technetium-tc-99m-tetrofosmin and Lymphoma

[(99m)TC]sestamibi and [(99m)TC]tetrofosmin are two lipophilic cationic complexes which were originally employed in myocardial perfusion imaging and then later applied as tumor-seeking agents in the evaluation of diverse human malignancies. Despite the wider use of fluorine-18-labeled fluorodeoxyglucose positron emission tomography (FDG-PET) in cancer imaging, the two cationic lipophilic agents still play a useful clinical role in oncology when single-photon emission computed tomography (SPET) instead of planar is used as the acquisition method. This review summarizes the results of studies on the use of these radiopharmaceuticals in lung cancer, malignant lymphomas and brain tumors. Their performance in the diagnosis and staging of the primary tumor, the prediction of cancer response to therapy, the monitoring of treatment and the detection of recurrence during follow-up is also compared. Numerous studies have shown that SPET procedures are highly sensitive and accurate in tumor patient management. However, the main limitation to both SPET and planar imaging alike is that under some conditions the images do not give a clear structural delineation of the pathologic processes detected with these procedures. This sometimes makes SPET images difficult to interpret and so reduces its diagnostic performance. Recently available hybrid SPET/CT devices appear to overcome this problem by providing both functional and anatomical data. Preliminary reports on SPET/CT in tumor imaging have demonstrated that SPET/CT can provide more clinical information than SPET or CT alone in some cases. The possible role of integrated dual-modality images using SPET with SM or TF is also briefly discussed.

Topics: Brain Neoplasms; Humans; Lung Neoplasms; Lymphoma; Medical Oncology; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Subtraction Technique; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Non-invasive imaging methods in the evaluation of chemotherapy response in malignant tumours are currently being explored. Standard Nuclear Medicine procedures seem to offer the clinician a promising tool in the management of those oncologic patients, who might benefit from chemotherapy. Early studies focused on the relationship between radionuclides used in tumour diagnosis and factors associated with multidrug resistance (MDR). The tumour expression of P-glycoprotein (Pgp) and multidrug resistance-related protein-1 expression (MRP) have been suggested as important factors in the failure of chemotherapy. Most studies found an association between Pgp levels and (99m)Tc-sestamibi ((99m)Tc-MIBI) or (99m)Tc-Tetrofosmin uptake ((99m)Tc-TF). Currently investigations in nuclear medicine oncology are focusing on the potential role of radionuclide imaging in the assessment of chemotherapy. Recent papers discuss the usefulness of radionuclides as (99m)Tc-MIBI and (99m)Tc-TF as non-invasive procedures to predict and to monitor therapy response in patients affected by malignant tumours treatable using chemotherapy. This chapter will review the latest development in (99m)Tc-TF, giving an overview of recent investigations carried out using this radiotracer in therapy oncology, with emphasis on its potential role as predictor of tumour response.

Topics: Adult; Aged; Antineoplastic Agents; ATP Binding Cassette Transporter, Subfamily B, Member 1; Breast Neoplasms; Drug Resistance, Multiple; Female; Humans; Lung Neoplasms; Lymphoma; Male; Melanoma; Middle Aged; Multidrug Resistance-Associated Proteins; Neoplasms; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Sestamibi; Treatment Failure; Treatment Outcome

Technetium-99m (99mTc) tetrofosmin has been used as a tumor-seeking agent. However, its role in detecting lymphomas has not been widely investigated. The aim of the present study was to determine the uptake and clearance characteristics of 99mTc tetrofosmin in lymphoma cell lines. 99mTc sestamibi was also evaluated for comparison. Three lymphoma cell lines (U-937: monocyte-like, histiocytic lymphoma, human; RAMOS: B-lymphoma cell line, American Burkitt lymphoma, lymphoblastoid, human; Hs445: Hodgkin's disease, lymphoid, human) were studied. After incubation of radiotracers 99mTc tetrofosmin and 99mTc sestamibi in medium for 0, 10, 20, 30, 60, 120 and 180 min, the uptake and clearance of each radiotracer were measured in the three lymphoma cell lines. The uptake of 99mTc tetrofosmin was lower than that of 99mTc sestamibi in these lymphoma cell lines. Among the three cell lines, Hs445 showed the greatest 99mTc tetrofosmin uptake capacity. RAMOS and U-937 showed similar 99mTc tetrofosmin uptake capacities. 99mTc tetrofosmin accumulated in the three tested lymphoma cell lines, especially in the Hodgkin's disease cell line. However, in comparison with 99mTc sestamibi, 99mTc tetrofosmin may not be the best radiotracer for detection of lymphoma.

Topics: Biological Transport; Hodgkin Disease; Humans; Kinetics; Lymphoma; Lymphoma, B-Cell; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Technetium Tc 99m Sestamibi; Tumor Cells, Cultured

The purposes of this study were to predict the chemotherapy response of untreated malignant lymphomas (ML) using a technetium-99m tetrofosmin (Tc-TF) scan and to compare Tc-TF results with P-glycoprotein (Pgp) expression. Before undergoing chemotherapy, 25 patients with ML were enrolled in this study. Tc-TF scan was performed 10 min after intravenous injection of Tc-TF. Immunohistochemical analyses were performed on multiple sections of ML specimens to evaluate Pgp expression. The chemotherapy response was evaluated in the first 1-2 years after the completion of treatment. The mean tumor-to-background ratio of the 15 patients with good responses (3.23+/-0.56) was significantly higher than that of the ten patients with poor responses (1.18+/-0.11). All of the 15 patients with good responses had positive Tc-TF scan results, but negative Pgp expression. Among the ten patients with poor responses, all had negative Tc-TF scan results, but six had positive Pgp expression and four had negative Pgp expression. Significant differences in the incidences of good and poor responses were found between patients with positive Tc-TF scan results and patients with negative Tc-TF scan results and between patients with positive Pgp expression and patients with negative Pgp expression. No significant differences in the incidences of good and poor responses were found between Hodgkin's disease patients and non-Hodgkin's lymphoma patients, stage I-II patients and III-IV patients, patients aged >40 and patients aged < or =40 years, and patients with and without B symptoms. Compared with other prognostic factors, Tc-TF scan results and Pgp expression more accurately predict the chemotherapy response in patients with ML.

Topics: Adult; Aged; ATP Binding Cassette Transporter, Subfamily B, Member 1; Disease Progression; Female; Humans; Lymphoma; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Prognosis; Radiopharmaceuticals