Kidney Tumor in a von Hippel-Lindau (VHL) Patient With Intensely Increased Activity on 68Ga-DOTA-TATE PET/CT

Al18F-NOTA-Octreotide PET/CT and 18F-FDG PET/CT for Detecting Cerebellar Hemangioblastoma in a Patient With Von Hippel-Lindau Disease

ABSTRACT

Von Hippel-Lindau disease is a hereditary syndrome associated with various benign and malignant tumors, including hemangioblastomas. A 42-year-old man with a history of Von Hippel-Lindau disease underwent surgery for pancreatic neuroendocrine tumor and renal clear cell carcinoma and was recommended to undergo Al18F-NOTA-octreotide and 18F-FDG PETCT examination to assess potential metastases. 18F-FDG PET/CT showed low uptake in the right cerebellum, which demonstrated increased Al18F-NOTA-octreotide activity. Cerebellar mass resection surgery was performed. Pathological result was consistent with hemangioblastoma. This case report indicates the significant role of Al18F-NOTA-octreotide in the diagnosis of hemangioblastoma.

68Ga-DOTANOC PET/CT for Screening and Surveillance of Von Hippel-Lindau (VHL) disease

Purpose

Hereditary tumor syndrome Von Hippel-Lindau (VHL) disease is characterized by various benign and malignant tumors that are known to express somatostatin receptors (SSTR). We evaluated the role of 68Ga-DOTANOC PET/CT scan in patients with positive germline mutation of the VHL gene, presented initially or on follow-up, for the detection of recurrent or synchronous/metachronous lesions.

Methods

Fourteen patients (8 males; 6 females) with mean age 30 ± 9.86 years were retrospectively analyzed, were tested positive for VHL on gene dosage analysis, and underwent 68 Ga-DOTANOC PET/CT scan for disease evaluation. The number and site of lesions were determined. The tracer uptake was analyzed semi-quantitatively by calculating the maximum standardized uptake values (SUVmax) of lesion.

Results

Four of the 14 patients underwent scan for initial diagnosis as baseline, 6 patients for post-therapy disease status, and 4 patients for initial diagnosis as well as follow-up evaluation of the disease. A total of 67 lesions were detected in 14 patients. The sites of lesions were cerebellar/vertebral/spinal (17; mean SUVmax = 7.85); pancreatic neuroendocrine tumor (NET) (11; mean SUVmax = 20.64); retina (3; mean SUVmax = 10.46); pheochromocytoma (10; mean SUVmax = 16.32); paragangliomas (3; mean SUVmax = 10.65); pancreatic cyst (9; mean SUVmax = 2.54); and renal cyst (8; mean SUVmax = 1.56) and miscellaneous lesions constituted 6 lesions.

Conclusion

Our results show that 68 Ga-DOTANOC PET/CT may be a useful modality for screening and follow-up of associated tumors in patients with germline gene mutation for VHL. It can be used as a one-stop imaging modality for VHL patients and may substitute for separate radiological investigations, making it more convenient for patients in terms of time and cost.

68Ga-DOTATATE Avid Metastatic Vertebral Renal Cell Carcinoma in the Setting of von Hippel-Lindau Syndrome

Although rare, a metastatic renal cell carcinoma could present with 68Ga-DOTATATE avidity. A 66-year-old man with von Hippel-Lindau syndrome (VHL) presented with 68Ga-DOTATATE uptake in the pancreatic head, splenic hilar region, and multiple osseous sites, including the right lateral portion of the T9 vertebrae. Biopsy of the T9 lesion confirmed metastatic renal cell carcinoma. Various VHL-associated cancers may display 68Ga-DOTATATE avidity, which can change and guide clinical decisions for the patient.

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.

Current status and future prospects of PET-imaging applications in patients with gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs)

Gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs) represent a heterogeneous group of rare neoplasms with increasing incidence over the last decades. Localization of GEP-NETs and their metastases is a vital component for the implementation of accurate and patient-tailored treatment strategies. Addressing this challenge requires the employment of multidisciplinary imaging approaches, with hybrid positron emission tomography/computed tomography (PET/CT) imaging techniques standing at the forefront of this effort. GEP-NETs exhibit several pathophysiologic characteristics, which can serve as highly specific molecular targets that can be effectively visualized and quantified by means of PET-radiopharmaceuticals, facilitating diagnosis, accurate staging and efficient monitoring of treatment response. Furthermore, the capability for whole-body, in-vivo, non-invasive characterization of the molecular heterogeneity of the disease, provides strong prognostic information, while enabling the selection of patients suitable for precision-based theranostic approaches. The dual tracer (¹⁸F-FDG & ⁶⁸Ga-DOTA-peptides) PET/CT imaging approach is the current optimal diagnostic imaging strategy, since it enables tumor localization, accurate staging, non-invasive whole-body total tumor burden characterization of disease heterogeneity, while providing strong prognostic information and guidance towards treatment strategy. Moreover, ⁶⁴Cu-DOTATATE has been recently approved by FDA for SSTRs positive NETs, promising substantial diagnostic and logistical benefits. Furthermore, ¹⁸F-DOPA offers diagnostic capabilities for serotonin-secreting GEP-NETs which are not characterized by cell-surface over-expression of somatostatin receptors (SSTRs) and cannot be seen on morphological imaging. In addition, PET/CT with agents targeting the expression of glucagon-like peptide-1 receptor (GLP-R1) should be considered in cases of clinical suspicion for insulinomas that cannot be detected by morphological imaging or STTRs PET/CT imaging.

Targeting vulnerable atherosclerotic plaque via PET-tracers aiming at cell-surface overexpression of somatostatin receptors

Cardiovascular disease (CD) is the leading cause of death in the developed world, with major atherothrombotic events, being mainly attributed to the rupture of unstable, vulnerable atherosclerotic lesions, leading to blood flow obstruction. Since unstable atherosclerotic plaques frequently do not cause hemodynamically significant blood flow restriction, conventional stress imaging tests cannot depict the vulnerable, high-risk for rupture atherosclerotic lesions. Therefore, molecular imaging techniques targeting specific pathophysiologic features related to atherosclerotic plaque rupture mechanism, hold promise for precise and individualized treatment strategies of CD. In the current report, we describe in a patient diagnosed with pancreatic neuroendocrine tumor, the selective uptake of ⁶⁸Ga-DOATATE by an atherosclerotic lesion in the thoracic aorta. This data indicates that ⁶⁸Ga-DOTATATE, which is a positron emitting tomography tracer, targeting the recruitment of macrophages taking place in the vulnerable plaque, could potentially serve as an imaging probe for the detection of high-risk, prone to rupture plaques.

Pediatric applications of Dotatate: early diagnostic and therapeutic experience

In recent years, new somatostatin receptor agents (SSTRs) have become available for diagnostic imaging and therapy in neuroendocrine tumors. The novel SSTR ligand DOTA-DPhel-Tyr3-octreotate (Dotatate) in particular can be linked with ⁶⁸Gallium for diagnostic imaging purposes, and with the β-emitter ¹⁷⁷Lutetium for radiotherapy in the setting of neuroendocrine tumors. Dotatate imaging offers distinct advantages in the evaluation of neuroendocrine tumors compared to standard techniques, including greater target-to-background ratio and lesion conspicuity, high sensitivity/specificity, improved spatial resolution with positron emission tomography (PET)/CT or PET/MR, and decreased radiation exposure. Although currently off-label in pediatrics, Dotatate theranostics in children are being explored, most notably in the setting of neuroblastoma and hereditary neuroendocrine syndromes. This article provides a multicenter case series of Dotatate imaging and therapy in pediatric patients in order to highlight the spectrum of potential clinical applications.

PET/CT and PET/MRI in ophthalmic oncology (Review)

Orbital and ocular anatomy is quite complex, consisting of several tissues, which can give rise to both benign and malignant tumors, while several primary neoplasms can metastasize to the orbital and ocular space. Early detection, accurate staging and re-staging, efficient monitoring of treatment response, non-invasive differentiation between benign and malignant lesions, and accurate planning of external radiation treatment, are of utmost importance for the optimal and individualized management of ophthalmic oncology patients. Addressing these challenges requires the employment of several diagnostic imaging techniques, such as high-definition digital fundus photography, ultrasound imaging, optical coherence tomography, optical coherence tomography (OCT)-angiography, computed tomography (CT) and magnetic resonance imaging (MRI). In recent years, technological advances have enabled the development of hybrid positron emission tomography (PET)/CT and PET/MRI systems, setting new standards in cancer diagnosis and treatment. The capability of simultaneously targeting several cancer-related biochemical procedures using positron emitting-radiopharmaceuticals, while morphologically characterizing lesions by CT or MRI, together with the intrinsic quantitative capabilities of PET-imaging, provide incremental diagnostic information, enabling accurate, highly efficient and personalized treatment strategies. Aim of the current review is to discuss the current applications of hybrid PET/CT and PET/MRI imaging in the management of patients presenting with the most commonly encountered orbital and ocular tumors.

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.

68Ga-DOTATATE Uptake in a Soft Tissue Metastasis From Clear Cell Renal Cell Cancer

A 64-year-old man with a history of metastatic clear cell renal cell cancer was referred for progress Ga-DOTATATE PET/CT imaging. Ga-DOTATATE PET/CT imaging demonstrated increased DOTATATE uptake (SUVmax 13.8) in the left thigh localized to a soft tissue lesion. Cytopathology of the resected lesion was in keeping with a clear cell renal cell cancer metastasis. This case illustrates that Ga-DOTATATE accumulation in a soft tissue lesion can be due to a clear cell renal cell cancer metastasis.

Fibrous Dysplasia Mimicking Malignancy on 68Ga-DOTATATE PET/CT

Fibrous dysplasia of the bone is a developmental benign skeletal disorder characterized by replacement of normal bone and normal bone marrow with abnormal fibro-osseous tissue. We report on a case of a biopsy-proven fibrous dysplasia lesion in the left temporal bone, with intensely increased activity (SUVmax, 56.7) on Ga-DOTATATE PET/CT. The presented data indicate cell surface overexpression of somatostatin receptors by fibrous dysplastic cells and highlight the need of cautious management of Ga-DOTATATE-avid bone lesions, which could mimic malignancy especially in patients with history of neuroendocrine tumors.