Prospective evaluation of the clinical utility of 18-fluorodeoxyglucose PET CT scanning in patients with von hippel-lindau-associated pancreatic lesions

New Developments in VHL-Associated Neuroendocrine Neoplasms

PURPOSE OF REVIEW

The purpose of this review is to outline the current knowledge on epidemiology, diagnosis and management of neuroendocrine neoplasms (NENs) that develop in the context of Von Hippel-Lindau (VHL) syndrome.

RECENT FINDINGS

Pancreatic NENs develop in 8-17% of VHL patients (vPNENs) and are mostly multi-focal, cystic and non-functioning. Surgical resection is recommended for vPNENS > 3 cm that exhibit higher metastatic potential or in tumors with short doubling time while in the 20% of cases with metastatic disease the HIF-2 A inhibitor belzutifan is considered a promising option. Pheochromocytomas arising in VHL type 2 are often bilateral and have a noradrenergic phenotype while they are associated with increased risk of recurrence. High-specific activity [131I]-MIBG and sunitinib are the treatment options with the highest level of evidence whereas studies on belzutifan are evolving. Life-long surveillance and management in the context of a multidisciplinary team are suggested to achieve the best clinical outcome.

Is There a Role for Biomarkers in Surveillance of Pancreatic Neuroendocrine Neoplasms in Von Hippel-Lindau Disease?

Von Hippel-Lindau (VHL) disease is an autosomal dominant disorder characterized by the development of multi-organ neoplasms. Among the manifestations of VHL are pancreatic neuroendocrine neoplasms (panNENs). In order to detect these lesions in a timely manner, patients are enrolled in a surveillance program, in accordance with the several existing VHL guidelines. However, these guidelines remain unclear about the role of biomarkers in diagnosing panNENs, despite the benefits a biomarker may offer regarding early detection of new lesions, thereby possibly limiting radiation exposure, and improving quality of life. The aim is to determine which biomarkers might be available in VHL patients and to assess their clinical relevance in diagnosing panNENs in VHL patients.

We searched the databases of PubMed/Medline, Embase, and Web of Science to identify relevant articles. Seven studies assessing the diagnostic or prognostic value of biomarkers were included. The results from these studies were conflicting. Since no evident association between VHL-related panNENs and biomarkers was established in studies with larger study populations, currently biomarkers do not play a significant role in early detection or follow-up for panNENs in VHL patients. The absence of evidence underscores the need for specific research to address this unmet need.

Management recommendations for pancreatic manifestations of von Hippel-Lindau disease

Von Hippel-Lindau disease (VHL) is a multineoplasm inherited disease manifesting with hemangioblastoma of the central nervous system and retina, adrenal pheochromocytoma, renal cell carcinoma, pancreatic neuroendocrine tumors and cysts, and neoplasms/cysts of the ear, broad ligament, and testicles. During 2018-2020, the VHL Alliance gathered several committees of experts in the various clinical manifestations of VHL to review the literature, gather the available evidence on VHL, and develop recommendations for patient management. The current report details the results of the discussion of a group of experts in the pancreatic manifestations of VHL along with their proposed recommendations for the clinical surveillance and management of patients with VHL. The recommendations subcommittee performed a comprehensive systematic review of the literature and conducted panel discussions to reach the current recommendations. The level of evidence was defined according to the Shekelle variation of the Grading of Recommendations, Assessment, Development, and Evaluation grading system. The National Comprehensive Cancer Network Categories of Evidence and Consensus defined the committee members' interpretation of the evidence and degree of consensus. The recommendations encompass the main aspects of VHL-related pancreatic manifestations and their clinical management. They are presented in a clinical orientation, including general planning of screening and surveillance for pancreatic neuroendocrine tumors, utility of biochemical biomarkers, the optimal choice for imaging modality, indirect risk stratification, indications for tissue sampling of VHL-related pancreatic neuroendocrine tumors, and interventions. These recommendations are designed to serve as the reference for all aspects of the screening, surveillance, and management of VHL-related pancreatic manifestations.

Update on Hereditary Renal Cancer and Imaging Implications

Up to 8% of renal cancers are thought to have a hereditary component. Several hereditary renal cancer syndromes have been identified over the last few decades. It is important for the radiologist to be aware of findings associated with hereditary renal cancer syndromes to detect tumors early, enroll patients in appropriate surveillance programs, and improve outcomes for the patient and affected family members. This review discusses from a radiologist's perspective well-known hereditary renal cancer syndromes and emerging genetic mutations associated with renal cancer that are less well characterized, focusing on imaging features and known associations.

The utility of 68Gallium-DOTATATE PET/CT in the detection of von Hippel-Lindau disease associated tumors

PURPOSE

Patients with von Hippel-Lindau (VHL) disease may develop various tumors, including neuroendocrine tumors of the pancreas (PNETs) and adrenal, central nervous system and retinal hemangioblastomas, kidney tumors and more. ⁶⁸Ga-DOTATATE positron emission tomography (PET)/computerized tomography (CT) has been shown to be highly accurate for tumors with cells expressing somatostatin receptors. We aimed to assess the performance of ⁶⁸Ga-DOTATATE PET/CT in patients with VHL disease.

METHODS

Patients with a diagnosis of VHL were enrolled in a prospective study and underwent surveillance imaging for pancreatic lesions (n = 301). The current analysis includes 73 evaluations with multiple imaging modalities of 36 patients (2.1 ± 0.8 evaluations/patient, range 1-4) for a head-to-head comparison of ⁶⁸Ga-DOTATATE PET/CT, CT and/or MRI. In this post-hoc analysis we compared the detection rates of various imaging modalities for PNETs and for any extrapancreatic tumors located within the scan field of CT/MRI of the abdomen.

RESULTS

⁶⁸Ga-DOTATATE PET/CT detected a total of 206 lesions, CT detected 208 lesions and MRI detected 94 lesions in 61, 66 and 33 scans, respectively. ⁶⁸Ga-DOTATATE PET/CT (3.4 ± 0.1 per scan) was superior than CT (3.2 ± 0.1 per scan, p = 0.02) with a similar trend when comparing with MRI (2.8 ± 0.1 per scan, p = 0.03) in detecting lesions in any anatomic locations.

CONCLUSIONS

⁶⁸Ga-DOTATATE PET/CT had a significantly higher detection rate when compared with anatomic imaging for all lesions, and comparable detection rate for pancreatic lesions in VHL patients. Hence, given the higher accuracy and lower radiation exposure associated with ⁶⁸Ga-DOTATATE PET/CT, its potential role in the surveillance of VHL-associated lesions should be further studied.

Imaging of pancreatic neuroendocrine tumors: recent advances, current status, and controversies

Recently, there have been a number of advances in imaging pancreatic neuroendocrine tumors (panNETs), as well as other neuroendocrine tumors (NETs), which have had a profound effect on the management and treatment of these patients, but in some cases are also associated with controversies. Areas covered: These advances are the result of numerous studies attempting to better define the roles of both cross-sectional imaging, endoscopic ultrasound, with or without fine-needle aspiration, and molecular imaging in both sporadic and inherited panNET syndromes; the increased attempt to develop imaging parameters that correlate with tumor classification or have prognostic value; the rapidly increasing use of molecular imaging in these tumors and the attempt to develop imaging parameters that correlate with treatment/outcome results. Each of these areas and the associated controversies are reviewed. Expert commentary: There have been numerous advances in all aspects of the imaging of panNETs, as well as other NETs, in the last few years. The advances are leading to expanded roles of imaging in the management of these patients and the results being seen in panNETs/GI-NETs with these newer techniques are already being used in more common tumors.

Tumors in von Hippel-Lindau Syndrome: From Head to Toe-Comprehensive State-of-the-Art Review

Von Hippel-Lindau syndrome (VHL) is an autosomal-dominant hereditary tumor disease that arises owing to germline mutations in the VHL gene, located on the short arm of chromosome 3. Patients with VHL may develop multiple benign and malignant tumors involving various organ systems, including retinal hemangioblastomas (HBs), central nervous system (CNS) HBs, endolymphatic sac tumors, pancreatic neuroendocrine tumors, pancreatic cystadenomas, pancreatic cysts, clear cell renal cell carcinomas, renal cysts, pheochromocytomas, paragangliomas, and epididymal and broad ligament cystadenomas. The VHL/hypoxia-inducible factor pathway is believed to play a key role in the pathogenesis of VHL-related tumors. The diagnosis of VHL can be made clinically when the characteristic clinical history and findings have manifested, such as the presence of two or more CNS HBs. Genetic testing for heterozygous germline VHL mutation may also be used to confirm the diagnosis of VHL. Imaging plays an important role in the diagnosis and surveillance of patients with VHL. Familiarity with the clinical and imaging manifestations of the various VHL-related tumors is important for early detection and guiding appropriate management. The purpose of this article is to discuss the molecular cytogenetics and clinical manifestations of VHL, review the characteristic multimodality imaging features of the various VHL-related tumors affecting multiple organ systems, and discuss the latest advances in management of VHL, including current recommendations for surveillance and screening. ©RSNA, 2018 An earlier incorrect version of this article appeared online. This article was corrected on April 9, 2018.

18F-FDG PET/CT Volumetric Parameters are Associated with Tumor Grade and Metastasis in Pancreatic Neuroendocrine Tumors in von Hippel-Lindau Disease

BACKGROUND

Approximately 8-17 % of patients with von Hippel-Lindau (VHL) syndrome develop pancreatic neuroendocrine tumors (PNETs), with 11-20 % developing metastases. Tumor grade is predictive of prognosis.

OBJECTIVE

The aim of this study was to determine if preoperative metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were associated with metastatic disease and tumor grade.

METHODS

Sixty-two patients with VHL-associated PNETs prospectively underwent ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT). MTV, TLG, and maximum standardized uptake value (SUV_max) were measured using a semi-automatic method. Surgically resected PNETs were classified according to 2010 World Health Organization tumor grade classification. MTV, TLG, and SUV_max were analyzed by metastatic disease and tumor grade using the Mann-Whitney test.

RESULTS

A total of 88 PNETs were identified by CT and ¹⁸F-FDG PET/CT, 10 of which were non-FDG-avid. Histologic grading was available for 20 surgical patients. Patients with metastatic PNETs had a higher TLG (median 25.9 vs. 7.7 mean SUV [SUV_mean]*mL; p = 0.0092) compared with patients without metastasis, while patients with grade 2 PNETs had a higher MTV (median 6.9 vs. 2.6 mL; p = 0.034) and TLG (median 41.2 vs. 13.1 SUV_mean*mL; p = 0.0035) compared with patients with grade 1 PNETs. No difference in tumor size or SUV_max was observed between the groups.

CONCLUSIONS

Patients with metastatic PNETs have a higher TLG compared with patients without metastasis. Grade 2 PNETs have a higher MTV and TLG compared with grade 1 PNETs. Tumor size and SUV_max were not associated with grade. Volumetric parameters on ¹⁸F-FDG PET/CT may be useful in detecting higher grade PNETs with a higher malignant potential that may need surgical intervention.

Von Hippel-Lindau: Current Evidence in Diagnosis, Treatment, and Nursing Implications

BACKGROUND

Von Hippel-Lindau (VHL) is a rare autosomal dominant hereditary disorder that predisposes individuals to benign and malignant tumors in the brain, eyes, kidneys, pancreas, genital tract, or other body parts. The VHL gene, which is located on the short arm of chromosome 3, prevents cells from dividing too rapidly. Mutations in the VHL gene result in uncontrollable cell growth and tumor formation.

OBJECTIVES

The purpose of this article is to summarize the current research literature describing diagnosis, treatment, and nursing implications of VHL.

METHODS

Three electronic databases, relevant journals, and relevant websites were searched.

FINDINGS

The majority of patients affected with VHL have an affected parent, but a small percentage develop VHL from a new mutation that takes place in a single egg or sperm during conception or from a post-conception mutation. Genetic testing, either through sequence analysis, Southern blot analysis, or quantitative polymerase chain reaction, is considered standard in evaluating patients suspected of having VHL. A diagnosis of VHL can be made by identifying one VHL tumor for a patient who has a confirmed family history of VHL. The presence of at least two tumors is required to make a diagnosis of VHL in a patient without a positive family history. The nursing role includes providing resources on VHL genetic counseling, genetic testing, and palliative care.

Clinical features of pancreatic involvement in von Hippel-Lindau disease: a retrospective study of 55 cases in a single center

BACKGROUND

von Hippel-Lindau (VHL) disease is an autosomal dominant disorder characterized by the development of multiple tumors in the central nervous system and visceral organs. In this study, we describe clinical features of pancreatic involvement in VHL disease, of which there have been few reported studies to date.

METHODS

We reviewed medical records of 63 VHL patients, diagnosed at Asan Medical Center between January 1995 and December 2013. Demographic, genetic, and radiologic features, and the clinical course of VHL patients with pancreatic involvement were retrospectively analyzed.

RESULTS

Among the 63 VHL patients, 55 (87.4%) had VHL-associated pancreatic lesions (male: female, 31:24; median age at onset, 33 years; range, 12-67 years). These presented as single simple cysts (n = 5, 9.1%), multiple simple cysts (n = 14, 25.5%), serous cystadenoma (n = 29, 52.7%), or neuroendocrine tumors (NETs) (n = 17, 30.9%). Genetic tests were performed on 35 of the 55 patients (63.6%) and VHL gene mutations were observed in 28 of them (80%). Of the 55 patients, 11 received surgical treatment, 2 received endoscopic ultrasonography-guided ethanol ablation therapy as local treatment for NET, and 42 patients were followed regularly without intervention (20%, 3.6%, and 76.4%, respectively).

CONCLUSION

Pancreatic involvement in VHL disease is common, with a prevalence of 87.4%. Serial screening imaging studies for the early detection of VHL-associated NET are necessary in individuals at risk of VHL disease. A large-scale epidemiological study of VHL disease is needed to examine the natural course of the disease and the prognosis for pancreatic involvement.

Von Hippel-Lindau disease

von Hippel-Lindau (VHL) disease is an inheritable condition with an incidence of 1 in 36000 live births. Individuals with VHL develop benign and malignant tumors including retinal and central nervous system hemangioblastomas, clear cell renal cell carcinomas (RCC), pheochromocytomas, pancreatic neuroendocrine tumors and endolymphatic sac tumors (ELSTs). VHL is caused by germline loss of function of the VHL gene on one allele at chromosome 3p25-26. A somatic "second hit" event leads to the loss of the other allele and tumor formation. Loss of VHL function in cells leads to increased expression and stabilization of hypoxia inducible factor (HIF). VHL protein/HIF pathway has been implicated in tumorigenesis for hemangioblastomas, RCC and other VHL tumors. Clinical examination, imaging, and genetic testing for VHL mutations confirm VHL disease. Management of VHL disease largely consists of surgical resection of symptomatic tumors (hemangioblastomas), tumors prone to metastasize (RCC larger than 3cm), or tumors causing hormonal symptoms (pheochromocytomas). Despite advances in early diagnosis and management of VHL disease, life expectancy for VHL patients remains low at 40-52 years. Secondary effects from VHL manifestations are mitigated by routine surveillance and early detection. In this chapter, we summarize the current state of knowledge in VHL disease.