Detection of hepatic metastases from cancers of the gastrointestinal tract by using noninvasive imaging methods (US, CT, MR imaging, PET): a meta-analysis

Is Non-Contrast CT Adequate for the Evaluation of Hepatic Metastasis in Patients Who Cannot Receive Iodinated Contrast Media?

Objective

To evaluate the appropriateness of follow-up with only non-enhanced CT (NECT) in patients with gastrointestinal cancer.

Subjects and Methods

This retrospective study included 323 patients with colorectal and gastric cancer who underwent two consecutive CT examinations (CT1 and CT2), including non-contrast and portal venous phase CT images, with an interval of 1 year. Patients were divided into 2 groups: Group A included patients with no hepatic metastasis on CT1 and with or without newly developed metastasis on CT2 to evaluate the diagnostic performance of NECT for detecting newly developed hepatic metastasis; Group B included patients with known hepatic metastasis both on CT1 and CT2 to evaluate the accuracy of NECT for the assessment of hepatic metastasis based on RECIST criteria (version 1.1). Contrast-enhanced CT (CECT) images were considered as reference standards.

Results

Group A included 172 patients (M:F = 107:65; mean age, 62.6 years). Among them, 57 patients had 95 metastases (mean size, 2.2 ± 1.3 cm). Per patient and per lesion sensitivity for diagnosing newly developed hepatic metastasis was 56.1–66.7% and 52.6–56.8%, respectively. In terms of small metastases (<1.5 cm), per lesion sensitivity was significantly decreased to 28.1–34.4% (P < 0.05). Metastasis size measurements were significantly smaller on NECT (P < 0.001) compared with reference standards. In Group B, the accuracy of response evaluation based on RECIST criteria was 65.6–72.2%.

Conclusions

NECT showed inadequate diagnostic performances in both detecting newly developed hepatic metastasis and evaluating the response of hepatic metastasis based on RECIST criteria.

FDG PET/CT in the liver: lesions mimicking malignancies

PURPOSE

18F-fluorodeoxyglucose (FDG) PET/CT is invaluable in managing liver lesions, in particular in the evaluation of suspected liver metastases. It is both sensitive and specific in detecting liver metastases from a wide range of primary cancers, and may change clinical management, most commonly by detecting additional lesions and decreasing the number of futile surgeries. However, some benign lesions may also show increased metabolic activity which can lead to false positive PET findings. We describe some of these lesions and their imaging characteristics that may help in differentiating them from malignant metastases.

METHODS

e reviewed all whole body FDG PET/CT studies performed over a 5-year period in our institution, and identified those with focal liver lesions showing increased FDG uptake for which histological results were available.

RESULTS

majority of lesions showing increased metabolic activity were due to malignant disease, such as metastases or primary liver tumours. However, we also found increased FDG uptake in non-neoplastic lesions such as Cryptococcosis, abscesses, and secondary inflammation from cholecystitis. Increased metabolic activity was also seen in some benign neoplasms such as hepatic adenomas and hemangioendotheliomas.

CONCLUSION

DG PET/CT is currently the most sensitive non-invasive imaging modality for the detection of hepatic metastases, particularly from the gastrointestinal tract. False positive results are rare, and have been described mainly in abscesses. However, other lesions can also show increased metabolic activity, and failure to differentiate these from metastases may result in inappropriate treatment.

EUS-derived criteria for distinguishing benign from malignant metastatic solid hepatic masses

BACKGROUND

Detection of hepatic metastases during EUS is an important component of tumor staging.

OBJECTIVE

To describe our experience with EUS-guided FNA (EUS-FNA) of solid hepatic masses and derive and validate criteria to help distinguish between benign and malignant hepatic masses.

DESIGN

Retrospective study, survey.

SETTING

Single, tertiary-care referral center.

PATIENTS

Medical records were reviewed for all patients undergoing EUS-FNA of solid hepatic masses over a 12-year period.

INTERVENTIONS

EUS-FNA of solid hepatic masses.

MAIN OUTCOME MEASUREMENTS

Masses were deemed benign or malignant according to predetermined criteria. EUS images from 200 patients were used to create derivation and validation cohorts of 100 cases each, matched by cytopathologic diagnosis. Ten expert endosonographers blindly rated 15 initial endosonographic features of each of the 100 images in the derivation cohort. These data were used to derive an EUS scoring system that was then validated by using the validation cohort by the expert endosonographer with the highest diagnostic accuracy.

RESULTS

A total of 332 patients underwent EUS-FNA of a hepatic mass. Interobserver agreement regarding the initial endosonographic features among the expert endosonographers was fair to moderate, with a mean diagnostic accuracy of 73% (standard deviation 5.6). A scoring system incorporating 7 EUS features was developed to distinguish benign from malignant hepatic masses by using the derivation cohort with an area under the receiver operating curve (AUC) of 0.92; when applied to the validation cohort, performance was similar (AUC 0.86). The combined positive predictive value of both cohorts was 88%.

LIMITATIONS

Single center, retrospective, only one expert endosonographer deriving and validating the EUS criteria.

CONCLUSION

An EUS scoring system was developed that helps distinguish benign from malignant hepatic masses. Further study is required to determine the impact of these EUS criteria among endosonographers of all experience.

An efficient nano-based theranostic system for multi-modal imaging-guided photothermal sterilization in gastrointestinal tract

Since understanding the healthy status of gastrointestinal tract (GI tract) is of vital importance, clinical implementation for GI tract-related disease have attracted much more attention along with the rapid development of modern medicine. Here, a multifunctional theranostic system combining X-rays/CT/photothermal/photoacoustic mapping of GI tract and imaging-guided photothermal anti-bacterial treatment is designed and constructed. PEGylated W18O49 nanosheets (PEG-W18O49) are created via a facile solvothermal method and an in situ probe-sonication approach. In terms of excellent colloidal stability, low cytotoxicity, and neglectable hemolysis of PEG-W18O49, we demonstrate the first example of high-performance four-modal imaging of GI tract by using these nanosheets as contrast agents. More importantly, due to their intrinsic absorption of NIR light, glutaraldehyde-modified PEG-W18O49 are successfully applied as fault-free targeted photothermal agents for imaging-guided killing of bacteria on a mouse infection model. Critical to pre-clinical and clinical prospects, long-term toxicity is further investigated after oral administration of these theranostic agents. These kinds of tungsten-based nanomaterials exhibit great potential as multi-modal contrast agents for directed visualization of GI tract and anti-bacterial agents for phothothermal sterilization.

PET/Computed Tomography in the Diagnosis and Staging of Gastric Cancers

Although there has been a reduction of the incidence and mortality of gastric cancer, it remains among the commonest causes of cancer-related death. Accurate staging and evaluation of treatment response are vital for management. PET is used to complement anatomic imaging in cancer management. PET/computed tomography (CT) has demonstrated its potential value for preoperative staging, evaluation of response to therapy, and detection of recurrence. Not all types of gastric cancers have a high affinity for fluorodeoxyglucose. PET/CT in the evaluation and staging of gastric cancer is not established, but studies indicate that there may be an evolving role for this imaging modality.

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.

The impact of PET/CT on the management of hepatic and extra hepatic metastases from gastrointestinal cancers

PURPOSE

To investigate the efficacy of positron emission tomography/computed tomography (PET/CT) in detection and management of hepatic and extrahepatic metastases from gastrointestinal cancers.

MATERIALS AND METHODS

Between February 2008 and July 2010, patients histopathologically diagnosed with gastrointestinal cancer and showing suspected metastasis on CT screening were subsequently evaluated with PET/CT. All patients were subgrouped according to histopathological origin and localization of the primary tumor. Localization of gastrointestinal cancers was further specified as lower gastrointestinal system (GIS), upper GIS, or hepato-pancreato-biliary (HPB). Both accuracy and impact of CT and PET/CT on patient management were retrospectively evaluated.

RESULTS

One hundred and thirteen patients diagnosed histopathologically with gastrointestinal cancers were retrospectively evaluated. Seventy-nine patients had adenocarcinoma and 34 patients other gastrointestinal tumors. Forty-one patients were in the upper GIS group, 30 patients in the HPB group, and 42 patients in the lower GIS group. Evaluation the diagnostic performance of PET/CT for suspected metastasis according to histopathological origin of the tumor, revealed that the sensitivity of PET/CT - although statistically not different - was higher in adenocarcinomas than in non-adenocarcinomas (90% (95% CI, 0.78-0.96) vs. 71.4% (95% CI, 0.45-0.88), P=0.86). The specificity was not significantly different (85.7% (95% CI, 0.70-0.93) vs. 85% (95% CI, 0.63-0.94), P=1.00). In the overall patient group; CT was significantly more sensitive than PET/CT for detection of hepatic metastases (94.7% vs. 78.9%, P=0.042), whereas PET/CT was significantly more specific than CT (48% vs. 98.7%, P<0.001). In subgroup analysis, sensitivity was not significantly different (P>0.05) but specificity was significantly higher in PET/CT than CT (P<0.05). The specificity of PET/CT was highest in upper GIS (100%) and HPB (100%) subgroups. In the overall patient group; for detection of extrahepatic metastasis, the sensitivity of CT (75%) and PET/CT (87.5%) showed no significant difference (P=0.437). However, PET/CT was significantly more specific than CT (88.7% vs. 70.4%, P=0.007). In subgroup analysis, no significant difference was found between CT and PET/CT either in sensitivity or in specificity (P>0.05). The specificity of PET/CT was highest in the lower GIS subgroup (93%). The management of 45 patients (39.8%) was revised after PET/CT evaluation.

CONCLUSIONS

PET/CT has a higher specificity than CT in detecting suspected hepatic and extrahepatic metastases of gastrointestinal cancers, and has an impact of nearly 40% on changing patient management strategies.

Real-time contrast-enhanced sonographically guided biopsy or radiofrequency ablation of focal liver lesions using perflurobutane microbubbles (sonazoid): value of Kupffer-phase imaging

OBJECTIVES

To evaluate the utility of Kupffer-phase imaging by real-time contrast-enhanced sonography using the perflurobutane microbubble contrast agent Sonazoid (GE Healthcare, Oslo, Norway) in guiding biopsy or radiofrequency (RF) ablation of focal liver lesions.

METHODS

A total of 75 patients (mean age, 59.7 years) who were referred for percutaneous biopsy (n = 42) or RF ablation (n = 33) were included in the study. Grayscale sonography and contrast-enhanced sonography using Sonazoid were performed in all patients before the procedure. The conspicuity of each targeted liver lesion on grayscale sonography, vascular-phase contrast-enhanced sonography, and Kupffer-phase contrast-enhanced sonography was graded using a 5-point scale. Lesion detection rates were calculated, and the conspicuity of the lesions among the imaging modalities was compared. The technical success of the procedures was also assessed.

RESULTS

The procedures were conducted in 66 patients (biopsy in 41 and RF ablation in 25) under real-time guidance by Kupffer-phase contrast-enhanced sonography. Lesion detection rates were 77.3% (58 of 75), 84.0% (63 of 75), and 92.0% (69 of 75) on grayscale sonography, vascular-phase contrast-enhanced sonography, and Kupffer-phase contrast-enhanced sonography, respectively, and were significantly different among the 3 modalities (P= .034). Overall, lesion conspicuity was significantly increased on vascular-phase and Kupffer-phase contrast-enhanced sonography compared to grayscale sonography (P < .001). Technical success rates for the procedures were 95.2% (40 of 42) for biopsy and 69.7% (23 of 33) for RF ablation.

CONCLUSIONS

Kupffer-phase imaging by contrast-enhanced sonography using Sonazoid increases the conspicuity of the liver lesions compared to grayscale sonography, and it is useful for real-time guidance of percutaneous biopsy or RF ablation of focal liver lesions.

FDG PET/CT in the management of colorectal and anal cancers

OBJECTIVE

CT remains the imaging modality of choice in the diagnosis of colorectal cancer (CRC) and anal cancer. However, advances in imaging have expanded the role of MRI and PET/CT. This article focuses on the evolving role of FDG PET/CT in the diagnosis, radiation therapy planning, therapy assessment, and posttherapy monitoring of CRC and anal cancer.

CONCLUSION

FDG PET/CT is a valuable imaging modality that impacts the clinical management of patients with CRC and those with anal cancer.

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.

Differentiation between Malignant and Benign Solitary Lesions in the Liver with (18)FDG PET/CT: Accuracy of Age-related Diagnostic Standard

OBJECTIVE

This study was to determine the reliability of age-stratified diagnostic index in differential diagnosis of malignant and benign solitary lesions in the liver using fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography ((18)FDG PET/CT).

METHODS

The enrolled 272 patients with solitary lesions in the liver were divided into three age groups, younger group (under 50 years), middle-aged group (50-69 years), and elderly group (70 years and above). Patients' ages were compared, and the optimal cut-offs of the standard uptake value (SUV) ratio (tumor-to-non-tumor ratio of the SUV), as well as areas under the curves (AUC), were evaluated in terms of malignant and benign lesions in each age group by using receiver operating characteristic (ROC) analysis. Based on optimal cut-offs, the sensitivity, specificity, accuracy were calculated, and the diagnostic accordance rate was compared between each age group and all patients, supported by (18)FDG PET/CT imaging data.

RESULTS

There was a significant age difference between the malignant and benign groups (t=3.905 p=0.0001). ROC analysis showed that the optimal cut-off value in all patients, younger group, middle-aged group and elderly group was 1.25, 1.17, 1.45 and 1.25 for SUVratio, and 0.856, 0.962, 0.650, 0.973 for AUC. The chi-square test proved that diagnostic accordance rate of (18)FDG PET/CT in younger group and elderly group were superior to that in all patients (χ(2)=13.352, P=0.0003) and (χ(2)=8.494, P=0.0036). Conversely, overall diagnostic accordance rate in all patient group was higher than that in middle-aged group (χ(2)=9.057, P=0.0026). Representative (18)FDG PET/CT imaging findings are demonstrated.

CONCLUSION

This study indicates that diagnostic optimal cut-offs of SUVratio of liver solitary lesions of (18)FDG PET/CT were different in each age group. In addition, the diagnostic performance of SUVratio was better in younger and elderly groups than that in all patients, and was poorer in middle-aged group than that in all patients. Therefore, age difference appears to be one of the important factors for discriminating malignant liver lesions from benign ones using (18) FDG PET/CT.

"Vanishing liver metastases"-A real challenge for liver surgeons

Expanded surgical intervention in colorectal liver metastasis (LM) and improved chemotherapy led to increasing problem of disappearing liver metastases (DLM). Treatment of those continues to evolve and poses a real challenge for HPB surgeons. This review discusses a clinical approach to DLM, emphasizing crucial steps in clinical algorithm. Particular issues such as imaging, intraoperative detection and surgical techniques are addressed. A step-by-step algorithm is suggested.

Targeted nanotechnology for cancer imaging

Targeted nanoparticle imaging agents provide many benefits and new opportunities to facilitate accurate diagnosis of cancer and significantly impact patient outcome. Due to the highly engineerable nature of nanotechnology, targeted nanoparticles exhibit significant advantages including increased contrast sensitivity, binding avidity and targeting specificity. Considering the various nanoparticle designs and their adjustable ability to target a specific site and generate detectable signals, nanoparticles can be optimally designed in terms of biophysical interactions (i.e., intravascular and interstitial transport) and biochemical interactions (i.e., targeting avidity towards cancer-related biomarkers) for site-specific detection of very distinct microenvironments. This review seeks to illustrate that the design of a nanoparticle dictates its in vivo journey and targeting of hard-to-reach cancer sites, facilitating early and accurate diagnosis and interrogation of the most aggressive forms of cancer. We will report various targeted nanoparticles for cancer imaging using X-ray computed tomography, ultrasound, magnetic resonance imaging, nuclear imaging and optical imaging. Finally, to realize the full potential of targeted nanotechnology for cancer imaging, we will describe the challenges and opportunities for the clinical translation and widespread adaptation of targeted nanoparticles imaging agents.

[Synopsis on clinical practice guideline of gastric cancer in Korea: an evidence-based approach]

Although, gastric cancer is quite common in Korea, the treatment outcome is relatively favorable compared to that of Western countries. However, there is no Korean multidisciplinary guideline for gastric cancer and thus, a guideline adequate for domestic circumstances is required. Experts from related societies developed 22 recommendation statements for the diagnosis (n=9) and treatment (n=13) based on relevant key questions. Evidence levels based on systematic review of literatures were classified as five levels from A to E, and recommendation grades were classified as either strong or weak. The topics of this guideline cover diagnostic modalities (endoscopy, endoscopic ultrasound, radiologic diagnosis), treatment modalities (surgery, therapeutic endoscopy, chemotherapy, radiotherapy) and pathologic evaluation. External review of the guideline was conducted at the finalization phase.

A novel use of biomarkers in the modeling of cancer activity based on the theory of endobiogeny

Introduction:

Cancer is a complex disorder whose detection and monitoring remains challenging. A biological modeling system, the biology of functions (BoF), claims to be able to evaluate physiologic elements related to carcinogenic activity. A pilot study was undertaken to evaluate the accuracy of the BoF in detecting differences between cancer cases and matched controls.

Materials and Methods:

A retrospective case control study was performed using the BoF analyses of 46 patients with all types of solid and hematgenous cancers, active and inactive (total cases), and 46 controls from a private practice. The standard BoF panel of 17 biomarkers was evaluated. Sixty-two of 150 BoF indices derived from these biomarkers were pre-selected for analysis based on their relationship to cancer physiology. The data was analyzed with the Wilcoxon Signed Ranks Test using SPSS software.

Results:

Of the 62 indices, 7 were found to be statistically significant in comparing total cancer cases to controls: βMSH/αMSH, Estrogen Fraction #5, Comparative Genital Androgeny, Thyroid, Genito-thyroid, Catabolism/Anabolism and Pro-inflammatory.

Conclusions:

In a small retrospective case control study, statistically significant differences were found between cancer cases and controls in 7 BoF indices. These indices are indicators of physiological conditions consistent with cancer growth. These results warrant further study of this biological modeling system in cancer patients.

Liver metastases: Contrast-enhanced ultrasound compared with computed tomography and magnetic resonance

The development of ultrasound contrast agents with excellent tolerance and safety profiles has notably improved liver evaluation with ultrasound (US) for several applications, especially for the detection of metastases. In particular, contrast enhanced ultrasonography (CEUS) allows the display of the parenchymal microvasculature, enabling the study and visualization of the enhancement patterns of liver lesions in real time and in a continuous manner in all vascular phases, which is similar to contrast-enhanced computed tomography (CT) and contrast-enhanced magnetic resonance imaging. Clinical studies have reported that the use of a contrast agent enables the visualization of more metastases with significantly improved sensitivity and specificity compared to baseline-US. Furthermore, studies have shown that CEUS yields sensitivities comparable to CT. In this review, we describe the state of the art of CEUS for detecting colorectal liver metastases, the imaging features, the literature reports of metastases in CEUS as well as its technique, its clinical role and its potential applications. Additionally, the updated international consensus panel guidelines are reported in this review with the inherent limitations of this technique and best practice experiences.

The Role of PET Imaging Before, During, and After Percutaneous Hepatic and Pulmonary Tumor Ablation

The combination of anatomic and metabolic information provided by positron emission tomography (PET)/computed tomography makes it an important imaging modality to be obtained in conjunction with percutaneous ablation of primary and secondary malignancies of the lungs and liver. Advantages include more accurate preprocedural staging to determine appropriate treatment options, intraprocedural guidance to target difficult-to-see lesions, and postprocedural detection of residual or recurrent disease. Future applications of PET include strategies for intraprocedural guidance with real-time determination of incompletely ablated tumor, and combined PET/magnetic resonance imaging before, during, and after ablation for greater sensitivity to detect disease.

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

Background:

The aim of the PROMETEO-01 Study was to define the diagnostic accuracy of imaging techniques in colorectal cancer liver metastasis (CRCLM) patients.

Methods:

Patients referred to Bologna S. Orsola-Malpighi Hospital performed a computed-tomography scan (CT), magnetic resonance (MR), 18F-FDG-PET/CTscan (PET/CT) and liver contrast-enhanced-ultrasound (CEUS); CEUS was also performed intraoperatively (i-CEUS). Every pathological lesion was compared with imaging data.

Results:

From December 2007 to August 2010, 84 patients were enrolled. A total of 51 (60.71%) resected patients were eligible for analysis. In the lesion-by-lesion analysis 175 resected lesions were evaluated: 67(38.3%) belonged to upfront resected patients (group-A) and 108 (61.7%) to chemotherapy-pretreated patients (group-B). In all patients the sensitivity of MR proved better than CT (91% vs 82% P=0.002), CEUS (91 vs 81% P=0.008) and PET/CT (91% vs 60% P=0.000), whereas PET/CT showed the lowest sensitivity. In group-A the sensitivity of i-CEUS, MR, CT, CEUS and PET/CT was 98%, 94%, 91%, 84% and 78%, respectively. In group-B the i-CEUS proved equivalent in sensitivity to MR (95% and 90%, respectively, P=0.227) and both were significantly more sensitive than other procedures. The CT sensitivity in group-B was lower than in group-A (77% vs 91%, P=0.024).

Conclusions:

A thoraco-abdominal CT provides an adequate baseline evaluation and guides judgment as to the resectability of CRCLM patients. In the subset of candidates for induction chemotherapy to increase the chance of liver resection, the most rational approach is to add MR for the staging and restaging of CRCLM.

Clinical practice guidelines for gastric cancer in Korea: an evidence-based approach

Although gastric cancer is quite common in Korea, the treatment outcome is relatively favorable compared to those in western countries. However, there are currently no Korean multidisciplinary guidelines for gastric cancer. Experts from related societies developed guidelines de novo to meet Korean circumstances and requirements, including 23 recommendation statements for diagnosis (n=9) and treatment (n=14) based on relevant key questions. The quality of the evidence was rated according to the GRADE evidence evaluation framework: the evidence levels were based on a systematic review of the literature, and the recommendation grades were classified as either strong or weak. The applicability of the guidelines was considered to meet patients' view and preferences in the context of Korea. The topics of the guidelines cover diagnostic modalities (endoscopy, endoscopic ultrasound, and radiologic diagnosis), treatment modalities (surgery, therapeutic endoscopy, chemotherapy, and radiotherapy), and pathologic evaluation. An external review of the guidelines was conducted during the finalization phase.

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.

Imaging strategies before beginning treatment of colorectal liver metastases

The management of colorectal intrahepatic metastases before resection is multidisciplinary and radiologists and nuclear medicine specialists play a major role. In accordance with the French National Guide for appropriate use of diagnostic imaging, the approach should be multimodal: a chest-abdomen and pelvic (CAP) CT scan and hepatic MRI are mandatory while PET-CT provides important additional information, in particular on intra-abdominal extrahepatic metastases. This multimodal approach emphasizes the importance of early and appropriate use of imaging in these patients, as well as the central role of multidisciplinary meetings in oncology.

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.

Metabolic information on staging FDG-PET-CT as a prognostic tool in the evaluation of 97 patients with gastric cancer

BACKGROUND AND OBJECTIVE

Gastric cancer remains a leading cause of malignancy-related mortality. Many patients with locally advanced disease succumb despite peri-operative chemotherapy and the survival benefit of chemotherapy for advanced disease is modest, suggesting that current staging is imperfect. The role of fluorine-18-2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in the staging of gastric cancer remains to be determined. This study aimed to determine, and compare with computerized tomography (CT), the association between FDG-PET uptake in the primary tumour and regional lymph nodes, and overall survival in patients with all stage gastric cancer.

METHODS

Patients with histologically confirmed gastric cancer (any stage) who, at diagnosis, had received a staging FDG-PET-CT at our institution between 2006 and 2011 were included. Records were retrospectively analysed. Patients with >50 % of tumour above the gastro-oesophageal junction or an active second malignancy were excluded.

RESULTS

97 patients were included in the analysis. Surgery with curative intent was performed in 68 patients. In univariate analysis, an association with overall survival was seen in patients who had FDG-PET-positive primary tumours (hazard ratio (HR) for death 3.33, 95 % confidence interval (95 % CI) 1.63-6.80, p = 0.001). FDG-PET lymph node positive (vs node negativity) was associated with inferior overall survival (HR 8.66, 95 % CI 4.59-16.37, p < 0.0001), and remained an independent predictor in the multivariate analysis. In contrast, positive lymphadenopathy identified on CT was not associated with overall survival (HR 1.34, 95 % CI 0.79-2.29, p = 0.82).

CONCLUSION

FDG-PET-positive tumours are associated with an inferior overall survival. In contrast to CT, FDG-PET-positive lymphadenopathy is associated with a decreased overall survival.

Clinical application of 18F-fluorodeoxyglucose positron emission tomography for assessment and evaluation after therapy for malignant hepatic tumor

Positron emission tomography (PET) is widely available and its application with 2-[(18)F] fluoro-2-deoxy-D-glucose ((18)F-FDG) in oncology has become one of the standard imaging modalities in diagnosing and staging of tumors, and monitoring the therapeutic efficacy in hepatic malignancies. Recently, investigators have measured glucose utilization in liver tumors using (18)F-FDG and positron emission tomography/computer tomography (PET/CT) in order to establish a diagnosis of tumors, assess their biologic characteristics and predict therapeutic effects on hepatic malignancies. The PET/CT with (18)F-FDG may further enhance the hepatic malignancy diagnostic algorithm by accurate diagnosis, staging, restaging and evaluating its biological characteristics, which can benefit the patients suffering from primary and metastatic hepatic tumors such as hepatocellular carcinoma (HCC), cholangiocarcinoma (CCC), and metastatic liver tumor.

Current and emerging surveillance strategies to expand the window of opportunity for curative treatment after surgery in colorectal cancer

Colorectal cancer is the third most common cancer globally. At diagnosis, more than 70% of patients have nonmetastatic disease. Cure rates for early-stage colorectal cancer have improved with primary screening, improvements in surgical techniques and advances in adjuvant chemotherapy. Despite optimal primary treatment, 30-50% of these patients will still relapse. While death will result from widespread metastatic disease, patients with small volume oligometastatic disease are still considered curable with aggressive multimodality therapy. Hence, early detection of relapsed cancer when it is still amenable to resection expands the window of opportunity for cure. Here, the authors review the modalities currently employed in clinical practice and the evidence supporting intensive surveillance strategies. The authors also discuss ongoing clinical trials examining specific surveillance programs and emerging modalities that may be deployed in the future for early detection of metastatic disease.

Surgical management of patients with bowel obstructions secondary to gastric cancer

AIM: To assess whole-body fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the management of small bowel obstructions (SBOs) secondary to gastric cancer and its role in treatment strategies.

METHODS: The medical records of all of the patients who were admitted for an intestinal obstruction after curative resection for gastric cancer were retrospectively reviewed. PET/CT was performed before a clinical treatment strategy was established for each patient. The patients were divided into 2 groups: patients with no evidence of a tumor recurrence and patients with evidence of a tumor recurrence. Tumor recurrences included a local recurrence, peritoneal carcinomatosis or distant metastases. The primary endpoint was the 1-year survival rate, and other variables included patient demographics, the length of hospital stay, complications, and mortality.

RESULTS: The median time between a diagnosis of gastric cancer and the detection of a SBO was 1.4 years. Overall, 31 of 65 patients (47.7%) had evidence of a tumor recurrence on the PET/CT scan, which was the only factor that was associated with poor survival. Open and close surgery was the main type of surgical procedure reported for the patients with tumor recurrences. R0 resections were performed in 2 patients, including 1 who underwent combined adjacent organ resection. In the group with no evidence of a tumor recurrence on PET/CT, bowel resections were performed in 7 patients, adhesiolysis was performed in 7 patients, and a bypass was performed in 1 patient. The 1-year survival curves according to PET/CT evidence of a tumor recurrence vs no PET/CT evidence of a tumor recurrence were significantly different, and the 1-year survival rates were 8.8% vs 93.5%, respectively. There were no significant differences (P = 0.71) in the 1-year survival rates based on surgical vs nonsurgical management (0% with nonoperative treatment vs 20% after exploratory laparotomy).

CONCLUSION: ¹⁸F-FDG PET/CT can be used to identify the causes of bowel obstructions in patients with a history of gastric cancer, and this method is useful for planning the surgical management of these patients.

Follow-up: the evidence

There is currently no consensus on the best strategy for the follow-up of patients who have undergone surgical treatment with curative intent for gastric cancer. The wide variation in recommendations for surveillance among international experts and hospital schedules clearly reflects a lack of an established body of evidence on this subject. Consequently, most of the international guidelines aimed at early detection of disease recurrence gloss over details concerning the mode, duration, and intensity of surveillance since they cannot be based on an acceptable grade of recommendation. Very few report anything other than the detection of recurrences or death as the primary endpoints, and, given the poor survival of patients with recurrent gastric cancer, the prognostic effect of early detection seems doubtful. In recent years, an increasing focus on evidence-based medicine, which has coincided with a growing concern about costs and efficiency in medicine, has caused a reevaluation of most surveillance practices. In this paper, we review and discuss the current body of evidence and follow-up practices after curative resection of gastric cancer.

Interrelationship between liver hemodynamics and tumor metabolism in liver metastases: diagnostic value of Doppler perfusion index revisited

It should be expected that the hepatic blood flow increase in the cases with liver metastasis. We aimed to find out if there is a correlation between Doppler parameters and hepatic metabolic activity in oncology patients. 35 patients with hepatic metastases who were identified by 18F-fluorodeoxyglucose positron emission tomography scan and assessed with Doppler ultrasound were included in this prospective study. Patients with hepatic disease, cardiac dysfunction, dehydration, history of alcoholism, intake of antihypertensive or vasoactive medication were excluded. Volume flow of the proper hepatic artery and the portal vein were measured in the hepatoduodenal ligament by Doppler sonography. Doppler perfusion index (the ratio of the hepatic artery flow to the total liver blood flow) and flow volumes of 31 age matched subjects were compared. Both flow of the proper hepatic artery and portal vein were found to be significantly higher in patients with liver metastasis. The mean Doppler perfusion index value was 0.2 ± 0.13 in hepatic metastases whereas 0.13 ± 0.05 in control group. Doppler perfusion index was significantly higher in liver metastases (p=0.008). A positive correlation was found between the maximum standardized uptake value of the liver and flow volume of the proper hepatic artery (r=0.774, p=0). Blood flow of the proper hepatic artery and Doppler perfusion index correlates with hepatic standardized uptake value. Flow measurements of the liver may become an important parameter for selecting patients for further positron emission tomography scan and following-up the response after systemic and local therapeutic procedures.

Unnecessary surgery can be avoided by judicious use of PET/CT scanning in colorectal cancer patients

AIM

This study aims to determine the role of positron emission tomography (PET)/computed tomography (CT) in changing the management plan in patients with metastatic or recurrent colorectal cancer (CRC) and to evaluate the role of PET/CT in patients with an unexplained rise in carcinoembryonic antigen (CEA).

MATERIALS AND METHODS

A total of 60 consecutive patients with CRC, who had PET/CT, were identified between 2008 and 2010. All patients had CT scans prior to the PET/CT. Data were collected from clinic letters, CT and PET CT reports and pathology results and cross-checked with the patient's notes.

RESULTS

Patients were aged between 43 and 85 years [33 males, 27 females]. CEA was raised in 37 patients and normal in 23. Results of PET/CT were compared with that of CT scan and 33 out of the 60 patients (55%) had PET/CT results which were different to that of CT scan and 27 patients (45%) had similar PET/CT and CT results. PET scan appropriately altered the management in 23/60 patients (38%) and avoided unnecessary surgery in 14 patients. PET/CT had a sensitivity of 86% and specificity of 84%. In patients with an unexplained rise in CEA, PET/CT was positive in only one out of ten (10%) patients.

CONCLUSION

PET/CT is valuable in deciding the management outcome in patients with metastatic or recurrent colorectal cancer. Unnecessary surgery might be avoided by careful use of PET/CT scanning in colorectal cancer patients. PET/CT might not be of value in patients with an unexplained rise in CEA.

Gastric carcinoma: imaging diagnosis, staging and assessment of treatment response

Gastric carcinoma (GC) is one of the most common causes of cancer-related death worldwide. Surgical resection is the only cure available and is dependent on the GC stage at presentation, which incorporates depth of tumor invasion, extent of lymph node and distant metastases. Accurate preoperative staging is therefore essential for optimal surgical management with consideration of preoperative and/or postoperative chemotherapy. Multidetector computed tomography (MDCT) with its ability to assess tumor depth, nodal disease and metastases is the preferred technique for staging GC. Endoscopic ultrasonography is more accurate for assessing the depth of wall invasion in early cancer, but is limited in the assessment of advanced local or stenotic cancer and detection of distant metastases. Magnetic resonance imaging (MRI), although useful for staging, is not proven to be effective. Positron emission tomography (PET) is most useful for detecting and characterizing distant metastases. Both MDCT and PET are useful for assessment of treatment response following preoperative chemotherapy and for detection of recurrence after surgical resection. This review article discusses the usefulness of imaging modalities for detecting, staging and assessing treatment response for GC and the potential role of newer applications including CT volumetry, virtual gastroscopy and perfusion CT in the management of GC.

'Go with the flow ': a review of methods and advancements in blood flow imaging

Physics has delivered extraordinary developments in almost every facet of modern life. From the humble thermometer and stethoscope to X-Ray, CT, MRI, ultrasound, PET and radiotherapy, our health has been transformed by these advances yielding both morphological and functional metrics. Recently high resolution label-free imaging of the microcirculation at clinically relevant depths has become available in the research domain. In this paper, we present a comprehensive review on current imaging techniques, state-of-the-art advancements and applications, and general perspectives on the prospects for these modalities in the clinical realm.

Positron emission tomography in malignancies of the liver, pancreas and biliary tract - indications and potential pitfalls

Abstract Malignancies of the hepato-pancreatico-biliary (HPB) system are relatively common and generally characterized by a dismal prognosis. Positron emission tomography (PET) is a functional imaging technique that has emerged as an important modality in oncological decision-making. The principal radiopharmaceutical in PET imaging is the glucose analog (18)F-fluorodeoxyglucose, which is able to detect altered glucose metabolism in malignant tissue. PET is typically used in conjunction with computed tomography (CT), and previous studies have supported several uses of PET/CT in HPB malignancies, including staging, differential diagnostics and monitoring of treatment response and progress of disease. A review of PET/CT in the context of HPB malignancies will be presented, including indications and potential pitfalls.

A comparative study of FDG PET/CT and enhanced multi-detector CT for detecting liver metastasis according to the size and location

PURPOSE

The aim of this study was to compare the diagnosability between (18)F-fluorodeoxyglucose (FDG) PET/CT and enhanced multi-detector CT (MDCT) for the detection of liver metastasis (LM) according to the size and location in liver and to evaluate standard maximum standardized uptake values (SUVmax) of all liver metastatic lesions.

MATERIALS AND METHODS

One hundred two consecutive patients with malignancy who underwent both FDG PET/CT and MDCT for LM evaluation were retrospectively reviewed. Among them, 56 patients with LM were enrolled in this study. LM was confirmed by follow-up imaging studies after at least 6 months or by histopathology. FDG PET/CT and MDCT images were visually analyzed using three-point scale by the consensus of two radiologists and two nuclear medicine physicians. The size and location (central vs. sub-capsular) of the all liver lesions were evaluated using MDCT images. Furthermore, SUVmax of all liver lesions on FDG PET/CT images were calculated.

RESULTS

A total of 146 liver lesions were detected by FDG PET/CT and MDCT and 142 of the lesions were diagnosed as LM. The detection rates of MDCT and FDG PET/CT for LM by visual analysis were 77 and 78%, respectively. There was no significant difference of detection rate according to the overall location and size of the lesions. However, FDG PET/CT was more sensitive than MDCT for detecting small and sub-capsular LM. The detection rate of FDG PET/CT for LM was 68% by the cutoff SUVmax of 2.7.

CONCLUSIONS

Although the diagnosabilities of MDCT and FDG PET/CT for detecting LM were comparable, FDG PET/CT is superior to MDCT for detecting small LM located in the sub-capsular portion of liver.

Diagnosis and staging of cancer of the esophagus and esophagogastric junction

Esophageal/esophagogastric junction cancer staging in the 7th edition of the AJCC staging manual is data driven and harmonized with gastric staging. New definitions are Tis, T4, regional lymph node, N, and M. Nonanatomic characteristics (histopathologic cell type, histologic grade, cancer location) and TNM classifications determine stage groupings. Classifications before treatment define clinical stage (cTNM or ycTNM). Current best clinical staging modalities include endoscopic ultrasonography for T and N and CT/PET for M. Classifications at resection define pathologic stage (pTNM or ypTNM). Accurate pathologic stage requires communication/cooperation between surgeon and pathologist. Classifications are defined at retreatment (rTNM) and autopsy (aTNM).

Metachronous rectum metastases from gastric adenocarcinoma: a case report

Introduction. Hepatic metastases of gastric adenocarcinomas are frequently observed due to the drainage into portal vein. Intestinal metastases disseminate from gastrocolic and mesenteric ligaments but they are seen very rarely and in most cases detected in postmortem studies. Case Report. A 74-year-old female patient with no known history of disease. Her complaints on application were epigastric pain, burning, and constipation. Gastroscopy showed a submucosal mass in the greater curvature of fundus and in colonoscopy, a mass with polypoid appearance that narrows the lumen at the rectum was detected. No far metastases or pathology were detected. Pathology report from gastric biopsy material demonstrated well-differentiated adenocarcinoma. Cytokeratin 7 (CK7) was found to be extensively strongly positive, Cytokeratin 20 (CK20) was negative in the immunohistochemical staining of the biopsy obtained from rectosigmoid area. Conclusion. Gastric cancer is among the frequent cancers today, most of which are adenocarcinomas. Although most of the metastases are observed in the liver, lungs, lymph nodes, and peritoneum, it should be remembered that intestinal metastases may be seen without the presence of any other metastatic focus. Our case is the first in literature reporting a rectum metastasis without any other organ metastasis.

[Multidisciplinary management of rectal cancer]

In the last 10 years, a number of important European randomized published studies investigated the optimal management of rectal cancer. In order to define an evidence-based approach of the clinical practice based, an international consensus conference was organized in Italy under the endorsement of European Society of Medical Oncology (ESMO), European Society of Surgical Oncology (ESSO) and European Society of Therapeutic Radiation Oncology (ESTRO). The aim of this article is to present highlights of multidisciplinary rectal cancer management and to compare the conclusions of the international conference on 'Multidisciplinary Rectal Cancer Treatment: looking for an European Consensus' (EURECA-CC2) with the new National Comprehensive Cancer Network (NCCN) guidelines.

Meta-analysis of gadoxetic acid disodium (Gd-EOB-DTPA)-enhanced magnetic resonance imaging for the detection of liver metastases

Objective

To determine the accuracy of MR imaging with Gd-EOB-DTPA for the detection of liver metastases.

Materials and Methods

PUBMED, EMBASE, the Web of Science, and the Cochrane Library were searched for original articles published prior to February 2012. The criteria for the inclusion of articles were as follows: reported in the English language; MR imaging with Gd-EOB-DTPA was performed to detect liver metastases; histopathologic analysis (surgery, biopsy), intraoperative observation (manual palpatation, intraoperative ultrasonography), and/or follow-up US was the reference standard; and data were sufficient for the calculation of true-positive or false-negative values. The methodological quality was assessed by using the quality assessment of diagnostic studies instrument. The data were extracted to calculate sensitivity, specificity, predictive value, diagnostic odds ratio, and areas under hierarchical summary receiver operating characteristic (HSROC) curve to perform heterogeneity test and threshold effect test, as well as publication bias analysis and subgroup analyses.

Results

From 229 citations, 13 were included in the meta-analysis with a total of 1900 lesions. We detected heterogeneity between studies and evidence of publication bias. The methodological quality was moderate. The pooled weighted sensitivity with a corresponding 95% confidence interval (CI) was 0.93 (95% CI: 0.90, 0. 95), the specificity was 0.95 (95% CI: 0.91, 0.97), the positive likelihood ratio was 18.07 (95% CI: 10.52, 31.04), the negative likelihood ratio was 0.07 (95% CI: 0.05, 0.10), and the diagnostic odds ratio was 249.81 (95% CI: 125.12, 498.74). The area under the receiver operator characteristic curve was 0.98 (95% CI: 0.96, 0.99).

Conclusion

MR imaging with Gd-EOB-DTPA is a reliable, non-invasive, and no-radiation-exposure imaging modality with a high sensitivity and specificity for detection of liver metastases. Nonetheless, it should be applied cautiously, and large scale, well-designed trials are necessary to assess its clinical value.