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This study aimed to compare 18 F-PSMA-1007 PET/CT with 68 Ga-PSMA-11 PET/CT for initial staging in intermediate- and high-risk prostate cancer (PCa) patients.Forty treatment-naive, biopsy-proven, intermediate- or high-risk PCa patients were prospectively recruited. Each patient underwent PET/CT with 68 Ga-PSMA-11 and 18 F-PSMA-1007 (within 2 weeks). Assessment of both set of images included delineating number and characteristics of lesions, measurement of tracer uptake (SUV max ), miPSMA scoring, and PET-based stage categorization.Intraprostatic lesions were detected in all patients by both tracers with concordant PET-based T stage. Median SUV max of the dominant PSMA-positive prostatic lesions was not significantly different with 18 F-PSMA-1007 and 68 Ga-PSMA-11 (19.9 vs 19.4, P = 0.127, n = 40). Prostatic miPSMA scores were similar in 31/40 (77.5%) patients with both tracers (weighted κ = 0.71). In 23/40 (57.5%) patients, regional lymph nodes (n = 171) were detected by both tracers. Few additional PET-positive regional lymph nodes (n = 3) were exclusively detected by 18 F-PSMA in 2 patients without altering PET-based N stage. Extraregional lymph nodes (n = 123 in 17/40 patients) and visceral metastatic lesions (n = 18 in 3/40 patients) were detected concordantly by both tracers. PET-positive marrow based and skeletal metastases (n = 71) were detected in 14/40 (35%) patients by both tracers. Few additional marrow and skeletal lesions (n = 7) were exclusively detected on 18 F-PSMA-1007 in 5/14 patients, potentially upstaging PET-based M stage in 2/5 patients. Both radiotracers showed excellent interreader agreement for region-wise detection of lesions.Our results suggest that 18 F-PSMA-1007 PET/CT is comparable to 68 Ga-PSMA-11 PET/CT in detecting primary and metastatic lesions of PCa.

Duramycin, a 19 amino acids peptide, is known for its potential to target phosphatidylethanolamine. During cell death (apoptosis), rearrangement of membrane phospholipids results in the externalization of phosphatidylethanolamine to the outer leaflet of the cell membrane, which can be imaged using 68Ga-NOTA-duramycin. We report 68Ga-NOTA-duramycin imaging in a 50-year-old man with biopsy-proven diffuse large B-cell lymphoma planned for anthracycline-based chemotherapy. 68Ga-NOTA-duramycin PET/CT imaging along with 18F-FDG PET/CT was performed before and after 2 cycles of chemotherapy. The tracer avidity in interim 68Ga-NOTA-duramycin PET/CT showed its diagnostic potential to assess early response to chemotherapy.

Adrenocortical carcinoma (ACC) is a rare malignancy with a prevalence of 1 to 2 cases/million/year. The diagnosis depends upon endocrine workup followed by imaging with CT, MRI, and 18F-FDG PET/CT. The treatment includes surgical resection, debulking surgery, chemotherapy, and radiotherapy. However, patients do not respond well to any of the available therapies. We present noninvasive imaging of histopathology-proven ACC patients using 68Ga-DOTAGA-IAC PET/CT, specific for integrin αvβ3. 68Ga-DOTAGA-IAC PET/CT 45 minutes after IV injection showed a decent tumor-to-background ratio and could be used as a promising radiotracer for metastatic and recurrent ACC.

OBJECTIVE The aim of this study was to compare the performance of angiogenesis-specific 68Ga-RGD2 PET/CT with Disease Activity Score 28-erythrocyte sedimentation rate (DAS28-ESR) in assessing disease activity and treatment response in rheumatoid arthritis (RA). METHODS This was a prospective study comparing the performance of 68Ga-RGD2 PET/CT and DAS28-ESR in 30 RA patients. All of them underwent 68Ga-RGD2 PET/CT scan from head to toe and clinical examination at the baseline. A repeat scan and clinical examination were done in 27 patients after 3 months of treatment with disease-modifying antirheumatic drugs ± steroids. Three PET parameters, that is, PJC (PET-positive joint count), aSUVmax (average SUVmax), and hSUVmax (highest SUVmax), of positive joints were compared with the DAS28-ESR for disease activity assessment and response evaluation. RESULTS Among the 3 PET parameters, PJC showed a significant correlation with the DAS28-ESR (0.64, P < 0.01). A significant change was observed with treatment in the DAS28-ESR and PET parameters of 27 patients at follow-up. There was significant correlation between percentage changes in DAS28-ESR and scan parameters such as PJC (0.689, P < 0.001), aSUVmax (0.712, P < 0.001), and hSUVmax (0.555, P = 0.003) values. The absolute change in aSUVmax value could accurately discriminate (area under the curve, 0.98; P = 0.001) European League Against Rheumatism responders from nonresponders. CONCLUSIONS 68Ga-RGD2 PET/CT is a promising tool for objective assessment of disease activity and treatment response in patients with RA.

Radiation-induced thyroid dysfunction is very rarely associated with peptide receptor radionuclide therapy (PRRT) for neuroendocrine tumors using β-emitting radionuclides. With the emergence of α radionuclide such as 225Ac, PRRT using these radionuclides has shown better results; however, data on the toxicity profile are limited. This is a case report describing the thyroid dysfunction developed in a patient with inoperable metastatic neuroendocrine tumor with unknown primary after PRRT using 225Ac-DOTATATE, which has never been reported previously.

The aim of this study was to assess the utility of presynaptic dopaminergic imaging using 99mTc-TRODAT-1 SPECT/CT and 18F-FDOPA PET/CT and compare their performance in Parkinson's disease (PD), Parkinson-plus syndrome (PPS), and essential tremor (ET).A total of 103 patients (PD = 48, PPS = 19, and ET = 36) were enrolled prospectively. Hoehn and Yahr (HY) staging and MDS-UPDRS (Movement Disorder Society-Sponsored Revision of Unified Parkinson's Disease Rating Scale) were done for PD and PPS cases. All the patients underwent 99mTc-TRODAT-1 SPECT/CT and 18F-FDOPA PET/CT brain scan. The scans were analyzed visually and semiquantitatively. Average pixel count and SUVmean of the striatum were calculated in SPECT and PET images, respectively, to calculate the specific uptake ratio of striatum (SUR). Comparison of scan findings and SURs among different groups and correlation with clinical characteristics was done.Symmetrical comma-shaped uptake was seen in bilateral striatum in ET cases with mean SURs significantly higher than in cases of early PD (HY stage I and II, n = 37), PD and PPS both on SPECT and PET images (P ≤ 0.001). The mean SURs between PD and PPS showed no significant difference (SPECT, P = 0.17; PET, P = 0.61). Substantial agreement (weighted κ = 0.659) was found between 99mTc-TRODAT-1 and 18F-FDOPA for the detection of presynaptic dopaminergic dysfunction. Specific uptake ratio of striatum correlation between SPECT and PET was statistically significant (r = 0.67; P0.01). A negative but nonsignificant correlation was found between the SURs and HY staging/MDS-UPDRS.Both 99mTc-TRODAT-1 SPECT/CT and 18F-FDOPA PET/CT showed substantial agreement and proved to be potential imaging biomarker for the detection of dopaminergic dysfunction, thus assisting in differentiating early PD/PD and PPS from ET cases.

Purpose Advanced inoperable/metastatic neuroendocrine tumors (NETs) pose a therapeutic challenge with limited treatment options. Peptide receptor radionuclide therapy (PRRT), being specific in targeting the somatostatin receptors, is a promising and viable option in this setting. In this study, we intended to evaluate the role of PRRT as the first-line systemic therapy in advanced inoperable/metastatic NETs. Methods Data of consecutive patients of advanced inoperable/metastatic NETs treated with first-line Lu-DOTATATE at our center, from September 2012 to August 2019, were collected and analyzed. Results Forty-five patients (median age, 50 years; range, 14-72 years) with treatment-naive advanced NETs received a median cumulative dose of 27 GBq (range, 13.3-41.3 GBq; over 2-7 cycles) Lu-DOTATATE and 1250 mg/m capecitabine from days 0 to 14 of each PRRT cycle. Three patients were lost to follow-up, 2 had nonmeasurable lesions on CT, and hence, radiological response using Response Evaluation Criteria in Solid Tumors version 1.1 could be assessed in 40 patients. Twelve of 40 patients (30%) showed a partial response, whereas stable disease was observed in 22 of 40 patients (55%). Disease progression was limited to 6 of 40 patients (15%). Treatment-related adverse effects were minimal with grade 3/4 anemia, leukopenia, neutropenia, and hepatotoxicity observed in 2%, 2%, 4%, and 4% of the patients, respectively. Median progression-free survival was 48 months (95% confidence interval, 34.7-61.3 months). Conclusions Our results indicate the efficacy and safety of first-line PRRT in advanced NETs. Future randomized trials, comparing PRRT and somatostatin analogs in treatment-naive patients, are required to identify the definite sequence of treatment options for these patients.

131I scan plays a crucial role in the management of patients with differentiated thyroid cancer for the evaluation of remnant thyroid tissue, residual/recurrent metastatic disease, posttherapy tracer distribution, and response assessment to high-dose 131I therapy. Different causes secondary to physiological, pathological, and anatomical variations have been described for false-positive findings in the whole-body planar images. This case report of a patient of differentiated thyroid cancer with undocumented trauma to the left knee region a day before receiving the high-dose radioiodine therapy showed an interesting image finding of tracer uptake at unusual site in the posttherapy whole-body 131I scan.

Primary neuroendocrine tumor of the mediastinum is a relatively rare entity. In metastatic/inoperable disease, therapeutic options are limited to cytotoxic chemotherapy in poorly differentiated tumors and peptide receptor radionuclide therapy in case of well-differentiated tumors. We present the case of a 52-year-old man with mediastinal atypical carcinoid (grade II) neuroendocrine tumor showing mild somatostatin receptor expression and intense FDG avidity with progressive disease on chemotherapy. Chemokine receptor targeted PET/CT with CXCR4 (Ga-CXCR4) showed tracer avidity in tumor sites higher than the physiological sites, which may pave the way for CXCR4-targeted radionuclide therapy in this subgroup of patients.

Primary central nervous system lymphoma is an extranodal lymphoma originating in the brain, spinal cord, and leptomeninges, which rarely spreads outside the nervous system. Neurolymphomatosis is the term used to describe lymphomatous involvement of the cranial nerves (except optic nerve) and peripheral nerve roots or plexus. We report a case of a 23-year-old man presented with progressive weakness of all 4 limbs. F-FDG PET/CT revealed FDG-avid thickening along the multiple cranial nerve roots, spinal nerve roots, and brain parenchymal lesion. Core biopsy from the peripheral nerve root demonstrated the lymphomatous involvement.

PURPOSE This study was conducted to identify the role of hepatobiliary scintigraphy (HBS) in the management of biliary tract injuries. METHODS We retrospectively studied 54 patients (28 male and 26 female patients) aged 3 to 78 years with evidence of bile leak on HBS performed between January 2015 and October 2017. Following intravenous injection of Tc-mebrofenin, dynamic images were acquired for 30 minutes followed by static images until 24 hours. SPECT/CT was performed in patients with suspicion of bile leak on the planar images. Patients were classified as those with free intraperitoneal or localized bile leak. Any abdominal drain output was documented, and its statistical significance was assessed using Mann-Whitney U test. Subsequent management was also documented. RESULTS Of the 54 patients, 28 demonstrated free intraperitoneal bile leak and 26 localized leak on HBS. Thirty-four patients (24 with free intraperitoneal leak and 10 with localized leak) had an abdominal drain. Drain output was significantly higher in patients with free intraperitoneal leak compared with patients with localized leak (370 vs 78 mL/d per patient, P < 0.01). All patients with free intraperitoneal bile leak underwent interventional procedures such as endoscopic retrograde cholangiopancreatography and stenting or Roux-en-Y hepaticojejunostomy later on. Patients with localized bile leak were managed conservatively and were free of symptoms at 1-year follow-up. CONCLUSIONS Our findings indicate that, in addition to detecting biliary leak, HBS may be used to identify patients with localized bile leak (48% of patients in our study) who do not require active intervention.

Breast cancer is the most common cancer in women with rising incidence worldwide. F-FDG PET/CT imaging has already established itself as a pivotal modality for staging, restating and response assessment in patients with carcinoma breast. The complex biology of this cancer is increasingly being decoded and various molecular targets have been identified and exploited for guiding the treatment at various time points during the course of the disease. We here depict a series of various metabolic and receptor targeting PET radiotracers in breast cancer patients which may help us understand the in vivo biology of this tumor.

Skull base osteomyelitis is 1 of the complications of a middle ear infection seen mainly in immunocompromised individuals. A 3-phase bone scan and clinical, laboratory, and other radiological imaging are used for the diagnosis. However, in previously operated cases, bone scan findings are not reliable. We present a case of a 70-year-old man with persistent ear discharge postsurgery and with 3-phase bone scan negative for active infection. However, a subsequent 18F-FDG-labeled autologous leukocyte PET/CT study was able to diagnose the presence of active infection.

Continuous ambulatory peritoneal dialysis is a convenient alternate form of treatment in patients receiving hemodialysis for renal failure. Sometimes during the procedure, patients may develop scrotal swelling because of patent processus vaginalis. The diagnostic utility of the peritoneal scintigraphy, an infrequently performed nuclear medicine scan to identify peritoneoscrotal communication, has been reported by many authors. Most of the previous case reports in the literature demonstrated unilateral peritoneoscrotal communication. We present an interesting Tc-sulfur colloid peritoneal scintigraphic image finding of bilateral peritoneoscrotal communication in a 67-year-old man who developed scrotal swelling while undergoing continuous ambulatory peritoneal dialysis.

PSMA-based radioligand therapies have shown the beneficial effect in metastatic castrate-resistant prostate cancer (mCRPC) patients when they become refectory to the established treatments with associated potential toxicities and high mortality rate. Ac-PSMA therapy is known to be remarkably effective in substantially pretreated mCRPC patients. However, posttherapy imaging is usually not performed as alpha emitters are really difficult to image. We presents a patient of mCRPC treated with Ac-PSMA-617, and his posttherapy whole-body scans acquired by using 3 different photopeaks (78, 218, and 440 keV) fairly demonstrated the tracer's distribution and the efficacy of targeted alpha therapy.

Primary lymph node gastrinoma has been defined as gastrin-producing tumor present in lymph nodes and predominantly found in well-defined anatomical region known as gastrinoma triangle. They are usually localized preoperatively with imaging, and their surgical resection results in long-term relief. The authors report a case of unresectable primary lymph nodal gastrinoma with liver metastases in a 14-year-old adolescent boy with proven histopathology detected on Ga-DOTANOC whole-body PET/CT scan followed by preoperative multiple Lu-DOTATATE cycles for cytoreduction. Subsequent surgical resection of residual mass resulted in complete response with a follow-up of around 4 years in this unusual case of Zollinger-Ellison syndrome.

Primary progressive aphasia is a neurodegenerative variant of frontotemporal lobe degeneration presenting with isolated selective impairment of language domain, not secondarily due to stroke. We present a case of middle-aged female patient who underwent F-FDG PET of the brain for evaluating progressively declining speaking ability associated with altered fluency of speech and occasional mutism. F-FDG PET revealed asymmetric hypometabolism involving the left inferior frontal gyrus along with left anterior cingulate gyrus suggestive of Broca's aphasia.

Purpose of the report Tuberculosis (TB) is a major health problem. Activated macrophages in TB lesions show high metabolic activity and can be assessed using F-FDG PET/CT. This retroprospective study was done to evaluate the utility of F-FDG PET/CT in initial assessment and therapeutic response in patients with TB. Materials and methods Eighty-seven patients (male-to-female ratio, 46:41) diagnosed with pulmonary TB and extrapulmonary TB underwent whole-body F-FDG PET/CT for initial assessment and a follow-up scan 3 to 4 months after initiation of antitubercular therapy (ATT). Visual and semiquantitative (SUVmax) analyses were used for scan assessment. Treatment responses on interim scans were categorized as complete metabolic response (CMR), favorable response to therapy (FRT), stable disease (SD), and disease progression (DP). CMR, FRT, and SD cases were considered as responders and DP cases as nonresponders. Treatment response was correlated with clinical outcome (mortality) and ATT duration. Results Baseline F-FDG PET/CT scans were positive in all the patients and detected additional disease sites than suspected clinically in 72% patients. On interim PET/CT, 13 patients showed CMR, 43 showed FRT, 8 showed SD, and 23 showed DP. A longer duration of ATT was seen in nonresponders (P ≤ 0.001) than responders. During follow-up, 9/87 patients died, out of which 8 patients were of DP group and 1 patient belonged to SD. Nonresponders showed 35% mortality compared with 1.6% in the responder group (P ≤ 0.001). Conclusions F-FDG PET/CT is a valuable imaging modality for disease mapping and assessing therapeutic response. Treatment response in the interim PET/CT done at 3 to 4 months predicted the duration of ATT and clinical outcome of the patients.

Immunoglobulin G4-related disease is a fibroinflammatory condition that has the tendency to involve almost every organ of the body. We report the case of a young asymptomatic man with right suprahilar opacity on chest radiograph detected during routine annual health check-up. Mediastinoscopic sampling of the lesion was inconclusive. F-FDG PET/CT done to characterize the lesion revealed hypermetabolic mass with areas of necrosis in the right paratracheal location. Histopathologic examination from the FDG PET/CT-guided biopsy sample was suggestive of immunoglobulin G4-related disease.

The aim of the study was to analyze the diagnostic and prognostic utility of F-FDG PET/CT to predict the disease-specific survival (DSS) with FDG uptake and tumor grade in recurrent chondrosarcoma.Retrospective analysis of FDG PET/CT findings in 31 previously treated patients (46 studies) with mean follow-up period of 40.7 ± 23.9 months (range, 3-77 months) from the date of first PET/CT study was done. Kaplan-Meier DSS analysis was made with respect to tumor grade, FDG uptake at the recurrent primary sites, and a combination of grade and FDG uptake as parameters.Recurrence (local and distant) was shown in 28 (60.8%) of 46 FDG PET/CT studies with sensitivity and specificity of 88.9% and 78.9%, respectively. The median SUVmax at the recurrent primary sites differed significantly (P = 0.008) among 3 tumor grade groups, with higher median SUVmax in higher grades. There was significant difference in median SUVmax among different grade groups except between grade II and grade III. Recurrent primary site SUVmax cutoff at 6.15 derived from the receiver operating characteristic curve yielded significant difference (P0.001) in mean DSS time. Significant difference in survival was noted between 3 different tumor grade groups (P = 0.016). The combination of SUVmax and grade improved the survival prediction than with grade alone.In recurrent chondrosarcoma, the recurrent primary site FDG uptake and grade were found to be reliable prognostic factors with respect to DSS. PET/CT in recurrence setting has the potential to predict tumor grade and survival and may assist in clinical management.

Immunoglobulin G4 (IgG4)-related disease is known to mimic multiple malignancies and always poses a diagnostic challenge. We report a case of a 20-year-old young man, who presented with unexplained recurrent episodes of fever and pain abdomen. F-FDG PET/CT revealed intense focal FDG avidity in the prostate. On further workup, he had an elevated serum IgG4 level, and a clinical diagnosis of immunoglobulin G4-related disease was kept. A follow-up FDG PET/CT after glucocorticoid therapy revealed resolution of FDG avidity in the prostate with fall in serum IgG4 levels, hence confirming a diagnosis of atypical immunoglobulin G4-related disease involving isolated prostate gland.

Persistent hyperinsulinemic hypoglycemia in adults is most commonly caused by insulinomas, which pose a diagnostic challenge to physicians, surgeons, and radiologists and require multimodality imaging for precise localization and staging. PET tracers such as F-FDOPA and glucagon-like peptide 1 receptor analogs have been used for imaging insulinomas. Glucagon-like peptide 1 receptor analogs have recently shown promising results in preoperative localization of these tumors, as all insulinomas express glucagon-like peptide 1 receptors. Ga-DOTA-Exendin PET and MRI done in the present case helped in precise localization and management of the culprit lesion, whereas contrast-enhanced CT and F-FDOPA PET failed to do so.

Ga-DOTANOC PET/CT is well documented in evaluation of well-differentiated neuroendocrine tumors and in other lesions with somatostatin receptor expression such as pheochromocytoma, paraganglioma, neuroblastoma, meningioma, and mesenchymal tumors causing oncogenic osteomalacia. Causes of interpretative pitfalls include prominent pancreatic uncinate process activity, inflammation, osteoblastic activity (degenerative bone disease/fracture/vertebral hemangioma), splenunculi/splenosis, and others. We present a case of extraskeletal paravertebral lesion detected in a known case of breast cancer with increased Ga-DOTANOC uptake later proved to be hemangioma. This is a novel finding and should be kept as a rare benign differential in evaluation of lesions with somatostatin receptor expression.

The utility of β-emitter 177Lu-DOTATATE in patients of neuroendocrine tumors (NETs) with widespread skeletal metastases is limited by its relatively modest response rates and a significant concern for hematotoxicity. In such situations, targeted α therapy with 225Ac-DOTATATE can be potentially beneficial. In this report, a 46-year-old man with rectal NET and extensive skeletal metastases was treated upfront with 6 cycles of 225Ac-DOTATATE at 8 weeks' intervals. The patient showed excellent symptomatic, biochemical, and radiological response with no grade 3/4 adverse events. The first-line use of 225Ac-DOTATATE, therefore, presents a novel strategy for metastatic NETs with high skeletal disease burden.

PURPOSE Accurate preoperative localization of parathyroid lesion(s) is crucial for successful surgical management of primary hyperparathyroidism (PHPT). This study was conducted to compare the effectiveness of ultrasonography (USG) of the neck, Tc-sestamibi (MIBI) imaging with or without SPECT/CT, and F-fluorocholine (FCH) PET/CT imaging in the preoperative localization of parathyroid lesions in patients with PHPT. METHODS Fifty-four consecutive patients with PHPT were included in this prospective study who underwent preoperative localization of the parathyroid lesion(s) using 3 diagnostic modalities followed by surgery. The sensitivity, positive predictive value, and accuracy of the 3 imaging procedures to accurately detect abnormal parathyroid glands were determined using histopathology as criterion standard with postoperative biochemical response confirmation. RESULTS F-fluorocholine PET/CT detected 52 of 54 patients and 52 of 56 lesions with histopathologically proven parathyroid adenomas on patient-based and lesion-based analysis, respectively. Preoperative USG, MIBI, and FCH PET/CT localized abnormal parathyroid gland(s) in 39 (72.2%), 43 (79.6%), and 54 (100%) patients, respectively. The sensitivity and positive predictive value were 69.3% and 87.1% for USG, 80.7% and 97.6% for MIBI, and 100% and 96.3% for FCH PET/CT. The accuracy was 62.9%, 79.6%, and 96.3% for USG, MIBI, and FCH PET/CT, respectively, in patient-wise analysis. In 6 patients with ectopic lesions, FCH PET/CT demonstrated higher sensitivity and accuracy than MIBI and USG (100% vs 66.6% and 16.7%, respectively). CONCLUSIONS Among the 3 imaging techniques tested simultaneously, FCH PET/CT was superior for accurate preoperative localization of parathyroid adenomas, especially for ectopic or small parathyroid lesions.

The aim of this study was to evaluate the incremental value of cocktail F-FDG/F-NaF PET/CT over F-FDG PET/CT alone for detection of skeletal metastases in breast cancer patients.Seventy patients with locally advanced/recurrent breast cancer were prospectively included. All patients underwent whole-body F-FDG PET/CT and cocktail F-FDG/F-NaF PET/CT within a span of 1 week. Both studies were evaluated to detect presence of skeletal/marrow metastases on PET/CT images by 2 nuclear medicine physicians. Clinical and radiological correlation/follow-up was used as criterion standard.Of 70 patients, 50 (71.0%) had locally advanced breast cancer, and 20 had recurrent breast cancer. On patient-wise analysis, both cocktail PET/CT and F-FDG PET/CT identified skeletal/marrow lesions in 23 (32.8%) of 70 patients. In 8 patients (11.4%), only cocktail PET/CT identified skeletal/marrow lesions, whereas F-FDG PET/CT was negative. In the rest of the 39 patients (55.8%), no skeletal/marrow lesion was identified on both scans. Good correlation was noted between cocktail PET/CT and F-FDG PET/CT results (r = 0.785, P0.0001). Cocktail PET/CT detected lesions in significantly more number of patients than F-FDG PET/CT alone (P = 0.007). On lesion-wise analysis, cocktail PET/CT detected more number of lesions in 20 patients as compared with F-FDG-PET/CT alone. Both scans detected same number of lesions in the rest of 11 patients with positive findings. A total of 32 additional lesions were identified on cocktail PET/CT imaging as compared with F PET/CT alone (P0.0001).Cocktail F-FDG and F-NaF PET/CT is superior to F-FDG PET/CT alone for the detection of skeletal/marrow metastases in breast cancer. It can be a better alternative to F-FDG PET/CT alone in facilities where both tracers are available.

68Ga-PSMA PET/CT is a commonly performed procedure in the staging of intermediate- and high-risk prostate cancer after biochemical recurrence. Uptake of 68Ga-PSMA in benign conditions is also reported in the literature. Docetaxel is the mainstay of treatment in high-volume hormone-sensitive prostate cancer and castration-resistant prostate cancer. The major treatment-emergent adverse drug reactions attributed to docetaxel include myelosuppression, alopecia, and asthenia. Interstitial pneumonitis is seen in less than 2% of docetaxel-treated patients. We present a case of metastatic castration-resistant prostate cancer, wherein docetaxel-induced interstitial pneumonitis was detected on 68Ga-PSMA PET/CT, after docetaxel treatment.

Ga-labeled prostate-specific membrane antigen (PSMA) ligand PET/CT is a rapidly evolving imaging modality for prostate cancer. However, with the widespread use of Ga-PSMA PET/CT, various reports of nonprostatic uptake of Ga-PSMA in both benign and malignant lesions have also appeared. We report a recently diagnosed case of prostate cancer demonstrating diffuse Ga-PSMA expression in both the lobes of thyroid gland, which on further clinical and biochemical investigations was established as hypothyroidism.

Estrogen receptor-expressing breast cancer exhibits better prognosis due to responsiveness to antiestrogen treatment. Therefore, knowledge of the estrogen receptor status of a tumor is an important prognostic and predictive indicator in breast cancer. We present noninvasive imaging of estrogen receptors with Tc tamoxifen that can identify the active tumor and approachable sites for biopsy. It may help in selection of patients for hormone replacement therapy and in assessment of receptor status in recurrent disease and also in response evaluation.

Differentiated thyroid cancer (DTC) with thyroglobulin elevation and negative I scintigraphy (TENIS) syndrome is a diagnostic and therapeutic dilemma. Treatment of differentiated thyroid cancer has an excellent outcome, but treatment options in TENIS are limited with the exception of surgically amenable disease. We present a case of TENIS syndrome with incidental detection of tumor thrombus in right pulmonary vein extending to the left atrium on F-FDG PET/CT and subsequently complicating as an occipital bleed. The timely detection of the thrombus facilitated early initiation of anticoagulant therapy. However, the intracranial bleed precluded the continuation of anticoagulant therapy.

Neoplasms arising from the urachus are extremely rare. We present a case of a young woman with mild abdominal pain and a palpable swelling in the mid abdomen with incidental detection of a subumbilical mass. Repeated fine-needle aspiration cytology failed to reveal the true nature of the lesion. F-FDG PET/CT showed tracer uptake in the cranial end of urachal remnant lesion. Core biopsy from the site with maximal FDG uptake turned out to be lymphomatous involvement in urachus, which is extremely rare and previously unreported.

Ga-prostate-specific membrane antigen (PSMA) ligand is a well-known tracer used in prostate cancer. Nevertheless, there are reports of unusual Ga-PSMA uptake in variety of benign lesions. We report a case of prostate cancer in which Ga-PSMA PET/CT revealed tracer avidity in the enhancing walls of cystic lesions in the brain consistent with the features of neurocysticercosis. The uptake of Ga-PSMA in neurocysticercosis is not known and may be attributed to angiogenesis occurring at the periphery of these lesions.

Immunoglobulin G4-related disease is an autoimmune entity with multisystem involvement. F-FDG PET/CT can provide important information about disease extent and severity and also aid in treatment response evaluation. We report a case of a 57-year-old woman presenting with abdominal discomfort, belching, and loss of weight in whom F-FDG PET/CT provided valuable information in diagnosis and monitoring treatment response.

The detection of synchronous or metachronous malignancies is on the rise with the advent of whole-body F-FDG PET/CT. It has shown its utility in detecting second primary carcinoma in patients undergoing imaging for evaluation of primary carcinoma, influencing the management and overall survival. Primary malignant melanoma of the lung is an extremely rare entity, accounting for 0.01% of all lung tumors. It is an even rare occurrence as a synchronous malignancy. We present the case of a 33-year-old woman with primary parotid myoepithelial carcinoma and incidental detection of second primary malignant melanoma of lung during F-FDG PET/CT imaging.

Chorea induced by diabetic nonketotic hyperglycemia is a rare and poorly understood entity with a favorable prognosis after correction of the hyperglycemia. We present a case of elderly diabetic woman with poorly controlled blood glucose levels, presenting with choreiform movements limited to the right side. F-FDG PET/CT showed marked hypometabolism in the basal ganglia contralateral to the side with hemichorea. The metabolic dysfunctions lead to nonketotic hyperglycemic chorea, although poorly understood; the index case demonstrated severe glucose hypometabolism in the striatum and adds to the other reported differential diagnoses for striatal hypometabolism.

F-FDG PET/CT imaging is an important diagnostic tool for accurate staging and assessment of response to neoadjuvant chemotherapy (NACT) in patients with locally advanced breast carcinoma (LABC). However, F-FDG being non-specific marker, it also accumulates in inflammatory conditions, leading to false positive results. Angiogenesis, an essential characteristic for tumor development, intrusion and metastasis can be imaged using Ga-labeled RGD tripeptide. We here depict a series of clinically staged LABC patients who underwent both Ga-DOTA-RGD2 and F-FDG PET/CT imaging for staging and illustrate the similarities and significant differences between the two tracers.

Multiple-myeloma (MM) is a malignant plasma cell proliferation disorder and the second most common blood malignancy after non-Hodgkin lymphoma. The chemokine (CXCR-4) receptor analogues are the newer agents being postulated for myeloma imaging and have shown good diagnostic performance. We report a case of plasmacytoma with suspicious renal cell carcinoma, in whom Ga CXCR-4 PET/CT revealed tracer-avid lesion in the left perinephric region. PET/CT-guided biopsy from the tracer-avid lesion revealed plasmacytoma. PET/CT-imaging and guided biopsy using Ga CXCR4 receptor ligand, proved its usefulness for accurate localization of the culprit lesion and helped in definitive management of the patient.

Primary neuroendocrine tumors of the liver are a diagnostic challenge. We present a rare case of primary hepatic neuroendocrine tumor in which Ga-DOTATATE PET/CT imaging played an important role in the diagnosis and follow-up.

Infection of aortic valve-tube graft, although rare, is associated with high morbidity and mortality. Early identification of site and extent of infection is not only challenging but also crucial for adequate patient management and prognostication of disease. Combined clinical, laboratory investigation and imaging modalities assist in the identification of aortic valve graft infection. Molecular imaging techniques like PET/CT using F-FDG and F-FDG-labeled autologous leukocytes (LALs) have improved the sensitivity for detection of infection, resulting in better outcome for these patients. F-FDG-labeled autologous leukocyte PET/CT in our patient after Bentall procedure accurately localized the site and extent of infection.

F-Fluorocholine is a relatively new, extremely versatile radiotracer for detecting proliferative or mitogenic activity. Its diagnostic potential has been explored in cancers of the prostate, liver, esophagus, breast, brain, and lung, as well as lymphoma, sarcoma, melanoma, and parathyroid adenomas. The authors present a case where fluorocholine PET/CT performed for characterizing a space-occupying lesion in the brain revealed intensely tracer-avid skull lesions with intracranial soft tissue component and multiple other skeletal lesions. Fine-needle aspiration cytology from the skull and chest wall lesions confirmed the diagnosis of plasma cell neoplasm.

Primary signet ring cell adenocarcinoma of the breast is a rare neoplasm. Similar to other mucinous neoplasms, it has low FDG avidity and poor prognosis compared with the traditional ductal/lobular carcinomas. We present a case of a 40-year-old woman with signet ring cell adenocarcinoma and skeletal fluorosis showing higher uptake of Ga-prostate-specific membrane antigen in the primary lesion and the metastatic sites compared with F-FDG on PET/CT imaging. Additionally, diffuse increased prostate-specific membrane antigen uptake was noticed in the entire skeleton, likely due to skeletal fluorosis.

Ga-labeled prostate-specific membrane antigen (PSMA) PET/CT is emerging as new reference standard for imaging of prostate cancer because of superb diagnostic performance in disease staging and recurrence detection. However, a number of isolated reports have been published recently regarding the nonspecific uptake of Ga-PSMA in nonprostatic benign or malignant pathologies. We describe the case of a 76-year-old man who underwent Ga-labeled PSMA PET/CT for suspicion of prostate cancer. Whole-body PET/CT of whom revealed tracer avidity in lipomatous lesion involving the left sartorius muscle. Histopathologic examination of lesion revealed a well-differentiated liposarcoma.

Immunoglobulin G4-related disease (IgG4-RD) with multisystem involvement is known to mimic various malignancies and can be diagnosed with high clinical suspicion. We hereby report an atypical case of IgG4-RD, who presented as an inflammatory pseudotumor resembling gall bladder malignancy with hepatic, omental, and subcutaneous involvement. The characteristic tracer uptake pattern described on FDG PET/CT may not be always present in IgG4-RD, especially in the setting of postabdominal surgery. FDG PET/CT revealed the disease progression despite glucocorticoids and aided in response evaluation after second-line drug, rituximab.

Ectopic Cushing syndrome constitutes approximately 10% of all patients with Cushing syndrome. The clinical features of hypercortisolism result from elevated levels of adrenocorticotropic hormone produced by a tumor. The present case presented with clinical and biochemical parameters suggestive of Cushing syndrome with normal pituitary and adrenals on imaging. Ga-DOTANOC PET/CT done to localize an ectopic adrenocorticotropic hormone-producing tumor revealed metastatic medullary carcinoma of the thyroid as the culprit lesion.

We report a case of adenocarcinoma prostate treated previously with radical prostatectomy and hormonal therapy who underwent Ga-labeled prostate-specific membrane antigen PET/CT for recurrence evaluation. In addition to radiotracer uptake in the prostate bed, unusual intense prostate-specific membrane antigen uptake was also noted in the left adrenal gland. With a clinical suspicion of pheochromocytoma, Ga-DOTANOC PET/CT was done, which revealed tracer-avid left adrenal lesion.

IgG4-related disease (IgG4-RD) continues to be a diagnostic challenge and a great mimicker of malignancies. We report here a case of young man who presented with subacute intestinal obstruction with initial imaging and clinical features suggestive of carcinoma colon. F-FDG PET/CT showed diffuse peritoneal carcinomatosis pattern typically seen with abdominal malignancies. However, the histopathology and the raised IgG4 levels diagnosed it to be IgG4-RD. Although F-FDG PET/CT has typical patterns corresponding to the multisystemic involvement of IgG4-RD, the index case did not show any such findings.

PET/CT with Ga-labeled prostate-specific membrane antigen (PSMA) is increasingly recognized as the best imaging modality for disease staging and detection of recurrent prostate cancer. Despite its name, PSMA expression has been reported in a number of nonprostatic benign and malignant pathologies. Apparently, angioneogenesis is the mechanism attributed to increased Ga-PSMA uptake at these sites. Here we illustrate the utility of Ga-PSMA in 5 nonprostatic malignancies that could open up new possibilities for diagnostics and theranostic concepts with PSMA labeled radioligands in nonprostate tumor entities.

The male breast cancer is very less common as compared with the female breast cancer. We report a case of 64-year-old man who presented with the history of lower urinary tract symptoms. The digital rectal examination revealed hard and nodular prostate, and serum prostate-specific antigen level was 23.4 ng/mL. Ga-labeled prostate-specific membrane antigen PET/CT revealed prostate-specific membrane antigen-expressing lesions in the prostate, axillary tail of the right breast, and axillary lymph nodes. Histology from prostate revealed prostate carcinoma, whereas fine-needle aspiration from the breast revealed invasive ductal carcinoma of the breast.