Usefulness of F-18-fluorodeoxyglucose positron emission tomography to confirm suspected pancreatic cancer: a meta-analysis

Medical oncology and pancreatic cancer: what the radiologist needs to know

The majority of PCs present as advanced disease, and treatment goals are for prolongation of life and palliation of the symptoms. Oncologists rely on our radiology colleagues to provide information on the extent of disease and the effectiveness of our treatment. The stakes rise in those patients where the disease has seemingly not spread and who might be treated with a goal of cure. For this subset of patients, medical oncologists and surgeons require as precise a radiologic description as possible in order to most accurately characterize the extent of the disease, in turn informing us as to the likelihood of a successful surgery and potential cure. In this paper, we review the fine points of imaging that distinguish resectable from borderline or unresectable patients, explain the principles of neoadjuvant and adjuvant therapy for pancreatic cancer, highlight some of the novel therapies now being pioneered in pancreatic cancer, and review radiologic features important for palliative care in patients with these tumors.

The role of imaging in the clinical practice of radiation oncology for pancreatic cancer

Advances in technology have enabled the delivery of high doses of radiation therapy for pancreatic ductal adenocarcinoma (PDAC) with low rates of toxicity. Although the role of radiation for pancreatic cancer continues to evolve, encouraging results with newer techniques indicate that radiation may benefit selected patient populations. Imaging has been central to the modern successes of radiation therapy for PDAC. Here, we review the role of diagnostic imaging, imaging-based planning, and image guidance in radiation oncology practice for PDAC.

PET-PANC: multicentre prospective diagnostic accuracy and health economic analysis study of the impact of combined modality 18fluorine-2-fluoro-2-deoxy-d-glucose positron emission tomography with computed tomography scanning in the diagnosis and management of pancreatic cancer

BACKGROUND

Pancreatic cancer diagnosis and staging can be difficult in 10-20% of patients. Positron emission tomography (PET)/computed tomography (CT) adds precise anatomical localisation to functional data. The use of PET/CT may add further value to the diagnosis and staging of pancreatic cancer.

OBJECTIVE

To determine the incremental diagnostic accuracy and impact of PET/CT in addition to standard diagnostic work-up in patients with suspected pancreatic cancer.

DESIGN

A multicentre prospective diagnostic accuracy and clinical value study of PET/CT in suspected pancreatic malignancy.

PARTICIPANTS

Patients with suspected pancreatic malignancy.

INTERVENTIONS

All patients to undergo PET/CT following standard diagnostic work-up.

MAIN OUTCOME MEASURES

The primary outcome was the incremental diagnostic value of PET/CT in addition to standard diagnostic work-up with multidetector computed tomography (MDCT). Secondary outcomes were (1) changes in patients' diagnosis, staging and management as a result of PET/CT; (2) changes in the costs and effectiveness of patient management as a result of PET/CT; (3) the incremental diagnostic value of PET/CT in chronic pancreatitis; (4) the identification of groups of patients who would benefit most from PET/CT; and (5) the incremental diagnostic value of PET/CT in other pancreatic tumours.

RESULTS

Between 2011 and 2013, 589 patients with suspected pancreatic cancer underwent MDCT and PET/CT, with 550 patients having complete data and in-range PET/CT. Sensitivity and specificity for the diagnosis of pancreatic cancer were 88.5% and 70.6%, respectively, for MDCT and 92.7% and 75.8%, respectively, for PET/CT. The maximum standardised uptake value (SUVmax.) for a pancreatic cancer diagnosis was 7.5. PET/CT demonstrated a significant improvement in relative sensitivity (p = 0.01) and specificity (p = 0.023) compared with MDCT. Incremental likelihood ratios demonstrated that PET/CT significantly improved diagnostic accuracy in all scenarios (p < 0.0002). PET/CT correctly changed the staging of pancreatic cancer in 56 patients (p = 0.001). PET/CT influenced management in 250 (45%) patients. PET/CT stopped resection in 58 (20%) patients who were due to have surgery. The benefit of PET/CT was limited in patients with chronic pancreatitis or other pancreatic tumours. PET/CT was associated with a gain in quality-adjusted life-years of 0.0157 (95% confidence interval -0.0101 to 0.0430). In the base-case model PET/CT was seen to dominate MDCT alone and is thus highly likely to be cost-effective for the UK NHS. PET/CT was seen to be most cost-effective for the subgroup of patients with suspected pancreatic cancer who were thought to be resectable.

CONCLUSION

PET/CT provided a significant incremental diagnostic benefit in the diagnosis of pancreatic cancer and significantly influenced the staging and management of patients. PET/CT had limited utility in chronic pancreatitis and other pancreatic tumours. PET/CT is likely to be cost-effective at current reimbursement rates for PET/CT to the UK NHS. This was not a randomised controlled trial and therefore we do not have any information from patients who would have undergone MDCT only for comparison. In addition, there were issues in estimating costs for PET/CT. Future work should evaluate the role of PET/CT in intraductal papillary mucinous neoplasm and prognosis and response to therapy in patients with pancreatic cancer.

STUDY REGISTRATION

Current Controlled Trials ISRCTN73852054 and UKCRN 8166.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

The Role of 18F-FDG PET/CT and PET/MRI in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains a difficult disease to treat and continues to portend a poor prognosis, as most patients are unresectable at diagnosis. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) combined with CT (PET/CT) has been a cornerstone in oncological imaging of different cancers; however, the role of PET/CT in PDAC is continually evolving and currently not well established. Studies have shown the potential of PET/CT in guiding the management of patients with PDAC, with possible added benefit over anatomic imaging with CT or MRI in certain scenarios. PET/CT may be useful in diagnosis, initial staging, treatment response assessment, differentiation of recurrent tumor from post-treatment fibrosis, and radiotherapy planning. Additionally, PET/CT may be a cost-effective modality due to upstaging of patients originally deemed as surgical candidates. Recently, the advent of simultaneous PET/MRI represents an exciting advancement in hybrid functional imaging with potential applications in the imaging of PDAC. The advantages of PET/MRI include simultaneous acquisition to improve registration of fusion images, lower radiation dose, superior soft tissue contrast, and availability of multiparametric imaging. Studies are underway to evaluate the utility of PET/MRI in PDAC, including in initial staging and treatment response assessment and to determine the subgroup of patients that will benefit from PET/MRI. Further studies are warranted in both PET/CR and PET/MRI to better understand the role of these modalities in PDAC.

Metastatic pancreatic carcinoma masquerading as cystic lung disease: a rare presentation

This 52‐year‐old male ex‐smoker presented with a six‐month history of progressive breathlessness and weight loss. He deteriorated acutely, and was admitted with severe type 1 respiratory failure. Apart from diffuse coarse crackles on chest auscultation, physical examination was unremarkable. High‐resolution computed tomography (HRCT) showed diffuse cystic changes throughout the lungs. A diagnosis of pulmonary Langerhans cell histiocytosis (PLCH) was considered. Further workup identified a coincidental pancreatic lesion of uncertain significance, which remained indeterminate on magnetic resonance imaging (MRI) and on positron emission tomography (PET). Transbronchial biopsy revealed enteric differentiated adenocarcinoma exhibiting lepidic spread, and autopsy later confirmed primary pancreatic malignancy. This case demonstrates that metastatic pancreatic malignancy can present with severe respiratory failure and masquerade as cystic lung disease.

Imaging Macrophage Accumulation in a Murine Model of Chronic Pancreatitis with 125I-Iodo-DPA-713 SPECT/CT

Pancreatitis remains a diagnostic challenge in patients with mild to moderate disease, with current imaging modalities being inadequate. Given the prominent macrophage infiltration in chronic pancreatitis, we hypothesized that ¹²⁵I-iodo-DPA-713, a small-molecule radiotracer that specifically targets macrophages, could be used with SPECT/CT to image pancreatic inflammation in a relevant experimental model. Methods: Chronic pancreatitis was induced with cerulein in C57BL/6 mice, which were contrasted with saline-injected control mice. The animals were imaged at 7 wk after induction using N,N-diethyl-2-(2-(3-¹²⁵I-iodo-4-methoxyphenyl)-5,7-dimethylpyrazolo[1,5-a]pyrimidin-3-yl)acetamide (¹²⁵I-iodo-DPA-713) SPECT/CT or ¹⁸F-FDG PET/CT. The biodistribution of ¹²⁵I-iodo-DPA-713 was determined under the same conditions, and a pair of mice was imaged using a fluorescent analog of ¹²⁵I-iodo-DPA-713, DPA-713-IRDye800CW, for correlative histology. Results: Pancreatic ¹²⁵I-iodo-DPA-713 uptake was significantly higher in treated mice than control mice (5.17% ± 1.18% vs. 2.41% ± 0.34% injected dose/g, P = 0.02), as corroborated by imaging. Mice imaged with ¹⁸F-FDG PET/CT showed cerulein-enhanced pancreatic uptake in addition to a moderate signal from healthy pancreas. Near-infrared fluorescence imaging with DPA-713-IRDye800CW showed strong pancreatic uptake, focal liver uptake, and gastrointestinal uptake in the treated mice, whereas the control mice showed only urinary excretion. Ex vivo fluorescence microscopy revealed a large influx of macrophages in the pancreas colocalizing with the retained fluorescent probe in the treated but not the control mice. Conclusion: These data support the application of both ¹²⁵I-iodo-DPA-713 SPECT/CT and DPA-713-IRDye800CW near-infrared fluorescence to delineate pancreatic, liver, or intestinal inflammation in living mice.

Identifying prognostic intratumor heterogeneity using pre- and post-radiotherapy 18F-FDG PET images for pancreatic cancer patients

BACKGROUND

To stratify risks of pancreatic adenocarcinoma (PA) patients using pre- and post-radiotherapy (RT) PET/CT images, and to assess the prognostic value of texture variations in predicting therapy response of patients.

METHODS

Twenty-six PA patients treated with RT from 2011-2013 with pre- and post-treatment 18F-FDG-PET/CT scans were identified. Tumor locoregional texture was calculated using 3D kernel-based approach, and texture variations were identified by fitting discrepancies of texture maps of pre- and post-treatment images. A total of 48 texture and clinical variables were identified and evaluated for association with overall survival (OS). The prognostic heterogeneity features were selected using lasso/elastic net regression, and further were evaluated by multivariate Cox analysis.

RESULTS

Median age was 69 y (range, 46-86 y). The texture map and temporal variations between pre- and post-treatment were well characterized by histograms and statistical fitting. The lasso analysis identified seven predictors (age, node stage, post-RT SUVmax, variations of homogeneity, variance, sum mean, and cluster tendency). The multivariate Cox analysis identified five significant variables: age, node stage, variations of homogeneity, variance, and cluster tendency (with P=0.020, 0.040, 0.065, 0.078, and 0.081, respectively). The patients were stratified into two groups based on the risk score of multivariate analysis with log-rank P=0.001: a low risk group (n=11) with a longer mean OS (29.3 months) and higher texture variation (>30%), and a high risk group (n=15) with a shorter mean OS (17.7 months) and lower texture variation (<15%).

CONCLUSIONS

Locoregional metabolic texture response provides a feasible approach for evaluating and predicting clinical outcomes following treatment of PA with RT. The proposed method can be used to stratify patient risk and help select appropriate treatment strategies for individual patients toward implementing response-driven adaptive RT.

Employing Metabolism to Improve the Diagnosis and Treatment of Pancreatic Cancer

Pancreatic ductal adenocarcinoma is on pace to become the second leading cause of cancer-related death. The high mortality rate results from a lack of methods for early detection and the inability to successfully treat patients once diagnosed. Pancreatic cancer cells have extensively reprogrammed metabolism, which is driven by oncogene-mediated cell-autonomous pathways, the unique physiology of the tumor microenvironment, and interactions with non-cancer cells. In this review, we discuss how recent efforts delineating rewired metabolic networks in pancreatic cancer have revealed new in-roads to develop detection and treatment strategies for this dreadful disease.

Multiparametric 18F-FDG PET/MR follow-up in a patient with autoimmune pancreatitis

Background

Positron emission tomography/magnetic resonance imaging (PET/MR) is a new multimodal imaging technique, which might improve the diagnostic performance not only in oncological patients but also in patients with non-neoplastic inflammatory lesions as routinely used ¹⁸F-FDG is not a cancer specific agent.

Case Presentation

Multiparametric ¹⁸F-FDG PET/MR in a woman with pain in the upper abdomen and inconclusive laboratory and clinical data presenting with moderately increased, diffuse ¹⁸F-FDG uptake with delayed contrast enhancement, diffusion-restriction and focal enlargement in the pancreatic body being suggestive for autoimmune pancreatitis (AIP). Follow-up ¹⁸F-FDG PET/MR after initiation of steroid therapy confirmed complete resolution of imaging abnormalities.

Conclusion

¹⁸F-FDG PET/MR might be valuable in the management of AIP providing complementary data regarding accurate diagnosis and monitoring therapy response to avoid unnecessary surgery.

Surveillance for neoplasia in the pancreas

Despite its low incidence in the general population, pancreatic cancer is one of the leading causes of cancer-related mortality. Survival greatly depends on operability, but most patients present with unresectable disease. Therefore, there is great interest in the early detection of pancreatic cancer and its precursor lesions by surveillance. Worldwide, several programs have been initiated for individuals at high risk for pancreatic cancer. Their first results suggest that surveillance in high-risk individuals is feasible, but their effectiveness in decreasing mortality remains to be proven. This review will discuss which individuals are eligible for surveillance, which lesions are aimed to be detected, and which surveillance modalities are being used in current clinical practice. Furthermore, it addresses the management of abnormalities found during surveillance and topics for future research.

Utility of 18 fludeoxyglucose in preoperative positon-emission tomography-computed tomography (PET-CT) in the early diagnosis of exocrine pancreatic cancer: A study of 139 resected cases

INTRODUCTION

In pancreatic ductal adenocarcinoma (PDA), surgical resection is the only curative treatment, but due to its late clinical presentation only 15-25% patients are candidates for curative resection. The aim of this prospective, single-center study is to determine the diagnostic utility of preoperative PET-CT for early detection of PDA and early panIN lesions.

METHODS

We studied the histopathological features of PDA and different panIN lesions in 139 surgical samples from patients undergoing pancreatic resection (from 2010-2014), comparing these results with preoperative PET-CT and MDCT study. For tumor diagnosis in PET-CT maximum standard SUV 2.5 was used. Pancreatic baseline SUVmax is the maximum uptake of the radiotracer 18-2FDG on the ROI curve determined for the area of the normal pancreas after pathological reassessment with areas not affected by tumours or preneoplastic lesions. Tumour Uptake Index is the ratio between the tumour SUVmax and pancreatic baseline SUVmax.

RESULTS

Using an standard maximum SUV value of 2.5, PET-CT sensitivity was 77.7% (108 of the 139 cases) against 75.5% (105 of the 139 cases) of MDCT. But when we combined this value with maximum SUV of normal pancreatic tissue from each patient, PET-CT sensitivity improved its value to 94.9%.

CONCLUSION

A combination of studies of PET-CT in tumor and non-tumor tissue of each patient might be a very useful diagnostic tool not only for preoperative diagnosis of PDA, but also for early panIN lesions.

Pancreatic cancer

Pancreatic cancer is a highly lethal disease, for which mortality closely parallels incidence. Most patients with pancreatic cancer remain asymptomatic until the disease reaches an advanced stage. There is no standard programme for screening patients at high risk of pancreatic cancer (eg, those with a family history of pancreatic cancer and chronic pancreatitis). Most pancreatic cancers arise from microscopic non-invasive epithelial proliferations within the pancreatic ducts, referred to as pancreatic intraepithelial neoplasias. There are four major driver genes for pancreatic cancer: KRAS, CDKN2A, TP53, and SMAD4. KRAS mutation and alterations in CDKN2A are early events in pancreatic tumorigenesis. Endoscopic ultrasonography and endoscopic ultrasonography-guided fine-needle aspiration offer high diagnostic ability for pancreatic cancer. Surgical resection is regarded as the only potentially curative treatment, and adjuvant chemotherapy with gemcitabine or S-1, an oral fluoropyrimidine derivative, is given after surgery. FOLFIRINOX (fluorouracil, folinic acid [leucovorin], irinotecan, and oxaliplatin) and gemcitabine plus nanoparticle albumin-bound paclitaxel (nab-paclitaxel) are the treatments of choice for patients who are not surgical candidates but have good performance status.

18F-FLT PET imaging of cellular proliferation in pancreatic cancer

Pancreatic ductal adenocarcinoma is known for its poor prognosis. Since the development of computerized tomography, magnetic resonance and endoscopic ultrasound, novel imaging techniques have struggled to get established in the management of patients diagnosed with pancreatic adenocarcinoma for several reasons. Thus, imaging assessment of pancreatic cancer remains a field with scope for further improvement. In contrast to cross-sectional anatomical imaging methods, molecular imaging modalities such as positron emission tomography (PET) can provide information on tumour function. Particularly, tumour proliferation may be assessed by measurement of intracellular thymidine kinase 1 (TK1) activity level using thymidine analogues radiolabelled with a positron emitter for use with PET. This approach, has been widely explored with [(18)F]-fluoro-3'-deoxy-3'-L-fluorothymidine ((18)F-FLT) PET. This manuscript reviews the rationale and physiology behind (18)F-FLT PET imaging, with special focus on pancreatic cancer and other gastrointestinal malignancies. Potential benefit and challenges of this imaging technique for diagnosis, staging and assessment of treatment response in abdominal malignancies are discussed.

Advancement in treatment and diagnosis of pancreatic cancer with radiopharmaceuticals

Pancreatic cancer (PC) is a major health problem. Conventional imaging modalities show limited accuracy for reliable assessment of the tumor. Recent researches suggest that molecular imaging techniques with tracers provide more biologically relevant information and are benefit for the diagnosis of the cancer. In addition, radiopharmaceuticals also play more important roles in treatment of the disease. This review summaries the advancement of the radiolabeled compounds in the theranostics of PC.

Current standards and new innovative approaches for treatment of pancreatic cancer

Pancreatic adenocarcinoma remains a devastating disease with a 5-year survival rate not exceeding 6%. Treatment of this disease remains a major challenge. This article reviews the state-of-the-art in the management of this disease and the new innovative approaches that may help to accelerate progress in treating its victims. After careful pre-therapeutic evaluation, only 15-20% of patients diagnosed with a pancreatic cancer (PC) are eligible for upfront radical surgery. After R0 or R1 resection in such patients, evidence suggests a significantly positive impact on survival of adjuvant chemotherapy comprising 6 months of gemcitabine or fluorouracil/folinic acid. Delayed adjuvant chemoradiation is considered as an option in cases of positive margins. Borderline resectable pancreatic cancer (BRPC) is defined as a tumour involving the mesenteric vasculature to a limited extend. Resection of these tumours is technically feasible, yet runs the high risk of a R1 resection. Neoadjuvant treatment probably offers the best chance of achieving successful R0 resection and long-term survival, but the best treatment options should be determined in prospective randomised studies. Gemcitabine has for 15 years been the only validated therapy for advanced PC. Following decades of negative phase III studies, increasing evidence now suggests that further significant improvements to overall survival can be achieved via either Folfirinox or gemcitabine + nab-paclitaxel regimens. Progress in systemic therapy may improve the chances of resection in borderline resectable pancreatic cancer (BRPC) or locally advanced PC. This requires first enhancing knowledge of the genetic events driving carcinogenesis, which may then be translated into clinical studies.

Pancreatic tumors imaging: An update

Currently, ultrasound (US), computed tomography (CT) and Magnetic Resonance imaging (MRI) represent the mainstay in the evaluation of pancreatic solid and cystic tumors affecting pancreas in 80-85% and 10-15% of the cases respectively. Integration of US, CT or MR imaging is essential for an accurate assessment of pancreatic parenchyma, ducts and adjacent soft tissues in order to detect and to stage the tumor, to differentiate solid from cystic lesions and to establish an appropriate treatment. The purpose of this review is to provide an overview of pancreatic tumors and the role of imaging in their diagnosis and management. In order to a prompt and accurate diagnosis and appropriate management of pancreatic lesions, it is crucial for radiologists to know the key findings of the most frequent tumors of the pancreas and the current role of imaging modalities. A multimodality approach is often helpful. If multidetector-row CT (MDCT) is the preferred initial imaging modality in patients with clinical suspicion for pancreatic cancer, multiparametric MRI provides essential information for the detection and characterization of a wide variety of pancreatic lesions and can be used as a problem-solving tool at diagnosis and during follow-up.

Diagnosis, Preoperative Evaluation, and Assessment of Resectability of Pancreatic and Periampullary Cancer

Periampullary region encircles a radius of 2 cm around the ampulla of Vater; accordingly, four distinct neoplasias with overlapping imaging features originate in the region. Each of these lesions has a different long-term prognosis; hence, imaging evaluation to characterize the lesion is important. Further certain specific features pertaining to the vascular invasion and systemic spread may decide about the treatment as well as surgical approach. An understanding of the advances in imaging and image processing technology as well as in the methods of image acquisition, for the purpose, is quite relevant towards etching out a rational pre-treatment evaluation protocol. Further, an evidence-based decision as to the choice of optimum modality for answering specific clinical question is of prime importance in achieving a reasonable post-treatment outcome. Pancreatic adenocarcinoma is the fourth most common cancer and a malignancy with one of the least 5-year survival rates (ranging from 6.8 to 15 % depending on peripancreatic extensions, dropping to 1.8 % for metastatic disease). A survival rate of 15-27 % can be achieved if the lesion is resectable but unfortunately, only 10-15 % of patients are eligible for resection. Cystic tumors of pancreas are a rarer variety of pancreatic neoplasia (5-15 % of pancreatic cysts and 1 % of all pancreatic cancers) which have a much better outcome and chances of resection. Being mostly incidentalomas, a timely differentiation of this lesion from the much more common pseudocyst (which would mandate a medical management and a different surgical protocol) is the key for curability. Lastly, the neuroendocrine tumors of pancreas are equally rare (1 % of all pancreatic tumors), but importantly due to associated clinical syndromes and their capability to metastasize early in the course of disease, a timely detection may hence be the key for successful treatment of these lesions. Imaging plays a vital role in the initial detection and characterization as well as in determination of resectability of each of these pancreatic neoplasias. Further, the differentiation of pancreatic head tumors from other periampullary neoplasias is important; the fact that most recurrences are as a result of surgical intervention in an otherwise inoperable disease while most treatment failures are due to improper characterization of the lesion is notable.

Management of borderline resectable pancreatic cancer

Pancreatic cancer is the fourth most common cause of cancer death in the United States. Surgery remains the only curative option; however only 20% of the patients have resectable disease at the time of initial presentation. The definition of borderline resectable pancreatic cancer is not uniform but generally denotes to regional vessel involvement that makes it unlikely to have negative surgical margins. The accurate staging of pancreatic cancer requires triple phase computed tomography or magnetic resonance imaging of the pancreas. Management of patients with borderline resectable pancreatic cancer remains unclear. The data for treatment of these patients is primarily derived from retrospective single institution experience. The prospective trials have been plagued by small numbers and poor accrual. Neoadjuvant therapy is recommended and typically consists of chemotherapy and radiation therapy. The chemotherapeutic regimens continue to evolve along with type and dose of radiation therapy. Gemcitabine or 5-fluorouracil based chemotherapeutic combinations are administered. The type and dose of radiation vary among different institutions. With neoadjuvant treatment, approximately 50% of the patients are able to undergo surgical resections with negative margins obtained in greater than 80% of the patients. Newer trials are attempting to standardize the definition of borderline resectable pancreatic cancer and treatment regimens. In this review, we outline the definition, imaging requirements and management of patients with borderline resectable pancreatic cancer.

State of the art and future directions of pancreatic ductal adenocarcinoma therapy

Pancreatic ductal adenocarcinoma (PDAC) is expected to become the second cause of cancer-related death in 2030. PDAC is the poorest prognostic tumor of the digestive tract, with 80% of patients having advanced disease at diagnosis and 5-year survival rate not exceeding 7%. Until 2010, gemcitabine was the only validated therapy for advanced PDAC with a modest improvement in median overall survival as compared to best supportive care (5-6 vs 3 months). Multiple phase II-III studies have used various combinations of gemcitabine with other cytotoxics or targeted agents, most in vain, in attempt to improve this outcome. Over the past few years, the landscape of PDAC management has undergone major and rapid changes with the approval of the FOLFIRINOX and gemcitabine plus nab-paclitaxel regimens in patients with metastatic disease. These two active combination chemotherapy options yield an improved median overall survival (11.1 vs 8.5 months, respectively) thus making longer survival a reasonably achievable goal. This breakthrough raises some new clinical questions about the management of PDAC. Moreover, better knowledge of the environmental and genetic events that underpin multistep carcinogenesis and of the microenvironment surrounding cancer cells in PDAC has open new perspectives and therapeutic opportunities. In this new dynamic context of deep transformation in basic research and clinical management aspects of the disease, we gathered updated preclinical and clinical data in a multifaceted review encompassing the lessons learned from the past, the yet unanswered questions, and the most promising research priorities to be addressed for the next 5 years.

Functional expression of sodium-glucose transporters in cancer

Glucose is a major metabolic substrate required for cancer cell survival and growth. It is mainly imported into cells by facilitated glucose transporters (GLUTs). Here we demonstrate the importance of another glucose import system, the sodium-dependent glucose transporters (SGLTs), in pancreatic and prostate adenocarcinomas, and investigate their role in cancer cell survival. Three experimental approaches were used: (i) immunohistochemical mapping of SGLT1 and SGLT2 distribution in tumors; (ii) measurement of glucose uptake in fresh isolated tumors using an SGLT-specific radioactive glucose analog, α-methyl-4-deoxy-4-[(18)F]fluoro-D-glucopyranoside (Me4FDG), which is not transported by GLUTs; and (iii) measurement of in vivo SGLT activity in mouse models of pancreatic and prostate cancer using Me4FDG-PET imaging. We found that SGLT2 is functionally expressed in pancreatic and prostate adenocarcinomas, and provide evidence that SGLT2 inhibitors block glucose uptake and reduce tumor growth and survival in a xenograft model of pancreatic cancer. We suggest that Me4FDG-PET imaging may be used to diagnose and stage pancreatic and prostate cancers, and that SGLT2 inhibitors, currently in use for treating diabetes, may be useful for cancer therapy.

Appropriateness criteria of FDG PET/CT in oncology

(18)Fluorine-2-fluoro-2-Deoxy-d-glucose ((18)F-FDG) positron emission tomography/computerized tomography (PET/CT) is a well-established functional imaging method widely used in oncology. In this article, we have incorporated the various indications for (18)FDG PET/CT in oncology based on available evidence and current guidelines. Growing body of evidence for use of (18)FDG PET/CT in select tumors is also discussed. This article attempts to give the reader an overview of the appropriateness of using (18)F-FDG PET/CT in various malignancies.

FDG PET/CT in Pancreatic and Hepatobiliary Carcinomas: Value to Patient Management and Patient Outcomes

Fludeoxyglucose F 18 ((18)F-FDG) PET/CT has not been shown to offer additional benefit in the initial diagnosis of pancreatic cancer, but studies show benefit of (18)F-FDG PET/CT in initial staging and patient prognosis. There is evidence for (18)F-FDG PET and (18)F-FDG PET/CT in staging and prognosis of cholangiocarcinoma and gallbladder cancer. (18)F-FDG PET/CT has shown promise in staging liver malignancies by detecting extrahepatic metastasis. There is evidence supporting the ability of PET/CT in predicting prognosis in patients with hepatocellular carcinoma. Evidence is evolving for the role of (18)F-FDGPET/CT in predicting prognosis and survival in patients with colorectal liver metastasis.

Endoscopic ultrasonography-fine needle aspiration versus PET-CT in undiagnosed mediastinal and upper abdominal lymphadenopathy: a comparative clinical study

BACKGROUND AND STUDY AIMS

The wide use of PET-CT for the staging of neoplasms has extended to enlarged lymph nodes of unknown origin. Nevertheless, upper abdominal and mediastinal nodes are accessible to endoscopic ultrasonography-fine needle aspiration (EUS-FNA), providing a cytological diagnosis, with a high diagnostic yield in previous reports. In this paper, we have compared the accuracy of both procedures in this particular setting.

PATIENTS AND METHODS

After the finding of a lymphadenopathy in a conventional CT, both PET-CT and EUS-FNA were performed. The endoscopist had no information about PET-CT results. FNA was performed after a systematic EUS exam, with a 25 G needle and no suction. We considered the pathologic results as the gold standard or, if not available, the patients' outcome as a surrogate marker.

RESULTS

A total of 54 patients were included. Common locations of nodes included subcarinal space (33.3%), porta hepatis (31.5%), upper mediastinum (15%), peripancreatic (7.4%), and other locations (12.8%). Adequate specimens were obtained in 48/54 patients (89%). The most common diagnoses based on cytology were benign/reactive (42%), epidermoid carcinoma (8.4%), lymphoma (8.4%), and ductal adenocarcinoma of pancreatic origin (6.3%). PET was positive in 67% of patients. The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of EUS-FNA were 91.3, 100, 100, 92.5, and 95.8%, respectively. The same values for PET-CT were 75, 25, 50, 50, and 50%, respectively.

CONCLUSION

In our series, EUS-FNA has proven to be the best diagnostic procedure to accurately establish the etiology of isolated adenopathies, showing a much better diagnostic yield than PET-CT, the role of which should be re-evaluated in this setting.

Novel imaging strategies for upper gastrointestinal tract cancers

Accurate pretherapeutic imaging is the cornerstone of all cancer treatment. Unfortunately, modern imaging modalities have several unsolved problems and limitations. The differentiation between inflammation and cancer infiltration, false positive and false negative findings as well as lack of confirming biopsies in suspected metastases may have serious negative consequences in cancer patients. This review describes some of these problems and challenges the use of conventional imaging by suggesting new combined strategies that include selective use of confirming biopsies and complementary methods to detect microscopic cancer dissemination.

Pancreatic cancer in chronic pancreatitis

Data exists to indicate a definite association between chronic pancreatitis and pancreatic cancer. The strength of this association varies between various causes of pancreatitis, with hereditary and tropical pancreatitis more likely to result in malignancy. Pathogenesis may involve genetic factors, diabetes, smoking and alcohol consumption. Clinically a significant overlap exists between the two conditions, with histology difficult to obtain and interpret in this setting. Biomarkers like CA19-9 and others may be useful, as is a variety of newer imaging modalities. Treatment needs to be individualised as surgery offers the only chance of cure, albeit in but a few.