metastases. Intraoperative color Doppler ultrasonography can be used to delineate the vascular anatomy and evaluate the blood flow volume and velocity in hepatectomy patients and recipients of deceased- and living-donor liver transplantation after vessel reconstruction and liver positioning. For liver surgeons, IOUS is an essential technique to perform highly curative hepatectomy safely, although recent advances have also been made in virtual modalities, such as real-time virtual sonography with 3D visualization.

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

Background

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

Methods

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

Results

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

Conclusion

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

Disappearing colorectal liver metastases: Strategies for the management of patients achieving a radiographic complete response after systemic chemotherapy

The mainstays of treatment for colorectal liver metastases (CRLMs) are surgery and chemotherapy. Chemotherapeutic benefits of tumor shrinkage and systemic control of micrometastases are in part counterbalanced by chemotoxicity that can modify the liver parenchyma, jeopardizing the detection of CRLM. This review addresses the clinical decision-making process in the context of radiographic and pathologic responses, the preoperative imaging workup, and the approaches to the liver for CRLM, which disappear after systemic chemotherapy.

Intraoperative Ultrasound Staging for Colorectal Liver Metastases in the Era of Liver-Specific Magnetic Resonance Imaging: Is It Still Worthwhile?

Background

To assess the efficacy of intraoperative ultrasound (IOUS) compared with liver-specific magnetic resonance imaging (MRI) in patients with colorectal liver metastases (CRLMs).

Methods

From January 2010 to December 2017, 721 patients underwent MRI as a part of preoperative workup within 1 month before hepatectomy and were considered for the study. Early intrahepatic recurrence (relapse at cut surface excluded) was assessed 6 months after the resection and was considered as residual disease undetected by IOUS and/or MRI. IOUS and MRI performance was compared on a patient-by-patient basis. Long-term results were also studied.

Results

A total of 2845 CRLMs were detected by MRI, and the median number of CRLMs per patient was 2 (1–31). Preoperative chemotherapy was administered in 489 patients (67.8%). In 177 patients, 379 new nodules were intraoperatively found and resected. Among 379 newly identified nodules, 317 were histologically proven CRLMs (11.1% of entire series). The median size of new CRLMs was 6 ± 2.5 mm. Relationships between intrahepatic vessels and tumors differed between IOUS and MRI in 128 patients (17.7%). The preoperative surgical plan was intraoperatively changed for 171 patients (23.7%). Overall, early intrahepatic recurrence occurred in 8.7% of cases. To assess the diagnostic performance, 24 (3.3%) recurrences at the cut surface were excluded; thus, 5.4% of early relapses were considered for analysis. The sensitivity of IOUS was superior to MRI (94.5% vs 75.1%), while the specificity was similar (95.7% vs 95.9%). Multivariate analysis at the hepatic dome or subglissonian and mucinous histology revealed predictive factors of metastases missing at MRI. The 5-year OS (52.1% vs 37.8%, p=0.006) and DF survival (45.1% vs 33%, p=0.002) were significantly worse among patients with new CRLMs than without.

Conclusions

IOUS improves staging in patients undergoing resection for CRLMs even in the era of liver-specific MRI. Intraoperative detection of new CRLMs negatively affects oncologic outcomes.

Intraoperative ultrasonography in patients undergoing surgery for Crohn's disease. Prospective evaluation of an innovative approach to optimize staging and treatment planning

Percutaneous ultrasonography (perc-US) and magnetic resonance enterography (e-MR) are the present standards for staging patients with Crohn's disease (CD). However, intraoperative data still have some discrepancies with preoperative ones. The contribution of intraoperative ultrasonography (IOUS) has never been evaluated. Sixty-five consecutive patients scheduled for ileal/colonic resection for CD between 2010 and 2014 were prospectively enrolled. All patients had perc-US, e-MR and IOUS. Data from different imaging modalities were compared. The reference standard was the final pathology. Surgery was scheduled because of intestinal obstruction (n = 31 patients), inflammatory mass (n = 21), fistula (n = 10), or abdominal pain/sepsis (n = 3). Fourteen (21.5%) patients had a major discrepancy between preoperative and intraoperative data that required a modification of the surgical planning (five additional ileal lesions, three unknown ileo-sigmoid fistulas, and six not confirmed CD sites). IOUS correctly staged CD in all but one patients (missed ileo-colonic fistula). Pathology data differed from Perc-US data in 13 (20%) patients, from e-MR data in 14 (21.5%), and from IOUS data in one (1.5%). The sensitivity of Perc-US, e-MR and IOUS was: for the identification of CD sites 84.2%, 86.1%, and 100%; for the identification of stenoses 86.8%, 86.8%, and 100%; for the identification of fistulas 75.0%, 81.3%, and 93.8%, respectively. IOUS contributed to the surgical planning in 8 (12.3%) patients. IOUS is a safe, feasible and easy-to-perform procedure that optimizes staging of CD and, in some patients, helps to better define the treatment strategy. It could be helpful to face complex disease presentations on the basis of objective and reproducible data.

Disappearing liver metastases: A systematic review of the current evidence

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

Utility of Image Guidance in the Localization of Disappearing Colorectal Liver Metastases

BACKGROUND

Colorectal liver metastases that demonstrate a complete radiographic response during chemotherapy are increasingly common with advances in chemotherapy regimens and are described as disappearing liver metastases (DLMs). However, these DLMs often continue to harbor residual viable tumor. If these tumors are found in the operating room with ultrasound (US), they should be treated. The intraoperative sonographic visualization of these lesions, however, can be hindered by chemotherapy-associated liver parenchyma changes. The objective of this study was to evaluate the use of an intraoperative image guidance system, Explorer (Analogic Corporation, Peabody, MA), to aid surgeons in the identification of DLMs initially undetected by US alone.

STUDY DESIGN

In a single-arm prospective trial, patients with colorectal liver metastases undergoing liver resection and/or ablation with one or more DLMs during neoadjuvant chemotherapy were enrolled. Intraoperatively, DLMs were localized with conventional US. Any DLM not found by conventional US was re-evaluated with the image guidance system. The primary outcome was the proportion of sonographically occult DLMs subsequently located by image-guided US.

RESULTS

Between April 2016 and November 2017, 25 patients with 61 DLMs were enrolled. Thirty-eight DLMs (62%) in 14 patients (56%) were not identified with US alone. Six (16%) DLMs in five patients (36%) were subsequently located with assistance of the image guidance system. The image guidance changed the intraoperative surgical plan in four of these patients.

CONCLUSIONS

Image guidance can aid surgeons in the identification of initially sonographically occult DLMs and facilitate the complete surgical clearance of all sites of liver disease.

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

Background

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

Methods

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

Results

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

Conclusion

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

A radiologist's point of view in the presurgical and intraoperative setting of colorectal liver metastases

Multidisciplinary management of patients with metastatic colorectal cancer requires in each phase an adequate choice of the most appropriate imaging modality. The first challenging step is liver lesions detection and characterization, using several imaging modality ultrasound, computed tomography, magnetic resonance and positron emission tomography. The criteria to establish the metastases resectability have been modified. Not only the lesions number and site but also the functional volume remnant after surgery and the quality of the nontumoral liver must be taken into account. Radiologists should identify the liver functional volume remnant and during liver surgical procedures should collaborate with the surgeon to identify all lesions, including those that disappeared after the therapy, using intraoperative ultrasound with or without contrast medium.

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

BACKGROUND

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

METHODS

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

RESULTS

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

DISCUSSION

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

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

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Hepatic resection for primary and secondary liver malignancies

Liver surgery has become the standard treatment of primary liver cancer and liver metastases from colorectal cancer. Also, patients with non-colorectal liver metastases are increasingly offered surgery due to the low morbidity and excellent long-term results. The evolution of two-stage procedures helps to increase resectability. Also, laparoscopic and robotic liver surgery are constantly developed.

I BRAZILIAN CONSENSUS ON MULTIMODAL TREATMENT OF COLORECTAL LIVER METASTASES. MODULE 2: APPROACH TO RESECTABLE METASTASES

Background:

Liver metastases of colorectal cancer are frequent and potentially fatal event in the evolution of patients.

Aim:

In the second module of this consensus, management of resectable liver metastases was discussed.

Method:

Concept of synchronous and metachronous metastases was determined, and both scenarius were discussed separately according its prognostic and therapeutic peculiarities.

Results:

Special attention was given to the missing metastases due to systemic preoperative treatment response, with emphasis in strategies to avoid its reccurrence and how to manage disappeared lesions.

Conclusion:

Were presented validated ressectional strategies, to be taken into account in clinical practice.

Oligometastatic Disease in Colorectal Cancer - How to Proceed?

BACKGROUND

Oligometastatic disease in colorectal cancer may affect the liver, lung, and peritoneum. This review mainly focuses on colorectal liver metastases (CRLM) and highlights recommendations and therapeutic strategies drawn from the current literature and consensus conferences. The following data address a paradigm shift in surgical approaches to CRLM, pushing the limits of multimodal treatment concepts.

METHODS

A systematic review of the relevant literature on multimodal treatment strategies for synchronous and metachronous CRLM is presented.

RESULTS

The choice of treatment strategy depends on the clinical scenario; however, perioperative chemotherapy and the liver-first concept in synchronous CRLM are favored with subsequent partial extended liver resection with or without various augmentation techniques for liver surgery.

CONCLUSION

Surgical strategies should be strongly defined with regard to an adequate liver remnant. All patients with synchronous CRLM should be evaluated by a multidisciplinary team.

Intraoperative Contrast-Enhanced Ultrasound in Colorectal Liver Metastasis Surgery Improves the Identification and Characterization of Nodules

INTRODUCTION

The sensitivity of preoperative assessment of colorectal liver metastases (CRLM) ranges from 74 to 80%. Intraoperative ultrasound (IOUS) associated with contrast-enhanced intraoperative ultrasound (CE-IOUS) may be able to improve this. Thus, the aims of this study were to assess the value of IOUS and CE-IOUS for the surgical approach and to determine risk factors both for the detection of new nodules and for the modification of the surgical strategy.

MATERIALS AND METHODS

Forty-three patients who underwent CRLM surgery were included. These patients had an MRI in the 8 weeks preceding surgery and benefited from intraoperative IOUS and CE-IOUS.

RESULTS AND DISCUSSION

The use of IOUS/CE-IOUS permitted the identification of 43 additional lesions and an improved characterization of nodules in 23 patients with a resulting modification of surgical strategy. Lesions were down-staged in six patients and up-staged in six patients. Chemotherapy (p = 0.02) and the presence of nodules in the left lobe (p = 0.04) were predictive factors for finding new nodules at IOUS/CE-IOUS. The discovery of a new nodule systematically modified surgical management. IOUS/CE-IOUS improved intraoperative management of liver metastases. The techniques enable pertinent modification of surgical resections and a reduction of residual lesions.

Management of disappearing colorectal liver metastases

The development of new potent systemic treatment modalities has led to a significant increase in survival of patients with colorectal liver metastases. In the neo-adjuvant setting, these modalities can be used for patient selection, down staging, and conversion from non-resectable to resectable liver metastases. In addition, complete radiological disappearance of metastases can occur, the phenomenon of disappearing liver metastases. Because only a small percentage of these patients (0-8%) have a complete radiological response of all liver metastases, most patients will undergo surgery. At laparotomy, local residual disease at the site of the disappeared metastasis is still found in 11-67%, which highlights the influence of the imaging modalities used at (re)staging. When the region of the disappeared liver metastasis was resected, microscopically residual disease was found in up to 80% of the specimens. Alternatively, conservative management of radiologically disappeared liver metastases resulted in 19-74% local recurrence, mostly within two years. Obviously, these studies are highly dependent on the quality of the imaging modalities utilised. Most studies employed CT as the modality of choice, while MRI and PET was only used in selective series. Overall, the phenomenon of disappearing liver metastases seems to be a radiological rather than an actual biological occurrence, because the rates of macroscopic and microscopic residual disease are high as well as the local recurrence rates. Therefore, the disappeared metastases still require an aggressive surgical approach and standard (re)staging imaging modalities should include at least CT and MRI.

Missing metastases as a model to challenge current therapeutic algorithms in colorectal liver metastases

In oncosurgical approach to colorectal liver metastases, surgery remains considered as the only potentially curative option, while chemotherapy alone represents a strictly palliative treatment. However, missing metastases, defined as metastases disappearing after chemotherapy, represent a unique model to evaluate the curative potential of chemotherapy and to challenge current therapeutic algorithms. We reviewed recent series on missing colorectal liver metastases to evaluate incidence of this phenomenon, predictive factors and rates of cure defined by complete pathologic response in resected missing metastases and sustained clinical response when they were left unresected. According to the progresses in the efficacy of chemotherapeutic regimen, the incidence of missing liver metastases regularly increases these last years. Main predictive factors are small tumor size, low marker level, duration of chemotherapy, and use of intra-arterial chemotherapy. Initial series showed low rates of complete pathologic response in resected missing metastases and high recurrence rates when unresected. However, recent reports describe complete pathologic responses and sustained clinical responses reaching 50%, suggesting that chemotherapy could be curative in some cases. Accordingly, in case of missing colorectal liver metastases, the classical recommendation to resect initial tumor sites might have become partially obsolete. Furthermore, the curative effect of chemotherapy in selected cases could lead to a change of paradigm in patients with unresectable liver-only metastases, using intensive first-line chemotherapy to intentionally induce missing metastases, followed by adjuvant surgery on remnant chemoresistant tumors and close surveillance of initial sites that have been left unresected.

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

BACKGROUND

Hepatobiliary contrast enhanced MRI is known to be the most sensitive imaging modality for detection of colorectal hepatic metastasis. To date no study has investigated the rate of disappearing lesions with gadoxetic acid MR (Eovist/Primovist), or characterized the pathologic response of lesions which disappear on gadoxetic acid MR.

METHODS

Retrospective review of hepatic resections for colorectal metastases between 01/2008 and 01/2014 was performed to evaluated the rate of disappearance of lesions on gadoxetic acid MR and the rate of complete pathologic response in the lesions that disappear. "Disappearing lesions" were lesions on baseline imaging that were not identifiable on pre-operative Eovist MRI. Complete pathologic response was defined as no viable tumor on pathology or by lack of recurrence within 1 year.

RESULTS

In 23 patients, 200 colorectal metastases were identified on baseline imaging. On pre-operative Eovist MR 77 of the 200 lesions (38.5%) were "disappearing" lesions. At surgical pathology or 1 year follow-up imaging, 42 of 77 lesions (55%) demonstrated viable tumor (21) or recurrence (21). Thirty of 77 lesions (39%) were nonviable at pathology (10) or without evidence of recurrence at 1 year (20). 5 lesions were indeterminate.

DISCUSSION

Despite disappearance on Eovist MR imaging (the most sensitive available imaging modality), 38.5% of all colorectal metastases disappeared and of those, 55% were viable.

Impact of surgical margin clearance for resection of secondary hepatic malignancies

Over the past several decades, there has been increasing discussion regarding the optimal management of secondary liver malignancies. Traditionally, resection has only been recommended if it could be accomplished with negative microscopic margins of at least 10 mm. However, many investigators have pushed this limit to offer resection to patients with narrower margins. We review the data regarding the impact of margin clearance on outcomes for patients undergoing hepatic metastasectomy.

Complete pathological response of unresectable liver metastases from colorectal cancer after trans-arterial chemoembolization with drug-eluting beads loaded with irinotecan (DEBIRI) and concomitant systemic FOLFOX: A case report from the FFCD 1201 trial

INTRODUCTION

Most liver metastases from colorectal cancer (CRC) are unresectable at diagnosis. Systemic chemotherapy allows secondary surgical resection in 10 to 20% of patients. Hepatic intra-arterial treatments could enhance response and resection rate. We therefore designed a prospective phase II trial testing the transarterial chemoembolization (TACE) using drug-eluting beads loaded with irinotecan (DEBIRI) with concomitant systemic FOLFOX regimen, the FFCD 1201 trial, in patients with liver limited metastatic CRC.

CASE REPORT

A 48-year old patient was operated from an occlusive sigmoid adenocarcinoma. Magnetic resonance imaging showed 6 bilobar liver metastasis. The patient was considered as non-eligible for surgery initially. Patient was included in the FFCD 1201 trial and received 5 cycles of FOLFOX and 2 sessions of DEBIRI, with a quite good tolerability. Post-treatment evaluation showed a partial response and sufficient tumor shrinkage to make liver metastasis resectable. Right hepatectomy associated with wedge resection in the left liver was performed and pathological findings showed a complete pathological response (CPR).

CONCLUSION

Combination of DEBIRI with FOLFOX could increase tumor shrinkage leading to secondary resection of liver metastases from CRC. This combination may also, as shown here for the first time in a patient with unresectable LM, induce CPR of all LM, known to be associated with better outcome. Our case also emphasizes the difficulty to morphologically assess pathological response and the need for new tool to better select patients who should be resected. Further results of the FFCD 1201 trial will bring more information on this new combination therapy.

Disappearing liver metastases from colorectal cancer: impact of modern imaging modalities

BACKGROUND

Chemotherapy is often used before a resection for colorectal liver metastases. After chemotherapy, metastases may disappear on cross-sectional imaging but residual metastatic disease may still exist. The aim of this retrospective study was to investigate the impact of new advancements in imaging technology such as magnetic resonance imaging (MRI) with liver-specific contrast (Gd-EOB-DTPA) and contrast-enhanced intra-operative ultrasound (CE-IOUS) on disappearing liver metastases (DLM).

METHODS

Twenty-nine patients with one or more DLM undergoing surgical exploration were included. Pre-operative imaging consisted of contrast-enhanced multi-detector computed tomography (MDCT) and/or MRI with liver-specific contrast. At surgery, CE-IOUS was used when tumours known from pre-chemotherapy imaging were not found by inspection or intra-operative ultrasound.

RESULTS

Patients presented 66 DLM. At surgical exploration, 42 DLM were identified and treated (64%). CE-IOUS detected one additional DLM not found by intra-operative ultrasound. For metastases ≤10 mm on histological analysis, imaging sensitivities for MRI and MDCT before surgery but after chemotherapy were 26/49 (53%) and 24/66 (36%), respectively.

CONCLUSION

A majority of DLM are identified during surgery using intra-operative ultrasound, with only little additional value of CE-IOUS. The sensitivities of post-chemotherapy imaging modalities for small metastases are low in the setting of DLM. For surgical planning, an optimized pre-chemotherapy imaging is essential.

The role of intraoperative ultrasonography in the diagnosis and management of focal hepatic lesions

Intraoperative ultrasonography (IOUS) has been widely utilized in hepatic surgery both as a diagnostic technique and in the course of treatment. Since IOUS involves direct-contact imaging of the target organ, it can provide high spatial resolution without interference from the surrounding structures. Therefore, IOUS may improve the detection, characterization, localization, and local staging of hepatic tumors. IOUS is also a real-time imaging modality capable of providing interactive information and valuable guidance in a range of procedures. Recently, contrast-enhanced IOUS, IOUS elastography, and IOUS-guided hepatic surgery have attracted increasing interest and are expected to lead to the broader implementation of IOUS. Herein, we review the various applications of IOUS in the diagnosis and management of focal hepatic lesions.

Differential diagnosis of liver tumours using intraoperative real-time tissue elastography

Background

Real-time tissue elastography is an innovative tool that informs the surgeon about tissue elasticity by applying the principle of ultrasonography. The aim of this study was to investigate the accuracy of intraoperative real-time tissue elastography (IORTE) for the detection and characterization of liver tumours.

Methods

Between October 2010 and November 2011, IORTE was performed for liver lesions after the completion of routine B-mode intraoperative ultrasonography (IOUS). The elasticity images of all tumours, except those of cysts, were classified into six categories according to modified criteria (types 1–6), according to the degree of strain contrast with the surrounding liver. The concordance of IORTE with pathological examination of the tumour, B-mode IOUS and clinical diagnosis after follow-up was assessed.

Results

Images were obtained from 92 hepatocellular carcinomas (HCCs), 92 adenocarcinomas, 19 other malignant tumours and 18 benign tumours in 158 patients. Using a minilinear probe, 73 of 88 HCCs were classified as having a ‘HCC pattern’ (type 3, 4 or 5), resulting in a sensitivity of 83·0 per cent, a specificity of 67·2 per cent and an accuracy of 73·7 per cent. Some 66 of 90 adenocarcinomas were classified as ‘adenocarcinoma pattern’ (type 6), resulting in a sensitivity of 73·3 per cent, specificity of 95·1 per cent and accuracy of 85·9 per cent. IORTE detected seven new lesions (8 per cent).

Conclusion

IORTE is useful for the detection and characterization of liver tumours.

Colorectal cancer with liver metastases: Neoadjuvant chemotherapy, surgical resection first or palliation alone?

Colorectal cancer (CRC) is one of the commonest cancers with 1.2 million new cases diagnosed each year in the world. It remains the fourth most common cause of cancer-related mortality in the world and accounts for > 600000 cancer-related deaths each year. There have been significant advances in treatment of metastatic CRC in last decade or so, due to availability of new active targeted agents and more aggressive approach towards the management of CRC, particularly with liver-only-metastases; however, these drugs work best when combined with conventional chemotherapy agents. Despite these advances, there is a lack of biomarkers to inform us about the accurate management of the patients with metastatic CRC. It is therefore imperative to carefully select the patients with comprehensive multi-disciplinary team input in order to optimise the management of these patients. In this review we will discuss various treatment options available in management of colorectal liver metastases with potential guidance on how and when to choose these options along with consideration on future directions in management of this disease.

Potentially resectable metastatic colorectal cancer: an individualized approach to conversion therapy

Colorectal cancer is one of the most common cancers worldwide. In recent years, the survival of patients with metastatic disease has improved due to the developments in both medical and surgical care. Patients with technically unresectable metastatic disease could benefit from a multidisciplinary approach for their possible shift toward a technically resectable condition; the choice of the most effective systemic treatment is then crucial to allow conversion to resectability. Systemic conversion therapy may include chemotherapy agents' combinations (fluoropyrimidine, irinotecan and oxaliplatin), with or without targeted agents (cetuximab, panitumumab, bevacizumab). The choice of the best treatment option has to be evaluated by taking into account each patient's baseline characteristics, biological and pathological information and surgical strategy. In particular, the role of some biologic characteristics of the disease, namely the mutational status of EGFR-pathway oncogenes, is emerging as an important predictive factor of response to anti-EGFR targeted agents. Patients presenting with colorectal cancer metastases should be evaluated for multimodal management with curative intent as the appropriate chemotherapy regimen may induce tumor shrinkage, conversion to resectability and improved survival.

[Neoadjuvant chemotherapy or primary surgery for colorectal liver metastases. Pro primary surgery]

Approximately 50 % of patients with colorectal cancer (CRC) develop liver metastases, with the liver being the only site of metastasis in the majority of patients. Liver resection is the standard treatment of CRC liver metastases as it achieves a 5-year survival of 36-51 %. The primary goal in the treatment of non-resectable liver metastases is to achieve resectability by preoperative chemotherapy as even secondary liver resection after down-sizing is associated with improved overall survival. Furthermore, resectability can be increased by two-stage surgical procedures; however, the assessment of resectability varies widely even among experts in the field. In cases of suspected non-resectability patients should therefore be liberally admitted for a second opinion to centers of liver surgery. Perioperative chemotherapy in primarily resectable cases has only demonstrated an improvement in recurrence-free survival in subgroup analyses. Moreover, modern potent chemotherapy regimens increase the surgical morbidity depending on the duration of treatment: the lower the histological response of the metastases and the more treatment cycles are applied, the higher is the parenchymal damage with related surgical morbidity. Therefore, perioperative chemotherapy of resectable liver metastases should be viewed with caution and should not be considered the standard of care.

Surgical management of disappearing colorectal liver metastases

BACKGROUND

Owing to expanded surgical indications for colorectal liver metastasis (CRLM) and improved systemic therapy, hepatic surgeons are increasingly faced with the problem of disappearing (no longer visible on imaging) liver metastasis (DLM).

METHODS

A review of relevant studies was performed. Studies that reported on DLM associated with preoperative chemotherapy for CRLM were identified, and data were synthesized and tabulated. The PubMed database was searched for relevant articles published between January 2000 and December 2012.

RESULTS

A complete response on imaging does not necessarily equate with a complete clinical or pathological response. Rather, residual macroscopic disease is found in about 25-45 per cent of patients at the time of operation. Even among patients with a complete pathological response, long-term remission occurs in only 20-50 per cent of those treated with systemic therapy. A durable response of DLM is more common following the use of hepatic artery infusion therapy.

CONCLUSION

Liver resection should include all original sites of disease if possible.

Comparison of laparoscopic and open intraoperative ultrasonography for staging liver tumours

BACKGROUND

Laparoscopic liver surgery must reproduce open surgical steps. Intraoperative ultrasonography (IOUS) is mandatory, but reliability of laparoscopic IOUS has been poorly evaluated. The aim of this study was to compare laparoscopic versus open IOUS in staging liver tumours.

METHODS

All patients scheduled for liver resection between September 2009 and March 2011 were considered. Inclusion criteria were primary and metastatic tumours. Exclusion criteria were: hilar/gallbladder cholangiocarcinoma, ten or more lesions, repeat resection, laparoscopic hepatectomy, adhesions and unresectability. Following percutaneous ultrasonography and thoracoabdominal computed tomography (CT), and on indication contrast-enhanced (CE) liver magnetic resonance imaging (MRI) and/or positron emission tomography (PET)-CT, patients were scheduled for laparoscopy, laparoscopic IOUS, then laparotomy, open IOUS and Partial hepatectomy. Data were collected prospectively. Reference standards were final pathology and 6-month follow-up results.

RESULTS

Sixty-five patients were included, who had a median of 3 preoperative imaging studies (ultrasonography/CT 100 per cent, CE-MRI 67 per cent, PET-CT 54 per cent). A total of 119 lesions were diagnosed. Laparoscopic IOUS detected 22 additional lesions (+18·5 per cent) in 14 patients. Open IOUS detected two additional lesions, but did not confirm four lesions; overall 20 additional lesions (+16·8 per cent) were detected in ten patients. Pathology confirmed 14 newly detected malignant nodules (+11·8 per cent) in eight patients. After 6 months ten new nodules were identified in six patients. The sensitivity of preoperative imaging, laparoscopic IOUS and open IOUS was 83·1, 92·3 and 93·0 per cent respectively; accuracy was 79, 82 and 88 per cent. In comparison with open IOUS, the sensitivity and accuracy of laparoscopic IOUS were 98·6 and 94 per cent.

CONCLUSION

Laparoscopic IOUS is a reliable tool for staging liver tumours with a performance similar to that of open IOUS in detecting new nodules.

Usefulness of contrast-enhanced intraoperative ultrasonography (CE-IOUS) in patients with colorectal liver metastases after preoperative chemotherapy

AIMS

The aim of this study was to evaluate the ability of contrast-enhanced intraoperative ultrasonography to detect colorectal liver metastases after preoperative chemotherapy compared with intraoperative ultrasound and preoperative imaging techniques.

METHODS

From January 2010 to December 2011, 28 patients with colorectal liver metastases underwent intraoperative ultrasonography and contrast-enhanced intraoperative ultrasonography during hepatectomy following preoperative chemotherapy. The findings were compared to preoperative imaging using contrast-enhanced ultrasonography, computed tomography, magnetic resonance imaging, and/or fluorodeoxyglucose positron emission tomography.

RESULTS

Preoperative imaging techniques detected 58 metastatic lesions in 28 patients. In 32 % of patients (n = 9), intraoperative ultrasound detected 24 missed hepatic nodules. In 14 % of patients (n = 4), contrast-enhanced intraoperative ultrasonography detected an additional six nodules and change in operative management occurred in 18 % of patients. Using univariate analysis, we found three factors significantly related to detection of additional metastases with contrast-enhanced intraoperative ultrasonography: three or more metastases before chemotherapy (p = 0.047), resolution of at least one metastasis (p = 0.011), and small liver metastases (largest lesion size ≤20 mm) after chemotherapy (p = 0.007).

CONCLUSION

In patients undergoing surgery for colorectal liver metastases after chemotherapy, contrast-enhanced intraoperative ultrasonography improved both the sensitivity of intraoperative ultrasonography to detect liver metastases and the R0 hepatic resection rate.