Multiple Synchronous Thoracoabdominal Duplication Cysts With Ectopic Gastric Mucosa Detected on 99mTc-Pertechnetate Scintigraphy and SPECT/CT.

ABSTRACT: Thoracoabdominal duplication cysts are a congenital malformation of the posterior primitive foregut with synchronous thoracic and abdominal duplication cysts being found in up to 15% of cases. The presentation of duplication cysts depends on their location, size, and other factors, like the presence of ectopic functioning gastric mucosa, which is reported in 20%-30% of duplication cysts. 99mTc-pertechnetate scintigraphy along with SPECT/CT helps in the preoperative localization of ectopic functioning gastric mucosa in these duplication cysts. We report the scintigraphic and SPECT/CT findings of one such case, which helped in the final diagnosis and management of the patient.

SISCOS in focal cortical dysplasia: localization and comparative analysis with MRI.

PURPOSE: This study evaluates the efficacy of SISCOS (Subtraction ictal-interictal SPECT coregistered to SPECT) in localizing the epileptogenic zone (EZ) in focal cortical dysplasia (FCD), comparing its predictive performance with MRI and post-surgical outcomes based on ILAE classification. METHODS: 84 patients with drug refractory epilepsy (DRE) who were operated and had histopathology consistent with FCD, were included in the study. All patients had undergone a complete work-up including SISCOS and MRI for EZ localization, followed by discussion in the multidisciplinary epilepsy surgery meeting prior to surgery. Ictal & interictal perfusion SPECT studies were performed with Tc-99 m Ethylene Cysteinate Dimer (Tc-99 m ECD) followed by SISCOS analysis using SPM2 and Bioimage Suite 2.6. Concordance for localization was determined by comparing with the surgical resection site and post-surgical outcomes were assessed using the ILAE classification. RESULTS: The concordance for EZ localization demonstrated by SISCOS was 73.8% and MRI was 82.1%. 52 patients (61.9%) had good surgical outcome and 31(59%) of these were FCD type 2. In patients with discordant MRI findings, SISCOS was able to provide localisation in 86% (13/15), with 69.2% showing good surgical outcomes. Sensitivity of SISCOS and MRI was 73% (95% CI = 59-84.8%) and 78% (95% CI = 67.5-90.3%) respectively with no significant difference between the two. In FCD type I, both SISCOS and MRI revealed a similar a sensitivity of 76.4% (95%CI = 50.1-93.2%). Concordant cases exhibited higher seizure-free odds ratios for both modalities. CONCLUSION: SISCOS is effective in localizing the EZ in FCD patients, comparable to MRI. Integrating SISCOS and MRI enhances lesion detection, especially in MRI discordant cases. A comprehensive diagnostic approach utilizing SISCOS and MRI can optimize the non-invasive pre-surgical assessment in DRE thereby guiding surgical decision-making in a resource-limited setting.

New PET Tracers for Symptomatic Myeloma.

Multiple myeloma (MM) is a hematologic malignancy characterized by the clonal proliferation of plasma cells within the bone marrow. Accurate staging and monitoring of disease progression are crucial for effective management. PET imaging has emerged as a powerful tool in the diagnosis and management of MM, with radiotracers like 18F-fluorodeoxyglucose and novel agents playing a pivotal role. This review explores the current state of PET imaging in multiple myeloma, focusing on its role in initial staging, response assessment, and prognosis prediction, with an emphasis on recent advancements.

Rare Presentation of En Cuirasse Detected on 18-F FDG PET/CT in a Case of Recurrent Breast Carcinoma.

Carcinoma en cuirasse is a type of cutaneous metastasis from different malignancies. En cuirasse although is a rare entity, most commonly occurs in cases of recurrent breast carcinoma after surgery or very rarely months or years after diagnosis of primary tumor. We report a rare case of neck carcinoma en cuirasse in a 47-year-old Indian female who is a known case of recurrent carcinoma left breast postmodified radical mastectomy, chemotherapy, and radiotherapy referred for fluorodeoxyglucose positron emission tomography-computed tomography following another six cycles of chemotherapy for response assessment.

Role of 18 F-FDG PET/CT for providing a targeted approach for etiology of PUO.

AIM: This study aimed to evaluate the potential role of 18F-fluorodeoxyglucose PET/computed tomography (18F-FDG PET/CT) in providing a targeted approach for diagnosing the etiology of Pyrexia of Unknown Origin (PUO). METHODS: A total of 573 PUO patients were included in this ambispective study, with a mean age of 39.40 ±â€…4.6 years. Patients underwent FDG PET/CT scans using dedicated hybrid scanners. PET/CT data were interpreted by experienced nuclear medicine physicians. The study analyzed the guidance provided by FDG PET/CT for appropriate biopsy sites and assessed concordance between PET/CT findings and histopathological examination. RESULTS: Out of the 573 patients, a final diagnosis was reached for 219 patients, including malignancy, infectious causes, noninfectious inflammatory causes (NIID), and precancerous conditions. FDG PET/CT played a crucial role in guiding clinicians to appropriate biopsy sites, contributing to a higher diagnostic yield. Concordance between PET/CT findings and histopathological examination emphasized the noninvasive diagnostic potential of PET/CT in identifying underlying causes of PUO. Overall, FDG PET/CT contributed to guiding the appropriate site of biopsy or concordance of the first differential diagnosis with the final diagnosis in 50.05% of cases. CONCLUSION: This study highlights the valuable role of FDG PET/CT in providing a targeted approach for diagnosing PUO, showcasing its potential in guiding clinicians towards appropriate biopsy sites and improving the diagnostic yield. The findings underscore the importance of integrating FDG PET/CT into the diagnostic pathway for PUO, ultimately enhancing patient management and outcomes. Further prospective studies are necessary to validate these results and refine the integration of FDG PET/CT in the diagnosis of PUO.

Discordant Molecular Imaging Findings with 2-[18F]FDG and [68Ga]Ga-PSMA PET/CT in a Patient with Both Bladder and Prostate Cancer.

The prevalence of double primary prostate and bladder cancer is not uncommon. Though both share a common pathway of malignant transformation, they bear to differ in the case of 2-[18F]FDG PET/CT and [68Ga]Ga-PSMA uptake. We present a case of double primary cancer involving the bladder and prostate, where the prostatic primary showed intense [68Ga]Ga-PSMA uptake with non-avid skeletal and pulmonary metastases, which showed intense 2-[18F]FDG uptake, thus showing discordance due to different clonal origins.

Axillary Lymph Node in Extra-Ocular Retinoblastoma - Benign or Malignant?

A 1-year-old male child presented with whitish discoloration of pupil of the left eye and swelling over the left axilla. A contrast-enhanced magnetic resonance imaging of the brain and orbits performed revealed left eye extra-ocular retinoblastoma. 18F-fluorodeoxyglucose positron emission tomography/computed tomography scan was done in this child as a part of baseline staging of retinoblastoma in an ongoing research project. The scan revealed left eye extra-ocular retinoblastoma along with calcified left axillary level I lymph node.

99mTechnetium-Ubiquicidin Scan with Single-Photon Emission Computed Tomography/Computed Tomography in Skull Base Osteomyelitis.

Malignant otitis externa (MOE) with skull base osteomyelitis (SBO) is an aggressive infection that predominantly affects elderly, diabetic, or immunocompromised patients, and is associated with high disease-specific mortality. Pseudomonas aeruginosa is the most isolated microorganism. External otitis associated with granulation tissue and pain is the most common presenting feature; a biopsy is obtained to rule out malignancy. A proper consensus is lacking regarding the best imaging modality for early initial diagnosis and follow-up. 99mTechnetium (99mTc)-labeled ubiquicidin (UBI) 29-41 is a bacterial attaching peptide that does not bind to activated leukocytes. We report a case of SBO initially misdiagnosed as a chronic otitis media, but later proved to be a case of MOE. 99mTc methylene diphosphonate bone scan and 99mTc-UBI 29-41 scan with single-photon emission computed tomography/computed tomography scans were performed to corroborate the clinical diagnosis. SBO remains a great challenge due to its increasing prevalence and high morbidity are difficult to diagnose and are often confused with cholesteatoma and neoplastic process. The UBI scan could be an auxiliary noninvasive diagnostic alternative in early diagnosis.

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

Purpose: Hereditary tumor syndrome Von Hippel-Lindau (VHL) disease is characterized by various benign and malignant tumors that are known to express somatostatin receptors (SSTR). We evaluated the role of 68Ga-DOTANOC PET/CT scan in patients with positive germline mutation of the VHL gene, presented initially or on follow-up, for the detection of recurrent or synchronous/metachronous lesions. Methods: Fourteen patients (8 males; 6 females) with mean age 30 ± 9.86 years were retrospectively analyzed, were tested positive for VHL on gene dosage analysis, and underwent 68 Ga-DOTANOC PET/CT scan for disease evaluation. The number and site of lesions were determined. The tracer uptake was analyzed semi-quantitatively by calculating the maximum standardized uptake values (SUVmax) of lesion. Results: Four of the 14 patients underwent scan for initial diagnosis as baseline, 6 patients for post-therapy disease status, and 4 patients for initial diagnosis as well as follow-up evaluation of the disease. A total of 67 lesions were detected in 14 patients. The sites of lesions were cerebellar/vertebral/spinal (17; mean SUVmax = 7.85); pancreatic neuroendocrine tumor (NET) (11; mean SUVmax = 20.64); retina (3; mean SUVmax = 10.46); pheochromocytoma (10; mean SUVmax = 16.32); paragangliomas (3; mean SUVmax = 10.65); pancreatic cyst (9; mean SUVmax = 2.54); and renal cyst (8; mean SUVmax = 1.56) and miscellaneous lesions constituted 6 lesions. Conclusion: Our results show that 68 Ga-DOTANOC PET/CT may be a useful modality for screening and follow-up of associated tumors in patients with germline gene mutation for VHL. It can be used as a one-stop imaging modality for VHL patients and may substitute for separate radiological investigations, making it more convenient for patients in terms of time and cost.

Role of 18 F-FDG PET/CT in the diagnosis of benign vs. malignant tumor thrombus.

PURPOSE: Hypercoagulable state is a complication of various infections, and inflammatory processes and is a common scenario in cancer patients also. Timely diagnosis and treatment are essential to reduce further complications in such patients. The present study aimed to assess the role of FDG PET/CT in the diagnosis of benign vs. malignant tumor thrombus and to determine cut-off SUVmax to differentiate them. PATIENTS AND METHODS: We retrospectively reviewed all FDG PET/CT scans of patients done in our department from January 2017 to March 2022. All scans were reviewed by two experienced nuclear medicine physicians. A total of 135 patients who had venous or arterial thrombus in FDG PET/CT scans were included. All the FDG PET/CT scans of 135 patients were analyzed for primary tumor site and/or site of thrombus. Additional clinical data were collected for patients with benign conditions in the form of ESR and CRP if available and doubtful cases were followed up by HPE reports and/or CEMRI. The SUV max of the primary tumor(in cancer patients), thrombus, and background (aorta) were calculated. RESULTS: A total of 135 patients (108 cancer patients and 27 with benign thrombus) were included with an age range of 3 to 86 years (median 50 years). There were 91 males and 44 females. Of 108 cancer patients, the most common cancers were hepatocellular cancer - 38 (35.18%), renal cell cancer - 28(25.92%), and carcinoma of the thyroid - 6 (5.55%). Of 108 cancer patients, 36 (33.33%) had tumor thrombosis in inferior vena cava, 31 (28.70%) in the portal vein, and 41 (37.96%) in other vessels (renal vein, jugular vein, etc.). Of 27 patients with benign conditions,13 had venous thrombi, 11 had arterial thrombus and three had atrial thrombus and the most common thrombus sites were thoraco-abdominal aorta in seven (25.92%) and right atrium in three (11.11%) patients. In the subgroup of 108 oncological patients, the mean SUV max of the primary tumors was 17.67 (range 2.1-91.0; median 10.82), thrombi were 17.61 (range 2.14-90.11; median 14.56) and background was 5.29 (range 0.29-25.00; median 3.12). Of 27 patients with benign conditions, the mean SUV max of the thrombi was 11.09 (range 1.98-31; median 8.10) and the background was 9.80 (range 1.46-24.50; median 10.20) The ESR was raised in 13 of 26 patients (mean 35.84, range 10.98-62.00, median 35.00) and CRP was raised 22 of 26 patients (mean11.46, range 3.45-24.50, median 20.40). Upon plotting the receiver operating curve, a cutoff SUV max of 12.7 with a sensitivity of 62.96% and specificity of 77.77% was produced to demarcate tumor thrombus from benign thrombus. CONCLUSION: FDG PET/CT plays a significant role in the detection of thrombo-embolic disease and can differentiate benign thrombus from tumor thrombus.

Incidentally Detected Gastrointestinal Stromal Tumor in a Patient with Carcinoma Prostate: 68Ga-Prostate-Specific Membrane Antigen Versus 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography.

Uptake of 68Ga-prostate-specific membrane antigen (PSMA) in various nonprostatic tumors is well documented in the literature. We present a case of a gastrointestinal stromal tumor, incidentally detected on 68Ga-PSMA positron emission tomography/computed tomography imaging in a patient who underwent imaging for a suspected recurrence of carcinoma prostate.

A Curious Case of Suspicious Lymphadenopathy in a Hereditary Spherocytosis Patient Reported as Extramedullary Hematopoiesis.

We present a case of a 23-year-old male patient with complaints of fever, cough, and persistent anemia for the past 6 months and with a known history of hereditary spherocytosis. Computed tomography (CT) thorax demonstrated multiple paravertebral lesions in the bilateral thoracic cavities, suggestive of lymphadenopathy; subsequently, 18Flurodeoxyglucose PET/CT was done with suspicion of lymphoma, which showed no significant metabolic activity in those lesions. Thus, in view of clinical and metabolic status, lesions were considered extramedullary hematopoiesis (EMH). This case highlights the importance of considering EMH, while interpreting suspicious lymphadenopathy in cases of chronic anemia and also possible scan findings in the same.

Omicron Variant of COVID-19: Imaging Pattern on F-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography.

We report a case of omicron infection in a biopsy-proven case of carcinoma breast sent for staging F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) during the omicron COVID wave. FDG PET/computed tomography (CT) revealed increased FDG uptake in nasopharyngeal, oropharynx, and tonsillar regions and bilateral cervical lymph nodes along with uptake in primary carcinoma and locoregional lymph nodes. Based on the clinical history and specific pattern of FDG PET/CT findings (as suggested by SNMMI Taskforce), COVID history and reverse transcription polymerase chain reaction positivity was elicited.

Solitary Subcutaneous Tissue Metastasis as Recurrence in a Case of Primary Angiosarcoma of Breast: Findings on 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography.

Primary angiosarcomas of the breast are rare tumors, with a fatal outcome. We present a rare case of an operated primary angiosarcoma of the right breast in a 20-year-old female who showed disease recurrence in the right posterior arm subcutaneous tissue on 18F-fluorodeoxyglucose positron emission tomography-computed tomography after 1 year of surgery without any other visceral metastasis.

An Unusual Case of Simultaneous Cricoid and Thyroid Cartilage Metastases from Prostatic Adenocarcinoma on 68Ga-PSMA PET/CT.

Although prostate cancer can metastasize to any part of the body, laryngeal cartilage metastasis is extremely rare and few cases have been published so far. Here we present the case of a 65-year-old male patient, recently diagnosed with prostate adenocarcinoma, referred for staging with 68Ga-PSMA PET/CT. He was found to have extensive skeletal metastasis along with cartilage metastasis involving both thyroid and cricoid cartilages.

Extramedullary Infiltration in Multiple Organs in a Relapsed Case of Acute Lymphoblastic Leukemia on 18F-Fluorodeoxyglucose Positron Emission Tomography.

T-cell acute lymphoblastic leukemia (ALL) is hematological malignancy with a propensity to involve extramedullary organs. We present the case of a 7-year-old child who was diagnosed with disease free from ALL for 1 year and then developed fever. 18F-fluorodeoxyglucose positron emission tomography/computed tomography revealed extramedullary infiltration of ALL in lungs, pancreas, kidneys, bone, muscles, and subcutaneous tissues.