Difference analysis in prevalence of incidental pancreatic cystic lesions between computed tomography and magnetic resonance imaging

Global Prevalence of Pancreatic Cystic Lesions in the General Population on Magnetic Resonance Imaging: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Understanding the burden of pancreatic cystic lesions (PCLs) in the general population is important for clinicians and policymakers. In this systematic review, we sought to estimate the global prevalence of PCLs using magnetic resonance imaging (MRI) and to investigate factors that contribute to its variation.

METHODS

We searched MEDLINE, EMBASE, and Cochrane Central, from database inception through February 2023. We included full-text articles that reported the prevalence of PCLs using MRI in the general population. A proportional meta-analysis was performed, and the prevalence of PCLs was pooled using a random-effects model.

RESULTS

Fifteen studies with 65,607 subjects were identified. The pooled prevalence of PCLs was 16% (95% confidence interval [CI], 13%-18%; I2 = 99%), most of which were under 10 mm. Age-specific prevalence of PCLs increased from 9% (95% CI, 7%-12%) at 50 to 59 years, to 18% (95% CI, 14%-22%) at 60 to 69 years, 26% (95% CI, 20%-33%) at 70 to 79 years, and 38% at 80 years and above (95% CI, 25%-52%). There was no difference in prevalence between sexes. Subgroup analysis showed higher PCL prevalence when imaging findings were confirmed by independent radiologist(s) (25%; 95% CI, 16%-33%) than when chart review alone was used (5%; 95% CI, 4%-7%; P < .01). There was no independent association of PCL prevalence with geographic location (Europe, North America, or Asia), MRI indication (screening vs evaluation of non-pancreatic pathology), enrollment period, sample size, magnet strength (1.5 vs 3 tesla), and MRI sequence (magnetic resonance cholangiopancreatography vs no magnetic resonance cholangiopancreatography).

CONCLUSION

In this systematic review, the global prevalence of PCLs using a highly sensitive noninvasive imaging modality ranged between 13% and 18%.

The multidisciplinary pancreatic cyst clinic: A collaborative approach to streamlined management

BACKGROUND

Pancreatic cysts are often incidentally detected on routine imaging studies. Of these, mucinous cysts have a malignant potential. Several guidelines propose different management strategies, and implementation in patient care is inconsistent in the absence of dedicated infrastructure.

METHODS

To address the challenges of pancreatic cyst diagnosis and management, we established a multidisciplinary pancreas cyst clinic (PCC) within our health system. This clinic encompasses both tertiary care academic centers and community hospitals, with leadership from surgical oncology, gastroenterology, and radiology. Our PCC's primary goal is to provide accurate diagnosis and tailored management recommendations for all patients with pancreatic cysts. Additionally, we maintain a prospective database to study the disease's natural history and the outcomes of various treatment strategies.

CLINIC INFRASTRUCTURE

The clinic meets once per week for 45 min virtually via Zoom in the mornings. Patients are referred via electronic medical record (EMR) order, telephone call, or email from patient or referring provider. A dedicated advanced practice provider reviews referrals several times per day, calls patients to gather clinical data, ensures imaging is uploaded, and coordinates logistical aspects of the meeting during the dedicated time. Conferences are attended by representatives from surgery, radiology, medical pancreatology, and interventional gastroenterology. Each patient case is reviewed in detail and recommendations are submitted to referring providers and patients via an EMR message and letter. For patients requiring imaging surveillance, patients are followed longitudinally by the referring provider, gastroenterology team, or surgical team. For patients requiring endoscopic ultrasound (EUS) or surgical consultation, expedited referral to these services is made with prompt subsequent evaluation.

RESULTS

A total of 1052 patients from our health system were evaluated between 2020 and 2021. Of these, 196 (18.6 %) underwent EUS, 41 (3.9 %) underwent upfront surgical resection, and the remainder were referred to gastroenterology (141-13.4 %), surgery (314-29.8 %), or back to their referring provider (597-56.7 %) for ongoing surveillance in collaboration with their primary care provider (PCP). Of cysts under surveillance, 61.3 % remained stable, 13.2 % increased in size, and 2 % decreased in size. A total of 2.3 % of patients were recommended to discontinue surveillance.

CONCLUSIONS

The PCC provides infrastructure that has served to provide multidisciplinary review and consensus recommendations to patients with pancreatic cysts. This has served to improve the application of guidelines while providing individualized recommendations to each patient, while aiding non-expert referring providers throughout the region.

The Role of Magnetic Resonance Imaging (MRI) in the Diagnosis of Pancreatic Cystic Lesions (PCLs)

Pancreatic cystic lesions (PCLs) are a common incidental finding on cross-sectional imaging. Given the high signal to noise and contrast resolution, multi-parametric capability and lack of ionizing radiation, magnetic resonance imaging (MRI) has become the non-invasive method of choice to predict cyst type, risk stratify the presence of neoplasia, and monitor changes during surveillance. In many patients with PCLs, the combination of MRI and the patient's history and demographics will suffice to stratify lesions and guide treatment decisions. In other patients, especially those with worrisome or high-risk features, a multimodal diagnostic approach that includes endoscopic ultrasound (EUS) with fluid analysis, digital pathomics, and/or molecular analysis is often necessary to decide on management options. The application of radiomics and artificial intelligence in MRI may improve the ability to non-invasively stratify PCLs and better guide treatment decisions. This review will summarize the evidence on the evolution of MRI for PCLs, the prevalence of PCLs using MRI, and the MRI features to diagnose specific PCL types and early malignancy. We will also describe topics such as the utility of gadolinium and secretin in MRIs of PCLs, the limitations of MRI for PCLs, and future directions.

Pancreatic Cystic Lesions on MRI: What Is The Likelihood of a Present or Future Diagnosis of Pancreatic Carcinoma?

BACKGROUND

Pancreatic cystic lesions (PCLs) are followed for years due to older and likely biased works demonstrating a strong association with pancreatic carcinoma; more recent data are needed clarifying this relationship.

PURPOSE

To determine the association between PCLs on MRI and a synchronous or future diagnosis of pancreatic carcinoma.

STUDY TYPE

Single-center retrospective cohort.

POPULATION

A total of 192 patients (111 female, 58%) with median age 66 years (range 26-87 years) with PCLs on abdominal MRI from 2011 to 2016.

FIELD STRENGTH/SEQUENCES

1.5 T and 3 T, including T₂ WI, T₁ WI, diffusion weighted imaging and contrast-enhanced T₁ WI.

ASSESSMENT

Each PCL was reviewed independently by 2 of 10 fellowship-trained abdominal radiologists. Fukuoka guideline worrisome features and high-risk stigmata were evaluated. Follow-up imaging and clinical notes were reviewed within a system that captures pancreatic carcinoma for the region, for a median follow-up of 67 months (interquartile range: 43-88 months).

STATISTICAL TESTS

Pancreatic carcinoma prevalence and incidence rate for future carcinoma with 95% confidence intervals (95% CI). Fisher exact test, logistic regression with odds ratios (OR) and the Wilcoxon rank-sum test were used to assess PCL morphologic features with the Kolmogorov-Smirnov test used to assess for normality. P < 0.05 defined statistical significance.

RESULTS

The prevalence of pancreatic carcinoma on initial MRI showing a PCL was 2.4% (95% CI: 0.9%, 5.2%). Thickened/enhancing cyst wall was associated with pancreatic carcinoma, OR 52 (95% CI: 4.5, 1203). Of 189 patients with a PCL but without pancreatic carcinoma at the time of initial MRI, one developed high-grade dysplasia and none developed invasive carcinoma for an incidence rate of 0.97 (95% CI: 0.02, 5.43) and 0 (95% CI: 0, 3.59) cases per 1000 person-years, respectively.

DATA CONCLUSION

A low percentage of patients with a PCL on MRI had a pancreatic carcinoma at the time of initial evaluation and none developed carcinoma over a median 67 months of follow-up.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: 5.

Imaging Modalities for Early Detection of Pancreatic Cancer: Current State and Future Research Opportunities

Simple Summary

While survival rates for many cancers have improved dramatically over the last 20 years, patients with pancreatic cancer have persistently poor outcomes. The majority of patients with pancreatic cancer are not suitable for potentially curative surgery due to locally advanced or metastatic disease stage at diagnosis. Therefore, early detection would potentially improve survival of pancreatic cancer patients through earlier intervention. Here, we present clinical challenges in the early detection of pancreatic cancer, characterise high risk groups for pancreatic cancer and current screening programs in high-risk individuals. The aim of this scoping review is to investigate the role of both established and novel imaging modalities for early detection of pancreatic cancer. Furthermore, we investigate innovative imaging techniques for early detection of pancreatic cancer, but its widespread application requires further investigation and potentially a combination with other non-invasive biomarkers.

Abstract

Pancreatic cancer, one of the most lethal malignancies, is increasing in incidence. While survival rates for many cancers have improved dramatically over the last 20 years, people with pancreatic cancer have persistently poor outcomes. Potential cure for pancreatic cancer involves surgical resection and adjuvant therapy. However, approximately 85% of patients diagnosed with pancreatic cancer are not suitable for potentially curative therapy due to locally advanced or metastatic disease stage. Because of this stark survival contrast, any improvement in early detection would likely significantly improve survival of patients with pancreatic cancer through earlier intervention. This comprehensive scoping review describes the current evidence on groups at high risk for developing pancreatic cancer, including individuals with inherited predisposition, pancreatic cystic lesions, diabetes, and pancreatitis. We review the current roles of imaging modalities focusing on early detection of pancreatic cancer. Additionally, we propose the use of advanced imaging modalities to identify early, potentially curable pancreatic cancer in high-risk cohorts. We discuss innovative imaging techniques for early detection of pancreatic cancer, but its widespread application requires further investigation and potentially a combination with other non-invasive biomarkers.

Utility of gadolinium for identifying the malignant potential of pancreatic cystic lesions

PURPOSE

To determine if gadolinium is necessary for the diagnosis of a pancreatic cystic lesion (PCL) as benign or malignant by assessing inter- and intra-observer agreement and diagnostic accuracy for the presence of worrisome features/high-risk stigmata on non-contrast MRI compared to MRI with and without contrast, with cytopathology as a reference standard.

METHODS

The institutional database was searched to identify consecutive patients that underwent EUS/FNA or surgical resection of an asymptomatic PCL performed from 01/01/2015 to 01/01/2019. Two abdominal radiologists independently evaluated PCLs on MRI with all sequences except for contrast-enhanced sequences followed by a second reading with data from the entire MRI including pre- and post-contrast sequences. Cyst size, growth, and the presence of worrisome features/high-risk stigmata were assessed for each cyst on both datasets.

RESULTS

There were 87 patients with 87 pancreatic cysts; 76(87.4%) were benign and 11 (12.7%) were malignant. The presence of any worrisome features/high-risk stigmata for reader 1 was concordant on both MRIs in 95.4% (83/87; k = 0.874) of cases and for reader 2 was concordant in 96.6% (84/87; k = 0.920) of cases. The diagnostic accuracy of the two datasets when the presence of any worrisome feature/high-risk stigmata was predictive of malignancy was identical for reader 1 (AUC = 0.622 for both; p = 1.0) and similar for reader 2 (AUC 0.569 and 0.589; p = 0.08) for both MRI datasets.

CONCLUSION

The addition of gadolinium had no significant impact in the diagnosis of a benign versus malignant PCL, with similar intra-observer agreement and diagnostic accuracy for both readers when using contrast-enhanced and unenhanced MRI datasets.

Cystic Neoplasms of the Pancreas: Differential Diagnosis and Radiology Correlation

Although the probability of pancreatic cystic neoplasms (PCNs) being detected is raising year by year, their differential diagnosis and individualized treatment are still a challenge in clinical work. PCNs are tumors containing cystic components with different biological behaviors, and their clinical manifestations, epidemiology, imaging features, and malignant risks are different. Some are benign [e.g., serous cystic neoplasms (SCNs)], with a barely possible that turning into malignant, while others display a low or higher malignant risk [e.g., solid pseudopapillary neoplasms (SPNs), intraductal papillary mucinous neoplasms (IPMNs), and mucinous cystic neoplasms (MCNs)]. PCN management should concentrate on preventing the progression of malignant tumors while preventing complications caused by unnecessary surgical intervention. Clinically, various advanced imaging equipment are usually combined to obtain a more reliable preoperative diagnosis. The challenge for clinicians and radiologists is how to accurately diagnose PCNs before surgery so that corresponding surgical methods and follow-up strategies can be developed or not, as appropriate. The objective of this review is to sum up the clinical features, imaging findings and management of the most common PCNs according to the classic literature and latest guidelines.

Opportunistic Detection for Pancreatic Cystic Lesions During Chest Multidetector CT Scans for Lung Cancer Screening

Purpose

The purpose of this study was to analyze the prevalence of and risk factors for incidental pancreatic cystic lesions (PCLs) in the Chinese general population. Furthermore, the association between baseline imaging findings and PCL progression was also investigated.

Patients and Methods

A total of 9826 individuals who underwent computed tomography (CT) examinations for lung cancer screening between January 1, 2018 and January 1, 2019 were included in this study. The participants’ CT imaging findings and biochemical biomarker levels were reviewed and analyzed. PCLs detected during the screening were followed up for 12 months. Associations between imaging findings and clinical factors with PCL progression were explored.

Results

PCLs were observed in 172 of the 9826 participants. The crude prevalence of PCLs in total population was 1.75%. In subjects aged >60 years, the prevalence of PCLs was 3.2% (102/3151). The occurrence of PCLs was significantly increased with an increase of age in both men and women (p < 0.001). High-risk PCLsL commonly located in pancreatic head showed extrapancreatic growth, and had high urea levels (p = 0.005, p = 0.015, p = 0.002, respectively) compared with low-risk PCLs. Location in the pancreatic head (odds ratio (OR) = 6.286, 95% confidence interval (CI): 1.842–21.452) and extrapancreatic growth (OR = 4.049, 95% CI: 1.235–13.333) were risk factors for PCL progression.

Conclusion

PCLs are not uncommon in the Chinese general population. Location in the pancreatic head and extrapancreatic growth are the independent predictors of high-risk of PCLs and PCL progression.

Variation in Radiologists' Follow-Up Imaging Recommendations for Small Cystic Pancreatic Lesions

OBJECTIVE

This study aimed to determine the incidence, identify imaging and patient factors, and measure individual radiologist variation associated with follow-up recommendations for small focal cystic pancreatic lesions (FCPLs), a common incidental imaging finding.

METHODS

This institutional review board-approved retrospective study analyzed 146,709 reports from abdominal CTs and MRIs performed in a large academic hospital from July 1, 2016, to June 30, 2018. A trained natural language processing tool identified 4,345 reports with FCPLs, which were manually reviewed to identify those containing one or more <1.5-cm pancreatic cysts. For these patients, patient, lesion, and radiologist features and follow-up recommendations for FCPL were extracted. A nonlinear random-effects model estimated degree of variation in follow-up recommendations across radiologists at department and division levels.

RESULTS

Of 2,872 reports with FCPLs < 1.5 cm, 708 (24.7%) had FCPL-related follow-up recommendations. Average patient age was 67 years (SD ± 11). In all, 1,721 (60.0%) reports were for female patients; 59.3% of patients had only one cyst. In multivariable analysis, older patients had slightly lower follow-up recommendation rates (odds ratio [OR]: 0.98 [0.98-1.00] per additional year), and lesions associated with main duct dilatation and septation were more likely to have a follow-up recommendation (ORs: 1.93 [1.11-3.36] and 2.88 [1.89-4.38], respectively). Radiologist years in practice (P = .51), trainee presence (P = .21), and radiologist gender (P = .52) were not associated with increased follow-up recommendations. There was significant interradiologist variation in the Abdominal Imaging Division (P = .04), but not in Emergency Radiology (P = .31) or Cancer Imaging Divisions (P = .29).

DISCUSSION

Interradiologist variation significantly contributes to variability in follow-up imaging recommendations for FCPLs.