Pradeep Bhambhvani

¹⁸F-FDG PET and PET/CT patient preparation: a review of the literature.

For many types of cancer, 18F-FDG PET/CT is commonly used in evaluation and management, including tumor diagnosis, staging, restaging, treatment monitoring, and radiation therapy planning. Meticulous patient preparation including restrictions of diet and activity and management of blood glucose levels in diabetic patients, as well as an awareness of the effect of medications and environmental conditions, plays an important role toward obtaining good-quality images, which are essential for accurate interpretation. Protocol guidelines for performing PET/CT have been proposed by various societies and groups, including the Society of Nuclear Medicine and Molecular Imaging, the European Association of Nuclear Medicine, the American College of Radiology, and the National Cancer Institute. Standardization of the PET/CT procedure is necessary to enable use of metabolic parameters as imaging biomarkers in routine clinical decision making and to ensure reproducibility and allow comparison examinations across different sites. Though several published articles, including various society guidelines, have addressed the relevant patient preparation variables individually, we believe there is need for further clarification. This article summarizes existing data and proposes a standard patient preparation protocol.

99mTc-Tilmanocept: A Novel Molecular Agent for Lymphatic Mapping and Sentinel Lymph Node Localization

Preoperative lymphatic mapping in conjunction with intraoperative γ-probe detection is widely used for sentinel node localization in melanoma, breast cancer, and other malignancies. 99mTc-radiocolloids have been the standard radiotracers used for sentinel node mapping. 99mTc-tilmanocept is a receptor-binding molecular imaging agent approved by the U.S. Food and Drug Administration for lymphatic mapping and lymph node localization in breast cancer, melanoma, clinically node-negative squamous cell carcinoma of the oral cavity, and other solid tumors. It has several advantages over conventional radiocolloids, including rapid injection site clearance, high sentinel node extraction, and low distal node accumulation, which can lead to efficient resource use.

Nuclear imaging of cardiac amyloidosis

Amyloidosis is a multi-system disorder affecting various organs and histologically defined by deposition of abnormal proteins (amyloid fibrils) with characteristic staining pattern. Cardiac involvement may be seen with AL amyloidosis, characterized by deposition of light chains, and TTR amyloidosis, characterized by deposition of transthyretin, either genetically abnormal (mutant transthyretin, familial form of cardiac amyloidosis) or normal (wild-type transthyretin-wt, senile systemic amyloidosis). Cardiac amyloidosis (CA) is an underdiagnosed clinical entity affecting 50% of the patients with AL amyloidosis, in almost all patients with wt-TTR amyloidosis and with variable frequency of cardiac involvement in mutant-TTR amyloidosis depending on the underlying mutation. Under-diagnosis is partly due to the inherent difficulty in making a definitive diagnosis of CA, for which endomyocardial biopsy remains the gold standard. Tissue-based diagnosis, however, is an invasive approach and it is not uncommon for patients either to be considered too high of a risk to undergo biopsy, or refuse biopsy. In these cases, diagnosis of CA relies on (a) obtaining tissue from a different site (abdominal fat pad, salivary glands etc.) and (b) identifying signs indicative of CA on cardiac magnetic resonance imaging. Another reason why diagnosis of CA is challenging is because its cardinal echocardiographic features (increased ventricular wall thickness, impaired diastolic function) are also frequently seen with other common disorders, most notably hypertensive heart disease and other restrictive cardiomyopathies. Despite the difficulty in identifying patients with the disorder, it is important not only to identify patients at early stages of the disease in order to institute appropriate therapy, but also to differentiate between AL-CA and TTR-CA subtypes. The latter is due to their differing prognosis, AL-CA carrying the worst and wt-TTR generally believed to have the most favorable prognosis in terms of patient survival. Timely intervention and initiation of treatment is also essential. In the past, it was common belief that no effective therapy for CA existed; however, this is no longer the case. Patients with AL-CA may see improvement in their survival of up to 12 years with appropriate chemotherapy. The traditional treatment for TTR-CA is liver transplantation, with novel pharmacological agents under development. In the face of these advances and prognostic implications of CA, it is essential to make the correct diagnosis using prompt and reliable non-invasive imaging modalities. This will allow not only for differentiation amongst the subtypes of CA (AL versus TTR), but also from other myocardial disorders with similar imaging characteristics, such as hypertensive heart disease and other restrictive cardiomyopathies, for which distinctively different management is required. In the recent years, scientific interest has focused on the use of nuclear cardiac imaging for the early detection of CA. Planar imaging alone or with single-photon emission computed tomography (SPECT) using nonamyloid-specific, bone-avid radiotracers (Tc-DPD [3,3-diphosphono-1,2-propanodicarboxylic acid], Tc-MDP [methylene diphosphonate], Tc-HMDP [hydroxymethylene diphosphonate], and Tc-PYP [pyrophosphate]) have been found to be more effective in detecting TTR myocardial deposits. Recent data Reprint requests: Efstathia Andrikopoulou, MD, Division of Cardiovascular Disease, Department of Medicine, The University of Alabama at Birmingham, Birmingham, AL; eandrikopoulou@bwh.harvard.edu J Nucl Cardiol 2019;26:505–8. 1071-3581/

Evaluation of Tumor-Induced Osteomalacia with 111In-Pentetreotide Scintigraphy

34.00 Copyright 2017 American Society of Nuclear Cardiology.

PET/MR Imaging in Head and Neck Cancer: Current Applications and Future Directions

In cases of nonhereditary osteomalacia associated with hypophosphatemia and inadequate response to vitamin D supplementation, one should consider the possibility of tumor-induced osteomalacia, a paraneoplastic syndrome caused by small mesenchymal tumors often found in obscure locations. We present a case of tumor-induced osteomalacia in which 111In-pentetreotide scintigraphy aided in accurate localization of the culprit brachial plexus tumor and cure after resection.

Nuclear imaging of cardiac amyloidosis. ‘We’ve only just begun’

Clinical PET/MR imaging is being implemented at institutions worldwide as part of the standard-of-care imaging for select oncology patients. This article focuses on oncologic applications of PET/MR imaging in cancers of the head and neck. Although current published literature is relatively sparse, the potential benefits of a hybrid modality of PET/MR imaging are discussed along with several possible areas of research. With the increasing number of PET/MR imaging scanners in clinical use and ongoing research, the role of PET/MR imaging in the management of head and neck cancer is likely to become more evident in the near future.

18F-FDG PET/CT Findings in Portal Vein Thrombosis and Liver Metastases

Cardiac amyloidosis is an infiltrative/restrictive cardiomyopathy caused by the abnormal extracellular deposition of protein fibrils in the myocardium which most commonly presents as heart failure with preserved ejection fraction. The clinical presentation often overlaps with other more common cardiovascular diseases (for example, hypertrophic cardiomyopathy, hypertensive heart disease, aortic stenosis) leading to missed and/ or delayed diagnosis. The type of cardiac amyloidosis depends on the deposited precursor proteins. The most common deposited precursor proteins include immunoglobulin light chains, transthyretin, and serum amyloid A, with light chain (AL) and transthyretin amyloidosis (ATTR) being the most common forms seen in clinical practice. ATTR has 2 subtypes, hereditary/mutant ATTR caused by a hereditary amino acid mutation in the transthyretin molecule and senile or wild-type ATTR (ATTR-wt) seen with advancing age. Patients with AL and ATTR cardiac amyloidosis have overlapping imaging features on echocardiography and cardiac MRI. It is clinically important to differentiate these subtypes since they have different clinical courses (milder clinical presentation for ATTR with slower progression), prognosis (AL is much worse), and therapies (chemotherapy for AL and liver or heart-liver transplantation for familial ATTR). This differentiation may gain additional importance in the near future with the introduction of novel therapies that target the transthyretin protein and therefore would be specific for the treatment of the ATTR subtype. The diagnosis is often confirmed either by demonstrating amyloid deposits on endomyocardial biopsy or by demonstrating histologic amyloid deposits on biopsy from extracardiac tissues (e.g., abdominal fat pad, rectum, etc.) in patients with clinical/imaging suspicion of cardiac involvement. Endomyocardial biopsy coupled with immunohistochemistry or mass spectroscopy, the current gold standard for diagnosis of cardiac amyloidosis, is invasive and requires expertise. While echocardiography and cardiac MRI are clinically used in the evaluation of cardiac amyloidosis, their findings are not specific. Further, they are unable to differentiate between the amyloid subtypes (AL versus ATTR), which can be better addressed by nuclear imaging. Several SPECT and PET agents have been investigated including Technetium 3,3-diphosphono-1,2-propanodicarboxylic acid (Tc-DPD) Tc pyrophosphate (Tc-PYP), 99mTc-labeled aprotinin, C-labeled Pittsburgh compound B (C-PIB), F-Florbetapir among others (reviewed in Ref). While not useful for the diagnosis of cardiac amyloidosis, I mIBG has been shown to identify cardiac sympathetic denervation that is known to occur in the early stages of ATTR-type amyloidosis. For PET imaging, the most commonly used cardiac tracers include C-PIB and F-florbetapir. A pilot study by Antoni and colleagues showed obvious CPIB uptake in the LV wall of all 10 patients with cardiac amyloidosis (7 AL and 3 ATTR subtypes), whereas no LV uptake was seen in any of the 5 healthy controls. In half of the patients, C-PIB uptake was also visually detectable in the right ventricular wall. Reprint requests: Pradeep Bhambhvani, MD, Division of Molecular Imaging and Therapeutics, Department of Radiology, The University of Alabama at Birmingham, Birmingham, AL; pbhambhvani@uabmc.edu J Nucl Cardiol 2018;25:191–4. 1071-3581/

Role of multimodality imaging including Thallium-201 myocardial perfusion imaging in the diagnosis and monitoring of treatment response in cardiac sarcoidosis

34.00 Copyright 2016 American Society of Nuclear Cardiology.

Primary Hyperparathyroidism-Related Brown Tumors Mimicking Other Giant Cell-Containing Skeletal Tumors: Role of Correlative Imaging in Diagnosis

18F-FDG PET/CT is a valuable noninvasive tool in oncologic imaging, and its application in the diagnosis of liver metastases has been very convincing. Both the sensitivity and the specificity of 18F-FDG PET/CT are high for detecting liver metastases from various tumors including colorectal, breast, and lung. Such liver metastases are typically 18F-FDG–avid. We present atypical 18F-FDG PET findings in a lung cancer patient with known liver metastases and PVT.

A case of longitudinal care of a patient with cardiac sarcoidosis

Sarcoidosis is a multisystem granulomatous disorder of unknown etiology that can involve any organ in the body including the heart. The clinical manifestation of cardiac sarcoidosis is variable and includes asymptomatic state, conduction abnormalities, ventricular arrhythmias, heart failure and sudden death. Advanced imaging modalities like cardiac MRI and PET are increasingly being utilized in the work-up. PET is not widely available and MRI may not be an option in patients with pacemaker and/or implantable defibrillator (ICD). Myocardial perfusion imaging with Thallium201 or Tc-99m Sestamibi remains an alternative approach especially to monitor therapy as illustrated in our patient. In institutions not equipped with PET CT, diagnosis of cardiac sarcoidosis can be made by following the revised guidelines of the Japanese society of granulomatous disorders, which are based on the clinical findings, myocardial perfusion imaging and cardiac MR, elaborated at the bottom of our discussion. CLINICAL SUMMARY