Management Algorithm for Cystic Pancreatic Lesions

Utilization of texture features of volumetric ADC maps in differentiating between serous cystadenoma and intraductal papillary neoplasms

INTRODUCTION

The rising incidence of incidental detection of pancreatic cystic neoplasms has compelled radiologists to determine new diagnostic methods for the differentiation of various kinds of lesions. We aim to demonstrate the utility of texture features extracted from ADC maps in differentiating intraductal papillary mucinous neoplasms (IPMN) from serous cystadenomas (SCA).

METHODS

This retrospective study was performed on 136 patients (IPMN = 87, SCA = 49) split into testing and training datasets. A total of 851 radiomics features were extracted from volumetric contours drawn by an expert radiologist on ADC maps of the lesions. LASSO regression analysis was used to determine the most predictive set of features and a radiomics score was developed based on their respective coefficients. A hyper-optimized support vector machine was then utilized to classify the lesions based on their radiomics score.

RESULTS

A total of four Wavelet features (LHL/GLCM/LCM2, HLL/GLCM/LCM2, /LLL/First Order/90percent, /LLL/GLCM/MCC) were selected from all of the features to be included in our classifier. The classifier was optimized by altering hyperparameters and the trained model was applied to the validation dataset. The model achieved a sensitivity of 92.8, specificity of 90%, and an AUC of 0.97 in the training data set, and a sensitivity of 83.3%, specificity of 66.7%, and AUC of 0.90 in the testing dataset.

CONCLUSION

A support vector machine model trained and validated on volumetric texture features extracted from ADC maps showed the possible beneficence of these features in differentiating IPMNs from SCAs. These results are in line with previous regarding the role of ADC maps in classifying cystic lesions and offers new evidence regarding the role of texture features in differentiation of potentially neoplastic and benign lesions.

[Cystic pancreatic lesions-indications, timing and reasons for surveillance]

BACKGROUND

Cystic pancreatic lesions are detected incidentally at an increasing rate. Often, the patients present asymptomatically. Hence, the resulting clinical consequences remain challenging and unsettling for both physicians and patients.

OBJECTIVES

Status of current recommendations in handling cystic pancreatic lesions.

MATERIALS AND METHODS

Selective literature search of PubMed while taking current guidelines into account.

RESULTS

Correct diagnostic classification of the cystic lesion is crucial since further action depends on the type of cystic lesion. Resection is generally recommended for mucinous cystic neoplasms (MCN), solid pseudopapillary neoplasms (SPN), and intraductal papillary mucinous neoplasms (IPMN) with relevant risk criteria such as prominent main-duct dilation. Surveillance is recommended for IPMN without risk criteria, as long as comorbidities and life expectancy of the patient will allow preventive resection over the years. SCNs are benign and only symptomatic SCNs require resection. Inflammatory pancreatic cysts should only be treated under certain circumstances.

Pancreatic serous cystic neoplasm mimicking intraductal papillary mucinous neoplasm: Two case reports and literature review

RATIONALE

Serous cystic neoplasms (SCNs) are treated as benign lesions. It is widely known that SCN rarely have a connection with the main pancreatic duct (MPD), which helps differentiate them from other cystic lesions, such as intraductal papillary mucinous neoplasm (IPMN). However, very rare cases where the SCN appears connected to the MPD cause diagnostic confusion.

PATIENT CONCERNS

We present 2 patients with SCN (1 male, 54, and 1 female, 42). Both patients were asymptomatic, without abnormal laboratory results.

DIAGNOSIS

In both cases, abdominopelvic computed tomography and pancreatic magnetic resonance imaging scans revealed a multilobulated cystic lesion in communication with the MPD. Since the size of each patient's lesion was >3 cm and there was connectivity with the MPD, it was strongly suspected to be a branch duct-type IPMN with worrisome features rather than SCN and surgical intervention was considered.

INTERVENTIONS

Both neoplasms were misdiagnosed as IPMN due to appearing connected with the MPD on radiologic imaging. Surgery was performed.

OUTCOMES

A final diagnosis of microcystic serous cystadenoma of the pancreas without connectivity of MPD was confirmed in both patients.

LESSONS

An unnecessary surgery was performed due to atypical radiologic features in which the pancreatic duct seems to be connected to the pancreatic cystic lesion on magnetic resonance imaging, leading to misdiagnosis of SCN as IPMN. Particular attention should be paid to interpretation of clinicoradiologic findings of pancreatic cystic lesions, especially to the decision of surgical intervention. Also, awareness of presence of the atypical radiologic features of SCN may broaden the knowledge base of radiologists.

LESSONS

An unnecessary surgery was performed due to atypical radiologic features in which the pancreatic duct seems to be connected to the pancreatic cystic lesion on magnetic resonance imaging, leading to misdiagnosis of SCN as IPMN. Particular attention should be paid to interpretation of clinicoradiologic findings of pancreatic cystic lesions, especially to the decision of surgical intervention. Also, awareness of presence of the atypical radiologic features of SCN may broaden the knowledge base of radiologists.

[Diagnostic Imaging of pancreatic carcinoma-Update of the new guideline]

The new German S3 guidelines on ductal pancreatic adenocarcinoma were published for the first time on the homepage of the Association of the Scientific Medical Societies in Germany (AWMF) in December 2021 as a new update and thus the second update (first update 2013) and contain a large number of innovations in terms of diagnostics and treatment. The guidelines were organized and led by the German Society for Digestive and Metabolic Diseases (DGVS). In this article we would like to present the central content and innovations related to the radiological diagnostics of ductal pancreatic adenocarcinoma. The most important innovations are the highest recommendation strength in favor of computed tomography (CT) when assessing tumor spread as well as the adaptation of the European guidelines for cystic tumors by magnetic resonance imaging (MRI) with magnetic resonance cholangiopancreatography (MRCP) as the method of first choice. A further innovation is the implementation of a structured reporting of CT findings for describing the anatomical tumor resectability on the basis of the publication presented by the Abdominal Imaging Working Group and the Oncological Imaging Working Group of the German Radiological Society. There is no evidence for the implementation of radiological imaging in the field of aftercare or in the field of screening.

[Diagnostics and clinical management of premalignant diseases of the pancreas]

Pancreatic cancer is one of the most aggressive solid tumors and still has a poor prognosis. A delayed diagnosis at advanced stages and a poor response to systemic treatment frequently make a curative treatment impossible. Therefore, the identification of high-risk patients and screening them regularly is the most promising approach to improve the prognosis. Chronic pancreatitis as well as neoplastic pancreatic cysts can greatly increase the risk of developing pancreatic cancer. Furthermore, familial syndromes and germline mutations also confer an increased risk for development of pancreatic cancer. This article provides an overview of the various premalignant diseases of the pancreas. The value of the various imaging modalities, such as magnetic resonance imaging and endosonography are particularly discussed as well as the screening interval and the indications for surgical treatment are explained.