Ga-67 Citrate and Tc-99m MDP Uptake in the Lung and Stomach Associated with Hypercalcemia / 핵의학분자영상

Ga-67 scintigraphy demonstrated increased uptake in the lungs and stomach in a 26-year-old man with hypercalcemia. A primitive neuroectodermal tumor was confirmed by bone marrow examination. Tc-99m MDP uptake in the same locations as Ga-67 revealed by bone scintigraphy was consistent with metastatic calcification. Although the mechanism of Ga-67 uptake in metastatic calcification is not understood, the presence of an inflammatory process is suggested.

Comparison of Ga-67, Tl-201 and Tc-99m MIBI Imaging in Lymphoma Patients / 영남의대학술지

PURPOSE: Ga-67 scintigraphy has been used for the evaluation of tumors, especially lymphoma. Recently, Tl-201 and Tc-99m MIBI were also used to tumor imaging. Tl-201 and Tc-99m MIBI had better physiologic characteristics than Ga-67, so we studied 32 biopsy proven lymphoma patients (male 24, female 8, mean age 46 years) with Ga-67, Tl-201 or Tc-99m MIBI and compared the scan findings. MATERIALS AND METHODS: Twenty-three of 32 patients were injected 74-111 MBq (2-3 mCi) of Tl-201, before chemotherapy and imaged with dual-headed SPECT (Prism 2000, Picker, USA) at 30 minutes after injection. Delayed images were obtained after 3 hr in 8 patients. Twenty seven of 32 patients were injected 740 MBq (20 mCi) of Tc-99m MIBI and imaged at 30 minutes after injection. 111-185 MBq (3-5 mCi) of Ga-67 was injected in 12 patients and imaged at 48 and 72 hours after injection. Twenty eight patients were diagnosed as non-Hodgkin's lymphoma and others were Hodgkin's lymphoma. RESULTS: Twenty patients were positive on Tl-201 scan and 3 patients showed negative findings. One of these 3 patients, Tc-99m MIBI and Ga-67 scan were positive. Twenty two patients were positive on Tc-99m MIBI scan and 5 patients showed negative findings. One of these 5 patients, Tl-201 was positive and 2 were positive on Ga-67 scan. Ten of 12 patients showed positive findings on Ga-67 scan. The sensitivity of these agents were 83.3%, 87.0% and 81.5% for Ga-67, Tl-201 and Tc-99m MIBI, respectively. The sensitivity was highest in Tl-201 scan, but there were no significant differences among three tests. In this study, there was no significant difference of uptake ratios between early and delayed images of Tl-201. CONCLUSION: Scintigraphy with Tl-201 and Tc-99m MIBI in lymphoma patients have similar sensitivity with Ga-67.

Uptake of Ga-67 by Cultured Cells: Transferrin-dependent and Transferrin-independent Mechanisms / 대한암학회지

PURPOSE: We determined whether the uptake of Ga-67 by cultured cells occur by both transferrin (Tf)-dependent and independent mechanisms and the mechanism and magnitude of its uptake may vary as the degree of expression of the transformed phenotype. MATERIALS AND METHODS: Uptake of Ga-67 between the tansformed and untransformed cells was compared. Cells were incubated with Ga-67 in either the presence or absence of Tf and with complete medium containing Ga-67 after preincubating with anti-Tf receptor antibodies at 37oC in 8% CO2. Monolayers of cells were washed and trypsinized. Radioactivity and protein content of the samples were determined. RESULTS: Uptake of Ga-67 by cultured cells occurred both in Tf-bound and ionic form and was increased with radioactivity and time. The magnitude for the uptake of Tf-bound form was approximately 3 and 6-fold greater than ionic form. In the presence of Tf, uptake of Ga-67 was 2-fold greater in the transformed cells. Conversely, In the absence of Tf, it was 1.5-fold greater in the untransformed cells. Regardless of blocking the Tf receptor by anti-Tf receptor antibodies, a significant amount of intracellular Ga-67 uptake was found. CONCLUSION: Dual mechanisms exist for the uptake of Ga-67 by cultured cells. The primary important one was the Tf-dependent system. Tf-dependent and independent mechanisms and the magnitude operated oppositely in the transformed cells when compared to their untransformed counterpart.

A Case of Muscular Sarcoidosis diagnosed by Gallium-67 Scintigraphy and Magnetic Resonance Imaging / 대한핵의학회잡지

Gallium-67 scintigraphy is helpful in the assessment of active extrapulmonary sarcoidosis. Muscular involvement of sarcoidosis is often asymptomatic or nonspecific, and laboratory examinations do not provide convincing evidence of muscular involvement. We report a case of muscular sarcoidosis, which was detected by gallium-67 scintigraphy. In a patient who was suffering from fever and arthralgia of knee joint, gallium-67 scintigraphy showed mediastinal and hilar involvement of sarcoidosis with unexpected extensive muscular uptake. Magenetic resonance imaging revealed the detailed depiction of intramuscular infiltration of sarcoid granuloma. Gallium-67 scintigraphy is useful in detecting inflammatory muscular involvement of sarcoidosis as well as other multiorgan involvement.

Quantitative Ga-67 Scintigraphy in patients with Silicosis: Comparison with Chest X-ray and Pulmonary Function / 대한핵의학회잡지

PURPOSE:The International Labor Organization (ILO) has established an international standard for chest X-ray diagnosis of pneumoconiosis since 1980. However, there is a need for improved diagnosis and staging in occupational disease. We evaluated Ga-67 citrate scintigraphy quantitatively and correlated the scintigraphic findings with pulmonary function tests and chest X-ray result. MATERIALS AND METHODS: Twenty-five patients underwent whole body scintigraphy with additional chest and abdomen images 48 hrs after intravenous injection of 185 MBq of Ga-67 citrate. Ten normal controls were also studied. Regions of interest (ROI) were drawn on the posterior image to measure counts from the liver and lungs (Lung/Liver Ratio). RESULTS: L/L ratio according to the stages of chest X-ray classification were as follows; stage 0 (normal, n=10): 0.3948+/-0.0692, stage 1 (n=10): 0.5763+/-0.1837, stage 2 (n=11): 0.6849+/-0.1459, stage 3 (n=4): 0.9913+/-0.0712. There was a significant correlation between the scintigraphic L/L ratio and the X-ray stage (r=0.618, p0.05). CONCLUSION: Quantitative Ga-67 scintigraphy can be a useful method for staging of silicosis. However, it is not a method to assess pulmonary functional impairment.

Discrimination of Postradiotherapy Lung Fibrosis from Recurrence by Gallium-67 Scan in Lung Cancer / 대한치료방사선과학회지

The differentiation between post-radiotherapy lung fibrosis and tumor recurrence is often a dilemma to physicians. Twenty two patients with lung cancer who had received 45~60 Gy to the chest were chosen to study the possible role of gallium-67 scan. Seventeen squamous cell carcinomas were treated with only radiotherapy, 3 small cell carcinomas with combination chemotherapy, 2 adenocarcinomas with lobectomy. A total of 8 patients with pneumonitis with or without fibrosis and recurrence showed uptake of gallium at the site of inflammation. Of the 12 recurrences and residual diseases after radiotherapy, positive gallium uptake was present in 11 cases (92%). Of the 10 recurrence-free cases, all the 5 patients with pneumonitis revealed gallium accumulation. However, 4 of the 5 patients (805) with recurrence-free fibrosis have not accumulated gallium in the fibrotic areas. Fibrosis in 6 patients were developed after 8 months of completion of radiotherapy. These facts suggest that gallium-67 scan after 1 year post-treatment may aid for the discrimination of fibrosis from tumor recurrence unless pneumonitis is present.