The role of FDG-PET in the selection of patients with colorectal liver metastases

Complex Surgical Strategies to Improve Resectability in Borderline-Resectable Disease

Colorectal cancer is the third most common malignancy in the USA and continues to pose a significant epidemiologic problem, despite major advances in the treatment of patients with advanced disease. Up to 50 % of patients will develop metastatic disease at some point during the course of their disease, with the liver being the most common site of metastatic disease. In this review, we address the relatively poorly defined entity of borderline-resectable colorectal liver metastases. The workup and staging of borderline-resectable disease are discussed. We then discuss management strategies, including surgical techniques and medical therapies, which are currently utilized in order to improve resectability.

Predictors of early recurrence after resection of colorectal liver metastases

Background

Early recurrence after resection of colorectal liver metastases (CLM) is common. Patients at risk of early recurrence may be candidates for enhanced preoperative staging and/or earlier postoperative imaging. The aim of this study was to determine if there are any risk factors that specifically predict early liver-only and systemic recurrence.

Methods

Retrospective analysis of prospective database of patients undergoing liver resection (LR) for CLM from 2004 to 2006 was undertaken. Early recurrence was defined as occurring within 18 months of LR. Patients were classified into three groups: early liver-only recurrence, early systemic recurrence and recurrence-free. Preoperative factors were compared between patients with and without early recurrence.

Results

Two hundred and forty-three consecutive patients underwent LR for CLM. Twenty-seven patients (11%) developed early liver-only recurrence. Dukes C stage and male sex were significantly associated with early liver-only recurrence (P < 0.05). Sixty-six patients (27%) developed early systemic recurrence. Tumour size ≥3.6 cm and tumour number (>2) were significantly associated with early systemic recurrence (P < 0.001).

Conclusions

It is possible to stratify patients according to the risk of early liver-only or systemic recurrence after resection of CLM. High-risk patients may be candidates for preoperative MRI and/or computed tomography-positron emission tomography (CT-PET) scan and should receive intensive postoperative surveillance.

Positron emission tomography in hepatobiliary and pancreatic malignancies: a review

BACKGROUND

The prognosis for hepatobiliary and pancreatic malignancies is dismal. Surgery remains the primary curative option, but unresectable disease is often discovered during operative exploration. Positron emission tomography (PET) provides unique biological information different from current imaging modalities. The role of PET in detecting hepatobiliary and pancreatic malignancies has not yet been established. The purpose of this article was to review the literature on the use of PET in hepatobiliary and pancreatic malignancies.

DATA SOURCES

We performed an extensive search on PubMed using PET and hepatocellular, pancreatic, gallbladder, and cholangiocarcinoma as keywords, excluding articles not written in English or on nonhuman subjects, case reports, and series with <5 patients.

CONCLUSIONS

Although PET has shown usefulness in the diagnosis of certain cancers, current literature cautions against the use of PET for determining malignant potential of primary liver and pancreatic lesions. Literature on PET more strongly supports clinical roles for restaging of hepatobiliary and pancreatic malignancies, and for identifying metastatic disease.

The role of 18FDG PET/CT in the management of colorectal liver metastases

INTRODUCTION

Surgical resection remains the only potentially curative treatment for colorectal liver metastases (CLM). However, involvement of both the hepatic lobes or extrahepatic disease (EHD) can be a contra-indication for resection. The aim of the present study was to examine the addition of combined positron emission and computed tomography (PET/CT) to CLM staging to assess the effects upon staging and management.

METHODS

All CLM patients referred to a single centre between January 2005 and January 2009 were prospectively included. All underwent routine staging (clinical examination and computed tomography), followed by a whole body (18) fluoro-deoxy-glucose ((18)FDG)-PET/CT scan and Fong clinical risk score calculation.

RESULTS

Sixty-four patients were included [63% male with a median age of 63 years (age range 32-79 years)]. The addition of PET/CT led to disease upstaging in 20 patients (31%) and downstaging in two patients (3%). EHD was found in 24% of low-risk patients (Fong score 0-2) as compared with 44% of high-risk patients (Fong score 3-5) (P= 0.133). There was a trend towards a greater influence upon management in patients with a low score (44% vs. 17%; P= 0.080).

CONCLUSION

The addition of PET/CT led to management changes in over one-third of patients but there was no correlation between alterations in staging or management and the Fong clinical risk score; suggesting that PET/CT should be utilized, where available, in the pre-operative staging of CLM patients.

Added value of positron emission tomography imaging in the surgical treatment of colorectal liver metastases

OBJECTIVE

[F-18]-Fluorodeoxyglucose-positron emission tomography (FDG-PET) is used increasingly in the work-up to surgery for patients with potentially resectable colorectal liver metastases. This study evaluates the clinical effectiveness, impact on health care resources and cost-effectiveness of adding FDG-PET to the diagnostic algorithm alongside a randomized clinical trial from a health care perspective.

METHODS

In a randomized clinical trial, the net monetary benefit (NMB) of FDG-PET added to conventional diagnostic work-up (CWU) was determined in patients with colorectal liver metastases. Seventy-five patients were included in each arm. Change in clinical management, futile laparotomies, preoperative findings and all relevant health care consumption were prospectively documented during 3 years. To assess health-related quality of life European Quality of Life-5 Dimensions was administered at the time of randomization, 3 and 6 weeks postoperatively, and every 3 months postoperatively for 3 years. Quality-adjusted life years (QALYs) were calculated based on European Quality of Life-5 Dimensions outcomes.

RESULTS

In adding FDG-PET, diagnostic performance increased and futile laparotomies were reduced by 38%. Both health-related quality of life and QALYs showed no significant difference between the CWU and PET groups. For CWU and PET groups costs were euro 92,836 and euro 81,776, respectively, accumulated in 3 years after randomization. NMB ranged from euro 1004 to euro 11,060 depending on the monetary value given to a QALY. When costs for chemotherapy were disregarded, costs amounted to euro 15,874 for CWU and euro 18,664 for PET group.

CONCLUSION

Additional costs of FDG-PET in the diagnostic work-up of patients with potentially resectable colorectal liver metastases were compensated by a reduction in futile laparotomies. The NMB analysis showed savings over a relevant range of willingness to pay for a QALY.

Assessment of liver metastases from colorectal adenocarcinoma following chemotherapy: SPIO-MRI versus FDG-PET/CT

PURPOSE

This study compared superparamagnetic iron-oxide-enhanced magnetic resonance imaging (SPIO-MRI) and combined fluorodeoxyglucose positron emission tomography and computed tomography (FDG-PET/CT) in evaluating liver metastases from colorectal adenocarcinoma following chemotherapy.

MATERIALS AND METHODS

Nineteen patients were included in this retrospective study. SPIO-MRI and PET/CT results were compared with surgery, intraoperative ultrasound and pathology results in 11 patients and with the follow-up in eight patients.

RESULTS

SPIO-MRI and PET/CT identified 125 and 71 metastases, respectively. False negative lesions were 11 for SPIO-MRI and 65 for PET/CT. In the whole study population, the per-lesion analysis of SPIO-MRI and PET/CT showed a sensitivity of 92% and 52% (p<0.001) and the per-segment analysis a sensitivity of 99% and 79% (p<0.001), respectively. In patients who underwent surgery, the per-lesion analysis of SPIO-MRI and PET/CT showed a sensitivity of 85% and 58% (p<0.05) and the per-segment analysis a sensitivity of 97% and 63% (p<0.05), respectively. In patients who underwent follow-up, the per-lesion analysis of SPIO-MRI and PET/CT showed a sensitivity of 97% and 47% (p<0.001) and the per-segment analysis a sensitivity of 100% and 63% (p<0.007), respectively. For lesions ≥15 and <30 mm and for lesions <15 mm, SPIO-MRI demonstrated a higher sensitivity than PET/CT (p<0.001).

CONCLUSIONS

SPIO-MRI appears superior to PET/CT in evaluating liver metastases from colorectal adenocarcinoma following chemotherapy.

The impact of intraoperative ultrasonography on the surgical treatment of patients with colorectal liver metastases

Introduction

Intraoperative ultrasonography (IOUS) has been the standard in surgical decision making in oncologic liver surgery. Preoperative imaging techniques have improved substantially in resent years; therefore, the importance of IOUS might change. The current results of IOUS were compared with preoperative high-resolution helical CT scanning and the impact of IOUS on surgical decision making was evaluated.

Methods

A total of 100 consecutive patients who underwent open surgery for colorectal liver metastases within 4 weeks after preoperative imaging, performed with high-speed helical CT scanners, were included for this study. During surgery, IOUS was performed by a liver specialized radiologist. The findings on preoperative and intraoperative imaging and surgical exploration were compared regarding number, site, and size of the hepatic lesions. The preoperative surgical plan was compared with the final surgical treatment.

Results

One hundred patients with CRLM underwent 117 surgical treatments. In 38 patients IOUS differed from preoperative data. In 23 cases IOUS identified more metastatic lesions. In five patients, intraoperative findings identified smaller or less hepatic lesions. Additional information on the localization of the hepatic lesions was gathered by IOUS and changed the surgical treatment in ten cases. IOUS alone altered the surgical strategy 35 times during 117 procedures. In nearly all cases, discrepancy between the preoperative CT scan and IOUS resulted in a change of surgical treatment.

Conclusions

Despite improvement in preoperative imaging technology, the intraoperative use of ultrasonography remains of crucial importance. The detection of preoperatively unknown lesions remains high with great consequence on surgical therapy.

Additional value of FDG-PET/CT in management of "solitary" liver metastases: preliminary results of a prospective multicenter study

BACKGROUND AND AIM

The most common malignancy affecting the liver is metastasis from a wide variety of tumors, particularly those of gastrointestinal origin. Successful surgical removal of a solitary liver metastasis may significantly extend survival and optimal preoperative assessment in this regard is a mandatory prerequisite for proper patient selection. The addition of positron emission tomography/computed tomography (PET/CT) to other more conventional imaging procedures (e.g., ultrasound (US), CT, and magnetic resonance) has the potential to greatly improve the selection process by the combination of high-resolution anatomy afforded by CT directly combined with the functional scintigraphic map of intra- and extrahepatic lesions depicted by 2-deoxy-2-[F-18]fluoro-D-glucose (FDG)-PET. In this study, we assess the additional value of PET/CT in the management strategy of patients with solitary liver metastasis from colorectal and other cancers identified by conventional imaging methods.

METHODS

We evaluated 43 consecutive patients (17 males, 26 females, mean age 53 +/- 6 years) with known solitary liver metastasis. This sample consisted of 18 patients with colorectal cancer, 15 with nonsmall cell lung cancer, six with breast carcinoma, and four ovarian cancers. In addition to contrast-enhanced CT and US, all patients were studied with FDG-PET/CT before surgery. PET/CT was performed within 3 weeks of the initial diagnosis and the scans were read by two experienced radiologists/nuclear medicine specialists blinded to the clinical data. A final diagnosis was obtained at surgery in 31 patients, by fine needle biopsy in five, and long-term clinical, biochemical, and follow-up imaging in seven patients.

RESULTS

In 12 out of 43 patients (28%), PET/CT resulted in restaging disease and a change in therapy. Twenty-two of 31 patients with confirmed solitary liver lesions (71%) were disease-free, eight of 31 (26%) developed a new recurrence, and one of 31 (3%) died from disease progression over a 17 +/- 6-month follow-up interval. Nine of 12 patients (75%) with multiple metastases demonstrated by FDG-PET/CT were alive with disease and three of 12 (25%) deceased due to disease progression (p < 0.01) over a 17 +/- 6-month follow-up interval.

CONCLUSION

The addition of FDG-PET/CT to the routine assessment of patients with liver metastasis has a significant impact on disease staging and selection of suitable candidates for solitary liver metastasis resection and outcome.

Improved selection of patients for hepatic surgery of colorectal liver metastases with (18)F-FDG PET: a randomized study

With the increasing possibilities for surgical treatment of colorectal liver metastases, careful selection of patients who may benefit from surgical treatment becomes critical. The addition of PET to (18)F-FDG may significantly improve conventional staging by CT. Up to now, definitive evidence that the addition of (18)F-FDG PET to conventional staging leads to superior clinical results and improved clinical management in these patients has been lacking. In this randomized controlled trial in patients with colorectal liver metastases, we investigated whether the addition of (18)F-FDG PET is beneficial and reduces the number of futile laparotomies.

METHODS

A total of 150 patients with colorectal liver metastases selected for surgical treatment by imaging with CT were randomly assigned to CT only (n = 75) or CT plus (18)F-FDG PET (n = 75). Patients were followed up for at least 3 y. The primary outcome measure was futile laparotomy, defined as any laparotomy that did not result in complete tumor treatment, that revealed benign disease, or that did not result in a disease-free survival period longer than 6 mo.

RESULTS

Patient and tumor characteristics were similar for both groups. The number of futile laparotomies was 34 (45%) in the control arm without (18)F-FDG PET and 21 (28%) in the experimental arm with (18)F-FDG PET; the relative risk reduction was 38% (95% confidence interval, 4%-60%, P = 0.042).

CONCLUSION

The number of futile laparotomies was reduced from 45% to 28%; thus, the addition of (18)F-FDG PET to the work-up for surgical resection of colorectal liver metastases prevents unnecessary surgery in 1 of 6 patients.

PET/CT imaging in the diagnosis, staging, and follow-up of colorectal cancer

Colorectal cancer is a common malignancy that afflicts many in the western world. Imaging studies are frequently used to evaluate patients in the screening, staging and surveillance of colorectal cancer. Cross sectional imaging studies such as ultrasound, computed tomography and magnetic resonance imaging provide anatomic and morphologic information about tumor and patterns of spread. Positron emission tomography (PET) differs in that it provides information about tumor metabolism.[(18)F]Fluorodeoxyglucose PET has been clinically used for the evaluation of patients with a wide variety of cancers since most malignancies, including colorectal cancer, typically show increased glucose metabolism. This review present the positron emission tomography/computed tomography imaging findings that may be encountered in the diagnosis, staging and follow-up of patients with colorectal cancer.

Preoperative imaging for metastasectomy

For most solid neoplasms, medical imaging is a vital component of tumor staging and surveillance. Imaging strategies vary according to the type and grade of primary neoplasm, tumor stage at diagnosis, tumor markers, previous therapies, and patient symptoms. In this article, we address imaging of individual organs (lung, liver, adrenals) and outline imaging strategies for specific types of neoplasms.