Imaging Evaluation of Pancreatic Cancer

Role of artificial intelligence in the characterization of indeterminate pancreatic head mass and its usefulness in preoperative diagnosis

Artificial intelligence (AI) has been used in various fields of day-to-day life and its role in medicine is immense. Understanding of oncology has been improved with the introduction of AI which helps in diagnosis, treatment planning, management, prognosis, and follow-up. It also helps to identify high-risk groups who can be subjected to timely screening for early detection of malignant conditions. It is more important in pancreatic cancer as it is one of the major causes of cancer-related deaths worldwide and there are no specific early features (clinical and radiological) for diagnosis. With improvement in imaging modalities (computed tomography, magnetic resonance imaging, endoscopic ultrasound), most often clinicians were being challenged with lesions that were difficult to diagnose with human competence. AI has been used in various other branches of medicine to differentiate such indeterminate lesions including the thyroid gland, breast, lungs, liver, adrenal gland, kidney, etc. In the case of pancreatic cancer, the role of AI has been explored and is still ongoing. This review article will focus on how AI can be used to diagnose pancreatic cancer early or differentiate it from benign pancreatic lesions, therefore, management can be planned at an earlier stage.

CT and MR imaging features of mixed neuroendocrine-non-neuroendocrine neoplasm of the pancreas compared with pancreatic ductal adenocarcinoma and neuroendocrine tumor

OBJECTIVE

This study aimed to assess the computed tomography (CT) and magnetic resonance imaging (MRI) features of pancreatic mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN) and compare them with those of pancreatic ductal adenocarcinoma (PDAC) and neuroendocrine tumor (NET).

METHODS

Twelve patients with pancreatic MiNEN, 24 patients with PDAC, and 24 patients with NET, who underwent both contrast-enhanced CT and MRI, were included. Clinical data and the key imaging features were retrospectively evaluated by two independent readers and compared between MiNEN and PDAC or NET. Univariate and multivariable logistic regression analyses were performed to obtain predictors for pancreatic MiNEN.

RESULTS

Patients with pancreatic MiNEN more frequently presented with large size and heterogeneous and cystic components compared with PDAC (p < 0.031) and ill-defined irregular margins, progressive enhancement, and adjacent organ involvement compared with NET (p < 0.036). However, vascular invasion was less commonly seen in MiNEN than PDAC (p = 0.010). Moderate enhancement was observed more frequently in MiNEN than in PDAC or NET (p < 0.001). Multivariate logistic analyses demonstrated that moderate enhancement and ill-defined irregular margin were the most valuable features for the prediction of pancreatic MiNEN (p ≤ 0.044). The combination of the two features resulted in a specificity of 93.8%, sensitivity of 83.3%, and accuracy of 91.7%.

CONCLUSIONS

We have mainly described the radiological findings of pancreatic MiNEN with ill-defined irregular margin and moderate enhancement compared with PDAC and NET. The combination of imaging features could improve diagnostic efficiency and help in the selection of the correct treatment method.

Detection of pancreatic cancer with two- and three-dimensional radiomic analysis in a nationwide population-based real-world dataset

BACKGROUND

CT is the major detection tool for pancreatic cancer (PC). However, approximately 40% of PCs < 2 cm are missed on CT, underscoring a pressing need for tools to supplement radiologist interpretation.

METHODS

Contrast-enhanced CT studies of 546 patients with pancreatic adenocarcinoma diagnosed by histology/cytology between January 2005 and December 2019 and 733 CT studies of controls with normal pancreas obtained between the same period in a tertiary referral center were retrospectively collected for developing an automatic end-to-end computer-aided detection (CAD) tool for PC using two-dimensional (2D) and three-dimensional (3D) radiomic analysis with machine learning. The CAD tool was tested in a nationwide dataset comprising 1,477 CT studies (671 PCs, 806 controls) obtained from institutions throughout Taiwan.

RESULTS

The CAD tool achieved 0.918 (95% CI, 0.895-0.938) sensitivity and 0.822 (95% CI, 0.794-0.848) specificity in differentiating between studies with and without PC (area under curve 0.947, 95% CI, 0.936-0.958), with 0.707 (95% CI, 0.602-0.797) sensitivity for tumors < 2 cm. The positive and negative likelihood ratios of PC were 5.17 (95% CI, 4.45-6.01) and 0.10 (95% CI, 0.08-0.13), respectively. Where high specificity is needed, using 2D and 3D analyses in series yielded 0.952 (95% CI, 0.934-0.965) specificity with a sensitivity of 0.742 (95% CI, 0.707-0.775), whereas using 2D and 3D analyses in parallel to maximize sensitivity yielded 0.915 (95% CI, 0.891-0.935) sensitivity at a specificity of 0.791 (95% CI, 0.762-0.819).

CONCLUSIONS

The high accuracy and robustness of the CAD tool supported its potential for enhancing the detection of PC.

The role of the multidisciplinary tumor board (MDTB) in the assessment of pancreatic cancer diagnosis and resectability: A tertiary referral center experience

Background

The introduction of multidisciplinary tumor boards (MDTBs) for the diagnostic and therapeutic pathway of several oncological disease significantly ameliorated patients' outcomes. However, only few evidences are currently present on the potential impact of the MDTB on pancreatic cancer (PC) management. Aim of this study is to report how MDTB may influence PC diagnosis and treatment, with particular focus on PC resectability assessment and the correspondence between MDTB definition of resectability and intraoperative findings.

Methods

All patients with a proven or suspected diagnosis of PC discussed at the MDTB between 2018 and 2020 were included in the study. An evaluation of diagnosis, tumor response to oncological/radiation therapy and resectability before and after the MDTB was conducted. Moreover, a comparison between the MDTB resectability assessment and the intraoperative findings was performed.

Results

A total of 487 cases were included in the analysis: 228 (46.8%) for diagnosis evaluation, 75 (15.4%) for tumor response assessment after/during medical treatment, 184 (37.8%) for PC resectability assessment. As a whole, MDTB led to a change in treatment management in 89 cases (18.3%): 31/228 (13.6%) in the diagnosis group, 13/75 (17.3%) in the assessment of treatment response cohort and 45/184 (24.4%) in the PC resectability evaluation group. As a whole, 129 patients were given indication to surgery. Surgical resection was accomplished in 121 patients (93.7%), with a concordance rate of resectability between MDTB discussion and intraoperative findings of 91.5%. Concordance rate was 99% for resectable lesions and 64.3% for borderline PCs.

Conclusions

MDTB discussion consistently influences PC management, with significant variations in terms of diagnosis, tumor response assessment and resectability. In this last regard, MDTB discussion plays a key role, as demonstrated by the high concordance rate between MDTB resectability definition and intraoperative findings.

Radiomic Features at CT Can Distinguish Pancreatic Cancer from Noncancerous Pancreas

Purpose To identify distinguishing CT radiomic features of pancreatic ductal adenocarcinoma (PDAC) and to investigate whether radiomic analysis with machine learning can distinguish between patients who have PDAC and those who do not. Materials and Methods This retrospective study included contrast material-enhanced CT images in 436 patients with PDAC and 479 healthy controls from 2012 to 2018 from Taiwan that were randomly divided for training and testing. Another 100 patients with PDAC (enriched for small PDACs) and 100 controls from Taiwan were identified for testing (from 2004 to 2011). An additional 182 patients with PDAC and 82 healthy controls from the United States were randomly divided for training and testing. Images were processed into patches. An XGBoost (https://xgboost.ai/) model was trained to classify patches as cancerous or noncancerous. Patients were classified as either having or not having PDAC on the basis of the proportion of patches classified as cancerous. For both patch-based and patient-based classification, the models were characterized as either a local model (trained on Taiwanese data only) or a generalized model (trained on both Taiwanese and U.S. data). Sensitivity, specificity, and accuracy were calculated for patch- and patient-based analysis for the models. Results The median tumor size was 2.8 cm (interquartile range, 2.0-4.0 cm) in the 536 Taiwanese patients with PDAC (mean age, 65 years ± 12 [standard deviation]; 289 men). Compared with normal pancreas, PDACs had lower values for radiomic features reflecting intensity and higher values for radiomic features reflecting heterogeneity. The performance metrics for the developed generalized model when tested on the Taiwanese and U.S. test data sets, respectively, were as follows: sensitivity, 94.7% (177 of 187) and 80.6% (29 of 36); specificity, 95.4% (187 of 196) and 100% (16 of 16); accuracy, 95.0% (364 of 383) and 86.5% (45 of 52); and area under the curve, 0.98 and 0.91. Conclusion Radiomic analysis with machine learning enabled accurate detection of PDAC at CT and could identify patients with PDAC. Keywords: CT, Computer Aided Diagnosis (CAD), Pancreas, Computer Applications-Detection/Diagnosis Supplemental material is available for this article. © RSNA, 2021.

Preoperative misdiagnosis of pancreatic and periampullary cancer in patients undergoing pancreatoduodenectomy: A multicentre retrospective cohort study

INTRODUCTION

Whereas neoadjuvant chemo(radio)therapy is increasingly used in pancreatic cancer, it is currently not recommended for other periampullary (non-pancreatic) cancers. This has important implications for the relevance of the preoperative diagnosis for pancreatoduodenectomy. This retrospective multicentre cohort study aimed to determine the frequency of clinically relevant misdiagnoses in patients undergoing pancreatoduodenectomy for pancreatic or other periampullary cancer.

METHODS

Data from all consecutive patients who underwent a pancreatoduodenectomy between 2014 and 2018 were obtained from the prospective Dutch Pancreatic Cancer Audit. The preoperative diagnosis as concluded by the multidisciplinary team (MDT) meeting was compared with the final postoperative diagnosis at pathology to determine the rate of clinically relevant misdiagnosis (defined as missed pancreatic cancer or incorrect diagnosis of pancreatic cancer).

RESULTS

In total, 1244 patients underwent pancreatoduodenectomy of whom 203 (16%) had a clinically relevant misdiagnosis preoperatively. Of all patients with a final diagnosis of pancreatic cancer, 13% (87/679) were preoperatively misdiagnosed as distal cholangiocarcinoma (n = 41, 6.0%), ampullary cancer (n = 27, 4.0%) duodenal cancer (n = 16, 2.4%), or other (n = 3, 0.4%). Of all patients with a final diagnosis of periampullary (non-pancreatic) cancer, 21% (116/565) were preoperatively incorrectly diagnosed as pancreatic cancer. Accuracy of preoperative diagnosis was 84% for pancreatic cancer, 71% for distal cholangiocarcinoma, 73% for ampullary cancer and 73% for duodenal cancer. A prediction model for the preoperative likelihood of pancreatic cancer (versus other periampullary cancer) prior to pancreatoduodenectomy demonstrated an AUC of 0.88.

DISCUSSION

This retrospective multicentre cohort study showed that 16% of patients have a clinically relevant misdiagnosis that could result in either missing the opportunity of neoadjuvant chemotherapy in patients with pancreatic cancer or inappropriate administration of neoadjuvant chemotherapy in patients with non-pancreatic periampullary cancer. A preoperative prediction model is available on www.pancreascalculator.com.

The impact of the multidisciplinary tumor board (MDTB) on the management of pancreatic diseases in a tertiary referral center

BACKGROUND

The implementation of multidisciplinary tumor board (MDTB) meetings significantly ameliorated the management of oncological diseases. However, few evidences are currently present on their impact on pancreatic cancer (PC) management. The aim of this study was to evaluate the impact of the MDTB on PC diagnosis, resectability and tumor response to oncological treatment compared with indications before discussion.

PATIENTS AND METHODS

All patients with a suspected or proven diagnosis of PC presented at the MDTB from 2017 to 2019 were included in the study. Changes of diagnosis, resectability and tumor response to oncological/radiation treatment between pre- and post-MDTB discussion were analyzed.

RESULTS

A total of 438 cases were included in the study: 249 (56.8%) were presented as new diagnoses, 148 (33.8%) for resectability assessment and 41 (9.4%) for tumor response evaluation to oncological treatment. MDTB discussion led to a change in diagnosis in 54/249 cases (21.7%), with a consequent treatment strategy variation in 36 cases (14.5%). Change in resectability was documented in 44/148 cases (29.7%), with the highest discrepancy for borderline lesions. The treatment strategy was thus modified in 27 patients (18.2%). The MDTB brought a modification in the tumor response assessment in 6/41 cases (14.6%), with a consequent protocol modification in four (9.8%) cases.

CONCLUSIONS

MDTB discussion significantly impacts on PC management, especially in high-volume centers, with consistent variations in terms of diagnosis, resectability and tumor response assessment compared with indications before discussion.

Technical Note: Using virtual noncontrast images from dual-energy CT to eliminate the need of precontrast CT for x-ray radiation treatment planning of abdominal tumors†

PURPOSE

Radiation therapy (RT) planning frequently utilizes contrast-enhanced CT. However, dose calculations should not be performed on a contrast-enhanced CT because the patient will not receive bolus during treatment. It is typical to acquire CT twice during RT simulation: once before injection of bolus and once after. The registration between these datasets introduces errors. In this work, we investigate the use of virtual noncontrast images (VNC) derived from dual-energy CT (DECT) to eliminate the precontrast CT and the registration error.

METHODS

CT datasets, including conventional 120 kVp pre- and postcontrast CTs and postcontrast DECT, acquired for ten pancreatic cancer patients were evaluated. The DECTs were acquired simultaneously using a dual source (DS) CT simulator. VNC and virtual mono-energetic images (VMI) were derived from DECTs. Gross tumor volumes (GTV), planning target volumes (PTV), and organs at risks (OAR) were delineated on the postcontrast CT and then populated to the precontrast CT and the VNC. An IMRT plan (50.4 Gy in 28 fractions) was then optimized on the precontrast CT. Dose distributions were recalculated on the VNC images. Contours from the pre- and postcontrast CTs and the dose distributions based on both were compared.

RESULTS

On average, the distance of centroids of the populated duodenum contours on precontrast CT differed by 6.0 ± 4.0 mm from those on postcontrast CTs. The dose distributions on the precontrast CT and VNC were almost identical. The PTV mean and maximum doses differed by 0.1% and 0.2% between the two plans, respectively.

CONCLUSION

The VNC derived from DECT can be used to replace the conventional precontrast CT scan for RT planning, eliminating the need for an additional precontrast CT scan and eliminating the registration errors. Thus, VNC can become an important asset to the future of RT.

Unusual Case of Pancreatic Adenocarcinoma with Bladder Metastasis

Background: The pancreas can be the site of neoplasms of several histogenetic origins; in most cases, tumors derive from the exocrine component, and ductal adenocarcinoma certainly prevails over the others. This tumor displays remarkably aggressive behavior, and it is often diagnosed at a late stage of disease. Case presentation: We discuss the rare case of a 76-year-old male with locally advanced pancreatic head adenocarcinoma who developed uncommon metastatic disease. The bladder constitutes a very rare site of metastases, mostly deriving from melanoma, gastric, lung and breast cancers. The bladder's secondary involvement in pancreatic malignancies represents an extremely unusual occurrence, and there are very few cases described in the literature to date. Conclusions: The finding of pancreatic adenocarcinoma metastases leads to a poor prognosis, and patients who are diagnosed at this stage constitute 53% of cases, with a 5-year survival of 3%. Although rare, therefore, the diagnostic hypothesis of pancreatic ductal adenocarcinoma (DAC) metastases to the bladder must, in some cases, be considered, especially if accompanied by a clinical picture that may suggest it.

Barriers and enablers to the implementation of protocol-based imaging in pancreatic cancer: A qualitative study using the theoretical domains framework

BACKGROUND

Accurate pre-operative imaging plays a vital role in patient selection for surgery and in allocating stage-appropriate therapies to patients diagnosed with pancreatic cancer (PC). This study aims to: (1) understand the current diagnosis and staging practices for PC; and (2) explore the factors (barriers and enablers) that influence the use of a pancreatic protocol computed tomography (PPCT) or magnetic resonance imaging (MRI) to confirm diagnosis and/or accurately stage PC.

METHODS

Semi-structured interviews were conducted with radiologists, surgeons, gastroenterologists, medical and radiation oncologists from the states of New South Wales (NSW) and Victoria, Australia. Interviews were conducted either in person or via video conferencing. All interviews were recorded, transcribed verbatim, de-identified and data were thematically coded according to the 12 domains explored within the Theoretical Domains Framework (TDF). Common belief statements were generated to compare the variation between participant responses.

FINDINGS

In total, 21 clinicians (5 radiologists, 10 surgeons, 2 gastroenterologists, 4 medical and radiation oncologists) were interviewed over a four-month-period. Belief statements relevant to the TDF domains were generated. Across the 11 relevant domains, 20 themes and 30 specific beliefs were identified. All TDF domains, with the exception of social influences were identified by participants as relevant to protocol-based imaging using either a PPCT or MRI, with the domains of knowledge, skills and environmental context and resources being offered by most participants as being relevant in influencing their decisions.

CONCLUSIONS

To maximise outcomes and personalise therapy it is imperative that diagnosis and staging investigations using the most appropriate imaging modalities are conducted in a timely, efficient and effective manner. The results provide an understanding of specialists' opinion and behaviour in relation to a PPCT or MRI and should be used to inform the design of future interventions to improve compliance with this practice.

Imaging and Management of Pancreatic Cancer

Pancreatic cancer is an aggressive disease with rising incidence and high mortality despite advances in imaging and therapeutic options. Surgical resection is currently the only curative treatment, with expanding roles for adjuvant and neoadjuvant chemoradiation. Accurate detection, staging, and post-treatment monitoring of pancreatic cancer are critical to improving survival and imaging plays a central role in the multidisciplinary approach to this disease. This article will provide a broad overview of the imaging and management of pancreatic cancer with a focus on diagnosis and staging, operative and nonoperative treatments, and post-therapeutic appearances after surgery and chemoradiation therapy.

A Prospective Clinical Trial to Determine the Effect of Intraoperative Ultrasound on Surgical Strategy and Resection Outcome in Patients with Pancreatic Cancer

Surgical exploration in patients with pancreatic or periampullary cancer is often performed without intraoperative image guidance. Although intraoperative ultrasound (IOUS) may enhance visualization during resection, this tool has not been investigated in detail until now. Here, we performed a prospective cohort study to evaluate the effect of IOUS on surgical strategy and to evaluate whether vascular involvement and radicality of the resection could be correctly assessed with IOUS. IOUS was performed by an experienced abdominal radiologist during surgical exploration in 31 consecutive procedures. IOUS affected surgical strategy by either (i) having no effect, (ii) determining tumor localization, (iii) evaluating vascular involvement or (iv) waiving surgery. Radicality of the resections and vascular contact were determined during pathologic analysis and compared with preoperative imaging and IOUS findings. Overall, IOUS influenced surgical strategy in 61% of procedures. In 21 out of 27 malignant tumors, a radical resection was achieved (78%). Vascular contact was assessed correctly using IOUS in 89% compared with 74% of patients using preoperative imaging. IOUS can help the surgical team to assess the resectability and to visualize the tumor and possible vascular contact in real time during resection. IOUS may therefore increase the likelihood of achieving a radical resection.

Imaging of Pancreatic-Neuroendocrine Tumours: An Outline of Conventional Radiological Techniques

IIntroduction:

Pancreatic Neuroendocrine Tumours (p-NETs) are an important disease entity and comprise of peptide-secreting tumours often with a functional syndrome.

:

Accounting for a small percentage of all pancreatic tumours, they have a good overall survival rate when diagnosed early, with surgery being curative. The role of nuclear medicine in the diagnosis and treatment of these tumours is evident. However, the vast majority of patients will require extensive imaging in the form of conventional radiological techniques. It is important for clinicians to have a fundamental understanding of the p-NET appearances to aid prompt identification and to help direct management through neoplastic staging.

Methods:

This article will review the advantages and disadvantages of conventional radiological techniques in the context of p-NETs and highlight features that these tumours exhibit.

Conclusion:

Pancreatic neuroendocrine tumours are a unique collection of neoplasms that have markedly disparate clinical features but similar imaging characteristics. Most p-NETs are small and welldefined with homogenous enhancement following contrast administration, although larger and less welldifferentiated tumours can demonstrate areas of necrosis and cystic architecture with heterogeneous enhancement characteristics.

:

Prognosis is generally favourable for these tumours with various treatment options available. However, conventional radiological techniques will remain the foundation for the initial diagnosis and staging of these tumours, and a grasp of these modalities is extremely important for physicians.

Hypoenhancing prostate cancers on dynamic contrast-enhanced MRI are associated with poor outcomes in high-risk patients: results of a hypothesis generating study

PURPOSE

To investigate the association of hypoenhancement on dynamic Contrast enhanced (DCE) with prostate cancer patient outcomes.

MATERIAL AND METHODS

This was a single-institution retrospective Institutional Review Board (IRB)-approved cohort study of 54 men who had prostate Magnetic Resonance Imaging (MRI) within 6 months of cancer diagnosis between 01/2012 to 03/2014. Two readers independently identified the dominant MRI-lesions utilizing Prostate Imaging-Reporting and Data System-version2- guidelines. These lesions were classified as hypoenhancing or hyperenhancing, compared to normal peripheral zone using quantitative DCE analysis. The t test for unequal sample sizes and the two-sample Wilcoxon rank-sum tests were used to compare groups. Logistic regression determined if DCE characteristics predict the development of metastases or prostate cancer death.

RESULTS

Time-to-progression was significantly shorter for hypoenhancing tumors (6.2 vs. 24.8 months, p = 0.05). Men with these lesions had a higher odds of having poor outcome (univariate logistic regression, odds ratio (OR) 6.79, 95% confidence interval (CI) 1.45-31.72, p = 0.02; multivariate analysis, OR 2.05, 95% CI 0.30-13.72, p = 0.47). Hypoenhancing tumors were larger (33.1 vs. 19.1 mm, p < 0.001) and more likely to be intermediate (Gleason scores 3 + 4 and 4 + 3) and high-grade (Gleason scores ≥ 4 + 4) prostate cancers (p = 0.05). Men in the hypoenhancing group had a higher mean prostate-specific antigen (PSA) value (87.6 vs. 24.8 ng/dL, p = 0.01) and PSA density (1.54 vs. 0.72, p = 0.03). The mean K_trans and k_ep of hypoenhancing lesion were lower when compared to hyperenhancing lesions (p = 0.03 and p = 0.04). V_e values did not differ (p = 0.25).

CONCLUSION

Men with hypoenhancing prostate cancers may have a worse prognosis than men with hyperenhancing tumors.

Predictors of distant metastasis on exploration in patients with potentially resectable pancreatic cancer

BACKGROUND

Patients with potentially resectable pancreatic ductal adenocarcinoma (PDAC) are frequently found to be unresectable on exploration due to small distant metastasis. This study was to investigate predictors of small distant metastasis in patients with potentially resectable PDAC.

METHODS

Patients who underwent surgical exploration for potentially resectable PDAC from 2013 to 2014 were reviewed retrospectively and divided into two groups according to whether distant metastases were encountered on exploration. Then, univariate and multivariate logistic regression analyses were used to identify predictors of distant metastasis. A scoring system to predict distant metastasis of PDAC on exploration was constructed based on the regression coefficient of a multivariate logistic regression model.

RESULTS

A total of 235 patients were included in this study. Mean age of the study population was 61.7 ± 10.4 years old. Upon exploration, distant metastases were found intraoperatively in 62 (26.4%) patients, while the remaining 173 were free of distant metastases. Multivariate logistic regression analysis identified that age ≤ 62 years old (p < 0.001), male sex (p = 0.011), tumor size ≥4.0 cm (p < 0.001), alanine aminotransferase level (ALT) < 125 U/L (p < 0.001), and carbohydrate antigen (CA19-9) level ≥ 385 U/mL (p < 0.001) were independent risk factors for occult distant metastasis of PDAC. A preoperative scoring system (0-8 points) for distant metastasis on exploration was constructed using these five factors. The receiver operating characteristic curves showed that the area under the curve of this score was 0.85. A score of 6 points was suggested to be the optimal cut-off value, and the sensitivity and specificity were 85% and 69%, respectively.

CONCLUSIONS

Distant metastasis is still frequently encountered on exploration for patients with potentially resectable PDAC. Younger age, male sex, larger tumor size, low ALT level and high CA19-9 level are independent predictors of unexpected distant metastasis on exploration.

Reclassification of lesions in biopsies by fine-needle aspiration of pancreas and biliary tree using Papanicolaou classification

BACKGROUND

Our aim was to evaluate the application of the classification of the Papanicolaou Cytopathology Society for the report of biopsies by fine-needle aspiration (FNA) of pancreas and bile duct.

METHODS

The FNAs obtained consecutively during 1 year were analyzed. Descriptive statistics were performed and sensitivity, specificity, positive predictive value, negative predictive value, and cytohistological correlation were determined. The reference standard test was the histopathological study.

RESULTS

A total of 134 cases of FNA were reclassified with ultrasound guidance according to the classification of the Papanicolaou Society, the median age was 59 years (range, 25-80 years). A case interpreted as non-diagnostic was reclassified to category 4 and 3 cases with atypical cells were reclassified to category 5. All malignant cases remained unchanged. Surgical follow-up was performed in 35 patients (26.1%), with a cytohistological concordance in 21 cases (91.3%) and 2 discordant cases (8.7%), the reasons for the discrepancy were due to sampling error, one of them with scarce material to make a diagnosis of higher category, the other case with partial agreement, because cytology was observed atypical cylindrical epithelium, with histology of grade 2 neuroendocrine neoplasia and low grade mucinous intraepithelial neoplasia. In general, the sensitivity and specificity were 100% and 75% respectively, the positive predictive value 88% and the negative predictive value 100%.

CONCLUSIONS

The FNA guided with endoscopic ultrasound (EUS) and interpreted according to the Papanicolaou Cytopathology Society Classification is an accurate method to evaluate pancreatic and biliary tract lesions with a high positive predictive value of 88%.

Computed tomography findings after radiofrequency ablation in locally advanced pancreatic cancer

Purpose

The purpose of the study was to provide a systematic evaluation of the computed tomography(CT) findings after radiofrequency ablation (RFA) in locally advanced pancreatic cancer(LAPC).

Methods

Eighteen patients with intra-operative RFA-treated LAPC were included in a prospective case series. All CT-scans performed prior to RFA and 1 week and 3 months of post-RFA, according to standard regimen, were assessed by two radiologists in consensus, using standardized radiological scoring lists.

Results

51 CT-scans were assessed. One week after RFA, the ablation zone was visible in all patients as a (partially) sharply defined (83%), heterogeneous area (94%). At 3 months of follow-up, the ablation zone was completely invaded by tumor in 67% of patients and still present, but decreased in 33%. In two patients (11%), local thrombosis and/or occlusion of the superior mesenteric vein occurred. The occlusions persisted without clinical consequences and the thrombosis disappeared. A peripancreatic fluid collection was visible 1 week after RFA in 3 patients, wherein the ablation zone extended ventrally outside of the pancreas.

Conclusions

Directly after RFA for LAPC, a well-defined ablation zone is visible on CT-imaging. This ablation zone is usually replaced by tumor ingrowth after 3 months. Moreover, the ablation zone regularly included vascular structures, with rare asymptomatic venous occlusion or thrombosis and without adverse effects on arteries.

Electronic supplementary material

The online version of this article (10.1007/s00261-018-1519-y) contains supplementary material, which is available to authorized users.

Preoperative CT in patients with surgically resectable pancreatic adenocarcinoma: does the time interval between CT and surgery affect survival?

PURPOSE

The preoperative imaging-to-surgery time interval (ISI) influences the risk of unexpected progression (UP) found at surgery for pancreatic adenocarcinoma. We aimed to assess whether ISI influences disease recurrence and/or survival.

METHODS AND MATERIALS

A single-institution, ethics board-approved retrospective analysis of all patients who underwent attempted resection of pancreatic (PDAC) or periampullary adenocarcinoma (AmpAC) between 1st January 2010 and 31st December 2015 was performed. All patients underwent preoperative abdominal computed tomography (CT). Exclusion criteria were borderline resectable disease and neoadjuvant chemo/radiotherapy. Patients were followed up until 30th June 2016. The population was divided into ISI ≥/<25 days. Kaplan-Meier and Cox regression survival analyses were performed.

RESULTS

239 patients underwent surgical exploration. UP was found in 29 (12.1%) and these patients had longer ISI (median 46 vs. 29 days, p < 0.05). When intention-to-treat analysis was performed, there was no difference in overall survival (OS) between patients with ISI ≥/<25. In those who underwent resection, ISI did not influence disease-free survival (DFS) or OS for PDAC (n = 174). For AmpAC (n = 36), ISI ≥ 25 days was associated with longer OS (p < 0.05) but did not influence DFS. Longer ISI was independently associated with improved OS on regression analysis for AmpAC.

CONCLUSION

Performing surgery for resectable pancreatic adenocarcinoma within 25 days of abdominal CT reduces the chance of UP but does not confer a survival benefit. For those who undergo resection of AmpAC, a longer ISI was associated with longer OS. This probably represents a more biologically indolent disease in this cohort.

Advanced EUS Guided Tissue Acquisition Methods for Pancreatic Cancer

Pancreas cancer is a lethal cancer as the majority patients are diagnosed at an advanced incurable stage. Despite improvements in diagnostic modalities and management strategies, including surgery and chemotherapies, the outcome of pancreas cancer remains poor. Endoscopic ultrasound (EUS) is an important imaging tool for pancreas cancer. For decades, resected pancreas cancer and other cancer specimens have been used to identify tissue biomarkers or genomics for precision therapy; however, only 20% of patients undergo surgery, and thus, this framework is not useful for unresectable pancreas cancer. With advancements in needle technologies, tumor specimens can be obtained at the time of tissue diagnosis. Tumor tissue can be used for development of personalized cancer treatment, such as performing whole exome sequencing and global genomic profiling of pancreas cancer, development of tissue biomarkers, and targeted mutational assays for precise chemotherapy treatment. In this review, we discuss the recent advances in tissue acquisition of pancreas cancer.

Imaging mimics of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma is the most common primary malignancy of the pancreas. The classic imaging features are a hypovascular mass with proximal ductal dilatation. Different pancreatic pathologies can mimic the imaging appearance of carcinoma including other tumors involving the pancreas (pancreatic neuroendocrine tumors, lymphoma, metastasis, and rare tumors like pancreatic acinar cell carcinoma and solid pseudopapillary tumors), inflammatory processes (chronic pancreatitis and autoimmune pancreatitis), and anatomic variants (annular pancreas). Differentiation between these entities can sometimes be challenging due to overlap of imaging features. The purpose of this article is to describe the common entities that can mimic pancreatic cancer on imaging with illustrative examples and to suggest features that can help in differentiation of these entities.

Rare Tumors and Lesions of the Pancreas

There are a few entities that account for most solid and cystic masses of the pancreas. The pancreas harbors a wide array of diseases, including adenocarcinoma, and its variants, such as anaplastic and adenosquamous carcinoma. Other neoplasms include acinar cell carcinoma, solid pseudopapillary tumor, and sarcomas. Benign lesions include hamartomas, hemangiomas, lymphangioma, and plasmacytoma. Isolated metastases include renal cell carcinoma, melanoma, and other carcinomas. Benign inflammatory conditions, such as autoimmune pancreatitis and groove pancreatitis can also mimic solid neoplasms of the pancreas.

Preoperative Evaluation of a Pancreas Mass: Diagnostic Options

As modern abdominal imaging equipment advances, pancreatic lesion detection improves. Most of these lesions are incidental, and present a conundrum to the clinician and create great anxiety to the patient until a final diagnosis is made. For the practicing physician, the plethora of diagnostic options is overwhelming. The relevant question is, what is the most efficient algorithm to follow and to arrive at a timely and accurate diagnosis. This article presents a logical approach to the initial evaluation of a pancreatic lesion to get the most information possible with the least amount of testing, and to avoid duplicative measures.

How to treat pancreatic adenocarcinoma in elderly: How far can we go in 2017?

Pancreatic adenocarcinoma is one of the most fatal cancers that frequently affects older patients. Limited data suggest that older patients are as likely to benefit from surgery, radiation, and chemotherapy as younger patients. The only potentially curative approach for pancreatic cancer is surgery but this is only performed in less than 20% of patients considered resectable. With improvements in surgical techniques, older patients without major comorbidities show a course of disease after resection similar to that of younger patients. The use of adjuvant chemotherapy in an attempt to prolong survival is therefore reasonable for this population of patients. Historically, patients with locally-advanced disease will be offered gemcitabine as standard chemotherapy, with radiotherapy considered at a later time. In the majority, metastatic patients will preferably be offered gemcitabine chemotherapy, which can be used at a lower dose in frail or very old patients. In some cases in patients in a very good health condition, two recent intensive chemotherapies can be proposed with modified doses and a close follow-up: the 5-fluoroucil, leucovorin, irinotecan, oxaliplatin (FOLFIRINOX) regimen and the combination of gemcitabine plus nab-paclitaxel. For older patients with terminal disease and palliative needs, which is the majority of cases, better use of pain control and palliative measures can be beneficial. Each of these issues will be examined in detail in this review.