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Tumour sampling is indispensable to diagnostic and therapeutic decision making. Thus, 18F-FDG PET/CT has the potential to accurately discriminate between viable and non-viable tissues due to its ability to characterise the metabolism of visible tissues. This study’s objective was to evaluate the incremental utility of 18F-FDG PET-CT-guided metabolic biopsy in individuals with suspected lesions and a previous negative anatomical biopsy. This study included a total of 190 consecutive patients with probable malignancy and who had experienced a previous unsuccessful anatomical biopsy who underwent PET-CT-guided metabolic biopsy. We retrospectively analysed the patients’ medical records and imaging investigations to assess demographics, complications, pathologies, and final clinical diagnoses. Using multivariate logistic regression, correlation between several confounding factors that lead to post-procedural problems was evaluated. Adequate material was obtained in all patients, and 162 (85%) were found to be positive for malignancy with a diagnostic yield of 96.9%. In 25 (13.1%) patients, post-procedural complications were reported, with pneumothorax being the most prevalent issue. In evaluating oncological patients, metabolic biopsy provides a safer alternative therapy with a high diagnostic yield and comparable complications. PET-CT, being an essential component of cancer staging, may serve as a one-stop shop for the management of these patients’ conditions.

Neoplastic causes account for approximately 10% to 20% cases of PUO (pyrexia of unknown origin). The mechanisms by which malignancies induce fever are not fully understood. The release of pyrogenic cytokines either directly from tumor cells or from macrophages responding to tumor are likely to play a major role, which acts on the hypothalamus, causing a change in the thermostatic set point. We present a case of recurrent glioblastoma multiforme, who presented with PUO. 18F-FDG-labeled leukocyte PET/CT scan done for localization of infective focus demonstrated significant tracer accumulation at the periphery of the recurrent brain lesion. Subsequent excisional biopsy from the lesion was suggestive of noninfected recurrent glioblastoma multiforme.

Ovarian carcinomas generally metastasize within the peritoneal cavity due to exfoliation of malignant cells from primary tumor. Metastasis to the breasts is an unusual event and may mimic primary neoplastic disease. Usually, breast metastasis presents as a single isolated, well-circumscribed soft tissue lesion, and serous papillary carcinoma is the most common type of ovarian tumor that can metastasize to the breast. Concurrent bilateral breast metastasis is rare event. We present a follow-up case of metastatic carcinoma ovary, demonstrating FDG-avid soft tissue density masses in the bilateral breast parenchyma along with bilateral axillary lymphadenopathy, biopsy of which revealed metastatic deposits from carcinoma ovary.

Differentiating infection and sterile inflammation is the main clinical concern of clinicians as they are closely related to each other. Although 18 F-FDG PET/CT imaging is widely used, its main disadvantage is its lack of specificity to discriminate aseptic from septic inflammation. 18 F-WBC PET/CT scan is a promising tool for the accurate diagnosis of infection owing to its high specificity. The aim of the present study is to determine the utility of 18 F-WBC PET/CT in the diagnosis of occult infections and to assess its incremental value over routine 18 F-FDG PET/CT scan.This prospective observational diagnostic accuracy study included 33 patients with fever of unknown origin or suspected periprosthetic infection and raised C-reactive protein and total leukocyte count. All the patients underwent both 18 F-WBC PET/CT scan and 18 F-FDG PET/CT scan using a standard protocol on 2 different days. Images of both the scans were evaluated by both visual analyses based on uptake intensity and quantitative grading based on lesion-to-background SUV max values. For interpretation of FDG PET/CT images, visual scoring of grade 0 (undetectable or no uptake), grade 1a (less than liver uptake), grade 1b (equivalent to liver uptake), grade 2 (higher than liver uptake), and grade 3 (higher than cerebellum uptake) was used. 18 F-WBC PET/CT images were also interpreted visually as grade 0 (undetectable or no uptake), grade 1a (significantly less than lumbar vertebrae or liver uptake for truncal lesions, and in case of extremity lesion slightly higher than neighboring soft tissue uptake or less than neighboring bone marrow uptake), grade 1b (equivalent to liver or lumbar vertebrae uptake for truncal lesions, and in case of extremity lesion significantly higher than neighboring soft tissue uptake or higher than neighboring bone marrow uptake), grade 2 (higher than liver or bone marrow uptake), and grade 3 (higher than twice the liver or bone marrow uptake). Similarly, a quantitative grading was also done based on lesion-to-background SUV max using a circular region of interest manually drawn. For both 18 F-FDG and 18 F-WBC PET/CT, the lesion-to-background ratio of1.5 was recorded as grade 0, 1.5-2.5 as grade 1a, 2.5-3.5 as grade 1b, 3.5-4.5 as grade 2, and4.5 as grade 3. Final diagnosis was made by histopathological, microbiological analysis, or clinical-radiological workup.Twenty-nine foci of suspected infection were found in 25/33 patients by either 18 F-FDG PET/CT or 18 F-WBC PET/CT scan. No abnormal uptake of either 18 F-FDG or 18 F-FDG WBC scan was seen in 8 patients. There was a concordance of 18 F-FDG PET/CT and 18 F-WBC PET/CT in 28 sites each using grade 1b of visual and quantitative analysis, respectively. Of the 29 suspicious infected foci, 18 were proven positive for infection (14/18 sites by the histopathological/microbiological culture and the rest 4/18 sites by clinical/radiological workup). Culture of aspirates or biopsy from 11/29 suspicious sites was proven noninfective. Seven of 11 suspicious sites were proven noninfective by clinical/radiological workup. The mean clinical follow-up was 8 months (1-15 months).Overall significantly higher diagnostic accuracy was demonstrated with 18 F-WBC PET/CT in comparison to 18 F-FDG PET/CT for the detection of infection ( P0.05). The highest diagnostic accuracy of 18 F-WBC PET/CT scan was reported with both grade 1b of visual as well as of quantitative analysis (lesion-to-background SUV max , 2.5-3.5) and grade 2 for both visual and quantitative analysis for 18 F FDG PET/CT.18 F-WBC PET/CT has a higher diagnostic accuracy over 18 F-FDG PET/CT for the diagnosis of occult infection.

Prostatic malignancy is the most common type of nonskin cancer and associated with significant morbidity and mortality. Early androgen deprivation therapy (ADT) is the treatment of choice in metastatic prostate cancer, whereas ADT delays progression of disease, but it is associated with significant adverse effects and frequently impairs the quality of life. Therefore, there is growing interest in treatments to postpone ADT while achieving a good progression-free survival. We present a case of oligometastatic prostate cancer, who was treated upfront with 177Lu-labeled PSMA radioligand therapy and demonstrated excellent response to a single dose of 177Lu-PSMA-617.

Occurrence of invasive fungal infections has gained significant attention during recent times in patients with COVID-19. Patients with severe form of COVID-19, such as those treated in the intensive care unit with prolonged steroid use, are particularly vulnerable to secondary bacterial and fungal infections. Disseminated systemic mycosis is a life-threatening condition, especially in immunocompromised patients. Here, we report a case of a recovered severe COVID-19 patient, who presented with persistent fever. 18F-FDG-labeled leukocyte scan revealed focal accumulation of radiotracer in the small intestine and right lung lower lobe. Subsequently, performed biopsy revealed mucormycosis.

PURPOSE To study the imaging patterns of Posterior cortical atrophy (PCA) and Dementia with Lewy bodies (DLB) on fluoro-deoxyglucose positron emission tomography computed tomography ([F]FDG PET/CT), identify areas of overlap and differences and to develop a prediction model to assist in diagnosis using univariate and multivariate analysis. METHODS A retrospective analysis of 72 patients clinically suspected of having posterior dementia was done. All patients underwent [FF]FDG PET/CT of the brain and dopamine transporter imaging with [[Tc]TRODAT-1 SPECT scan on separate days. The patients were divided into PCA with normal TRODAT uptake (n=34) and DLB with abnormal TRODAT uptake (n=38). The FDG PET/CT uptake patterns were recorded and areas of significant hypometabolism by z score analysis were considered as abnormal. Receiver operator characteristics (ROC) curve analysis was used to determine cutoff z scores and binary logistic regression analysis was used to determine the Odds ratio of being in the predicted groups. RESULTS Significantly hypometabolism was found in parieto-temporo-occipital association cortices and cingulate cortices in PCA patients. DLB patients showed significantly reduced uptake in the visual cortex. No significant difference was found between z score of occipital association cortex which showed hypometabolism in both groups. The cut-off z-score values derived from the ROC curve analysis were as follows- parietal association (cut-off-3, sensitivity-65.6%, specificity - 68.7%), temporal association (cut-off-2, sensitivity-78%, specificity-75%) and posterior cingulate (cut-off-0.5, sensitivity-93.7%, specificity-40.6%), their respective Odds ratio (with 95% confidence interval) for being in the PCA group as derived from univariate logistic regression were 3.66 (1.30-10.32), 10.71 (3.36-34.13) and 7.85 (1.57-39.17). The cut-off z score of primary visual cortex as derived from ROC curve was zero with sensitivity of 87.5%, specificity of 71.9%, and the Odds ratio for being the in the DLB group was 24.7 with 95% confidence interval of 5.99-101.85. CONCLUSION [F]FDG PET may be useful as a non-invasive diagnostic modality in differentiating the two posterior cortical dementias, despite significant overlap. Primary visual cortical hypometabolism can serve as an independent diagnostic marker for DLB, even in the absence of TRODAT imaging.

Background: Fluorine-18-fluorodeoxyglucose (18F-FDG)-positron emission tomography/computed tomography (PET/CT) is emerging as a useful imaging modality in suspected large-vessel vasculitis (LVV), owing to its ability to accumulate at the sites of inflammation within the arterial walls. However, there remains scope for standardization of reporting criteria to ensure reproducibility. Recently, a semiquantitative scoring system called “total vascular score” (TVS) has been suggested as a method to standardize and harmonize FDG PET/CT evaluation in LVV patients. The purpose of this study was to assess the clinical utility of the proposed semiquantitative grading scale in LVV patients. Materials and Methods: Patients presenting with clinical symptoms of vasculitis, who had undergone a baseline FDG-PET/CT were evaluated. 18F-FDG uptake in the major vessels was quantified with standardized uptake values (SUVsmax) using four-point scale by three independent nuclear physicians. TVS was calculated based on the calculation of the vascular uptake values with respect to mediastinal blood pool and liver uptake and the number of vessels involved. Results: A total of 106 PET-positive patients (74 males and 32 females) were evaluated. The most frequently involved vessels were thoracic aorta >abdominal aorta >subclavian arteries with mean SUVmax values of 4.05, 3.12, and 2.70, respectively. Mean TVS was 13.18 ± 3.4 (range 03–19) among 276 involved vessels. TVS showed significant positive correlation with erythrocyte sedimentation rate (r = 0.82; P < 0.005). 18 patients showed periarticular FDG uptake, with shoulder joint being the most commonly involved joint. Conclusion: The simplified visual and semiquantitative grading scale for interpretation and reporting classification provides better objectivity in diagnosis, communication with referring clinicians, and planning in patients of LVV.

Laparoscopic resection of tumor is often performed for benign and small insulinomas, or for those located in the body or tail of the pancreas. The precise preoperative and intraoperative localization of the insulinoma is critical to minimize the surgical intervention. Conventional imaging studies, i.e., MRI, CT, and endoscopic ultrasound have limited sensitivity due to the small size of the insulinomas. Angiography, intraarterial calcium stimulation, and venous sampling are invasive procedures with concomitant risk for complications. Exendin-4 PET/CT scan has shown to be of great value in preoperative localization of insulinomas. In the absence of the traditional gold standard, i.e., intraoperative ultrasound with manual palpation, in laparoscopic surgery, a simple enucleation procedure might not be possible. Gamma probe-assisted surgery is a new method of diagnosis and treatment which allows a small area of tissue to be identified and removed, while a large area of the organ or the system remains unaffected. We present a case of a 34-year-old man with clinical suspicion of insulinoma with negative conventional imaging and successful lesion localization with (68)Ga-Exendin-4 PET/CT scan in the pancreatic body, who underwent laparoscopic enucleation of the lesion with the aid of a hand-held gamma detecting probe.

We report a case who presented with facial swelling and breathlessness. Recent chest X-ray was suggestive of soft-tissue in the mediastinum. In view of the suspicion of mass being neoplastic, the patient was referred for positron emission tomography-computed tomography (PET-CT) scan. Whole-body fluorodeoxyglucose (FDG) PET-CT scan revealed a mildly FDG-avid large lobulated soft-tissue mass in the anterior mediastinum, seen to arising from right lobe of the thyroid gland, extending into the right hemithorax. Histopathological examination of the mass was compatible with adenomatous hyperplasia of the thyroid. Here, we report an unusual case of isolated single lobe hyperplasia of the thyroid gland, masquerading as an anterior mediastinal mass.

Phase analysis using gated single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) is a relatively new tool for the assessment of ventricular synchrony. Hypertension, diabetes, renal diseases, and dyslipidemia may affect the phase parameters though their impact is not well understood. The present study aimed to evaluate the incidence of the left ventricular mechanical dyssynchrony (LVMD) in end-stage renal disease (ESRD) patients with normal gated SPECT-MPI and QRS duration (

Purpose The aims of this study were to evaluate Tc-TRODAT-1 SPECT imaging patterns and to assess their correlation with disease severity in clinically diagnosed patients of Parkinson disease (PD). Methods The study included 241 patients with clinically diagnosed idiopathic Parkinson disease who underwent Tc-TRODAT-1 SPECT/CT scan. Binding ratios were calculated for each striatum, caudate, and putamen individually, by drawing region of interest. Occipital cortex region of interest was taken for background correction. Correlation of binding ratio with increasing clinical stage was derived, as described by modified Hoehn and Yahr scale. Results Median binding ratio was least in the contralateral putamen for all stages of modified Hoehn and Yahr. A statistically significant negative correlation was found between increasing disease severity and binding ratio in all subregions of striatum. Patients were clinically categorized into postural instability and gait disorder group and tremor-dominant PD group. No significant asymmetry was found between the left and right striatum in patients belonging to postural instability and gait disorder group and in those with bilateral tremors without lateralization. Conclusions Tc-TRODAT-1 SPECT is useful in early detection and in assessing disease severity of PD. A significant asymmetry with the contralateral side being affected more than the ipsilateral side can be attributed to tremor-dominant patients. The binding ratio of the ipsilateral striatum may serve useful as a marker of remaining functional dopaminergic neuronal reserve in the striatum.

Malignant melanoma is a highly aggressive tumor and surgical resection is the primary treatment. However, the chances of recurrence are quite high despite complete resection. The aim of study was to evaluate the 18F-fluorodeoxyglucose(18F-FDG) positron emission tomography–computed tomography (PET/CT) in detection of recurrent melanoma after curative surgery and its prognostic value. Fifty-four melanoma patients (32 women) with prior primary lesion resection were evaluated with 18F-FDG PET/CT for clinically suspicious recurrent disease. The diagnostic accuracy of 18F-FDG PET/CT (visual interpretation as well as semi-quantitative parameter) was determined on the basis of subsequent imaging and clinical follow-up. Melanoma-specific survival and risk of progression (hazard ratio [HR]) were assessed using Kaplan–Meier method and Cox regression analysis.18F-FDG PET/CT detected recurrent diseases in 36 (66%) patients including distant metastases in 13 patients and second synchronous malignancy in 2 patients. Overall, the sensitivity, specificity, positive predictive value, and negative predictive value of 18F-FDG PET/CT were 91.2%, 80.0%, 88.6%, and 84.2%, respectively, with area under the curve of 0.86 (95% confidence interval: 0.74–0.97; P < 0.05). Positive 18F-FDG PET/CT study was associated with a significantly shorter overall survival than negative study (30.8 ± 4.6 vs. 64.5 ± 6.9 months, P < 0.05). Apart from positive 18F-FDG PET/CT scan, maximum standardized uptake value (SUVmax) >2.7 and combination of both were independently associated with an increased risk of disease progression (HR = 7.72, 21.58, and 11.37, respectively; P < 0.05).18F-FDG PET/CT showed enhanced diagnostic performance in patients with suspicious recurrent malignant melanoma leading to appropriate management. FDG positivity along with SUVmax >2.7 provides important prognostic value in predicting the survival outcomes and assessing the risk of disease progression.

Skin metastases are rare from systemic malignancy, and incidence reported is between 0.7% and 9% in various malignancies and usually occur in advanced stage. Here, we report three cases, one each of carcinoma esophagus, carcinoma breast, and carcinoma lung, where patients presented with metastatic cutaneous lesions and positron-emission tomography-computed tomography (PET-CT) scan whole body helped in localizing the primary site. Whole-body fluorodeoxyglucose PET-CT scan helps in scanning whole body at once and detect occult primary and metastatic sites.

To test whether phase analysis indices from SPECT-MPI for left ventricular mechanical dyssynchrony (LVMD) are predictors of major adverse cardiac events (MACEs) in long-standing diabetes mellitus (DM). A total of 136 DM patients with normal perfusion and left ventricular systolic functions were followed up for about two years and divided into two groups according to the presence and the absence of MACEs. Thirteen (9.5%) patients experienced MACEs during follow-up. Patients experiencing MACEs showed significantly higher phase standard deviation (PSD) and wider phase bandwidth (PBW) than those who did not. Moreover, both PSD and PBW showed significant correlations (r = 0.25 and 0.27; P

We present a case of papillary thyroid cancer (post-thyroidectomy status) on regular treatment with suppressive Levothyroxine therapy. On follow-up at 6 months after radioactive iodine ablation for remnant thyroid tissue, her thyroglobulin, and anti-thyroglobulin levels were 0.06 ng/ml and 670 IU/ml, respectively. Low-dose whole-body I-131 scan was negative. To look for the cause of isolated increased anti-thyroglobulin level, a whole-body (18)F-FDG PET/CT was done which revealed multiple FDG-avid lytic skeletal lesions suggestive of metastases. For confirmation of diagnosis, (18)F-FDG PET/CT-guided metabolic biopsy was done, which revealed Langerhans’ cell histiocytosis on histopathological examination.

A 57-year-old man, on octreotide treatment for metastatic neuroendocrine tumor pancreas, was referred for whole-body Ga-DOTANOC PET/CT scan to evaluate treatment response. PET/CT scan revealed DOTANOC-avid lesion in the head of the pancreas with multiple tracer-avid soft tissue lesions in the liver, bilateral adrenal glands, and periportal lymph nodes. In addition, diffuse intense DOTANOC-avid mural thickening with intraluminal polypoidal mass formation was noted within the stomach causing significant luminal compromise, histopathological examination of which turned out be hypertrophic hypersecretory gastropathy. This case highlights the possibility of overexpression of somatostatin receptors in gastric hypertrophy, which has been little explored in literature.

We report a clinically asymptomatic, old treated case of carcinoma rectum, presenting with raised serum carcinoembryonic antigen level, referred for F-FDG PET/CT scan for restaging. Whole-body PET/CT scan revealed an isolated FDG-avid lesion in the left labia majora region, which on histopathology was found to be metastasis from carcinoma rectum. Subsequent F-FDG PET/CT done after 4 cycles of chemotherapy revealed favorable response to therapy. F-FDG PET/CT facilitates the detection of unusual site of metastasis and its subsequent response evaluation in the index case.

Objective: The aim of the present study was to perform calculation of the absorbed doses to organs at risk and to neuroendocrine tumors and to determine whether hepatic intra-arterial (IA) injection of 177Lu-DOTATATE Peptide Receptor Radionuclide Therapy (PRRT) would achieve higher intratumoral concentrations than standard intravenous administration of 177Lu-DOTATATE. Methods: 29 patients with Grade I-II, inoperable, metastatic gastro-entero-pancreatic neuroendocrine tumor (GEPNET) were prospectively identified and enrolled for the study. 15 patients of GEPNETs with liver-dominant metastatic disease and less than 3 sites of extrahepatic metastatic disease were administered a single dose of 177Lu-DOTATATE therapy through the selective catheterization of the hepatic artery (IA group). The other 14 patients received a single dose of 177 Lu- DOTATATE through standard intravenous route (IV group). For dosimetry, whole-body γ (anterior and posterior planar acquisitions) and SPECT/CT scans of the abdomen at 2, 24 and 96 h post 177Lu-DOTATATE administration were acquired. Dosimetric calculations were done using the HERMES software. Results: The mean dose per unit activity (DpA) in the liver and tumor lesions in the IA group differed significantly (p < 0.05) but differed insignificantly in spleen and kidneys (p > 05) with the IV group. The mean tumor/non-tumor concentration at 96 h was 76.83 ± 7.9 (range 10.2–251.3) in the IA group whereas it was 25.6 ± 5.9 (Range: 12–55) in the IV group. There was an average threefold increase in tumoral concentration over the standard intravenous group. Conclusion: IA administration of 177Lu-DOTATATE results in higher concentration and absorbed dose in hepatic metastases in patients of GEPNETs as compared to a single dose of PRRT administered through standard IV route, and thus seems to be a powerful tool to improve the efficacy of PRRT. Advances in knowledge: Measurement of the dose received by the tumor lesions and the critical organs is of paramount importance for the prognostication of a radionuclide therapy. Scant data exist on the dosimetric impact of IA administration of the therapy with 177Lu-DOTATATE on the tumors and other organs, and this study would add an impact towards the better treatment outcome in patients of neuroendocrine tumor with liver-dominant metastatic disease.

Glioblastoma multiforme is one of the most common malignant types of tumor arising from the central nervous system known for its devastating intracranial progress and dismal prognosis. Macroscopically evident and symptomatic spinal cord metastasis detected with FDG PET/CT imaging is a rare event. We present a rare case of symptomatic diffuse spinal metastases of glioblastoma multiforme in a 25-year-old woman, who has been previously treated surgically with gross tumor resection followed by adjuvant radiotherapy and chemotherapy with temozolomide.

The purpose of the study is to find out the overall incidence of superscan among different type of cancers, causes of superscan and its relationship with other parameters such as age, sex, duration of disease, and serum alkaline phosphatase (ALP) levels. This was a retro-prospective study. Records of all previous bone scans and reported patients of superscan were re-evaluated retrospectively. Patients who were diagnosed as having superscan in the preceding 3 years with confirmed histopathological diagnosis were included in the retrospective group. In the prospective group, all the patients who were reported to have superscan appearance over the past 2 years of prospective period were included. Total of 6027 bone scans were examined in a 5-year period and out of which 80 cases were diagnosed as superscan. The overall incidence of superscan in different type of cancers was 1.3% (80/6027). Prostate cancer (46/80) was the most common cause of superscan appearance followed by breast cancer (10/80). Out of 6027 patients referred for bone scan, 307 patients had prostate cancer on histopathological examination. Out of 307 patients with prostate cancer, 46 had superscan appearance. Incidence of superscan in prostate cancer was 14.98% (46/307), and 71.73% (33/46) prostate cancer patients with superscan had Gleason score of 8 and above 8 with mean serum prostate-specific antigen level was 178.42 ng/ml in symptomatic patients and 122 ng/ml in asymptomatic patients. Out of all patients with superscan, 71 patients (88.7%) had elevated serum ALP levels. Overall incidence of superscan in our study was 1.3% in different type of cancer patients, and the most common cause of superscan appearance was prostate cancer. Incidence of superscan appearance in prostatic cancer patients was 14.98%.

A 63-year-old man, recently diagnosed with carcinoma of the prostate (Gleason's score 4+4), with serum prostate-specific antigen 189.2 ng/mL, underwent Ga PSMA PET/CT scan for pretreatment staging. The study revealed abnormal tracer uptake in the prostatic bed region, the pelvic, abdominal, and mediastinal lymph nodes and diffuse metastases to the bilateral lungs. The lung metastasis was proved to be metastatic adenocarcinoma from analysis of bronchoalveolar lavage.

Malignant melanoma is a highly aggressive tumor and surgical resection is the primary treatment. However, the chances of recurrence are quite high despite complete resection. The aim of study was to evaluate the 18F-fluorodeoxyglucose(18F-FDG) positron emission tomography–computed tomography (PET/CT) in detection of recurrent melanoma after curative surgery and its prognostic value. Fifty-four melanoma patients (32 women) with prior primary lesion resection were evaluated with 18F-FDG PET/CT for clinically suspicious recurrent disease. The diagnostic accuracy of 18F-FDG PET/CT (visual interpretation as well as semi-quantitative parameter) was determined on the basis of subsequent imaging and clinical follow-up. Melanoma-specific survival and risk of progression (hazard ratio [HR]) were assessed using Kaplan–Meier method and Cox regression analysis. 18F-FDG PET/CT detected recurrent diseases in 36 (66%) patients including distant metastases in 13 patients and second synchronous malignancy in 2 patients. Overall, the sensitivity, specificity, positive predictive value, and negative predictive value of 18F-FDG PET/CT were 91.2%, 80.0%, 88.6%, and 84.2%, respectively, with area under the curve of 0.86 (95% confidence interval: 0.74–0.97; P < 0.05). Positive 18F-FDG PET/CT study was associated with a significantly shorter overall survival than negative study (30.8 ± 4.6 vs. 64.5 ± 6.9 months, P < 0.05). Apart from positive 18F-FDG PET/CT scan, maximum standardized uptake value (SUVmax) >2.7 and combination of both were independently associated with an increased risk of disease progression (HR = 7.72, 21.58, and 11.37, respectively; P < 0.05). 18F-FDG PET/CT showed enhanced diagnostic performance in patients with suspicious recurrent malignant melanoma leading to appropriate management. FDG positivity along with SUVmax >2.7 provides important prognostic value in predicting the survival outcomes and assessing the risk of disease progression.

A 28-year-old female presented with an incidentally detected mediastinal mass, found on routine chest X-ray. 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) was advised to plan course of further management. FDG-PET/CT findings were suggestive of an FDG-avid soft-tissue mass in the left posterior mediastinum in paravertebral location with left pleural effusion. Overall, PET/CT scan findings favored the possibility of a nerve sheath tumor. However, histopathology along with immunohistochemistry confirmed the diagnosis of Castleman disease.

A 68-year-old man, a known case of carcinoma prostate (Gleason score 4 + 4), status post transurethral resection of prostate cancer and radiotherapy, on hormonal treatment with rising prostate-specific antigen 9.0 ng/mL and penile swelling underwent Ga-PSMA PET/CT scan for metastatic workup and restaging. The study revealed abnormal tracer uptake in the prostatic bed region, the pelvic and inguinal lymph nodes, and metastases to the glans of penis and scrotum. The penile and scrotal lesion was proved to be metastatic adenocarcinoma from prostate on fine-needle aspiration cytology.

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.

Ga-labeled prostate-specific membrane antigen ligand PET-CT has emerged as a promising technique to evaluate the extent of disease in patients with prostate carcinoma. We are reporting a 63-year-old man with prostatic carcinoma subjected to Ga-prostate-specific membrane antigen ligand PET-CT for initial staging. In addition to the radiotracer uptake in known primary site (prostate), focal increased radiotracer uptake was also noticed in the left breast. Subsequent biopsy of the breast lesion revealed PASH (pseudoangiomatous stromal hyperplasia), which is a benign mesenchymal proliferative lesion that may present clinically as palpable mass requiring further evaluation to rule out malignancy.

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.

Testicular torsion is a common differential diagnosis of acute scrotal pain along with acute epididymo-orchitis, which may lead to testicular non-viability. Doppler ultrasound and testicular scintigraphy are two routinely used modalities for the assessment of testicular viability. However, in some cases, these investigations may prove inadequate in differentiating between the two entities with widely differing management. Here, we present a case of a 52-year-old male with questionable viability of testis, who was investigated initially using testicular scintigraphy and was further subjected to a regional 18F-FDG PET/CT scan, in view of inconclusive findings with the conventional modalities.

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.

Background: Phase analysis can be easily performed by different software to assess the left ventricular dyssynchrony from gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) with high precision. However, the normal values of histogram bandwidth (HBW) and phase standard deviation (PSD) and their comparison using different programs have not been fully elucidated and actively being evaluated at present. The aim of this study was to determine the phase analysis parameters values and to compare the phase indices of two commonly used programs in a group of patients with normal gated SPECT-MPI. Methods: Phase parameters were retrospectively evaluated in 138 consecutive nondiabetic patients having a normal gated SPECT-MPI using the quantitative gated SPECT (QGS) and Emory Cardiac Toolbox (ECTb) software. HBW, PSD, and phase entropy were calculated separately using both programs. Results: The fair correlation between software programs was observed. HBW and PSD in QGS and ECTb were 26.20 ± 9.7 and 25.46 ± 8.0 (r-value. 56, SEE 6.65) and 6.64 ± 2.5 and 7.65 ± 2.5 (r = 0.54, SEE 2.14), respectively. The value of phase entropy in QGS program was 45.08 ± 6.3. A fair correlation between phase entropy and PSD in QGS was observed (r = 0.44, 95% confidence interval-0.29–0.56). Conclusion: Phase analysis parameters derived from gated SPECT-MPI in patients with normal myocardial perfusion are program dependent and may differ. The results cannot be interchangeably used in the same patients.

Assessment of left ventricular mechanical dyssynchrony (LVMD) using phase analysis of gated SPECT-MPI is well established. However, there is little information about the influence of diabetes mellitus on phase analysis. The present work was to evaluate the LVMD in longstanding type II diabetes mellitus (DM) patients with normal gated SPECT-MPI. Retrospective analysis of 146 (86 type II diabetics for > 5 years’ duration and 60 nondiabetics) consecutive patients with normal gated SPECT-MPI and adequate LVEF was done. Sixty age- and sex-matched nondiabetic served as control. LVMD was determined from the cutoff values (> mean + 2 SD) observed for phase standard deviation (PSD) and phase bandwidth (PBW) from the control subjects. Multivariate logistic regression analysis was applied to assess the correlation between various confounding factors. LVMD was detected in 24 (28%) diabetic patients with the pre-defined cut-off values for PSD (> 10.8) and PBW (> 35.6) derived from the controls. Hyperlipidemia, overweight/obesity, duration of DM and its long-term complications were independently associated with LVMD, with long-term complications being the highest risk factor (OR 28.00; P

Neonatal cholestasis is a common cause of jaundice among newborns. Hepatobiliary scintigraphy plays an important role in the diagnosis of neonatal cholestasis by ruling out extrahepatic biliary atresia, which is one of the common causes. Phenobarbitone and ursodeoxycholic acid (UDCA) have been used to improve the specificity of hepatobiliary scintigraphy in ruling out obstructive causes of neonatal cholestasis syndrome (NCS). The present study was undertaken to compare the utility of phenobarbitone and UDCA in augmenting hepatobiliary scintigraphy in the evaluation of NCS.Seventy-four consecutive patients with NCS referred for hepatobiliary scintigraphy were initially subjected to a baseline scan. Twenty patients showed tracer activity in the intestine within 24 h after injection, thus ruling out obstructive cholestasis. Fifty-four patients who did not show any tracer activity in the intestine were categorized as nonexcretors. Four nonexcretors were lost to follow-up and were excluded from the study. Fifty nonexcretors showing scan features suggestive of obstructive cholestasis were further randomized into those receiving phenobarbitone (n=20), UDCA (n=20), or placebo (n=10). These groups were further evaluated with drug-augmented hepatobiliary scintigraphy, after premedication, for any excretory activity in the intestine.Out of 50 patients who were evaluated with drug-augmented hepatobiliary scintigraphy two patients from the phenobarbitone group and one patient each from UDCA and placebo groups showed a change in excretory pattern from the baseline scan. However, these results were statistically nonsignificant (P=1.00). In the present study, drug-augmented (phenobarbitone or UDCA) hepatobiliary scintigraphy did not seem to improve the results (negative predictive value) for ruling out an obstructive cause of neonatal cholestasis.

Co-existence of thyroid nodules with Graves' disease has been reported in various studies. 10-15% of such nodules harbor thyroid cancer with papillary thyroid cancer being the commonest. Medullary thyroid cancer (MTC) in nodules associated with Graves' disease is rare. On literature survey, we came across 11 such cases reported so far. We report a 62-year-old female with Graves' disease who also had a thyroid nodule that on fine-needle aspiration cytology and the subsequent postthyroidectomy histopathological examination was reported to be MTC.

We report a case of 23-year-old man who presented with complaints of progressive abdominal distension for the past 3 months along with the loss of appetite and weight and had a large solid cystic mass in the left half of the abdominal cavity revealed on ultrasonography and contrast-enhanced CT of the abdomen. Subsequent biopsy and histopathology revealed it to be neuroblastoma. Ga-DOTANOC PET/CT scan performed to rule out distant metastasis showed intense radiotracer uptake distributed throughout the skeleton, mimicking a super scan.

A 28-year-old female presented with an incidentally detected mediastinal mass, found on routine chest X-ray. 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) was advised to plan course of further management. FDG-PET/CT findings were suggestive of an FDG-avid soft-tissue mass in the left posterior mediastinum in paravertebral location with left pleural effusion. Overall, PET/CT scan findings favored the possibility of a nerve sheath tumor. However, histopathology along with immunohistochemistry confirmed the diagnosis of Castleman disease.

Early diagnosis is imperative for adequate management of patients with osmotic demyelination syndrome (ODS), which is usually a result of rapid shifts of osmolality secondary to rapid correction of hyponatremia. Magnetic resonance imaging (MRI) with its special sequences is the investigation of choice for early detection of the osmotic changes in the brain. We report a case of clinically suspected ODS with noncontributory MRI and positive fluoro-2-deoxy-d-glucose positron emission tomography (FDG PET) scan with statistical parametric mapping (SPM) analysis, which localized the focal hypermetabolism in the basal ganglia, thalamus, pons, and cerebellum.

Ollier's disease is characterized by multiple skeletal enchondroma. There are published data regarding Ollier's disease being associated with vascular malformations and non-skeletal neoplasms. We report a case of Ollier's disease in a young male associated with osteochondroma, low grade glioma in the insular cortex of brain and Gilbert's syndrome. Technetium-99m methylene diphosphonate whole body bone scan is a sensitive investigation to ascertain the complete extent of skeletal involvement particularly the asymptomatic sites.

Technetium-99m sestamibi MPS is a commonly employed imaging study for myocardial perfusion; however, incidental extracardiac sestamibi uptake requires further evaluation, and the tracer uptake in the thorax/mediastinum may be pathological. The authors present a case of significant extra-cardiac uptake seen on stress MPS images helping in the incidental detection of bronchial carcinoid.

We report a case of clinically asymptomatic patient of prostate cancer who was previously subjected to radical prostatectomy presenting with a rising serum prostate-specific antigen level of 6.6 ng/mL. Whole-body PET/CT with Ga-labeled prostate-specific membrane antigen ligand was performed to assess for disease recurrence, which revealed an intense tracer uptake in a soft tissue mass in left hemithorax mimicking lung metastasis; which later turned out to be splenic tissue.

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.