Conflict of Interest in Research--The Clinician Scientist's Perspective

Conflict of interest (COI) in research represents situations that pose risks of undue influence on scientific objectivity and judgment because of secondary interests. This is complex but is inherent to biomedical research. The role of a clinician scientist can be conflicted when scientific objectivity is perceived to compete with scientific success (publications, grants), partiality to patients (clinical trials), obligations to colleagues (allowing poor scholarship to pass), research sponsors (industry), and financial gains (patents, royalties). While there are many ways which COIs can occur in research, COI mitigations remain reliable. Collaborations between investigators and industry are valuable to the development of novel therapies and undue discouragement of these relationships may inadvertently harm the advancement of healthcare. As a result, proper management of COI is fundamental and crucial to the maintenance of long-term, mutually beneficial relationships between industry and academia. The nature of COI in research and methods of mitigation are discussed from the perspective of a clinician scientist.

Atypical enhancement pattern of hepatocellular carcinoma with portal vein thrombosis on multiphasic CT

<p><b>INTRODUCTION</b>The 2005 American Association for Study of Liver Diseases (AASLD) diagnostic criteria allow non-invasive diagnosis of hepatocellular carcinoma (HCC) based on their enhancement pattern but we have observed a high incidence of atypical enhancement characteristics in HCC associated with portal vein thrombosis. This study seeks to examine the radiological features of this particular subgroup.</p><p><b>MATERIALS AND METHODS</b>Patients with HCC and portal vein thrombosis who underwent pre-treatment multiphasic CT imaging were drawn from a surgical database. The arterial, portal venous and delayed phase images were assessed qualitatively and quantitatively (with region of interest [ROI] analysis) for lesion hypervascularity and washout. The background enhancement of the left and right lobes of the liver was also quantifi ed by ROI analysis.</p><p><b>RESULTS</b>Twenty-fi ve lesions in 25 patients were selected for analysis. Qualitative analysis showed that 10/25 (40%) lesions demonstrated arterial hypervascularity while 16/25 (64%) lesions showed washout. Ten out of 25 (40%) lesions demonstrated both arterial hypervascularity and washout. Quantitative analysis showed that the average absolute lesion enhancement from precontrast to arterial phases was 49.1 (± 17.1) HU for hypervascular lesions compared to 23.8 (± 16.6) HU for non-hypervascular lesions (P <0.01). The mean absolute enhancement of the background liver parenchyma in the arterial phase was 13.79 (± 7.9) HU for hypervascular lesions compared to 36.6 (± 30.6) HU for non-hypervascular lesions (P = 0.03).</p><p><b>CONCLUSION</b>A large proportion of HCC with portal vein thrombosis lack characteristic arterial hypervascularity, which may be secondary to compensatory increased arterial supply to the background liver. This is a potential pitfall when applying imaging criteria for diagnosis of HCC.</p>

An approach to the ethical evaluation of innovative surgical procedures

While there is an ethical obligation to improve clinical outcomes by developing better therapies, surgical innovation has largely progressed without the strict regulations required of novel pharmaceutical products. We explore the reasons why new surgical techniques are frequently introduced without the benefit of randomised controlled trials, and present an approach to the ethical evaluation of novel surgical procedures.

Wash-out of hepatocellular carcinoma: quantitative region of interest analysis on CT

<p><b>INTRODUCTION</b>This study aims to determine if the quantitative method of region-of-interest (ROI) analysis of lesion attenuation on CT may be a useful adjunct to the conventional approach of diagnosis by visual assessment in assessing tracer wash-out in hepatocellular carcinomas.</p><p><b>MATERIALS AND METHODS</b>From a surgical database of 289 patients from 2 institutions, all patients with complete surgical, pathological and preoperative multiphasic CT scans available for review were selected. For each phase of scanning, HU readings of lesion obtained (Lesion(arterial), Lesion(PV) and Lesion(equilibrium)) were analysed using receiver operating curves (ROC) to determine the optimal method and cut-off value for quantitative assessment of tumour wash-out (Lesion(arterial - equilibrium), Lesion(PV - equilibrium) or Lesion(peak - equilibrium)).</p><p><b>RESULTS</b>Ninety-four patients with one lesion each met the inclusion criteria. The area under the curve (AUC) values for Lesion(arterial - equilibrium) (0.941) was higher than the AUC for Lesion(pv - equilibrium) (0.484) and for Lesion(peak - equilibrium) (0.667). Based on ROC analysis, a cut-off of 10HU value for Lesion(arterial - equilibrium) would yield sensitivity and specificity of 91.5% and 80.9%, respectively. ROI analysis detected 9/21 (42.9%) of lesions missed by visual analysis. Combined ROI and visual analysis yields a sensitivity of 82/94 (87.2%) compared to 73/94 (77.7%) for visual analysis alone.</p><p><b>CONCLUSION</b>Using a cut-off of 10 HU attenuation difference between the arterial and equilibrium phases is a simple and objective method that can be included as an adjunct to visual assessment to improve sensitivity for determining lesion wash-out on CT.</p>

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

<p><b>INTRODUCTION</b>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.</p><p><b>MATERIALS AND METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>Surgical debridement with closure of drains and a policy of performing delayed necrosectomy are viable in our population.</p>

Image-guided radiofrequency ablation of liver malignancies: experience at Singapore General Hospital

<p><b>UNLABELLED</b>The aim of this paper was to study the efficacy, side effects and complications of radiofrequency (RF) ablation of primary and metastatic liver malignancies.</p><p><b>MATERIALS AND METHODS</b>We retrospectively reviewed 57 patients (39 men, 18 women; mean age, 63 years; age range, 44 to 83 years) who underwent RF ablation for liver malignancies from January 2002 to December 2004. A total of 87 tumours were ablated - 71 (81.6%) hepatocellular carcinomas and 16 (18.4%) metastases (from primaries in the colon, stomach and pancreas). RF ablation was performed either percutaneously (n = 71) under conscious sedation or intraoperatively (n = 16) under general anaesthesia. Follow-up ranged from 1 month to 41 months (mean, 15.2) and included computed tomography (CT) 1 day, 1 month and 3 months after ablation, and half-yearly thereafter. Patients were observed for local tumour progression and for the emergence of new tumours.</p><p><b>RESULTS</b>Four patients with a total of 5 tumours were lost to follow-up. Of the remaining 82 tumours treated, complete ablation was attained in 66 tumours after a single procedure, giving a primary effectiveness rate of 80.5%. Seven (8.5%) required 2 procedures to achieve complete ablation, giving a secondary effectiveness rate of 89% after 2 ablations. One tumour (1.2%) required 3 procedures to achieve complete ablation. One tumour required 4 procedures to date, with the latest follow-up CT still demonstrating incomplete ablation. Two tumours (2.4%) had an initial RF ablation and subsequent transarterial chemoembolisation (TACE). One tumour had an initial RF ablation followed by 32Phosphorus-biosilicon (BrachySil) injection, the latter as part of a Phase IIA trial. One tumour required 2 RF ablations and a subsequent TACE. Lastly, 3 tumours received initial RF ablation but subsequent local tumour progression was not treated as the patients were deemed unfit for repeat ablation. No procedure-related deaths or major complications were encountered. Minor complications were reported in 2 patients (3.8%) - subcapsular haematoma and thermal injury to the adjacent gastric antrum, both not necessitating surgical intervention.</p><p><b>CONCLUSIONS</b>RF ablation is an effective, safe and relatively simple procedure for the treatment of unresectable liver malignancies.</p>