Functional retention of Tc-99m MIBI in mediastinal lymphomas as a predictor of chemotherapeutic response demonstrated by consecutive thoracic SPECT imaging.
Tc-99m MIBI is used as a tumor imaging agent and has been proposed to measure p-glycoprotein function, which plays an important role in tumor multidrug resistance to chemotherapy. It has been reported that lung cancer and breast cancer with a high retention of Tc-99m MIBI have been more responsive to chemotherapy than tumors with low retention. Thus Tc-99m MIBI SPECT could be used as a measure of p glycoprotein function and consequently may serve as a predictor of the tumor's responsiveness to chemotherapeutic agents. Described here are two patients with lymphomas, one with non-Hodgkin's lymphoma and the other with Hodgkin's disease, who underwent Tc-99m MIBI thoracic SPECT before and after chemotherapy. The sequential studies demonstrated a reduction in tumor size and diminished tumor uptake in one patient and disappearance of tumor uptake after a course of chemotherapy in the other patient. The data suggest that elevated Tc-99m MIBI uptake in a tumor as a result of retention by p glycoprotein not only demonstrates mediastinal involvement of lymphomas but also may be used to forecast responsiveness to chemotherapy.
VA Medical Center, and Division of Nuclear Medicine, University of Kentucky Medical Center, Lexington 40511, USA.
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WJ
Shih
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Rastogi
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Stipp
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Magoun
J
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Coupal
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D006689:Hodgkin Disease / Q000000981:diagnostic imaging* / Q000188:drug therapy; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging* / Q000188:drug therapy; D008297:Male; D008479:Mediastinal Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy; D008875:Middle Aged; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi