technetium-tc-99m-tetrofosmin and Tuberculosis--Pulmonary

In this paper, data available on nuclear medicine imaging using commercially available radiopharmaceuticals for the differentiation, staging, and prediction or assessment of the response to treatment in tuberculosis (TB) are reviewed. Limited available studies suggest that single photon emission computed tomography (SPECT) using either 201Tl, 99mTc-sestamibi, or 99mTc-tetrofosmin is accurate (≥85%) and has a high negative predictive value (≥90%) for the differentiation of TB from carcinoma in patients presenting with a solitary pulmonary nodule (SPN). The criteria for detection of TB on 201Tl SPECT are nondepiction of the suspicious lesion in the delayed image or a negative retention index [washout on the delayed images (3–4 h postinjection) vs. the early image (5–15 min postinjection)] and a comparable-to-background uptake on 99mTc-sestamibi or 99mTc-tetrofosmin SPECT. Another SPECT tracer of potential interest for the differentiation of TB from malignant SPN that warrants further exploration, is N-isopropyl-p-[123I]iodoamphetamine (123I-IMP). In contrast, 18F-fluorodeoxyglucose (18F-FDG) PET is unable to differentiate malignancy from TB and thus cannot be used as a tool to reduce futile biopsy/thoracotomy in these patients. A limited number of studies have reported on the potential of nuclear medicine imaging in assessment of the extent of disease in patients with extrapulmonary TB using 67Ga-citrate SPECT and 18F-FDG PET, respectively. 67Ga-citrate SPECT was shown to be as sensitive as bone scintigraphy for the detection of bone infection and was found to be complementary to computed tomography (CT) imaging. 18F-FDG PET was found to be significantly more efficient when compared with CT, respectively, in over half of patients for the identification of sites of lymph node involvement that were missed by CT and often the only sites of extrapulmonary TB identified. Unfortunately, 18F-FDG PET findings did not lead to alterations in treatment planning in any of the patients under study. Additional studies confirming these findings are urgently required. Similar to the setting of SPN, 18F-FDG PET cannot differentiate malignant lymph node involvement from lymph node involvement by TB. These results and the recent findings of Demura and colleagues using 18F-FDG PET further suggest that nuclear medicine imaging techniques could be used for the evaluation of therapeutic response. Prospective studies, focusing on specific subgroups of patients in whom such an imag

Topics: Diagnosis, Differential; Fluorodeoxyglucose F18; Gallium Radioisotopes; Humans; Iofetamine; Lung Neoplasms; Magnetic Resonance Imaging; Nuclear Medicine; Organophosphorus Compounds; Organotechnetium Compounds; Positron-Emission Tomography; Prognosis; Radiopharmaceuticals; Sensitivity and Specificity; Technetium Tc 99m Sestamibi; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Tuberculosis, Pulmonary

Topics: Female; Humans; Lung; Male; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Tuberculosis, Pulmonary

Topics: Aged; Humans; Male; Organophosphorus Compounds; Organotechnetium Compounds; Pneumoconiosis; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity; Technetium Tc 99m Medronate; Thoracic Vertebrae; Tuberculosis, Pulmonary; Tuberculosis, Spinal

Technetium-99m-tetrofosmin, an agent that is widely used in myocardial imaging, has been reported to accumulate in several types of malignancies, including lung tumors. Yet, there is limited knowledge about its role in imaging infection or inflammatory lesions. The aim of this study was to investigate the role of 99mTc-tetrofosmin scintigraphy in pulmonary tuberculosis in cases with active and inactive tuberculosis in comparison with radiological and microbiological findings.. Twenty-seven patients with active pulmonary tuberculosis (APTB) and 6 patients with inactive pulmonary tuberculosis (IPTB), proven by sputum smears and cultures, were included in this study. Mean age of the group was 42.6+/-13 yr. Nine months after therapy, 99mTc-tetrofosmin scintigraphy was repeated in 6 patients with APTB to evaluate response to therapy. Ten-minute anterior and posterior chest images were acquired 20 and 60 min after the injection of 370 MBq (10 mCi) 99mTc-tetrofosmin. The images were evaluated both visually and semiquantitatively by two blinded nuclear medicine physicians. For semiquantitative evaluation, regions of interest (ROIs) were drawn over the lesion (L) and nonlesion areas (NL). The mean count values of ROIs were obtained and L/NL ratios were calculated.. According to the visual evaluations, 99mTc-tetrofosmin uptake was Grade (+) in 4 (15%) and Grade (++) in 23 (85%) patients with APTB. Technetium-99m-tetrofosmin uptake was negative in 5 patients with IPTB. Grade (+) 99mTc-tetrofosmin uptake was observed in only one inactive case. After therapy, there was no 99mTc-tetrofosmin uptake in 3 patients, which correlated well with chest radiography and clinical findings. In the other 2 patients, 99mTc-tetrofosmin uptake was slightly decreased when compared with a previous scan that correlated with radiological and clinical findings. In 1 patient with bilateral lung disease, 99mTc-tetrofosmin uptake decreased on the right lung lesions, whereas the left lung lesions persisted with no change. The mean early and delayed L/NL ratios of APTB were 1.53+/-0.22 and 1.45+/-0.21, respectively. Although 99mTc-tetrofosmin uptake in APTB lesions was more visually marked in early images than that in delayed images, there was no statistically significant difference between these two sets of images.. Technetium-99m-tetrofosmin scintigraphy showed increased uptake in APTB lesions related to disease activity. After treatment, 99mTc-tetrofosmin uptake disappeared or decreased, correlating well with radiological and clinical findings. Technetium-99m-tetrofosmin scintigraphy may have a complementary role in the assessment of APTB as well as in follow-up treatment.

Topics: Adolescent; Adult; Aged; Female; Follow-Up Studies; Humans; Lung; Male; Metabolic Clearance Rate; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiography, Thoracic; Radionuclide Imaging; Radiopharmaceuticals; Sputum; Tissue Distribution; Tuberculosis, Pulmonary

99Tcm-tetrofosmin planar imaging was performed in 30 patients with malignant and benign lung lesions. There were 21 cases of primary lung cancer (10 squamous cell, 5 small cell, 4 adenocarcinoma and 2 large cell) and 9 benign lung lesions (4 pneumonia, 3 tuberculosis, 1 infected bronchiectasis and 1 bronchiectasis obliterans). Anterior and posterior planar thorax images were obtained 30 min after the intravenous injection of 740 MBq (20 mCi) of 99Tcm-tetrofosmin. Visual and quantitative evaluations were performed. For the quantitative evaluation, regions of interest were drawn over the lesioned area (L) and over the contralateral non-lesioned area (N). Of 21 malignant primary lesions; 19 (90%) showed 99Tcm-tetrofosmin accumulation. Four (44%) of the nine benign lung lesions (3 cases of pneumonia and the one case of active tuberculosis) showed uptake. The mean L/N ratios for the malignant and benign lesions were 1.63 +/- 0.29 and 1.64 +/- 0.19, respectively. There were no significant differences (P > 0.05) in the L/N ratios of the malignant and benign lesions or the various histological types of cancer. In conclusion, 99Tcm-tetrofosmin was highly sensitive (90%) in detecting malignant lung lesions, but it had poor specificity (55%).

Topics: Adenocarcinoma; Adult; Aged; Bronchiectasis; Bronchiolitis Obliterans; Carcinoma, Large Cell; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Evaluation Studies as Topic; Female; Humans; Lung Diseases; Lung Neoplasms; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Pneumonia; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity; Tuberculosis, Pulmonary