title: The role of Tc-99m sestamibi imaging in predicting clinical response to chemotherapy in lung cancer.
abstract: Multidrug resistance (MDR) is a major problem in lung cancer. Tc-99m methoxyisobutyl isonitrile (MIBI) has been demonstrated to be a non-invasive marker to diagnose MDRI related P-glycoprotein (Pgp) and multidrug resistance-associated protein (MRP) expression in various solid tumors. The aim of this study was to evaluate the relationship between the degree of Tc-99m MIBI uptake and its retention on delayed images and the response to chemotherapy in lung cancer. Twenty-three patients (1 woman and 22 men, age range 40-67 years) with lung cancer (9 small cell and 14 non-small cell) were examined with Tc-99m MIBI imaging before chemotherapy. After i.v. administration of 740 MBq Tc-99m MIBI, planar and SPECT imaging at 30 minutes and 2 hours was performed. Tumor to normal lung uptake ratio (T/N) and percent retention were measured. Response to chemotherapy was evaluated according to follow-up CT and grouped as complete responders (CR), partial responders (PR) and non-responders (NR). Clinical follow-up and CT evaluation revealed that 12 patients had partial remission, 4 patients had complete remission and 7 patients had no-remission after chemotherapy. Statistically, there was no significant correlation between early (30 min), delayed (2 hr) T/N ratios and percent retention of Tc-99m MIBI with chemotherapeutic response of the lung cancer among the three groups (p > 0.05). Results of the current study imply that Tc-99m MIBI uptake and the retention index may not correlate with chemotherapy response in lung cancer, so that the accuracy of this method needs to be verified in a larger series with additional investigation at the molecular level.
authors.affiliation: Department of Nuclear Medicine, Medical Faculty, Ege University, Izmir, Turkey. ayseguld@med.ege.edu.tr
authors.forename: Aysegul
authors.initials: A
authors.lastname: Dirlik
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Burak
authors.forename: Tuncay
authors.initials: T
authors.lastname: Goksel
authors.forename: Ruya
authors.initials: R
authors.lastname: Erinc
authors.forename: Haydar
authors.initials: H
authors.lastname: Karakus
authors.forename: Zehra
authors.initials: Z
authors.lastname: Ozcan
authors.forename: Ali
authors.initials: A
authors.lastname: Veral
authors.forename: Mustafa
authors.initials: M
authors.lastname: Ozhan
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000188:drug therapy; D018288:Carcinoma, Small Cell / Q000000981:diagnostic imaging / Q000188:drug therapy; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D000970:Antineoplastic Agents; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi