⁶⁸Ga-labeled prostate-specific membrane antigen (PSMA) ligand positron emission tomography/computed tomography imaging (PET/CT) is a rapidly evolving imaging modality for prostate cancer. Many studies have proved its superiority in staging, restaging, and detecting the recurrent prostate cancer. However, case reports describing the incidental tracer uptake in benign and nonprostatic malignancies are also reported in the literature, thus questioning the specificity of the tracer. This pictorial assay illustrates the nonspecific tracer uptake encountered during PSMA PET/CT imaging, knowledge of which can increase the confidence of interpreting physicians and may also open a new path for peptide receptor radionuclide therapy in nonprostatic malignancies.

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Future remnant liver function (FRL-F) estimation is important before major liver resection to avoid posthepatectomy liver failure (PHLF). Conventionally, it is estimated by global dynamic liver function tests which assume homogeneous liver function and unable to calculate regional function. Computed tomography is another method to estimate FRL volume but assumes that volume is equivalent to function. Hence, a global and regional non-invasive liver function test is desirable. Studies were identified by MEDLINE, PubMed, and Google Scholar for articles from January 1990 to December 2017 using the following keywords “Mebrofenin, hepatobiliary scintigraphy (HBS), FRL-F, PHLF, portal vein embolization (PVE).” HBS with technetium-99 m galactosyl human serum albumin (Tc-99m GSA) and Tc-99m Mebrofenin is a known test for functional liver assessment. Restricted availability of Tc-99m GSA only in Japan is a main drawback for its global acceptance. However, Tc-99m Mebrofenin is routinely available to the rest of the world. A unique protocol for FRL-F estimation by Tc-99m Mebrofenin is described in detail in this review. Tc-99m Mebrofenin HBS has shown a strong correlation to 15 min indocyanine green clearance. HBS has been reported better in predicting the risk of PHLF with a 2.69%/min/m² cutoff of FRL-F. Tc-99m Mebrofenin HBS has been found better in stratification of PVE before major liver surgery as well. We concluded, Tc-99m Mebrofenin HBS was unique in calculating global and regional liver function and takes nonuniformity and underlying pathology in the account. Moreover, a single cutoff might fit in all for PHLF risk assessment and PVE stratification.

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Purpose: ¹⁸F-Fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) is now recognized as a staging investigation for locally advanced breast cancer. This retrospective review of data was performed to correlate the maximum standardized uptake value (SUV_max) of the primary tumor with the molecular subtype of breast cancer. Materials and Methods: Patients with biopsy-proven, treatment naïve, Stage III breast cancer, for whom ¹⁸F-FDG PET/CT data and immunohistochemistry 4 was available were included in the study. Correlations were deduced between the SUV_max of primary tumor to the molecular subtypes. Results: Three hundred and two patients were included in the study. Fifty-two (17.2%) tumors were Luminal A (LA), 131 (43.4%) Luminal B (LB), 42 (13.9%) human epidermal growth factor receptor-2 enriched (HE), and 77 (25.5%) basal-like (BL). SUV_max of the primary tumor differed significantly between LA and other subtypes (SUV_max: LA Median 7.4, LB 11.65, HE 13.5, BL 15.35, P < 0.001). Estrogen receptor (ER) and progesterone receptor (PR) positivity were inversely correlated to the SUV_max of the primary (SUV_max: ER + Median 10.4, ER - 14.2, P < 0.001, PR + 9.65, PR − 13.9, P < 0.001). There was a strong positive correlation observed between Ki67 and SUV_max (Pearson Coefficient 0.408, P < 0.001). A SUV_max value of 9.65 was determined as a cutoff on receiver operating characteristic curve to differentiate between LA and other subtypes with a sensitivity of 92.3% and specificity of 70.6%. Conclusions: SUV_max of primary showed a statistically significant difference between LA subtypes when compared to other subtypes. However, there was overlap of values in each subgroup and thus ¹⁸F-FDG PET/CT cannot be used to accurately assess the molecular characteristics of the tumor.

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Diffuse involvement of the pancreas in neuroendocrine tumor is a rare presentation, and its appearance on In-111 pentetreotide scan has not been reported earlier in the literature. We present the whole body images from In-111 pentetreotide scan, contrast-enhanced computed tomography images, and histopathology correlation.

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Introduction: The treatment for differentiated thyroid cancers (DTCs) has always been radioactive iodine 131I therapy after definitive surgical management. Clinicians are faced with therapeutic challenges when dealing with patients having thyroglobulin-elevated negative iodine scintigraphy (TENIS) syndrome (elevated serum thyroglobulin [Tg] levels but negative whole-body scans [WBSs]). Objective: The aim of the study was to determine the prevalence of TENIS syndrome in our local setting and to evaluate the use of 18-fluoro-2-deoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) in the management. Methodology: The data from DTC patients treated in the Department of Nuclear Medicine, Hospital Pulau Pinang from December 1, 2010, to November 30, 2016, with negative WBS and elevated Tg were reviewed. These patients should have undergone 18F-FDG PET-CT to be included in the study. Results: Only forty (10.4%) out of a total of 386 patients treated in Hospital Pulau Pinang during the study fulfilled the inclusion criteria. There were 28 women (70%) with median age of 59 years old. Thirty-four patients (85%) had papillary thyroid cancer (PTC) and six patients had follicular thyroid cancer. The use of 18F-FDG PET-CT revealed 23 patients (57.5%) with 18F-FDG avid metastases suggesting dedifferentiation of thyroid cancers. Based on this study, the probability of detecting FDG-avid disease is higher (P = 0.03) if 18F-FDG PET-CT was performed when Tg ≥15 ng/mL. Conclusion: TENIS syndrome constitutes a significant number of cases in our setting. Our data suggest a cutoff Tg ≥15 ng/mL for performing 18F-FDG PET-CT for these patients would be more beneficial than the currently American Thyroid Association recommended cutoff of 10 ng/mL.

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The nuclear medicine (NM) growth has gone through both evolutionary and revolutionary changes over decades, mostly attributable to the dynamic and responsive trends in the global development and deployment of radiopharmaceuticals (RPh), as well as the advent of superior technology imaging systems (single-photon emission computed tomography/computed tomography [CT], positron emission tomography [PET]/CT, PET/magnetic resonance) with quantification capability. There are naturally many crucial lessons learnt along the way of NM-RPh progress achieved. It is felt imperative for the NM-RPh community to have consensus-based list(s) of indications for NM, classified on the value-level basis, at NM gross-level and specific medical specialty-wise, and the corresponding RPh needed, to ensure harmonious communication with the referral medical fraternity and health-care policymakers. For this purpose, a “NM value-matrix” is proposed in terms of “NM utility grading” (unique value, significant value, useful value, and others) versus “patient volume” (i.e., large, medium, low, and rare cases), covering the established and emerging indications for NM procedure, and the corresponding RPh product(s) in use. A consensus-based NM Value-Matrix will portray in an unequivocal manner, the merits of NM-RPh options (also limitations, if any) for serving needy patients.

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Despite the increasing use of computed tomography pulmonary angiography to evaluate for pulmonary embolism (PE), ventilation/perfusion (V/Q) scintigraphy is still a fairly common examination. A rare finding on V/Q scintigraphy is whole-lung mismatched perfusion defect. Although this finding can occur with PE, it has an important, limited differential diagnosis. In this pictorial essay, we describe different causes of acquired whole-lung mismatched perfusion defect.

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Strongyloidiasis is an emerging tropical/subtropical parasitic infection commonly encountered in immunocompromised patients and often accompanied by life-threatening gram-negative bacteremia. We presented an interesting image of a critically ill 66-year-old lady, an asthmatic on high dose steroids, presenting with unexplained fever and vomiting where fluorodeoxyglucose positron emission tomography/computed tomography and endoscopic biopsy revealed this often neglected pathogenic nematode.

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Adenocarcinoma lung with upfront metastases to skeletal muscle is rarely encountered in clinical practice since skeletal muscles are highly resistant to dissemination from solid organs. Moreover, these muscle metastatic lesions generally present with pain and palpable mass to get detected clinically. However, silent skeletal muscle metastases without any symptoms or signs getting detected by functional imaging with whole body 18F-fluorodeoxyglucose positron emission/computed tomography (18FDG-PET/CT) scan have been scarcely described in literature, while we present such an interesting case in a 45-year-old female. She was diagnosed as a case of biopsy-proven metastatic adenocarcinoma lung after evaluation by 18FDG-PET/CT. Despite treatment with palliative chemoradiotherapy, her disease progressed, and she finally succumbed to her illness. This case is discussed to highlight an unusual scenario we encountered, the clinical course of the disease with its management and overall poor prognosis.

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Torsion ovary is one of the common emergencies in gynecology requiring surgery. Torsion ovary is generally caused by cystic lesions of ovary and benign tumors. Malignant tumors rarely present as torsion ovary. Krukenberg tumor presenting as torsion ovary is very rare with only a few case reports described in literature. Stomach is the most common primary site (70%) followed by colorectal, breast, lung, contralateral ovary, pancreatic, cholangiocarcinoma, and gallbladder carcinomas. Krukenberg tumor with primary in appendix is relatively rare. Here, we are presenting an unusual case of mucinous carcinoma appendix with Krukenberg tumor presenting as unilateral torsion ovary, demonstrating the role of whole-body F¹⁸ 2-Fluoro 2-deoxyglucose positron emission tomography/computed tomography scan in identifying the primary.

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A good percentage of adrenal masses in patients with known malignancy may be benign; thus, noninvasive characterization is important in preventing unnecessary biopsy. This case report represents a patient with papillary thyroid carcinoma and known lung metastasis for which she was followed up with whole-body fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) postradioactive iodine therapy. During the follow-up, she had developed an adrenal mass lesion seen by FDG PET/CT and further characterized by magnetic resonance imaging (MRI). This case demonstrates the potential importance of combining the molecular characterization by FDG PET/CT with the data derived from MRI in narrowing the differential diagnosis of an adrenal mass and suggesting the next diagnostic step in reaching the definitive diagnosis.

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Laryngeal paraganglioma is a rare neuroendocrine tumor arising from neural crest cells of larynx, contributing to 0.6% of the laryngeal tumors. Patients usually present with compressive symptoms such as hoarseness of voice. These tumors express somatostatin receptors, which can be imaged with radioligands such as ^99mTc labeled hydrazinonicotinyl-Tyr3-octreotide (HYNIC-TOC). The percentage of malignant transformation in laryngeal paraganglioma is 2%, and they usually metastasize to lymph nodes, bone, and liver. Here, we report a ^99mTc HYNIC-TOC scan of a 55-year-old male patient with recurrent laryngeal paraganglioma, who presented with painful multiple metastatic cutaneous nodules.

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Purpose of the Study: Rhenium-188 hydroxyethane 1,1-diphosphonic acid (HEDP) is a clinically established radiopharmaceutical for palliation of bone pain due to osseous metastases. Recently, the Bhabha Atomic Research Centre (BARC) had developed a freeze-dried kit for the preparation of rhenium-188 HEDP. The present study compares the radiochemistry aspects of indigenous BARC-HEDP kits with commercially available HEDP kits from Pars Isotope Company, Iran. Materials and Methods: Freeze-dried HEDP kits were obtained from Radiopharmaceuticals Division, BARC, and Pars Isotope Company, Iran. Following recommended procedures, rhenium-188 HEDP was prepared using freeze-dried kits from both sources using freshly eluted rhenium-188 sodium perrhenate obtained from a commercial tungsten-188/rhenium-188 generator. Results: Both kits could be used for the preparation of rhenium-188 HEDP in >95% radiochemical purity (RCP). Rhenium-188 HEDP prepared from both kits showed comparable in vitro stability as well as pharmacokinetic properties. The normal bone-to-soft tissue ratio observed for rhenium-188 HEDP prepared using BARC-HEDP kit and Pars-HEDP kit was 1.993 and 1.416, respectively. Conclusions: Both HEDP kits provided a user-friendly solution for the preparation of rhenium-188 HEDP. While Pars-HEDP-kit permits the addition of only 2 mL of rhenium-188 perrhenate solution per kit vial, BARC-HEDP-kit allows up to 5 mL. This feature permits the preparation of patient dose of rhenium-188 HEDP even with older generators providing rhenium-188 perrhenate having a low radioactive concentration (activity/mL). In addition, availability of an indigenous product is always preferable over imported options.

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A failure in any of the hardware components can lead to degradation in image quality and accuracy of quantification. Few artifacts may bring serious impacts on the image quality and finally lead to the wrong diagnosis. We encountered a sudden appearance of the cold area, being more prominently visible on Positron Emission Tomography image in comparison to the fused image. A daily quality assurance scan was performed to evaluate the status of the machine after giving a restart to the system. It was discovered that the module number 9–11 showed dark black color in the graph due to scarcity of counts indicating a failure/malfunctioning of the detector or electronic board-Cassette Electronic Module board (CEM board) supporting the module 9–11. Further evaluation of the system helped us diagnose that one of the electronic board (CEM Board) had become nonfunctional. A new functional electronic board (CEM board) was ordered and placed and the error rectified.

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Lymph node metastasis is widely believed to be one of the most powerful prognostic factors influencing the outcomes of many solid cancers, including esophageal cancers. The left supraclavicular node, famously described as the Virchow's node, is occasionally involved in patients with advanced gastrointestinal cancers. Virchow node involvement is considered “nonregional” in all the gastrointestinal cancers, except in esophageal cancers. On the other hand, axillary lymph node metastases (ALNMs) are considered “nonregional” in all gastrointestinal cancers, including esophageal cancers. Exceptionally, some experts share a contrarian view and consider ALNM and supraclavicular lymph node metastasis to represent a contiguous regional dissemination of esophageal cancer. The clinical presentation of ALNM in the vast majority of the patients with esophageal cancers has been reported to be metachronous. Synchronous presentation is exceedingly rare, and our patient is possibly the second case to be reported in the English language literature. The increasing role of ¹⁸F-fluorodeoxyglucose positron emission tomography computed tomography scans in aiding the staging workup in patients with esophageal cancers and ultimately influencing the choice of management in such rare scenarios is further discussed.

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F-18 FDG is a tracer of glucose metabolism, which is commonly used in PET/CT for oncological diagnosis and staging. F-18 FDG uptake represents the glycolytic activity in the cell. Physiological FDG concentration may be noted often in the muscles of head and neck, tongue, muscles on mastication, extra ocular muscles due to eye movements, cricopharyngeus and posterior cricoarytenoid muscles on phonation, etc. Here we report a case of Awake Bruxism, who came for F-18 FDG PET/CT for evaluation of Pyrexia of unknown origin (PUO), showing intense F-18 FDG uptake symmetrically in masticator muscles. Bruxism is a habit of involuntary spasmodic grinding or clenching of teeth. Many factors like psychosocial, genetic, certain medications and sleep disorders are known to be associated with bruxism. Therefore knowledge of physiological F-18 FDG uptake as well as artifactual uptake is essential for nuclear medicine physicians, to avoid ambiguity in diagnosis.

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Metastasis to the thyroid gland is rare; furthermore, intrathyroid metastasis from head and neck squamous cell carcinoma (SCC) is very unusual, with only nine previously documented cases four from intrathyroid metastasis from nasopharyngeal carcinoma, two from oral cavity, one each from oropharynx, larynx, and parotid. The reported case series are unique in nature and illustrates the role of fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) and ultrasound-guided biopsy in diagnosing clinically occult isolated intrathyroidal metastasis, which helps in the best management for an isolated intrathyroid metastases. This study details the cases of three patients who were diagnosed with intrathyroidal metastasis from SCC of the tongue by PET-CT, followed by USG-guided biopsy, who were treated with either surgery and or chemotherapy. Although intrathyroidal metastasis is an uncommon occurrence and signifies poor prognosis, early detection of an isolated intrathyroidal metastasis on imaging in an appropriately selected patients, radical surgery, and/or chemotherapy improve local control and quality of patient's life.

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Rare solitary metacarpophalangeal skeletal metastasis from poorly differentiated carcinoma of thyroid is reported in this communication. The case demonstrated excellent tumor marker and scan response to two fractions of radioiodine therapy (serum thyroglobulin 0.01 ng/ml at the time of the 3rd follow-up) and is being presently followed up on levothyroxine suppression.

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18F fluorodeoxyglucose positron-emission tomography/computed tomography (¹⁸F-FDG PET/CT) is a standard imaging tool in staging as well as response evaluation for lymphoma. Here, we present a young male with extensive extranodal lymphoma with cardiac involvement which presented as diffuse myocardial lesion mimicking hypertrophic obstructive cardiomyopathy. ¹⁸F-FDG PET/CT helped in the staging by revealing multiple systemic involvements. Interim PET after three cycles of chemotherapy showed a complete metabolic response to therapy in all the extranodal sites including the cardiac involvement, thus retrospectively confirming the lymphomatous involvement. Previous literature also conforms to the superior role of ¹⁸F-FDG PET/CT in the clinical management of extensive extranodal lymphoma.

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Lipomatous hypertrophy of the interatrial septum is a benign but less recognized pathology of the heart caused by benign fatty infiltration of the interatrial septum which most often spares the fossa ovalis. We share images of the incidentally detected fluorodeoxyglucose (FDG) uptake in the interatrial septum during the restaging of 18F-FDG positron emission tomography/computed tomography scan of cervical cancer.

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We report a 15-year-old girl referred to our department for a brain perfusion study with a diagnosis of Parry–Romberg syndrome with left hemifacial atrophy and left enophthalmos. In the presence of a normal magnetic resonance imaging, Tc-99m ECD brain perfusion revealed left temporal lobe hypoperfusion with preserved perfusion in rest of the cortical and subcortical regions and both cerebellar hemispheres.

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Introduction: Sub-acute thyroiditis possibly caused by a viral infection of thyroid gland is associated with a surge in thyroxine levels of the patient. Women in the younger age group are affected more than men. Markedly decreased radioactive iodine thyroid uptakes in a setting of thyrotoxicosis associated with elevated thyroxine levels and reduced thyroid stimulating hormone levels usually clinches the diagnosis. Patients mostly require symptomatic treatment with non-steroidal anti-inflammatory drugs. Sub-acute thyroiditis is a self-limiting disorder with most of the patients making a complete recovery in a span of three to six months. Being geographically and ethnically different the present studies was undertaken with an objective of understanding the clinical, laboratory and thyroid uptake profiles in patients of SAT during its natural history and also find the extent of genetic influences through its association with HLA B35. Materials and Methods: 32 patients in the age group of 20-59 years diagnosed to have sub-acute thyroiditis were studied. 18 patients out of 32 were subjected to HLA B35 testing. Other laboratory parameters that included hormonal profile and radioactive thyroid uptakes were performed. Results: Most of the patients were females and in their fourth decade of life. Thyroid stimulating hormone levels were decreased in 32 (100%). A majority of patients had normal anti TPO levels. All the patients had grossly decreased Tc-99m thyroid uptake levels at presentation. HLA B35 test done in 18 patients was reported positive in 10 (55.56%) patients. Conclusion: The present study is unique in having used serial Tc-99m thyroid scintigraphy in patients of SAT. A positive HLA B 35 is associated in a majority of patients conferring genetic susceptibility.

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Objective: The aim of the report is to present time efficient whole-body positron emission tomography/magnetic resonance imaging (PET/MRI) protocol evolved and tested for comprehensive evaluation of cancer patients. Materials and Methods: Whole body as well as regional simultaneous PET and MRI was performed on Biograph mMR (Siemens, Erlangen, Germany) Simultaneous PET/MRI system in 4500 clinical cases of various cancers from 2013 to 2017 with an in-house designed imaging protocol to assess its utility. Results: Using this protocol, the whole body is covered with optimized sequences (T1, T2, short tau inversion recovery, diffusion, and 3D volumetric interpolated breath-held) with PET which has been found adequate for complete metastatic workup in 30–45 min. With region-specific studies, it provides a comprehensive staging workup in an additional 10–15 min. The workflow offered additive advantages of effectively addressing incidentalomas besides being useful in terms of diagnostic utility. Conclusion: The proposed whole-body PET MRI imaging protocol used in a clinical setting is found acceptable and reasonably time efficient to optimally exploit the potentials of the technique in oncology.

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Choline is a natural substrate for phospholipid synthesis. F-18 labeled fluorocholine nowadays is routinely used for imaging brain tumors, parathyroid adenoma, and prostate cancer. It is synthesized through nucleophilic substitution reaction using dibromomethane and N, N-dimethylaminoethanol as primary and secondary precursors, respectively. However, sometimes, failures are encountered in F-18 fluorocholine production. Few problems and troubleshooting during synthesis are discussed here.

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