Changing trends in the clinicopathological features, practices and outcomes in the surgical management for cystic lesions of the pancreas and impact of the international guidelines: Single institution experience with 462 cases between 1995-2018

INTRODUCTION

The impact on clinical practice of the international guidelines including the Sendai Guidelines (SG06) and Fukuoka Guidelines (FG12) on the management of cystic lesions of the pancreas (CLP) has not been well-studied. The primary aim was to examine the changing trends and outcomes in the surgical management of CLP in our institution over time and to determine the impact of these guidelines on our institution practice.

METHODS

462 patients with surgically-treated CLP were retrospectively reviewed and classified under the 2 guidelines. The cohort was divided into 3 time periods: 1998-2006, 2007-2012 and 2013 to 2018.

RESULTS

Comparison across the 3 time periods demonstrated significantly increasing frequency of older patients, asymptomatic CLP, male gender, smaller tumor size, elevated Ca 19-9, use of magnetic resonance imaging (MRI) and use of endoscopic ultrasound (EUS) prior to surgery. There was also significantly increasing frequency of adherence to the international guidelines as evidenced by the increasing proportion of HR^SG06 and HR^FG12 CLP with a corresponding lower proportion of LR^SG06 and LR^FG12 being resected. This resulted in a significantly higher proportion of resected CLP whereby the final pathology confirmed that a surgery was actually indicated.

CONCLUSIONS

Over time, there was increasing adherence to the international guidelines for the selection of patients for surgical resection as evidenced by the significantly increasing proportion of HR^SG06 and HR^FG06 CLPs undergoing surgery. This was associated with a significantly higher proportion of patients with a definitive indication for surgery. These suggested that over time, there was a continuous improvement in our selection of appropriate CLP for surgical treatment.

Phase Ib/II randomized, open-label study of doxorubicin and cyclophosphamide with or without low-dose, short-course sunitinib in the pre-operative treatment of breast cancer

Background

Prolonged anti-angiogenic therapy destroys tumor vasculature, whereas vascular-normalizing doses may enhance intra-tumoral drug delivery. We hypothesize that low-dose, short-course sunitinib normalizes vasculature, enhancing chemotherapy efficacy.

Patients and Methods

In phase Ib, treatment-naïve breast cancer patients received four cycles of pre-operative doxorubicin/cyclophosphamide, with sunitinib before each cycle. The optimal dose of sunitinib leading to tumor vessel normalization on immunohistochemistry was identified. In phase II, subjects were randomized to chemotherapy alone or chemotherapy plus sunitinib at the recommended phase II dose (RP2D). Primary endpoint was pathological complete response (pCR) rate. Tumor and functional imaging biomarkers were evaluated serially.

Results

In phase Ib (n=9), sunitinib 12.5 mg daily for 7 days before each chemotherapy was established as RP2D. In phase II, patients receiving chemotherapy plus sunitinib (n=24) had similar pCR rates (5.0% versus 4.3%, p=1.00), but a higher incidence of chemotherapy dose delays (33.3% versus 8.7%, p=0.04), compared to those receiving chemotherapy alone (n=25). The addition of sunitinib to chemotherapy significantly increased vascular normalization index (VNI) and decreased lymphatic vessel density (D2-40) on immunohistochemistry [VNI:25.50±27.94% versus 49.29±31.84%, p=0.034; D2-40:3.29±2.70 versus 1.29±1.54, p=0.014, baseline versus post-cycle 1], and improved perfusion on DCE-MRI (K^trans:12.6±9.6 mL/100 g/min versus 16.3±10.7 mL/100 g/min, baseline versus post-cycle 1, p=0.015). Conversely, immunohistochemical and DCE-MRI parameters were not significantly altered by chemotherapy alone.

Conclusion

Low-dose, short-course sunitinib prior to anthracycline-based chemotherapy in breast cancer patients did not improve pCR and increased chemotherapy dose delays. However, the addition of sunitinib induced compelling pharmacodynamic evidence of vascular normalization. Further studies with alternative cytotoxic regimens should be explored.

SIRveNIB: Selective Internal Radiation Therapy Versus Sorafenib in Asia-Pacific Patients With Hepatocellular Carcinoma

Purpose Selective internal radiation therapy or radioembolization (RE) shows efficacy in unresectable hepatocellular carcinoma (HCC) limited to the liver. This study compared the safety and efficacy of RE and sorafenib in patients with locally advanced HCC. Patients and Methods SIRveNIB (selective internal radiation therapy v sorafenib), an open-label, investigator-initiated, phase III trial, compared yttrium-90 (⁹⁰Y) resin microspheres RE with sorafenib 800 mg/d in patients with locally advanced HCC in a two-tailed study designed for superiority/detriment. Patients were randomly assigned 1:1 and stratified by center and presence of portal vein thrombosis. Primary end point was overall survival (OS). Efficacy analyses were performed in the intention-to-treat population and safety analyses in the treated population. Results A total of 360 patients were randomly assigned (RE, 182; sorafenib, 178) from 11 countries in the Asia-Pacific region. In the RE and sorafenib groups, 28.6% and 9.0%, respectively, failed to receive assigned therapy without significant cross-over to either group. Median OS was 8.8 and 10.0 months with RE and sorafenib, respectively (hazard ratio, 1.1; 95% CI, 0.9 to 1.4; P = .36). A total of 1,468 treatment-emergent adverse events (AEs) were reported (RE, 437; sorafenib, 1,031). Significantly fewer patients in the RE than sorafenib group had grade ≥ 3 AEs (36 of 130 [27.7%]) v 82 of 162 [50.6%]; P < .001). The most common grade ≥ 3 AEs were ascites (five of 130 [3.8%] v four of 162 [2.5%] patients), abdominal pain (three [2.3%] v two [1.2%] patients), anemia (zero v four [2.5%] patients), and radiation hepatitis (two [1.5%] v zero [0%] patients). Fewer patients in the RE group (27 of 130 [20.8%]) than in the sorafenib group (57 of 162 [35.2%]) had serious AEs. Conclusion In patients with locally advanced HCC, OS did not differ significantly between RE and sorafenib. The improved toxicity profile of RE may inform treatment choice in selected patients.

Understanding K trans: a simulation study based on a multiple-pathway model

The transfer constant K ^trans is commonly employed in dynamic contrast-enhanced MRI studies, but the utility and interpretation of K ^trans as a potential biomarker of tumor vasculature remains unclear. In this study, computer simulations based on a comprehensive tracer kinetic model with multiple pathways was used to provide clarification on the interpretation and application of K ^trans. Tissue concentration-time curves pertaining to a wide range of transport conditions were simulated using the multiple-pathway (MP) model and fitted using the generalized kinetic (GK) and extended GK models. Relationships between K ^trans and plasma flow F _p, vessel permeability PS and extraction rate EF _p under various transport conditions were assessed by correlation and regression analysis. Results show that the MP model provides an alternative two-tier interpretation of K ^trans based on the vascular transit time. K ^trans is primarily associated with F _p and EF _p respectively, in the slow and rapid vascular transit states, independent of the magnitude of PS. The relative magnitudes of PS and F _p only serve as secondary constraints for which K ^trans can be further associated with EF _p and PS in the slow and rapid transit states, respectively.

Intravoxel incoherent motion and diffusion tensor imaging of early renal fibrosis induced in a murine model of streptozotocin induced diabetes

INTRODUCTION

To assess if parameters in intravoxel incoherent motion (IVIM) and diffusion tensor imaging (DTI) can be used to evaluate early renal fibrosis in a mouse model of diabetic nephropathy.

MATERIALS & METHODS

In a population of 38 male CD1 mice (8weeks old, 20-30g), streptozotocin induced diabetes was created in 20 mice via a single intraperitoneal injection of streptozotocin at 150mg/kg, while 18 mice served as control group. IVIM parameters were acquired at 0, 12 and 24weeks after injection of streptozotocin using a range of b values from 0 to 1200s/mm2. DTI parameters were obtained using 12 diffusion directions and lower b values of 0, 100 and 400s/mm2. DTI and IVIM parameters were obtained using region of interests drawn over the renal parenchyma. Histopathological analysis of the right kidney was performed in all mice. Results were analyzed using an unpaired t-test with P<0.05 considered statistically significant.

RESULTS

Renal cortex fractional anisotropy (FA) was significantly lower in the diabetes group at week 12 as compared with the control group. Renal cortex apparent diffusion coefficient and tissue diffusivity were significantly higher in the diabetes group at week 12 compared with the control group at 12weeks. Blood flow was significantly decreased at the renal medulla at 24weeks. Histopathological analysis confirmed fibrosis in the diabetes group at 24weeks.

CONCLUSION

FA is significantly reduced in diabetic nephropathy. FA might serve a potential role in the detection and therapy monitoring of early diabetic nephropathy.

A phase Ib study of selumetinib (AZD6244, ARRY-142886) in combination with sorafenib in advanced hepatocellular carcinoma (HCC)

BACKGROUND

Treatment with sorafenib, although associated with inhibition of tumour growth and angiogenesis in in vivo studies, leads to up-regulation of pERK. The addition of MEK inhibition could potentially abrogate this effect and potentiate anti-tumour activity. This phase I study investigated the maximum tolerated dose (MTD), safety, tolerability, pharmacokinetics (PK) and biomarker correlates of selumetinib combined with sorafenib in patients with advanced hepatocellular carcinoma (HCC).

METHODS

Patients with Child-Pugh (CP) score ≤7 were treated with 400 mg twice daily of sorafenib with escalating doses of selumetinib in a 3 + 3 study design. The dose-limiting toxicity (DLT) evaluation period was 28 days. PK of selumetinib was determined. Angiogenic effect was evaluated with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI).

RESULTS

Twenty-seven patients of Asian ethnicity were enrolled. The MTD was selumetinib 75 mg daily with sorafenib 400 mg twice daily. DLT included grade 3 transaminitis, diarrhoea and fatigue. Most common treatment-related adverse events at MTD (all grades) were diarrhoea (85%), rash (59%), hypertension (44%), fatigue (30%), anorexia (22%) and hand-foot syndrome (22%). Four patients (15%) had PR and 13 (48%) had SD. PR or SD was observed for ≥6 months in seven patients. The median overall survival was 14.4 months. Selumetinib exposures in combination with sorafenib were comparable to other monotherapy studies. A reduction in permeability-surface area product noted in DCE-MRI with treatment correlated with worse survival outcomes.

CONCLUSION

The MTD of selumetinib was 75 mg daily when combined with sorafenib 400 mg twice a day in CP ≤7 HCC. Acceptable adverse events and encouraging anti-tumour activity warrant further evaluation. DCE-MRI findings deserve prospective evaluation.

CLINICALTRIALSGOV IDENTIFIER

NCT01029418.

Preoperative platelet-to-lymphocyte ratio improves the performance of the international consensus guidelines in predicting malignant pancreatic cystic neoplasms

INTRODUCTION

To determine if neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were predictive of malignancy in pancreatic cystic neoplasms (PCN) and if these improved the performance of the international consensus guidelines (ICG) in the initial triage of these patients.

METHODS

318 patients with surgically-treated suspected PCN were retrospectively reviewed. Malignant neoplasms were defined as neoplasms harbouring invasive carcinoma. The optimal cut-off for NLR and PLR were determined by plotting the receiver operating characteristics (ROC) curves of NLR/PLR in predicting malignant PCN and utilizing the Youden index.

RESULTS

The optimal NLR and PLR cut-offs were determined to be 3.33 and 205, respectively. Univariate analyses demonstrated that symptomatic PCNs, age, obstructive jaundice, presence of solid component, dilatation of main pancreatic duct ≥10 mm, high NLR and high PLR were predictive of a malignant PCN. Multivariate analyses demonstrated that obstructive jaundice, presence of solid component, MPD ≥10 mm and high PLR but not NLR were independent predictors of a malignant PCN. A high PLR significantly predicted invasive carcinoma in patients classified within the ICG(HR) group. Comparison between the ROC curves of the ICG versus ICG plus high PLR in predicting malignant PCN demonstrated a significant improvement in the accuracy of the ICG when PLR was included [AUC 0.784 (95% CI: 0.740-0.829) vs AUC 0.822 (95% CI: 0.772-0.872) (p = 0.0032)].

CONCLUSIONS

High PLR is an independent predictor of malignancy in PCN. The addition of PLR as a criterion to the ICG improved the accuracy of these guidelines in detecting invasive neoplasms.

Are preoperative blood neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios useful in predicting malignancy in surgically-treated mucin-producing pancreatic cystic neoplasms?

INTRODUCTION

The aim of this study was to determine if neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were predictive of malignancy in mucin-producing pancreatic cystic neoplasms (MpPCN).

METHODS

One hundred and twenty patients with MpPCN were retrospectively reviewed. Malignant neoplasms were defined as neoplasms harbouring invasive carcinoma or high grade dysplasia. A high NLR and PLR were defined as ≥2.551 and ≥208.1, respectively.

RESULTS

High NLR was significantly associated with symptomatic tumors, larger tumors, solid component, main-duct IPMN, and Sendai high risk category. High PLR was significantly associated with jaundice and Sendai high risk category. On univariate analyses, symptomatic tumors, jaundice, solid component, dilated pancreatic duct, and both a high NLR and PLR were significant predictors of malignant and invasive MpPCN. On multivariate analyses, solid component and dilated pancreatic duct were independent predictors of malignant and invasive MpPCN. PLR was an independent predictor for invasive MpPCN. When MpPCN were stratified by the Fukuoka and Sendai Guidelines, both a high NLR and PLR were significantly associated with malignant neoplasms within the high risk categories.

CONCLUSIONS

PLR is an independent predictor of invasive carcinoma. The addition of PLR as a criterion to the FCG and SCG significantly improved the predictive value of these guidelines in detecting invasive neoplasms.

Evaluation of the Fukuoka Consensus Guidelines for intraductal papillary mucinous neoplasms of the pancreas: Results from a systematic review of 1,382 surgically resected patients

BACKGROUND

International consensus guidelines to guide management of intraductal papillary mucinous neoplasms (IPMN) were revised in Fukuoka and published in 2012. However, despite widespread acceptance of the Fukuoka Consensus Guidelines (FCG), the utility of these guidelines have not been well-validated. This systematic review was performed to evaluate the clinical utility of the FCG.

DESIGN

A computerized search of the PubMed and Scopus databases was performed to identify all studies evaluating the utility of the FCG in surgically resected IPMN. IPMN were stratified according to the FCG as high risk (HR), worrisome risk (WR), and low risk (LR). HR and WR IPMN were termed FCG+ve and LR IPMN were termed FCG-ve.

RESULTS

Seven studies analyzing 1,382 patients were included. There were 402 malignant neoplasms (29%), including 242 invasive IPMNs. There were 1,000 IPMN classified as FCG+ve. The FCG+ve group had a positive predictive value (PPV) ranging from 27 to 62% and the FCG-ve group had negative predictive value ranging from 82 to 100%. Pooled analysis demonstrated that there was 362 of 1,000 (36%) malignant FCG+ve IPMN and 342 of 382 (90%) benign FCG-ve IPMN. PPV of the HR group and the WR groups alone were 104 of 158 (66%) and 75 of 261 (29%), respectively. Forty of 382 (11%), including 22 (6%) invasive FCG-ve IPMN, were malignant. Twenty-six malignant including 18 invasive FCG-ve IPMN were reported from a single study. When the results from this study were excluded, there were only 14 of 241 malignant neoplasms (6%), including 4 of 241 (2%) invasive FCG-ve IPMN in the remaining 6 studies.

CONCLUSION

The FCG+ve criteria had a similarly low PPV compared with the 2006 consensus criteria. Stratification of IPMN into HR and WR groups resulted in a higher PPV in the HR group. Some malignant and even invasive IPMN may be missed by the FCG criteria.

Dynamic contrast-enhanced magnetic resonance imaging: applications in oncology

Dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) allows functional characterisation of tissue perfusion characteristics and acts as a biomarker for tumour angiogenesis. It involves serial acquisition of MRI images before and after injection of contrast, as such, tissue perfusion and permeability can be assessed based on the signal enhancement kinetics. The ability to evaluate whole tumour volumes in a non-invasive manner makes DCE MRI especially attractive for potential oncological applications. Here we provide an overview of the current research involving DCE MRI as a biomarker for the diagnosis and characterisation of malignancies, prediction of the therapeutic response and survival outcomes, as well as radiation therapy planning.

Are the Sendai and Fukuoka consensus guidelines for cystic mucinous neoplasms of the pancreas useful in the initial triage of all suspected pancreatic cystic neoplasms? A single-institution experience with 317 surgically-treated patients

BACKGROUND

The Sendai Consensus Guidelines (SCG) were formulated in 2006 and updated in Fukuoka in 2012 (FCG) to guide management of cystic mucinous neoplasms of the pancreas. This study aims to evaluate the clinical utility of the SCG and FCG in the initial triage of all suspected pancreatic cystic neoplasms.

STUDY DESIGN

Overall, 317 surgically-treated patients with a suspected pancreatic cystic neoplasm were classified according to the SCG as high risk (HR(SCG)) and low risk (LR(SCG)), and according to the FCG as high risk (HR(FCG)), worrisome (W(FCG)), and low risk (LR(FCG)). Cystic lesions of the pancreas (CLP) were classified as potentially malignant/malignant or benign according to the final pathology.

RESULTS

The presence of symptoms, proximal lesions with obstructive jaundice, elevated serum carcinoembryonic antigen/carbohydrate antigen 19-9 (CEA/CA 19-9), size ≥3 cm, presence of solid component, main pancreatic duct dilatation, thickened enhancing walls, and change in ductal caliber with distal atrophy were predictive of a potentially malignant/malignant CLP on univariate analyses. The positive predictive value (PPV) and negative predictive value (NPV) of HR(SCG) and HR(ICG2012) for a potentially malignant/malignant lesion was 67 and 88 %, and 88 and 92.5 %, respectively. There were no malignant lesions in both LR groups but some potentially malignant lesions such as cystic pancreatic neuroendocrine neoplasms with uncertain behavior were classified as LR.

CONCLUSION

The updated FCG was superior to the SCG for the initial triage of all suspected pancreatic cystic neoplasms. CLP in the LR(FCG) group can be safely managed conservatively, and those in the HR(FCG) group should undergo resection.

Evaluation of the Sendai and 2012 International Consensus Guidelines based on cross-sectional imaging findings performed for the initial triage of mucinous cystic lesions of the pancreas: a single institution experience with 114 surgically treated patients

BACKGROUND

The Sendai Consensus Guidelines (SCG) were formulated in 2006 to guide the management of mucinous cystic lesions of the pancreas (CLPs) and were updated in 2012 (International Consensus Guidelines, ICG 2012). This study aims to evaluate the clinical utility of the ICG 2012 with the SCG based on initial cross-sectional imaging findings.

METHODS

One hundred fourteen patients with mucinous CLPs were reviewed and classified according to the ICG 2012 as high risk (HR(ICG2012)), worrisome (W(ICG2012)), and low risk (LR(ICG2012)), and according to the SCG as high risk (HR(SCG)) and low risk (LR(SCG)).

RESULTS

On univariate analysis, the presence of symptoms, obstructive jaundice, elevated serum carcinoembryonic antigen (CEA)/carbohydrate antigen (CA)19-9, solid component, main pancreatic duct ≥ 10 mm, and main pancreatic duct ≥ 5 mm was associated with high grade dysplasia/invasive carcinoma in all mucinous CLPs. Increasing number of HR(SCG) or HR(ICG2012) features was associated with a significantly increased likelihood of malignancy. The positive predictive value of HR(SCG) and HR(ICG2012) for high grade dysplasia/invasive carcinoma was 46% and 62.5% respectively. The negative predictive value of both LR(SCG) and LR(ICG2012) was 100%.

CONCLUSION

Both the guidelines were useful in the initial cross-sectional imaging evaluation of mucinous CLPs. The ICG 2012 guidelines were superior to the SCG guidelines.

Adjuvant hepatic intra-arterial iodine-131-lipiodol following curative resection of hepatocellular carcinoma: a prospective randomized trial

BACKGROUND

The purpose of the present study was to determine whether intrahepatic injection of (131)I-lipiodol (Lipiodol) is effective against recurrence of surgically resected hepatocellular carcinoma (HCC).

METHODS

From June 2001 through March 2007, this nationwide multi-center prospective randomized controlled trial enrolled 103 patients 4-6 weeks after curative resection of HCC with complete recovery (52: Lipiodol, 51: Control). Follow-up was every 3 months for 1 year, then every 6 months. Primary and secondary endpoints were recurrence-free survival (RFS) and overall survival (OS), respectively, both of which were evaluated by the Kaplan-Meier technique and summarized by the hazard ratio (HR). The design was based on information obtained from a similar trial that had been conducted in Hong Kong.

RESULTS

The Lipiodol group showed a small, and nonsignificant, improvement over control in RFS (HR = 0.75; 95 % confidence interval [95 % CI] 0.46-1.23; p = 0.25) and OS (HR = 0.88; 95 % CI 0.51-1.51; p = 0.64). Only two serious adverse events were reported, both with hypothyroidism caused by (131)I-lipiodol and hepatic artery dissection during angiography.

CONCLUSIONS

The randomized trial provides insufficient evidence to recommend the routine use of (131)I-lipiodol in these patients.

Assessment of tumor blood flow distribution by dynamic contrast-enhanced CT

A distinct feature of the tumor vasculature is its tortuosity and irregular branching of vessels, which can translate to a wider dispersion and higher variability of blood flow in the tumor. To enable tumor blood flow variability to be assessed in vivo by imaging, a tracer kinetic model that accounts for flow dispersion is developed for use with dynamic contrast-enhanced (DCE) CT. The proposed model adopts a multiple-pathway approach and allows for the quantification of relative dispersion in the blood flow distribution, which reflects flow variability in the tumor vasculature. Monte Carlo simulation experiments were performed to study the possibility of reducing the number of model parameters based on the Akaike information criterion approach and to explore possible noise and tissue conditions in which the model might be applicable. The model was used for region-of-interest analysis and to generate perfusion parameter maps for three patient DCE CT cases with cerebral tumors, to illustrate clinical applicability.

A Phase 1 dose-finding and pharmacodynamic study of rapamycin in combination with bevacizumab in patients with unresectable hepatocellular carcinoma

BACKGROUND & AIMS

Preclinical studies have demonstrated the additive effect of rapamycin with bevacizumab for hepatocellular carcinoma treatment. We conducted a Phase 1 study to evaluate the safety and pharmacokinetics of the combination in patients with hepatocellular carcinoma.

METHODS

Adult participants with advanced hepatocellular carcinoma received intravenous bevacizumab (5mg/kg every 14 days) and oral rapamycin (1-6 mg/day; 3+3 dose escalation design). Computed tomography assessed tumour response and treatment safety. Pharmacokinetics assessment established rapamycin blood concentrations pre- and post-dose. Dynamic contrast-enhanced computed tomography analysed the tumour region for blood flow, permeability surface area product, fractional intravascular blood volume and extracellular-extravascular volume.

RESULTS

Twenty-four participants were treated. There were two dose limiting toxicities with rapamycin 5mg: grade 3 thrombocytopenia and grade 3 mucositis. The maximally tolerated dose of rapamycin was 4 mg. Adverse events (grade 1-2) included hyperglycaemia (83%), thrombocytopenia (75%), fatigue (46%), mucositis (46%), anorexia (42%), diarrhoea (33%) and proteinuria (12.5%). Of 20 evaluable participants, one reached complete response that lasted 4.5 months, two reached partial response, 14 reached stable disease and three had progressive disease. Median overall survival was 9.4 months; progression-free survival was 5.5 months. Dose level and steady state area under the concentration time curve for hour zero to infinity of rapamycin correlated inversely with blood flow rate and change in permeability-surface area. After 22 days of treatment, there were significant reductions from baseline in blood flow rate, permeability-surface area and fractional intracellular blood volume.

CONCLUSIONS

The recommended Phase 2 dose of rapamycin is 4 mg in combination with bevacizumab. Evidence of anti-vascular activity was observed together with promising clinical activity.

High temporal resolution dynamic contrast-enhanced MRI at 7 Tesla: a feasibility study with mouse liver model

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has been widely applied to evaluate microcirculatory parameters in clinical settings. However, pre-clinical studies involving DCE-MRI of small animals remain challenging with the requirement for high spatial and temporal resolution for quantitative tracer kinetic analysis. This study illustrates the feasibility of applying a high temporal resolution (2 s) protocol for liver imaging in mice by analyzing the DCE-MRI datasets of mice liver with a dual-input two-compartment tracer kinetic model. Phantom studies were performed to validate the T(1) estimates derived by the proposed protocol before applying it in mice studies. The DCE-MRI datasets of mice liver were amendable to tracer kinetic analysis using a dual-input two-compartment model. Estimated micro-circulatory parameters were consistent with liver physiology, indicating viability of applying the technique for pre-clinical drug developments.

Dynamic contrast-enhanced MRI of neuroendocrine hepatic metastases: A feasibility study using a dual-input two-compartment model

Neuroendocrine hepatic metastases exhibit various contrast uptake enhancement patterns in dynamic contrast-enhanced MRI. Using a dual-input two-compartment distributed parameter model, we analyzed the dynamic contrast-enhanced MRI datasets of seven patient study cases with the aim to relate the tumor contrast uptake patterns to parameters of tumor microvasculature. Simulation studies were also performed to provide further insights into the effects of individual microcirculatory parameter on the tumor concentration-time curves. Although the tumor contrast uptake patterns can be influenced by many parameters, initial results indicate that hepatic blood flow and the ratio of fractional vascular volume to fractional interstitial volume may potentially distinguish between the patterns of neuroendocrine hepatic metastases.

Graft-vs-tumor effect in patients with advanced nasopharyngeal cancer treated with nonmyeloablative allogeneic PBSC transplantation

While nonmyeloablative peripheral blood stem cell transplantation (NST) has shown efficacy against several solid tumors, it is untested in nasopharyngeal cancer (NPC). In a phase II clinical trial, 21 patients with pretreated metastatic NPC underwent NST with sibling PBSC allografts, using CY conditioning, thymic irradiation and in vivo T-cell depletion with thymoglobulin. Stable lymphohematopoietic chimerism was achieved in most patients and prophylactic CYA was tapered at a median of day +30. Seven patients (33%) showed partial response and three (14%) achieved stable disease. Four patients were alive at 2 years and three showed prolonged disease control of 344, 525 and 550 days. With a median follow-up of 209 (4-1147) days, the median PFS was 100 days (95% confidence interval (CI), 66-128 days), and median OS was 209 days (95% CI, 128-236 days). Patients with chronic GVHD had better survival-median OS 426 days (95% CI, 194-NE days) vs 143 days (95% CI, 114-226 days) (P=0.010). Thus, NST may induce meaningful clinical responses in patients with advanced NPC.

Sunitinib (SUTENT, SU11248) suppresses tumor growth and induces apoptosis in xenograft models of human hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common and third deadliest primary neoplasm. Since HCC is a particularly vascular solid tumor, we determined the antitumor and antiangiogenic activities of sunitinib malate, a potent inhibitor of two receptors involved in angiogenesis - vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptor (PDGFR). In the present study, we reported that treatment of HepG2 and SK-Hep-1 cells with sunitinib led to growth inhibition and apoptosis in a dose-dependent fashion. Sunitinib inhibited phosphorylation of VEGFR-2 at Tyr951 and PDGFR-beta at Tyr1021 both in vitro and in vivo. Sunitinib also suppressed tumor growth of five patient-derived xenografts. Sunitinib-induced tumor growth inhibition was associated with increased apoptosis, reduced microvessel density and inhibition of cell proliferation. This study provides a strong rationale for further clinical investigation of sunitinib in patients with hepatocellular carcinoma.

Phase I and biomarker study of ABT-869, a multiple receptor tyrosine kinase inhibitor, in patients with refractory solid malignancies

PURPOSE

To determine the safety and tolerability of ABT-869 at escalating doses and its effects on biomarkers relevant for antiangiogenic activity in patients with solid malignancies.

PATIENTS AND METHODS

Patients with solid malignancies refractory to or for which no standard effective therapy exists were enrolled onto escalating-dose cohorts and treated with oral ABT-869 once daily continuously.

RESULTS

Thirty-three patients were studied at doses of 10 mg/d, 0.1 mg/kg/d, 0.25 mg/kg/d, and 0.3 mg/kg/d. Dose-limiting toxicities in the first cycle (21 days) included grade 3 fatigue in a patient at 10 mg/d, grade 3 proteinuria and grade 3 hypertension in two separate patients at 0.25 mg/kg/d, and grade 3 hypertension and grade 3 proteinuria in two separate patients at 0.3 mg/kg/d, which was the maximum-tolerated dose. Other significant treatment-related adverse events included asthenia, hand and foot blisters, and myalgia. Oral clearance of ABT-869 was linear, with a mean of 2.7 +/- 1.2 L/h and half-life of 18.4 +/- 5.7 hours, with no evidence of drug accumulation at day 15. Two patients with lung cancer and one patient with colon cancer achieved partial response. Stable disease for more than four cycles was observed in 16 patients (48%). Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) showed dose-dependent reduced tumor vascular permeability that correlated with drug exposure. By day 15 of treatment, circulating endothelial cells were significantly reduced (P = .007), whereas plasma vascular endothelial growth factor was increased (P = .004).

CONCLUSION

ABT-869 by continuous once-daily dosing was tolerable at doses </= 0.25 mg/kg/d. Biomarker evidence of antiangiogenic activity and DCE-MRI evidence of tumor antiangiogenesis were observed together with promising clinical activity.

Effective inhibition of xenografts of hepatocellular carcinoma (HepG2) by rapamycin and bevacizumab in an intrahepatic model

PURPOSE

Hepatocellular carcinoma (HCC) displays a characteristic hypervascularity and depends on angiogenesis for tumor growth, which thus provides a potential target for therapeutic approaches to HCC. In this study, through the use of combined micro-positron emission tomography (PET)/computed tomography (CT), we investigate if such a combined targeting of vascular endothelial growth factor (VEGF) activity and expression might retard HCC growth in an orthotopic intrahepatic xenograft model.

PROCEDURES

Xenograft models were created by intraportal vein injection of HepG2 cell suspensions in severe combined immunodeficient mice. The mice were then treated with (1) rapamycin (RAPA), a mammalian target of rapamycin pathway inhibitor; (2) bevazicumab (BEV), a VEGF monoclonal antibody; and (3) a RAPA/BEV combination.

RESULTS

Assessment of HCC progression using CT with Omnipaque and PET with 2-deoxy-2-(F-18)-fluoro-D: -glucose showed that mice treated with RAPA/BEV had the lowest standardized uptake values (SUVs). At week 2, mice treated with RAPA/BEV, RAPA, and BEV all showed a marked decrease in the SUV(max) readings with the greatest drop being observed in the RAPA/BEV group (1.33 + 0.26, 1.81 + 0.2, 2.05 + 0.4 vs. vehicle control 2.11 + 0.53).

CONCLUSIONS

Our results, supported by micro-PET/CT, suggest that RAPA/BEV represents a potential novel antiangiogenic therapy for the treatment of HCC.

Differentiation of benign and malignant parotid tumors using deconvolution-based perfusion CT imaging: Feasibility of the method and initial results

AIM

We evaluated the feasibility of perfusion CT (CTP) of the parotid gland and attempted to differentiate benign from malignant tumors.

MATERIALS AND METHODS

CTP was performed in 17 patients with benign tumors and 10 patients with malignant parotid tumors. Data were postprocessed by using deconvolution-based perfusion analysis. Postprocessing-generated maps showed blood flow (BF), blood volume (BV), mean transit time (MTT), and capillary permeability surface product (PS). Regions of interest were placed through the tumor site and the contralateral healthy parotid tissue. Ratios of the perfusion values between the tumors and the contralateral healthy structures were also calculated. Pearson correlation coefficients were determined to compare the agreement between the two readers.

RESULTS

Perfusion maps of all tumors were successfully obtained. High Pearson correlation coefficients comparing the two readers' visually measured abnormalities were observed (r=0.79-0.86, P=0.001) for all perfusion maps, The MTT and PS values between malignant and benign tumors were not significantly different. The BF and BV values were statistically significant different between the benign and malignant tumors (0.00<P<0.02). Only the BV ratio criterion between malignant and benign neoplasms was statistically significant (P<0.004).

CONCLUSIONS

CTP of the parotid gland is feasible and may differentiate malignant from non-malignant lesions by means of absolute BF, BV and BV ratio values.

How useful are clinical, biochemical, and cross-sectional imaging features in predicting potentially malignant or malignant cystic lesions of the pancreas? Results from a single institution experience with 220 surgically treated patients

BACKGROUND

This study aims to determine the use of preoperative clinical, biochemical, and cross-sectional imaging features for predicting malignancy in cystic lesions of the pancreas (CLP).

STUDY DESIGN

Two hundred twenty patients who underwent operations for CLP or suspected CLP were reviewed. Patients were divided into two groups, patients undergoing operations for pseudocysts and patients undergoing operations for suspected cystic neoplasms. The predictive effect of various preoperative factors on the malignant potential of CLP was evaluated.

RESULTS

Forty-four patients with a preoperative diagnosis of pseudocysts underwent operations for complications of pseudocyst. Forty-two were confirmed pathologically to have pseudocysts, but two were found, unexpectedly, to harbor malignant lesions. One hundred seventy-six patients underwent operations for suspected pancreatic cystic neoplasms. There were 70 benign, 51 potentially malignant, and 55 malignant CLP. On multivariate analysis, three factors, ie, elevated serum carcinoembryonic antigen (CEA) or carbohydrate antigen 19-9; cyst size > 3 cm; and presence of one or more of three morphologic features, such as solid component; peripheral calcification; and main duct dilation on cross-sectional imaging were independent predictors of malignancy. Presence of two or three of these factors had a positive predictive value of 88% in predicting a premalignant or malignant CLP.

CONCLUSIONS

Most pancreatic pseudocysts can be accurately diagnosed preoperatively. In patients with suspected pancreatic cystic neoplasms, elevated serum CEA or carbohydrate antigen 19-9, cyst size > 3 cm, and presence of suspicious morphologic features on imaging are predictors of potentially malignant or malignant CLP. Patients with a high likelihood of a potentially malignant or malignant lesion based on these three factors should undergo operation without additional investigations.

Pancreatic cysts: a proposed management algorithm based on current evidence

BACKGROUND

Currently, the management strategy of pancreatic cyst (PC) remains controversial because of the inability to diagnose this type of cyst accurately and the limited knowledge of its natural history. Previously, many clinicians have advocated an aggressive resectional policy. This approach is no longer appropriate, and the number of PCs detected incidentally has increased. This study reviews the present literature and attempts to provide a management algorithm of pancreatic cysts based on currently available evidence.

METHODS

A Medline search was conducted to identify studies investigating PC, with particular emphasis placed on studies addressing its diagnosis and management. Additional articles were obtained from the reference lists of key articles and recent reviews.

COMMENTS

Based on current evidence, the optimal management of PC remains an art and should be individualized based on the risk-benefit ratio of surgery, which is influenced by multiple factors, such as the patient's potential life expectancy, surgical risk; and malignant potential of the cyst. Our proposed management algorithm is based on an individual's predicted risk-benefit ratio of surgery. Prospective evaluation of the algorithm is needed to determine its integrity.

Comparison of scene-based interpolation methods applied to CT abdominal images

Three-dimensional (3-D) interpolation from 2-D image slices is widely used to aid the display, analysis and other biomedical image processing. We investigate the performance of 5 scene-based interpolation methods: linear, cubic spline, modified cubic spline and sine-based functions (Dirichlet apodization and Hanning apodization). We test our methods on four sets of computed tomography (CT) abdominal images, which have more organs in them compared to other biomedical images. Results show that, contrary to the 1-D or 2-D cases, linear interpolation acts as well as, even slightly better than all the other methods in the sense of signal to noise ratio in most cases, while the computational load of linear interpolation is only about half of the other methods. The reason for the relative high performance of linear interpolation is probably the large distance between consecutive images, which indicates low inter-slice correlation.

Pedunculated HCC or adrenal metastasis: a diagnostic conundrum

Hepatocellular carcinoma (HCC) is the commonest primary liver tumour. Recurrences are common in the liver although extrahepatic metastases can occur and frequently involve the adrenals. When this occurs in the right adrenal gland, it can be confused with an exophytic HCC arising from the posterior surface of the liver. The distinction between a primary HCC and a metastasis is important but can be difficult in this clinical setting. We report a 52-year-old man with recurrent HCC presenting as an "exophytic" posterior liver surface lesion that was actually a right adrenal metastasis. Although right-sided adrenal metastases of HCC can be difficult to distinguish from intrahepatic recurrences, even with modern diagnostic imaging, management either way involves surgical exploration and resection whenever possible.

Infected Pancreatic Necrosis – An Evaluation of the Timing and Technique of Necrosectomy in a Southeast Asian Population

Introduction: Acute pancreatitis appears to be less prevalent in multi-ethnic Southeast Asia, where the aetiology also appears to be influenced by ethnicity. As with acute pancreatitis elsewhere, however, pancreatic necrosis is a cause of significant mortality and the aim of this study was to review our institutional experience with pancreatic necrosectomy. Materials and Methods: The records of all patients who underwent pancreatic necrosectomy from January 2000 to December 2004 were analysed. Indications for surgery were the presence of infected necrosis, unresolving sepsis attributable to ongoing pancreatitis or the presence of gas in the pancreatic bed on imaging. Surgical debridement was achieved by debridement with closure over drains or by debridement with open packing. Results: The cohort comprised 14 of 373 patients admitted for acute pancreatitis (3.8%), with an overall mortality rate of 29%. All patients had infected necrosis with positive bacteriological cultures. Eight patients (57%) underwent debridement with closure over drains and 6 patients (43%) underwent debridement with open packing. All mortalities occurred in patients who underwent open packing, who were also associated with a higher mean Acute Physiology and Chronic Health Evaluation (APACHE) II score. The mortality rate in patients who underwent debridement less than 4 weeks after admission was 33% (2 of 6), compared with 25% (2 of 8) in patients who underwent debridement after 4 weeks. There were no mortalities in patients operated on after 6 weeks. Conclusion: Surgical debridement with closure of drains and a policy of performing delayed necrosectomy are viable in our population. Key words: Necrosectomy, Necrotising pancreatitis, Surgery

Infected pancreatic necrosis--an evaluation of the timing and technique of necrosectomy in a Southeast Asian population

INTRODUCTION

Acute pancreatitis appears to be less prevalent in multi-ethnic Southeast Asia, where the aetiology also appears to be influenced by ethnicity. As with acute pancreatitis elsewhere, however, pancreatic necrosis is a cause of significant mortality and the aim of this study was to review our institutional experience with pancreatic necrosectomy.

MATERIALS AND METHODS

The records of all patients who underwent pancreatic necrosectomy from January 2000 to December 2004 were analysed. Indications for surgery were the presence of infected necrosis, unresolving sepsis attributable to ongoing pancreatitis or the presence of gas in the pancreatic bed on imaging. Surgical debridement was achieved by debridement with closure over drains or by debridement with open packing.

RESULTS

The cohort comprised 14 of 373 patients admitted for acute pancreatitis (3.8%), with an overall mortality rate of 29%. All patients had infected necrosis with positive bacteriological cultures. Eight patients (57%) underwent debridement with closure over drains and 6 patients (43%) underwent debridement with open packing. All mortalities occurred in patients who underwent open packing, who were also associated with a higher mean Acute Physiology and Chronic Health Evaluation (APACHE) II score. The mortality rate in patients who underwent debridement less than 4 weeks after admission was 33% (2 of 6), compared with 25% (2 of 8) in patients who underwent debridement after 4 weeks. There were no mortalities in patients operated on after 6 weeks.

CONCLUSION

Surgical debridement with closure of drains and a policy of performing delayed necrosectomy are viable in our population.

Sclerosing haemangioma mimicking hepatocellular carcinoma

Sclerosing haemangioma is a rare variant of hepatic haemangioma. The radiological features on computed tomography and magnetic resonance imaging may not be typical for haemangioma and can be confused with hepatocellular carcinoma. We report sclerosing haemangioma occurring in a 65-year-old woman where the radiological features raise the possibility of hepatocellular carcinoma.

Focal nodular hyperplasia presenting as acute abdomen

Focal nodular hyperplasia (FNH) is a benign liver tumour with an asymptomatic course, rarely causing complications. When the diagnosis is certain, only watchful observation is necessary. We highlight an interesting case of a 42-year-old woman with a FNH that ruptured and became haemorrhagic, thus presenting as an acute surgical abdomen. The diagnosis was only established after surgical resection with histopathological confirmation. Although haemorrhage of hepatic FNH is extremely rare, this case highlights the small risk of rupture in large lesions.

Clinical mimicry of hepatocellular carcinoma: imaging-pathological correlation

This pictorial essay aims to show the clinical mimicry of hepatocellular carcinoma (HCC) and its diagnostic difficulty, and to create awareness among clinicians and radiologists of potential diagnostic pitfalls. A selected consecutive series of hepatectomies with proven HCC over a three-year period, identifying clinical presentation, blood results and imaging of patients with difficult preoperative diagnosis, was reviewed. The imaging of the focal liver lesions is presented pictorially with pathological correlation. Six patients out of 34 cases of resected HCC were diagnosed to have benign (three liver abscesses) and neoplastic (one Klatskin tumour, one colorectal liver metastasis, one gallbladder cancer) conditions. Compared to the rest in the series, all six patients had normal serum alpha fetoprotein levels. On computed tomography, the mosaic appearance of HCC mimicked locules of liver abscess while HCC with pseudocapsule (rim enhancement) was misdiagnosed as unilocular abscess or metastatic lesion. Arterial enhancement on contrast-enhanced triphasic computed tomography was useful in diagnosis of HCC. In summary, HCC can mimic benign and neoplastic clinical syndromes. The diagnosis of liver abscess can delay subsequent diagnosis of HCC and potentially complicate the treatment plan. Contrast-enhanced triphasic computed tomography or magnetic resonance imaging is useful to resolve difficult diagnosis, especially when the serum alpha fetoprotein level is not raised.

Hepatocellular carcinoma - issues in imaging

The imaging diagnosis of hepatocellular carcinoma is challenging as benign hypervascular lesions and arterioportal shunts (pseudolesions) often mimic it. There is also overlap in the imaging appearance from dysplastic and regenerating nodules. This article addresses the above imaging problems, examines proposed non-invasive imaging criteria for the diagnosis of hepatoma and discusses the optimal imaging modality.

Phased-array Magnetic Resonance Imaging of the Prostate with Correlation to Radical Prostatectomy Specimens: Local Experience

PURPOSE

To evaluate local experience of phased-array magnetic resonance imaging (MRI) in the staging of locally advanced prostate carcinoma with comparison to clinical staging.

METHODS

The study population was 21 patients who underwent preoperative MRI with pelvic phased-array coils followed by radical prostatectomy. The MRI findings were correlated with completely embedded serially sliced and whole-mounted sections of the prostate gland and clinical staging.

RESULTS

Overall accuracy of 57.1% was obtained, with specificity of 90.0% and sensitivity of 27.3%. All but one case of locally advanced disease missed by MRI was microscopic. Clinical staging in these cases also achieved accuracy of 57.1%, specificity of 90.0% and sensitivity of 27.3%.

CONCLUSIONS

MRI with a phased-array coil has high specificity but low sensitivity for detection of extraprostatic disease. Phased-array MRI does not image microscopic tumour extension. It did not perform better than clinical staging and is not recommended for routine staging.

Intrahepatic Biliary Cystadenoma Presenting with Obstructive Jaundice

Biliary cystadenoma (BCA) is a rare neoplasm of the bile duct with malignant potential. We report a case of intrahepatic BCA with an unusual presentation of obstructive jaundice. Computed tomography scan of the abdomen revealed a dilated common bile duct and intrahepatic ducts with internal septa. Endoscopic retrograde cholangiography showed an oval filling defect in the bile duct causing the obstruction. At laparotomy, this proved to be a multiloculated mucinous polyp in the common bile duct, with its origin in the left intrahepatic duct, detected using intraoperative choledochoscopy. A left hemihepatectomy was performed, and histology confirmed intrahepatic mucinous BCA with mesenchymal stroma. The imaging process and surgical options for BCA are discussed.

Endorectal magnetic resonance imaging and spectroscopy for the detection of tumor foci in men with prior negative transrectal ultrasound prostate biopsy

PURPOSE

We determined the ability of combined endorectal magnetic resonance imaging (MRI) and magnetic resonance spectroscopic imaging (MRSI) to detect prostate cancer foci prospectively in men with prior negative transrectal ultrasound (TRUS) prostate biopsy.

MATERIALS AND METHODS

Endorectal MRI with spectroscopy was performed in 24 consecutive patients with 1 or more prior negative TRUS prostatic biopsies for persistently increased prostate specific antigen and/or abnormal digital rectal examination. All studies were interpreted by a dedicated radiologist who reported areas of interest in the peripheral zone as normal, equivocal or suspicious on MRI and MRSI separately. Equivocal and suspicious areas were then correlated with a 3-dimensional prostate model. All patients underwent a standard TRUS 10-core peripheral zone biopsy with up to 4 additional biopsies targeted at the equivocal or suspected sites.

RESULTS

Prostate cancer was detected in 7 of 24 subjects (29.2%). Considering the equivocal category as test negative the sensitivity, specificity, positive and negative predictive values, and the accuracy of MRI, MRSI and combined MRI/MRSI for the detection of prostate cancer were 57.1%, 57.1% and 100.0%, 88.2%, 82.4% and 70.6%, 66.7%, 57.1% and 58.3%, 83.3%, 82.1% and 100%, and 79.2%, 75.0% and 79.2%, respectively. The site of positive biopsy correlated correctly in 50% and 28.6% of MRI and MRSI labeled suspicious cores, respectively.

CONCLUSIONS

MRI and MRSI have the potential to identify cancer foci and direct TRUS in patients with a previous negative TRUS biopsy. Further, larger studies are required to quantify the amount of benefit.

Radiologists' detection of mammographic abnormalities with and without a computer-aided detection system

The aim of this study was to to evaluate the role of a computer-aided program (CAD) in assisting detection of mammographic lesions by radiologists not specifically trained in mammography and its potential utility in breast screening. Mammograms were evaluated by radiologists not specifically trained in mammography first without, and then with, the CAD. Finally, the mammograms were evaluated by experienced mammographers who formed the reference standard. Two hundred and ninety four breasts were studied. In 257 breasts (87.4%), the CAD system did not help with the detection of abnormalities. It assisted radiologists in detecting abnormalities in 21 breasts (7.1%) with potential for detecting abnormalities in a further 13 breasts (4.4%). Only in three cases (1%) did it cause confusion in interpretation. There is overall increased sensitivity in detecting mammographic abnormalities with the aid of the CAD system from 74.4 to 87.2%, which is statistically significant. However, it failed to detect suspicious abnormalities in 71 breasts (24.1%). The CAD system improved detection of suspicious mammographic abnormalities by radiologists who are not specifically trained in mammography. However, there is also a substantial failure to detect suspicious mammographic features that cautions against over-reliance on the system, emphasizing its role as a second reader at best.

Clinical applications of MR cholangiopancreatography

INTRODUCTION

We review the clinical applications of magnetic resonance cholangiopancreatography (MRCP) and illustrate them with clinical examples.

METHODS

A literature search was performed in MedLine using the keywords "MR cholangiopancreatography" and "MRCP". The relevant articles were reviewed. The radiology information system was searched for MRCP examinations performed from July 1999 to December 2002. A surgical database of resected cases was also referenced. Illustrative cases were chosen in consultation with surgical authors to show the clinical applications of MRCP.

RESULTS

MRCP is useful for assessment of choledocholithiasis, choledochal cysts, pancreas divisum, primary sclerosing cholangitis, pancreatitis and anatomical variation of the biliary ducts. When complemented with dynamic gadolinium-enhanced studies, MRCP is useful for assessment of ductal cholangiocarcinoma, pancreatic and gall bladder neoplasms. Illustrative cases are provided.

CONCLUSION

MRCP is an important modality for the clinical assessment of biliary and pancreatic disorders.

Breath-hold fast recovery fast spin echo versus conventional non-breath-hold fast spin echo T2-weighted MR imaging of focal liver lesions

INTRODUCTION

We compare the breath-hold fast recovery fast spin echo (BHFRFSE) T2-weighted and non-breath-hold fast spin echo (NBHFSE) T2-weighted sequences in image quality and lesion characterisation of focal liver lesions.

MATERIALS AND METHODS

Fat-suppressed T2-weighted magnetic resonance (MR) images obtained with the 2 sequences (BHFRFSE and NBHFSE) in 79 patients with 113 liver lesions were analysed retrospectively. The image quality and nature of the lesions were evaluated by 2 experienced radiologists.

RESULTS

Based on receiver operating characteristic curve analysis, lesion characterisation was comparable for both sequences. The image quality of BHFRFSE was significantly better than that of NBHFSE. The NBHFSE missed 4 malignant lesions while BHFRFSE missed 2 malignant lesions.

CONCLUSION

BHFRFSE performs similarly to NBHFSE in image quality and liver lesion characterisation.

MR imaging and MR spectroscopy of adenocarcinoma of the prostate

INTRODUCTION

We examined the impact of magnetic resonance (MR) imaging and MR spectroscopy on the diagnosis and management of prostate cancer.

METHODS

A Medline search was performed and the relevant articles reviewed. The salient points are discussed and summarised.

RESULTS

MR imaging with phased-array and endorectal coils is not recommended for routine staging. It has a complementary role in improving the accuracy of local staging in patients with intermediate risk based on Partin's normogram. MR spectroscopy can be performed in conjunction with high-resolution anatomic MR imaging of the prostate. It exploits the increased choline and decreased citrate levels within malignant prostatic tissue compared with normal prostatic tissue, and can potentially improve the assessment of cancer location and extent within the prostate, as well as extracapsular spread in small retrospective studies. It also has the potential of providing a measure of the presence and extent of prostate cancer after therapy.

CONCLUSION

MR imaging is indicated in staging patients with intermediate risk based on Partin's normogram. Combined MR imaging and MR spectroscopy of the prostate is a promising imaging tool which can contribute to the diagnosis and management of prostate cancer when combined with clinical, biochemical and histological data. Large prospective studies must be performed to ascertain the true clinical value of combined MR imaging/MR spectroscopy for the management of prostate cancer patients.

Percutaneous drainage of liver abscess complicated by hepato-venous fistula

Severe systemic sepsis after percutaneous drainage of liver abscess is rare. We report two cases of hepato-venous fistulas between hepatic abscesses and hepatic/portal veins documented on abscessography during percutaneous drainage of liver abscesses, which resulted in severe sepsis and a stormy post drainage clinical course. Liver abscesses can rupture into the portal and hepatic veins causing worsening of systemic sepsis especially when they are in close proximity to each other. During percutaneous drainage, care must also be taken to avoid overinjection of the abscess, which can worsen the fistula. The ensuing sepsis is severe and requires aggressive intensive medical care and ventilatory support to tide the patient over the septic episode.

Current status in imaging of colorectal liver metastases

Colorectal cancer is a common malignancy that often metastasizes to the liver. Evaluation of the liver for metastases is important for staging and prognosis. Resection of limited hepatic metastases can result in prolonged survival. Imaging is vital to select appropriate patients to avoid unnecessary surgery. A variety of modern imaging tools can be used to detect and characterise hepatic lesions. These include contrast enhanced helical computed tomography (CT), CT arterial portography, magnetic resonance imaging (MRI) and intraoperative ultrasound (IOUS). Each has their advantages as well as disadvantages. Besides accuracy, availability, cost and presence of expertise determine the optimal modality or combination of modalities to use. The appearance of metastases on imaging can be correlated with histopathological abnormalities. Though metastases can often be distinguished from benign lesions, their appearances are by no means pathognomonic. Follow-up imaging for interval change and for assessment of response is often required.

Computed tomographic appearance of colorectal hepatic metastases

INTRODUCTION

This article reviews the various computed tomography (CT) appearances of hepatic metastases from colorectal primaries and assesses the frequency of occurrence of the various patterns.

MATERIALS AND METHODS

This is a retrospective study of the CT appearances of histologically proven colorectal hepatic metastases in a group of 52 patients who had undergone surgical hepatic resection between January 1994 and December 2001. A total of 74 hepatic metastatic lesions were reviewed. All lesions were examined in the portal venous phase.

RESULTS

A discernible rim was seen in 54 lesions (73%). Thick rim was present in 36 lesions (48.6%) and thin rim in 18 lesions (24.3%). Enhancement of the rim was present in 62 cases (83.8%). Increased central attenuation was seen in 38 lesions (51.4%). Of these, the centre was heterogeneous in 76.3% and scar-like in 23.7%. A non-enhancing rim was seen in 12 lesions (16.2%) which appeared as lesions with "bevelled edge". Thick enhancing rim with non-enhancing centre was the most common combination in 15 lesions (20.3%).

CONCLUSION

An enhancing rim could be seen in 83.8% of lesions. Increased central attenuation was present in 51.4% of the lesions. Familiarity with the various CT appearances may facilitate identification and diagnosis of colorectal liver metastases.