[Delayed complications after pancreatic surgery: Pancreatic insufficiency, malabsorption syndrome, pancreoprivic diabetes mellitus and pseudocysts]

BACKGROUND

Benign and malignant pathologies of the pancreas can result in a relevant chronic disease burden. This is aggravated by morbidities resulting from surgical resections as well as from progression of the underlying condition.

OBJECTIVE

The aim was to summarize the current evidence regarding epidemiology, pathophysiology, diagnosis and treatment of endocrine and exocrine pancreatic insufficiency, as well as of pancreatic pseudocysts.

MATERIAL AND METHODS

A selective literature search was performed and a summary of the currently available data on the surgical sequelae after pancreatic resection is given.

RESULTS

Reduction of healthy pancreatic parenchyma down to 10-15 % leads to exocrine insufficiency with malabsorption and gastrointestinal complaints. Orally substituted pancreatic enzymes are the therapy of choice. Loss of pancreatic islets and/or islet function leads to endocrine insufficiency and pancreoprivic diabetes mellitus. Inflammatory, traumatic and iatrogenic injuries of the pancreas can lead to pancreatic pseudocysts, which require endoscopic, interventional or surgical drainage if symptomatic. Finally, pancreatic surgery harbors the long-term risk of gastrointestinal anastomotic ulcers, bile duct stenosis, portal vein thrombosis and chronic pain syndrome.

CONCLUSION

As the evidence is limited, an interdisciplinary and individually tailored approach for delayed pancreatic morbidity is recommended.

Anti-platelet factor 4/heparin antibodies in patients with impaired graft function after liver transplantation

BACKGROUND

Heparin, the standard perioperative anticoagulant for the prevention of graft vessel thrombosis in patients undergoing liver transplantation (LT), binds to the chemokine platelet factor 4 (PF4). Antibodies that are formed against the resulting PF4/heparin complexes can induce heparin-induced thrombocytopenia. LT is a clinical situation that allows the study of T-cell dependency of immune responses because T-cell function is largely suppressed pharmacologically in these patients to prevent graft rejection.

OBJECTIVES

To investigate the immune response against PF4/heparin complexes in patients undergoing LT.

PATIENTS AND METHODS

In this prospective cohort study, 38 consecutive patients undergoing LT were systematically screened for anti-PF4/heparin antibodies (enzyme immunoassay and heparin-induced platelet aggregation assay), platelet count, liver function, and engraftment.

RESULTS

At baseline, 5 (13%) of 38 patients tested positive for anti-PF4/heparin IgG (non-platelet-activating) antibodies. By day 20, an additional 5 (15%) of 33 patients seroconverted for immunoglobulin G (two platelet-activating) antibodies. No patient developed clinical heparin-induced thrombocytopenia. Two of six patients with graft function failure had anti-PF4/heparin IgG antibodies at the time of graft function failure. Graft liver biopsy samples from these patients showed thrombotic occlusions of the microcirculation.

CONCLUSIONS

Anti-PF4/heparin IgG antibodies are generated despite strong pharmacologic suppression of T cells, indicating that T cells likely have a limited role in the immune response to PF4/heparin complexes in humans.

[Curriculum for Practical Surgical Education during Internships - with a Strategy for New Perspectives]

BACKGROUND

It seems that the experience gained in the courses of surgical training in medical education does not really motivate students for surgery in Germany. Inspired by this problem the Department of Surgery of the Klinikum rechts der Isar, Technical University of Munich has developed a substantial reform for the internship since 2009 with the aim of not only improving the quality of education significantly, but also the attractiveness and thus the fascination for the subject.

METHODS

Based on the slogan "We want to awaken your fascination for surgery" a structured and standardised training of all students in their internship regardless of the ward or section and local conditions was developed. For this purpose a completely new curriculum was steadily implemented into clinical practice, based on the following four basic principles: (i) integration and perception in the clinic, (ii) central and peripheral maintenance, (iii) systematic and individual training, (iv) evaluation and feedback at all levels. To analyse the effectiveness of the reform, standardised evaluations by students and faculty were carried out regularly.

RESULTS

To date, since the beginning of the reform in 2009, there has been an approximately linear increase in the number of students in the PJ surgery. The daily systematic courses showed a good to excellent rating in all formats. The comparison showed a clear increasing trend in all the values, in particular, the "integration into the overall hospital" significantly improved (mean, 4.7 vs. 5.5, p = 0.003). However, the point "motivating for surgery" (mean, 3.3) remains at a low level. But also medical educators were satisfied with the new curriculum for the internship students (mean, 4.5).

CONCLUSION

The reform was adopted universally in a very positive manner and the current data support the need for such a reform. Overall, the reform showed a positive development of the internship training in the surgical department of the faculty. The satisfaction of the students and teachers could be increased by gradual implementation of the reform. Even if a lot of individual aspects gain a higher acceptance, the main concern, the inspiration of the "fascination" of the central surgical field, the training in the operating room, seems to succeed only partially.

Postinterventional tumor necrosis predicts recurrence-free long-term survival in liver transplant patients with advanced hepatocellular carcinoma

BACKGROUND

Locoregional interventional bridging treatment (IBT) before liver transplantation (LT) is an accepted neoadjuvant approach in liver transplant patients with hepatocellular carcinoma (HCC). However, the effect of postinterventional tumor necrosis on posttransplantation outcome is known.

METHODS

A total of 93 consecutive liver transplant patients with HCC were included in this prospective trial. Fifty-nine patients underwent pretransplantation IBT, by either transarterial chemoembolization (n = 51) or radiofrequency ablation (n = 8). The extent of tumor necrosis assessed at explant pathology (≥50% tumor necrosis rate = extended post-IBT tumor necrosis; <50% tumor necrosis rate = less extended tumor necrosis) and its impact on recurrence-free survival in the context of other prognostic relevant histopathologic variables were analyzed in uni- and multivariate analyses.

RESULTS

Extended tumor necrosis was assessed in 44 patients among the IBT population, and tumor necrosis rate was <50% in 15 patients of the IBT and 34 patients of the non-IBT population, respectively. Five-year recurrence-free survival rates were 96% in patients with and 55% in patients without extended tumor necrosis rates (P < .001). Recurrence-free survival rates were similar between patients with HCC meeting the Milan criteria (85%) and those exceeding the Milan criteria but demonstrating extended post-IBT tumor necrosis on explant pathology (80%). On multivariate analysis, only microvascular invasion (odds ratio 6.4) and extended postinterventional tumor necrosis (odds ratio 9.2) were identified as independent histopathologic predictors of recurrence-free outcome (P < .05).

CONCLUSIONS

Extended tumor necrosis should be the major objective of neoadjuvant IBT in liver transplant patients with HCC, because it significantly improves posttransplantation outcome. Thereby, even patients with HCC beyond the Milan criteria may achieve excellent survival rates.

Surgeon-patient communication in oncology

Little is known about the quality of post-operative communications following oncological surgery and the satisfaction of patients with the communication process. Thirty-eight patients who underwent surgery for primary gastrointestinal cancer were interviewed before being discharged from the hospital. The patients' recall of information concerning the surgery, histological diagnosis, post-operative therapy and treatment goal was assessed. The congruence between the information provided by the surgeons and that retained by the patients was evaluated. The information provided by the surgeons about the diagnosis, histology and post-operative therapy plan was correctly recalled by over 92%, 81% and 97% of the patients respectively. Only 70% of the patients correctly recalled information about the goal of the treatment. Moreover, patients receiving only palliative treatment showed less recall of information about the treatment goal than patients receiving curative treatment (33% versus 89%). The surgeons reported that only 35% of the patients left the hospital completely informed. Overall, the patients were highly satisfied with their communication with their surgeon, and the patients' recall of information was generally good. The information given by the surgeons was often incomplete, however. Our explorative analysis showed that the quality of communication was often worse for patients with a palliative treatment goal than for patients with a curative treatment goal.

Transferring innovative freehand SPECT to the operating room: first experiences with sentinel lymph node biopsy in malignant melanoma

PURPOSE

The purpose of this study was to report on the first experiences with freehand single-photon emission-computed tomography (freehand SPECT) in sentinel lymph node biopsy (SLNB) in patients with malignant melanoma. Freehand SPECT is a novel imaging modality combining gamma probes, surgical navigation systems, and emission tomography algorithms, designed to overcome some of the limitations of conventional gamma probes.

METHODS

In this study 20 patients with malignant melanoma underwent conventional planar scintigraphy prior to surgery. In the operating room, the number and location of separable SLNs were detected first by a pre-incisional scan with freehand SPECT to render a 3D-image of the target site and afterwards by a scan with a conventional gamma probe. After SLNB another scan was performed to document the removal of all targeted SLNs.

RESULTS

Planar scintigraphy identified 40 SLNs in 26 nodal basins. Pre-incisional freehand SPECT mapped 38 of these nodes as well as one additional node in one patient (95.0% node based sensitivity). The results of freehand SPECT were identical to those of planar scintigraphy in 25 basins, while it missed one basin (96.2% basin based sensitivity). In comparison, the gamma probe failed to detect 7 nodes in 4 basins (82.5% node based sensitivity and 84.6% basin based sensitivity). After resection freehand SPECT detected 9 remaining radioactive spots, two of whichwere resected as they matched the position of SLNs detected on preoperative planar scintigraphy.

CONCLUSIONS

Freehand SPECT provides a real-time, intraoperative 3D-image of the radioactive labelled SLNs, facilitating their detection and resection.

European experts consensus statement on cystic tumours of the pancreas

Cystic lesions of the pancreas are increasingly recognized. While some lesions show benign behaviour (serous cystic neoplasm), others have an unequivocal malignant potential (mucinous cystic neoplasm, branch- and main duct intraductal papillary mucinous neoplasm and solid pseudo-papillary neoplasm). European expert pancreatologists provide updated recommendations: diagnostic computerized tomography and/or magnetic resonance imaging are indicated in all patients with cystic lesion of the pancreas. Endoscopic ultrasound with cyst fluid analysis may be used but there is no evidence to suggest this as a routine diagnostic method. The role of pancreatoscopy remains to be established. Resection should be considered in all symptomatic lesions, in mucinous cystic neoplasm, main duct intraductal papillary mucinous neoplasm and solid pseudo-papillary neoplasm as well as in branch duct intraductal papillary mucinous neoplasm with mural nodules, dilated main pancreatic duct >6mm and possibly if rapidly increasing in size. An oncological partial resection should be performed in main duct intraductal papillary mucinous neoplasm and in lesions with a suspicion of malignancy, otherwise organ preserving procedures may be considered. Frozen section of the transection margin in intraductal papillary mucinous neoplasm is suggested. Follow up after resection is recommended for intraductal papillary mucinous neoplasm, solid pseudo-papillary neoplasm and invasive cancer.

iTRAQ reveals candidate pancreatic cancer serum biomarkers: influence of obstructive jaundice on their performance

BACKGROUND

The aims of our study were to identify serum biomarkers that distinguish pancreatic cancer (pancreatic ductal adenocarcinoma, PDAC) patients from benign pancreatic disease patients and healthy subjects, and to assess the effects of jaundice on biomarker performance.

METHODS

Isobaric tags for relative and absolute quantification were used to compare pooled serum and pancreatic juice samples from a test set of 59 and 25 subjects, respectively. Validation was undertaken in 113 independent subjects.

RESULTS

Candidate proteins Complement C5, inter-α-trypsin inhibitor heavy chain H3, α1-β glycoprotein and polymeric immunoglobulin receptor were elevated in cancer, as were the reference markers CA19-9 and Reg3A. Biliary obstruction had a significant effect on the performance of the markers, in particular within the PDAC group where the presence of jaundice was associated with a significant increase in the levels of all six proteins (P<0.01). Consequently, in the absence of jaundice, proteins showed reduced sensitivity for PDAC patients over benign subjects and healthy controls (HCs). Similarly, in the presence of jaundice, markers showed reduced specificity for PDAC patients over benign subjects with jaundice. Combining markers enabled improved sensitivity for non-jaundiced PDAC patients over HCs and improved specificity for jaundiced PDAC patients over jaundiced benign disease subjects.

CONCLUSIONS

The presence-absence of jaundice in the clinical scenario severely impacts the performance of biomarkers for PDAC diagnosis and has implications for their clinical translation.

Randomised clinical trial: a 1-week, double-blind, placebo-controlled study of pancreatin 25 000 Ph. Eur. minimicrospheres (Creon 25000 MMS) for pancreatic exocrine insufficiency after pancreatic surgery, with a 1-year open-label extension

BACKGROUND

Pancreatic exocrine insufficiency (PEI) often occurs following pancreatic surgery.

AIM

To demonstrate the superior efficacy of pancreatin 25 000 minimicrospheres (Creon 25000 MMS; 9-15 capsules/day) over placebo in treating PEI after pancreatic resection.

METHODS

A 1-week, double-blind, randomised, placebo-controlled, parallel-group, multicentre study with a 1-year, open-label extension (OLE). Subjects ≥18 years old with PEI after pancreatic resection, defined as baseline coefficient of fat absorption (CFA) <80%, were randomised to oral pancreatin or placebo (9-15 capsules/day: 3 with main meals, 2 with snacks). In the OLE, all subjects received pancreatin. The primary efficacy measure was least squares mean CFA change from baseline to end of double-blind treatment (ancova).

RESULTS

All 58 subjects randomised (32 pancreatin, 26 placebo) completed double-blind treatment and entered the OLE; 51 completed the OLE. The least squares mean CFA change in the double-blind phase was significantly greater with pancreatin vs. placebo: 21.4% (95% CI: 13.7, 29.2) vs. -4.2% (-12.8, 4.5); difference 25.6% (13.9, 37.3), P < 0.001. The mean ± s.d. CFA increased from 53.6 ± 20.6% at baseline to 78.4 ± 20.7% at OLE end (P < 0.001). Treatment-emergent adverse events occurred in 37.5% subjects on pancreatin and 26.9% on placebo during double-blind treatment, with flatulence being the most common (pancreatin 12.5%, placebo 7.7%). Only two subjects discontinued due to treatment-emergent adverse events, both during the OLE.

CONCLUSIONS

This study demonstrates superior efficacy of pancreatin 25 000 over placebo in patients with PEI after pancreatic surgery, measured by change in CFA. Pancreatin was generally well tolerated at the high dose administered (EudraCT registration number: 2005-004854-29).

Heparin-binding EGF-like growth factor expression and biological action in human pancreatic cancer cells

The epidermal growth factor (EGF) receptor is activated by EGF and other EGF-like growth factors, including heparin-binding epidermal growth factor-like growth factor (HB-EGF). We characterized the biological actions of HB-EGF in PANC-1 and COLO-357 human pancreatic cancer cell lines, and determined whether the presence of HB-EGF in human pancreatic carcinomas correlates with patient survival. HB-EGF enhanced the growth of both cell lines in a dose-dependent manner, with a potency that was generally similar to that of EGF and transforming growth factor-alpha (TGF-alpha). HB-EGF also readily induced tyrosine phosphorylation of the EGF receptor in these cells. Immunohistochemical analysis of 47 pancreatic cancer tissues revealed the presence of HB-EGF immunoreactivity in the cancer cells in 50% of the tumors. However, the presence of HB-EGF was not associated with a statistically significant decrease in the post-operative survival period. Furthermore, coexpression of HB-EGF and the EGF receptor was not associated with shorter patient survival. These findings suggest that HB-EGF activates the EGF receptor in human pancreatic cancer cells, but that it is not involved in enhancing the biological aggressiveness of this malignancy in vivo.

Amphiregulin is a potent mitogen in human pancreatic-cancer cells - correlation with patient survival

The epidermal growth factor (EGF) receptor (EGFR) is activated by EGF and other EGF-like growth factors, including amphiregulin (AR). We characterized the localization and mitogenic action of AR in T3M4 and COLO-357 human pancreatic cancer cell lines and determined whether the presence of AR in human pancreatic cancers correlates with patient survival. Both T3M4 and COLO-357 cells were found to be extremely sensitive to AR, one-half maximal stimulation occurring at a concentration of 70 and 50 pM, respectively. The magnitude of the stimulatory effect was greater with AR than with EGF. Both cell lines exhibited AR immunostaining, which was present in a variable manner in the cytoplasm, nucleus and nucleoli. Immunohistochemical analysis of 62 pancreatic cancer tissues revealed the presence of nuclear and/or cytoplasmic AR immunoreactivity in the cancer cells. Cytoplasmic, but not nuclear localization of AR in the pancreatic cancer cells was associated with a statistically significant decrease in the post-operative survival period. The presence of EGFR alone in the cancer cells did not correlate with decreased survival, whereas coexpression of cytoplasmic AR and EGFR was associated with shorter survival. Distant metastases did not always exhibit cytoplasmic AR immunoreactivity. These findings point to the existence of an EGFR: AR autocrine loop in human pancreatic cancer which may contribute to its biological aggressiveness.

Betacellulin, a member of the epidermal growth-factor family, is overexpressed in human pancreatic-cancer

Human pancreatic ductal adenocarcinomas overexpress the epidermal growth factor (EGF) receptor. Betacellulin is a mitogenic polypeptide that binds and activates this receptor. To determine whether betacellulin has a role in human pancreatic cancer, we studied its expression in cultured human pancreatic cancer cell lines and in normal and cancerous pancreatic tissues. Five of 6 pancreatic cancer cell lines expressed the 3 kb betacellulin mRNA moiety, T3M4, MiaPaCa-2 and COLO-357 cells exhibiting the highest expression levels. EGF, heparin-binding EGF-like growth factor (HB-EGF), and basic fibroblast growth factor (bFGF) increased betacelullin mRNA levels. Only 2 of 15 normal samples and 1 of 10 cancer samples failed to exhibit the betacellulin transcript. Densitometric analysis of the autoradiographs revealed a 7.5-fold increase in betacellulin mRNA levels in the cancer tissues by comparison with the normal tissues. By in situ hybridization, the duct-like cancer cells exhibited many betacellulin mRNA in situ hybridization grains. These findings indicate that human pancreatic cancer cells express betacellulin in culture and in vivo, and suggest that this EGF-like ligand may participate in aberrant autocrine and paracrine activation of the EGF receptor in human pancreatic cancer.

Increased mdm2 expression and immunoreactivity in human pancreatic ductal adenocarcinoma

The murine double minute-2 (MDM2) gene encodes a 90 kDa protein which binds and inactivates the protein product of the p53 tumor suppressor gene. To elucidate the potential role of MDM2 in benign and malignant hyperproliferative conditions in the pancreas, we studied MDM2 expression in cultured human pancreatic cancer cells and in pancreatic tissues from normal donors, patients with pancreatic ductal adenocarcinoma and patients with chronic pancreatitis (CP). All the tested cell lines (PANC-1, COLO-357, HPAF and T3M4) expressed a 5.5 kilobase MDM2 mRNA transcript and exhibited nuclear MDM2 immunostaining. MDM2 mRNA levels were comparable in all 18 normal and 14 CP tissues for which RNA samples were available for analysis. By comparison with the normal samples, MDM2 mRNA levels were increased 6.4-fold in 8 of 12 human pancreatic cancer samples (p < 0.0001). All 8 samples exhibited nuclear MDM2 immunostaining, which was also present in 24 of 37 additional pancreatic cancers. Mild MDM2 immunoreactivity was seen in only 1 of 20 CP samples and in none of the 18 normal samples. These findings indicate that MDM2 is overexpressed in a majority of pancreatic adenocarcinomas, but not in CP samples. This selective overexpression raises the possibility that MDM2 may contribute to pancreatic neoplastic transformation by interfering with the growth-suppressing activity of wild-type p53.

Substance P and neprilysin in chronic pancreatitis

BACKGROUND/AIMS

We aimed to analyze substance P (SP) and neprilysin (NEP), the membrane metallopeptidase that degrades SP, in chronic pancreatitis (CP).

METHODS

SP and NEP mRNA levels were analyzed by qRT-PCR in tissue samples from 30 patients with CP and 8 organ donors. In addition, SP serum levels were determined before and after surgery in the same patients, by means of a competitive ELISA assay. Genetic and epigenetic analyses of the NEP gene were also performed.

RESULTS

SP mRNA expression levels were higher in CP tissues compared to controls (p = 0.0152), while NEP mRNA showed no significant differences between CP and healthy subjects (p = 0.2102). In CP patients, SP serum levels correlated with those in tissue, and after surgical resection SP serum levels were reduced compared to the preoperative values. Failure of NEP to overexpress in CP tissues was associated with significant miR-128a overexpression (p = 0.02), rather than with mutations in the NEP coding region or the presence of hypermethylation sites in the NEP promoter region.

CONCLUSION

Tissue and serum levels of SP were increased in CP, while NEP levels remained unaltered. In an SP/NEP-mediated pathway, it would appear that NEP fails to provide adequate surveillance of SP levels. Failure of NEP to overexpress could be associated with miRNA regulation.

Orthotopic liver transplantation in critically ill cirrhotic patients with multi-organ failure: a single-center experience

Due to the lack of donor organs for orthotopic liver transplantation (OLT) in Germany, a larger proportion of patients advance to multi-organ failure (MOF) before OLT. Twenty-three patients on the waiting list for OLT were admitted to our intensive care unit (ICU) from January 2007 until September 2009. They consisted of 16 men and 7 women of median (25th-75th percentile) age of 60 years (54-65). Acute Physiology and Chronic Health Evaluation (APACHE II) score upon ICU admission was 26 (19-34); Model of End-Stage Liver Disease (MELD) score was 29 (22-41); Sequential Organ Failure Assessment (SOFA) score was 12 (8-16). The 90-day mortality rate was 39%. A decrease in MELD score during the first 48 hours (-2 [-5-0] vs 2 [-1-4]; P=.019) was associated with survival. Thirteen patients underwent transplantation from the ICU. By the time of the OLT, the MELD scores had deteriorated to 38 (33-39) and SOFA scores to 19 (18-19). All patients were mechanically ventilated and received hemodynamic support with catecholamines. Ten of 13 patients (77%) received renal replacement therapy and/or single pass albumin dialysis. Eight of 13 patients (62%) had a SOFA score of 3 or 4 (organ failure) in each of the respective subscores for the cardiovascular, renal, and respiratory systems at the time of OLT. The 90-day mortality rate after OLT was 38% and the 1-year-mortality rate was 54%. Patients who did not survive 90 days post OLT showed lower MELD scores on admission (33 [18-35] vs 44 [32-46]; P=.045), an increased MELD during the first 48 hours (3 [1-4] vs -2 [-8-1]; P=.002), and a longer ICU stay before OLT (32 [18-37] vs 8 [2-15]; P=.006). In conclusion, OLT may be successful treatment for cirrhotic patients with MOF. Outcomes of MOF in cirrhotic patients may improve after OLT but are generally worse than acceptable. A shorter ICU waiting time seemed to be beneficial.

[Objective structured clinical examination (OSCE) on completion of surgical block practical training--twelve months experience with a hands-on examination]

BACKGROUND

According to the approval system for medical doctors, practical courses such as block practical training must be graded. The grading of the surgical block practical training at the Klinikum rechts der Isar, Technische Universität of Munich (TUM), was changed from single grades of each day to a final objective structured clinical examination (OSCE). We report about the experiences in the past 12 months with this relatively new form of examination.

METHODS

An OSCE was established as a practical exam with seven stations about suture techniques, internal fixation, first-aid education, hygiene and sterility, clinical examination and perioperative management. The feasibility of a comprehensive OSCE with the necessary modifications was studied and the grades had been compared.

RESULTS

In the past 12 months four surgical block placements for over three weeks had been organised with a total of 326 students. 309 students were admitted for the OSCE at the end of block practical training. The average score was 1.75. The medical student raters graded either equally or more stringently compared to the medical doctors. The transcript revealed in all OSCEs a normal distribution of grading with high validity. However, an adaptation of the evaluation forms and an extension of the stations with modified content was required to obtain the same test conditions for all students. The implementation of the OSCE on this scale is possible with adequate preparation time and sufficient financial support. The evaluation of the specimens after completion of the test were all positive.

CONCLUSION

The new medical approval system calls for restructuring, not only in teaching but also in the form of examination of the courses. Through this practical test, those skills of a student will be assessed that cannot be tested by the IMPP exam. Moreover, this examination form provides an excellent preparation for the practical part of the oral state examination. This OSCE is even feasible with high numbers of students and offers with appropriate adaptation of the evaluation forms and test stations, a normal distribution of grading.

Comparison of 3'-deoxy-3'-[¹⁸F]fluorothymidine positron emission tomography (FLT PET) and FDG PET/CT for the detection and characterization of pancreatic tumours

PURPOSE

Despite recent advances in clinical imaging modalities, differentiation of pancreatic masses remains difficult. Here, we tested the diagnostic accuracy of molecular-based imaging including 3'-deoxy-3'-[(18)F]fluorothymidine (FLT) positron emission tomography (PET) and [(18)F]fluorodeoxyglucose (FDG) PET/CT in patients with suspected pancreatic masses scheduled to undergo surgery.

METHODS

A total of 46 patients with pancreatic tumours suspicious for malignancy and scheduled for resective surgery were recruited prospectively. In 41 patients, FLT PET and FDG PET/CT scans were performed. A diagnostic CT performed on a routine basis was available in 31 patients. FLT PET and FDG PET/CT emission images were acquired according to standard protocols. Tracer uptake in the tumour [FDG and FLT standardized uptake value (SUV)] was quantified by the region of interest (ROI) technique. For FDG PET/CT analysis, correct ROI placement was ensured via side-by-side reading of corresponding CT images.

RESULTS

Of 41 patients, 33 had malignancy, whereas 8 patients had benign disease. Visual analysis of FDG and FLT PET resulted in sensitivity values of 91% (30/33) and 70% (23/33), respectively. Corresponding specificities were 50% (4/8) for FDG PET and 75% (6/8) for FLT PET. In the subgroup of patients with contrast-enhanced CT (n = 31), sensitivities were 96% (PET/CT), 88% (CT alone), 92% (FDG PET) and 72% (FLT PET), respectively. Mean FLT uptake in all malignant tumours was 3.0 (range SUV(max) 1.1-6.5; mean FDG SUV(max) 7.9, range 3.3-17.8; p < 0.001).

CONCLUSION

For differentiation of pancreatic tumours, FDG PET and FDG PET/CT showed a higher sensitivity but lower specificity than FLT PET. Interestingly, visual analysis of FLT PET led to two false-positive findings by misinterpreting physiological bowel uptake as pathological FLT uptake in the pancreas. Due to the limited number of patients, the clinical value of adding FLT PET to the diagnostic workup of pancreatic tumours remains to be determined.