Indian Journal of Nuclear Medicine最新文献

The Sister Mary Joseph's nodule is a rare umbilical metastatic lesion, occurring in 1%-3% of abdominopelvic adenocarcinomas. It represents the visible tip of the iceberg, and its presence is associated with a poor prognosis. We report the case of a 61-year-old postmenopausal female patient with rectosigmoid adenocarcinoma. An ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET) scan revealed, in addition to a large sigmoid mass, multiple hypermetabolic lumbo-aortic lymphadenopathies, secondary hypermetabolic pulmonary and hepatic nodules, and a large subcutaneous umbilical nodule consistent with a Sister Marie Joseph's nodule. This case supports the systematic use of ¹⁸F-FDG PET in oncologic evaluations involving suspicious umbilical nodules.

Sarcoidosis is a systemic noncaseating granulomatous immune-mediated disease with multiorgan involvement. Neurosarcoidosis was historically reported to occur in 5%-10% of all patients with sarcoidosis. Neurosarcoidosis can present with a myriad of clinical symptoms, including cranial neuropathy, myelopathy, and parenchymal involvement. Conventional imaging is often nonspecific and central nervous system biopsy to confirm the diagnosis is infrequently performed. Fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) is a useful modality in the evaluation of neurosarcoidosis, for assessing systemic involvement and identifying biopsiable site. We present the case of neurosarcoidosis with FDG PET/CT detected rare cranial and spinal radiculopathy lesions apart from other systemic findings.

Angiosarcoma is a rare type of soft-tissue sarcoma, constituting only 1% out of all soft-tissue sarcomas pathologically originating from lymphatic or vascular endothelial cells. Angiosarcomas are reported to be very aggressive with a high incidence of metastases to different sites; therefore, it is very important to determine disease extension and detect local recurrence and/or distant metastases for appropriate management. We report a case of a 55-year-old Indian male who presented with soft-tissue thickening of the left cheek for which biopsy revealed angiosarcoma and was referred for fludeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) to assess the extent of disease highlighting the potential role of FDG PET/CT in rare malignancies like angiosarcomas.

A 62-year-old woman with chronic nausea and epigastric pain underwent hepatobiliary scintigraphy. Gallbladder ejection fraction (GBEF) calculation suggested normal function. However, upon further review, a septate gallbladder was identified. This promoted a re-evaluation of the selected region of interest (ROI). The initial ROI included only the gallbladder fundus, leading to GBEF overestimation. Recalculation with a comprehensive ROI that encompassed both compartments yielded a lower GBEF, consistent with biliary dyskinesia or chronic cholecystitis. This case highlights the importance of ROI selection for accurate assessment of GBEF calculation in anatomical variations such as septate gallbladder and correlating functional studies with anatomical imaging.

Lung cancer is the leading cause of cancer and cancer-related deaths, and India ranks the fourth highest country. Lung cancer is a highly aggressive malignancy with a tendency for rapid progression, making early detection and prompt treatment essential for improving patient outcomes. Lung cancer can spread locally into surrounding tissue as well as travel through lymphatics to other parts of the body, most often to bone, brain, liver, and adrenal glands. Metastasis to pituitary and pineal glands is extremely rare. The differential diagnosis for pituitary metastasis could be pituitary adenoma where lesion usually lies at the anterior aspect of pituitary fossa, whereas metastasis is seen at the posterior aspect. There is a paucity of published literature, with only a few cases reported of pituitary and pineal gland metastasis. Hence, to add to the literature, we present a case of pituitary metastasis in an older woman with lung cancer.

Objectives: Bone scintigraphy is a sensitive imaging method to evaluate patients with suspected osteonecrosis. We assessed the diagnostic performance of combined bone single-photon emission computed tomography/computed tomography (SPECT/CT) (CBS) in patients with known rheumatic disease or other connective tissue disorders and clinical suspicion of osteonecrosis compared to magnetic resonance imaging (MRI).

Methods: This prospective diagnostic accuracy study included 70 patients with clinical suspicion of osteonecrosis in any bone who underwent a planar triple-phase bone scan along with a regional SPECT/CT (CBS) and regional MRI. MRI was considered the standard for diagnosing the sensitivity, specificity, predictive values, and accuracy of CBS. Cohen's kappa statistic of the agreement was also calculated.

Results: The distribution of the patients based on the joint regions suspected to have osteonecrosis is as follows: 21 hip, 43 knee, and six ankle. MRI detected osteonecrosis in 30/70 patients. CBS had a sensitivity of 100% (30/70 were detected) and a specificity of 97% (2/40 were false positive). Overall, there was good agreement between the two scans regarding the diagnosis of osteonecrosis (Cohen's kappa statistic = 0.94). In addition to the suspected sites, CBS detected osteonecrosis in 19 additional asymptomatic sites in 13 patients.

Conclusion: The study has demonstrated that CBS, which includes whole-body imaging and SPECT/CT, is highly sensitive in detecting osteonecrosis with accuracy comparable to regional MRI. Its inherent whole-body imaging technique enabled the detection of multifocal osteonecrosis. It can be used as an early investigating modality after routine plain radiography to establish the diagnosis.

Acute lymphoblastic leukaemia (ALL) is a prevalent cause of paediatric leukaemia. Patients with ALL typically exhibit symptoms such as fever, bleeding, weight loss, and bone pain. Blood investigations results predominantly show anaemia and pancytopenia with blast cells in the peripheral smear. While ALL primarily affects the bone marrow, it can also impact nearly every organ. There have been previous reports of extramedullary involvement of multiple organs in cases of ALL. This case represents a rare occurrence of ¹⁸F-fluorodeoxyglucose (FDG) avid symmetrically enlarged kidneys as initial presentation of ALL.

This case demonstrates extraosseous technetium-99m methylene diphosphonate (Tc-99m MDP) accumulation from an atypical ossifying fibromyxoid tumor (OFMT). A 63-year-old man presented with a 10-year history of a gradually enlarging, painless back mass. Physical examination revealed multiple hard, nontender subcutaneous nodules without signs of inflammation or pigmentation. Computed tomography scan of the back showed calcified masses. Whole-body bone scintigraphy revealed areas of increased Tc-99m MDP uptake in subcutaneous regions, suggesting extraosseous uptake. Histopathological examination of the back mass confirmed the diagnosis of atypical OFMT.

Purpose of the study: 1,3,4,6-tetra-O-acetyl-2-O-trifluoromethanesulfonyl-β-D-mannopyranose (mannose triflate), the precursor used for the synthesis of [¹⁸F] Fluorodeoxyglucose ([¹⁸F] FDG) is imported from a few commercial suppliers abroad. As part of self-reliance, a reliable synthesis and characterization of mannose triflate has been developed, details of which are reported in this paper.

Materials and methods: Synthesis of 1,3,4,6-tetra-O-acetyl-2-O-trifluoromethanesulfonyl-β-D-mannopyranose (Mannose triflate) carried by Triflation of 1,3,4,6-Tetra-O-acetyl-β-D-mannopyranose with Tf2O-pyridine under argon atmosphere for 6 h. Synthesized mannose triflate is used for the production of [¹⁸F] FDG using siemens explora FDG-4-automated module.

Results: Starting from 2.6 g of 1,3,4,6-Tetra-O-acetyl-β-D-mannopyranose, mannose triflate was synthesized with an overall yield of ~ 3.0 g (~80%). The synthesis was systematically scaled up to 52 g based on the experience from the initial small size batches. The characterization of the product was done by Infra Red, Nuclear Magnetic Resonance and Mass spectroscopy. The precursor was used in the manufacture of [¹⁸F] FDG using Siemens Explora synthesis module. Radiochemical yields of 55% ± 2% (decay uncorrected), radiochemical purity >96% were obtained which is comparable with the imported precursor. All the quality control parameters were within the limits as per pharmacopoeia when the in-house synthesized mannose triflate was used.

Conclusion: A large-scale preparation of mannose triflate is now carried out to satisfy the growing needs for FDG in positron emission tomography centers and hospitals.

Metastatic renal osteosarcoma is a rare entity. We report a case of a 52-year-old male postright nephrectomy status presented to us with metastatic renal osteosarcoma. 18-fluorine- fluorodeoxyglucose (¹⁸F-FDG) avid lesions were seen in the right renal bed with extension to adjacent hepatic parenchyma. The patient exhibited a favorable response to 6 cycles of carboplatin and doxorubicin with no FDG avid lesions in the postchemotherapy follow-up scan. On 6-month follow-up scan, scan findings reveal a recurrent lesion at the renal bed region infiltrating psoas muscle and liver metastatic lesion. This case highlights the use of ¹⁸F-FDG positron emission tomography/computed tomography in metastatic recurrent extraskeletal osteosarcoma.