technetium-tc-99m-tetrofosmin and Thymus-Neoplasms

Thymoma is an uncommon tumour, which is often asymptomatic and may be detected coincidentally on cross-sectional imaging performed for other reasons. We report a case of thymoma detected on myocardial scintigraphy performed for suspected coronary artery disease. Extracardiac pathology may be suggested by abnormal non-cardiac tracer uptake on myocardial scintigraphy. An awareness of the potential causes of this is essential to allow potentially life threatening non-cardiac disorders to be recognized and treated promptly.

Topics: Aged; Coronary Disease; Diagnosis, Differential; Humans; Incidental Findings; Male; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Thymoma; Thymus Neoplasms; Tomography, X-Ray Computed

Topics: Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography; Female; Heart Diseases; Humans; Incidental Findings; Middle Aged; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Thymoma; Thymus Neoplasms

Topics: Diagnosis, Differential; Humans; Male; Mediastinal Neoplasms; Middle Aged; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Thymoma; Thymus Neoplasms; Tomography, Emission-Computed, Single-Photon

99mTc-tetrofosmin single photon emission computed tomography (SPECT) is routinely used in the evaluation of coronary artery disease. A variety of different tumors, however, also demonstrate 99mTc-tetrofosmin uptake. We report six patients found with unexpected mediastinal and thoracic tumor uptake during Tc-tetrofosmin myocardial perfusion scintigraphy (MPS).. We investigated 2,155 patients with Tc-tetrofosmin MPS during 2006-2007. One thousand four hundred and eighty-six of these patients had no coronary history and were sent to our department due to newly developed thoracic complaint such as chest pain, dyspnea and others. Six hundred and sixty-nine patients had coronary history. All patients underwent 99mTc-tetrofosmin exercise study. Patients with unexpected extracardiac Tc-tetrofosmin findings during MPS were referred to PET/CT for further diagnostic investigation. Region of interest (ROI; 99mTc-tetrofosmin) and SUVmax (2-[F]fluoro-2-deoxy-D-glucose, F-FDG) were estimated and the results were compared with histological findings.. Abnormal mediastinal and/or thoracic activities were visualized in six of the 2,155 patients with 99mTc-tetrofosmin images. Subsequently, the patients underwent resection of a thymoma (n=2), nonsmall cell lung cancer (n=1) and breast cancer (n=3). In the patients with breast cancer one was a male patient with ductal, invasive breast cancer. Benign thymomas showed high 99mTc-tetrofosmin ROI >4.0 and low F-FDG SUVmax <2.0, whereas low 99mTc-tetrofosmin ROI <2.0 were found in nonsmall cell lung cancer and breast cancer and high F-FDG SUVmax >2.5 in these malignant tumors.. During Tc-tetrofosmin SPECT exercise stress tests performed in patients with suspected coronary artery disease, much more attention must be given to unexpected extracardiac uptakes. With 99mTc-tetrofosmin a large variety of different unknown tumors can be detected during MPS.

Topics: Aged; Breast Neoplasms, Male; Carcinoma, Non-Small-Cell Lung; Coronary Artery Disease; Female; Fluorodeoxyglucose F18; Heart; Humans; Lung Neoplasms; Male; Middle Aged; Myocardial Perfusion Imaging; Organophosphorus Compounds; Organotechnetium Compounds; Positron-Emission Tomography; Radiography; Radiopharmaceuticals; Thymoma; Thymus Neoplasms; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon

Thymoma is the most common primary tumor of the anterior mediastinum, accounting for 20% to 30% of all mediastinal tumors. The recurrence rate after total resection of the thymoma ranges from 8% to 18%. The authors describe a patient with recurrent malignant thymoma imaged with Tc-99m MIBI, Tc-99m tetrofosmin, and Tc-99m (V) DMSA. Early and delayed Tc-99m MIBI and Tc-99m tetrofosmin scintigraphy showed increased uptake in the mediastinal area, as did Tc-99m (V) DMSA scintigraphy. Coronal SPECT images obtained with Tc-99m MIBI, Tc-99m tetrofosmin, and Tc-99m (V) DMSA showed increased uptake in the mediastinal lesion seen on a computed tomograph of the chest. However, the normal blood-pool activity of the heart and great vessels imaged with Tc-99m (V) DMSA obscured the recurrent malignant thymoma. Although Tc-99m (V) DMSA is a useful tumor-seeking agent, Tc-99m MIBI and Tc-99m tetrofosmin SPECT are preferred to Tc-99m (V) DMSA to detect primary and recurrent malignant thymoma.

Topics: Aged; Female; Humans; Neoplasm Recurrence, Local; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Dimercaptosuccinic Acid; Technetium Tc 99m Sestamibi; Thymoma; Thymus Neoplasms

Topics: Aged; Humans; Male; Neoplasms, Multiple Primary; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sensitivity and Specificity; Thymoma; Thymus Neoplasms; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Topics: Adult; Female; Humans; Organophosphorus Compounds; Organotechnetium Compounds; Red-Cell Aplasia, Pure; Technetium; Thymoma; Thymus Neoplasms; Tomography, Emission-Computed, Single-Photon; Whole-Body Counting

Thallium (Tl) 201 and technetium (Tc) 99m tetrofosmin single-photon emission CT are routinely used in the evaluation of coronary artery disease. Mediastinal tumors demonstrate Tl 201 and Tc 99m tetrofosmin uptake. We report a 56-year-old man who developed chest pain after a previously successful angioplasty and stent of the left anterior descending coronary artery. He underwent a Tl 201, Tc 99m tetrofosmin exercise study. Abnormal mediastinal activity was visualized in both the Tl 201 and Tc 99m tetrofosmin images. Subsequently, the patient underwent resection of a stage II thymoma. Unanticipated focal extracardiac accumulation during myocardial scintiscanning should lead to further investigation to exclude mediastinal tumor.

Topics: Coronary Disease; Exercise Test; Humans; Male; Middle Aged; Neoplasms, Unknown Primary; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Thallium Radioisotopes; Thymectomy; Thymoma; Thymus Neoplasms; Tomography, Emission-Computed, Single-Photon

99mTc-tetrofosmin, Thallium-201-chloride (201Tl) and 99mTc-MIBI imagings were performed in a patient with malignant thymoma. Tracer uptake in the primary tumor was demonstrated. The tumor-to-background ratios of planar and SPECT imagings were 1.60 and 1.98 for 99mTc-tetrofosmin, 1.12 and 2.09 for 201Tl, and 1.19 and 1.80 for 99mTc-MIBI, respectively. In another patient 99mTc-tetrofosmin and 201Tl imagings were performed. Not only the primary tumor but also the direct invasions and metastatic lesions (bone metastases) were clearly detected. The tumor-to-background ratios of planar and SPECT imagings were 2.31 and 2.78 for 99mTc-tetrofosmin and 2.45 and 3.58 for 201Tl, respectively. In 99mTc-tetrofosmin scintigraphy we acquired delayed images, and the tumor-to-background ratios of planar and SPECT delayed images were 1.20 and 1.86, the retention ratios were -1.11 and -0.92 and the retention indices were -48.1 and -33.1, respectively. Our preliminary results suggest that 99mTc-tetrofosmin is useful in detecting not only the primary tumor but also metastatic lesions from malignant thymoma.

Topics: Aged; Bone Neoplasms; Humans; Male; Organophosphorus Compounds; Organotechnetium Compounds; Technetium Tc 99m Sestamibi; Thallium Radioisotopes; Thymoma; Thymus Neoplasms; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed