Fractional retention of technetium-99m-sestamibi as an index of P- glycoprotein expression in untreated breast cancer patients(1374 views) Del Vecchio S, Ciarmiello A, Pace L, Potena MI, Carriero MV, Mainolfi C, Thomas R, D'Aiuto G, Tsuruo T, Salvatore M
Keywords: Breast Carcinoma, Multidrug Resistance, P-Glycoprotein, Technetium-99m-Sestamibi, Methoxy Isobutyl Isonitrile Technetium Tc 99m, Monoclonal Antibody, Monoclonal Antibody Mrk 16, Unclassified Drug, Article, Autoradiography, Breast Cancer, Cancer Resistance, Clinical Article, Controlled Study, Drug Uptake, Female, Human, Intravenous Drug Administration, Priority Journal, Protein Expression, Radioisotope Distribution, Breast Neoplasms, Multiple, Immunoenzyme Techniques, Neoplasm Proteins, Risk Factors, Technetium Tc 99m Sestamibi,
Affiliations: Medicina Nucleare, Fac. di Medicina e Chirurgia, Via Pansini, 5, 80131 Naples, Italy
References: Not available.
Fractional retention of technetium-99m-sestamibi as an index of P- glycoprotein expression in untreated breast cancer patients
The multidrug-resistant phenotype is characterized by the reduced intracellular retention of several structurally and functionally unrelated cytotoxic compounds due to the energy-dependent pump activity of P- glycoprotein (Pgp). Because (99m)Tc-sestamibi is a suitable transport substrate of Pgp, we tested whether the time-dependent fractional retention of this tracer could be used as an index of Pgp expression in untreated breast carcinomas. Methods: Twenty-seven patients with histologically confirmed breast carcinoma were intravenously injected with 740 MBq (20 mCi) of (99m)Tc-sestamibi, and static planar images of the breast were obtained at 10, 60 and 240 min. The fractional retention of (99m)Tc-sestamibi was then calculated as the ratios between 60 and 10 min (R60/10) and between 240 and 10 min (R240/10) of decay-corrected counts/pixel registered in the region of interest drawn around the tumor. Surgically excised tumors were then obtained from each patient, and Pgp levels were determined using 125I- labeled MRK16 monoclonal antibody and in vitro quantitative autoradiography. Results: The fractional retention of (99m)Tc-sestamibi at 60 and 240 min was significantly higher in tumors with low Pgp levels (Group I, n = 18) as compared to that measured in tumors with high Pgp expression (Group II, n = 9) (13 < 0,001). In particular, R60/10 values were 0.86 and 0.59 in breast carcinomas of Groups I and II, respectively, whereas the values of R240/10 were 0.55 and 0.25 in low- and high-Pgp-expressing tumors, respectively. Conclusion: The determination of fractional retention of (99m)Tc-sestamibi may be used as a simple functional test for Pgp expression in untreated breast cancer. A preliminary estimate of the sensitivity and the specificity of the test indicates its potential use in clinical practice to identify patients with a high probability of developing multidrug resistance.
Fractional retention of technetium-99m-sestamibi as an index of P- glycoprotein expression in untreated breast cancer patients
No results.
Fractional retention of technetium-99m-sestamibi as an index of P- glycoprotein expression in untreated breast cancer patients
Hesse B, Tagil K, Cuocolo A, Anagnostopoulos C, Bardies M, Bax J, Bengel F, Busemann Sokole E, Davies G, Dondi M, Edenbrandt L, Franken P, Kjaer A, Knuuti J, Lassmann M, Ljungberg M, Marcassa C, Marie PY, Mckiddie F, O'connor M, Prvuolovich E, Underwood R * 3. 0 T perfusion MR imaging(876 views) Rivista Di Neuroradiologia (ISSN: 1120-9976), 2004; 17(6): 807-812. Impact Factor:0.023 ViewExport to BibTeXExport to EndNote