Targeted alpha therapy (TAT) is an active area of drug development as a highly specific and highly potent therapeutic modality that can be applied to many types of late-stage cancers. In order to properly evaluate its safety and efficacy, understanding biokinetics of alpha-emitting radiopharmaceuticals is essential. Quantitative imaging of alpha-emitting radiopharmaceuticals is often possible via imaging of gammas and positrons produced during complex decay chains of these radionuclides. Analysis of the complex decay chains for alpha-emitting radionuclides (Tb-149, At-211, Bi-212 (decayed from Pb-212), Bi-213, Ra-223, Ac- 225, and Th-227) with relevance to imageable signals is attempted in this mini-review article. Gamma camera imaging, single-photon emission computed tomography, positron emission tomography, bremsstrahlung radiation imaging, Cerenkov luminescence imaging, and Compton cameras are briefly discussed as modalities for imaging alpha-emitting radiopharmaceuticals.
Electrons ; Luminescence ; Positron-Emission Tomography ; Radioisotopes ; Radionuclide Imaging ; Radiopharmaceuticals ; Tomography, Emission-Computed ; Tomography, Emission-Computed, Single-Photon

positron emission tomography/computed tomography (PET/CT) in detecting hyperfunctioning parathyroid tissue (HPT) in patients with elevated parathyroid hormone levels with negative or inconclusive conventional imaging results and to compare the findings with those obtained using technetium-99m sestamibi (MIBI) scintigraphy and neck ultrasonography (US).MATERIALS AND METHODS: Images of 105 patients with hyperparathyroidism who underwent FCH PET/CT, dual-phase MIBI parathyroid scintigraphy (median interval: 42 days), and neck US were retrospectively analyzed. The gold standard was histopathological findings for 81 patients who underwent parathyroidectomy and clinical follow-up findings in the remaining 24 patients. Sensitivities, positive predictive values (PPVs), and accuracies were calculated for all imaging modalities.RESULTS: Among the 81 patients who underwent parathyroidectomy, either parathyroid adenoma (n = 64), hyperplasia (n = 9), neoplasia (n = 4), or both parathyroid adenoma and hyperplasia (n = 1) were detected, except 3 patients who did not show HPT. Of the 24 (23%) patients who were followed-up without operation, 22 (92%) showed persistent hyperparathyroidism. FCH PET/CT showed significantly higher sensitivity than MIBI scintigraphy and US in detection of HPT (p < 0.01). Sensitivity, PPV, and accuracy of FCH PET/CT were 94.1% (95/101), 97.9% (95/97), and 92.4% (97/105), respectively. The corresponding values for MIBI scintigraphy and US were 45.1% (46/102), 97.9% (46/47), and 45.7% (48/105) and 44.1% (45/102), 93.8% (45/48), and 42.9% (45/105), respectively. Among the 35 patients showing negative MIBI scintigraphy and neck US findings, 30 (86%) showed positive results on FCH PET/CT. FCH PET/CT could demonstrate ectopic locations of HPT in 11 patients whereas MIBI and US showed positive findings in only 6 and 3 patients, respectively.CONCLUSION: FCH PET/CT is an effective imaging modality for detection of HPT with the highest sensitivity among the available imaging techniques. Therefore, FCH PET/CT can be recommended especially for patients who show negative or inconclusive results on conventional imaging.]]>
Electrons ; Follow-Up Studies ; Humans ; Hyperparathyroidism ; Hyperplasia ; Neck ; Parathyroid Hormone ; Parathyroid Neoplasms ; Parathyroidectomy ; Positron-Emission Tomography ; Positron-Emission Tomography and Computed Tomography ; Radionuclide Imaging ; Retrospective Studies ; Ultrasonography

Neuroblastoma is an embryonal tumor of children that frequently presents with metastases. Our patient is a 6-year-old girl who was diagnosed to have neuroblastoma with diffuse metastatic disease throughout the skeleton as seen in her 123I-MIBG scan in the United States. 18F-FDG PET/CT scan was done in the Philippines after chemotherapy and gene therapy, and before 131I-MIBG therapy. No additional lesions were seen on PET.  131I-MIBG was then performed and an 131I-MIBG with SPECT/CT thereafter, which showed an increase in size and extent of the lesion in the head and a decrease in number of the skeletal metastases. New 131I-MIBG-avid posterior cervical lymph nodes were also localized through SPECT/CT. For this patient, a follow-up 123I/131I-MIBG scan would be more cost-effective in assessing response to therapy. Sectional imaging may be done to obviate the need for sedation of this young patient.

Human ; Female ; Child ; 3-iodobenzylguanidine ; Fluorodeoxyglucose F18 ; Genetic Therapy ; Lymph Nodes ; Neuroblastoma ; Positron Emission Tomography Computed Tomography ; Radionuclide Imaging ; Radiopharmaceuticals

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.
Diagnosis, Differential ; Fluorodeoxyglucose F18 ; Humans ; Male ; Middle Aged ; Positron-Emission Tomography and Computed Tomography ; Radionuclide Imaging ; Spermatic Cord Torsion ; Testis ; Ultrasonography

No abstract available.
Amyloidosis/*radionuclide imaging ; Female ; Fluorodeoxyglucose F18/*diagnostic use ; Humans ; Liver Diseases/*radionuclide imaging ; Multiple Myeloma/*complications ; *Positron-Emission Tomography and Computed Tomography ; Radiopharmaceuticals/*diagnostic use

We report the first case in Korea of a chronic expanding hematoma, which presented as a huge mass in the pleural cavity. A 67-year-old woman exhibiting a slowly-expanding intrathoracic mass, as revealed by a chest radiograph, was admitted to our hospital. The patient had undergone a pneumonectomy 37 years earlier during treatment for pulmonary tuberculosis. Computed tomography revealed a huge mass in her right hemithorax. The differential diagnosis of this mass included chronic empyema combined with a malignancy, such as lymphoma or a soft tissue sarcoma. The tumor, which was classified as an encapsulated chronic hematoma, was removed surgically. Samples sent for histopathological and microbiological analysis revealed no evidence of neoplasia or infection. The patient was finally diagnosed with a chronic expanding hematoma of the thorax. This case is particularly rare due to the patient's development of a very large mass after undergoing treatment for tuberculosis more than 30 years earlier.
Tomography, X-Ray Computed ; Radiography, Thoracic ; Positron-Emission Tomography ; Pleural Cavity/*pathology/radiography/radionuclide imaging ; Male ; Humans ; Hematoma/*pathology/radiography/radionuclide imaging ; Dyspnea/etiology ; Chronic Disease ; Aged

OBJECTIVE: Angiomyolipoma is the most common benign kidney tumor. However, literature describing FDG PET findings on renal angiomyolipoma (AML) is limited. This study reports the FDG PET and PET/CT findings of 21 cases of renal AML. MATERIALS AND METHODS: The study reviews FDG PET and PET/CT images of 21 patients diagnosed with renal AML. The diagnosis is based on the classical appearance of an AML on CT scan with active surveillance for 6 months. The study is focused on the observation of clinical and radiographic features. RESULTS: Six men and 15 women were included in our study. The mean age of the patients was 57.14 +/- 9.67 years old. The mean diameter of 21 renal AML on CT scans was 1.76 +/- 1.00 cm (Min: 0.6 cm; Max: 4.4 cm). CT scans illustrated renal masses typical of AMLs, and the corresponding FDG PET scans showed minimal FDG activities in the area of the tumors. None of the 21 AMLs showed a maximum standardized uptake value (SUVmax) greater than 1.98. No statistically significant correlation was present between SUVmax and tumor size. CONCLUSION: Renal AMLs demonstrate very low to low uptake on FDG PET and PET/CT imaging in this study. When a fat-containing tumor in the kidney is found on a CT scan, it is critical to differentiate an AML from a malignant tumor including an RCC, liposarcoma, and Wilms tumor. This study suggests that FDG PET or PET/CT imaging is useful for differentiating a renal AML from a fat-containing malignant tumor.
Angiomyolipoma/*radionuclide imaging ; Contrast Media/diagnostic use ; Ehlers-Danlos Syndrome ; Female ; Fluorodeoxyglucose F18/diagnostic use ; Humans ; Kidney Neoplasms/*radionuclide imaging ; Male ; Middle Aged ; *Positron-Emission Tomography ; *Positron-Emission Tomography and Computed Tomography ; Radiopharmaceuticals/diagnostic use ; Retrospective Studies

Single-photon emission computed tomography/computed tomography (SPECT/CT) is an already established nuclear imaging modality. Co-registration of functional information (SPECT) with anatomical images (CT) paved the way to the wider application of SPECT. Recent advancements in quantitative SPECT/CT have made it possible to incorporate quantitative parameters, such as standardized uptake value (SUV) or %injected dose (%ID), in gamma camera imaging. This is indeed a paradigm shift in gamma camera imaging from qualitative to quantitative evaluation. In fact, such quantitative approaches of nuclear imaging have only been accomplished for positron emission tomography (PET) technology. Attenuation correction, scatter correction, and resolution recovery are the three main features that enabled quantitative SPECT/CT. Further technical improvements are being achieved for partial-volume correction, motion correction, and dead-time correction. The reported clinical applications for quantitative SPECT/CT are mainly related to Tc-99m-labeled radiopharmaceuticals: Tc-99m diphosphonate for bone/joint diseases, Tc-99m pertechnetate for thyroid function, and Tc-99m diethylenetriaminepentaacetic acid for measurement of glomerular filtration rate. Dosimetry before trans-arterial radio-embolization is also a promising application for Tc-99m macro-aggregated albumin. In this review, clinical applications of Tc-99m quantitative SPECT/CT will be discussed.
Evaluation Studies as Topic ; Gamma Cameras ; Glomerular Filtration Rate ; Positron-Emission Tomography ; Radionuclide Imaging ; Radiopharmaceuticals ; Sodium Pertechnetate Tc 99m ; Thyroid Gland ; Tomography, Emission-Computed, Single-Photon

Primary meningeal melanomatosis is a rare, aggressive variant of primary malignant melanoma of the central nervous system, which arises from melanocytes within the leptomeninges and carries a poor prognosis. We report a case of primary meningeal melanomatosis in a 17-year-old man, which was diagnosed with 18F-fluorodeoxyglucose (F-18 FDG) PET/CT, and post hoc F-18 FDG PET/MRI fusion images. Whole-body F-18 FDG PET/CT was helpful in ruling out the extracranial origin of melanoma lesions, and in assessing the therapeutic response. Post hoc PET/MRI fusion images facilitated the correlation between PET and MRI images and demonstrated the hypermetabolic lesions more accurately than the unenhanced PET/CT images. Whole body F-18 FDG PET/CT and post hoc PET/MRI images might help clinicians determine the best therapeutic strategy for patients with primary meningeal melanomatosis.
Adolescent ; Brain Neoplasms/*diagnosis/radionuclide imaging ; Fluorodeoxyglucose F18/diagnostic use ; Humans ; *Magnetic Resonance Imaging ; Male ; Melanoma/*diagnosis/radionuclide imaging ; Meningeal Neoplasms/*diagnosis/radionuclide imaging ; *Positron-Emission Tomography and Computed Tomography ; Radiopharmaceuticals/diagnostic use ; Whole Body Imaging

No abstract available.
Adult ; Angiomyolipoma/pathology/*radiography/radionuclide imaging ; Carcinoma, Hepatocellular/pathology/radiography/radionuclide imaging ; Female ; Humans ; Immunohistochemistry ; Liver Function Tests ; Liver Neoplasms/pathology/radiography/radionuclide imaging ; Magnetic Resonance Imaging ; Positron-Emission Tomography ; Tomography, X-Ray Computed