Tracers to Monitor the Response to Chemotherapy: In Vitro Screening of Four Radiopharmaceuticals

Abstract

In the presence of doxorubicin, the uptake of 18F-deoxyglucose, 125I-deoxyuridineribose and, to a lesser extent, 125I-methyltyrosine is more pronouncedly reduced in MDR- cells than in MDR+ cells. The reversal of doxorubicin-resistance of MDR+ cells by verapamil was also reflected by the uptake of 18F-deoxyglucose, 125I-deoxyuridineribose, and 125I-methyltyrosine. 99mTc-tetrofosmin uptake reflected P-glycoprotein expression without exposure to doxorubicin.

Is Technetium-99m Sestamibi Imaging Able to Predict Pathologic Nonresponse to Neoadjuvant Chemotherapy in Breast Cancer? A Meta-analysis Evaluating Current Use and Shortcomings

“…12 99m Tc-sestamibi was originally validated as a transport substrate for Pgp, 13 which is encoded by the multidrug resistance (MDR) gene and functions as an energydependent efflux pump for many drugs. 14,15 At present, 99m Tcsestamibi allows for in vivo assessment of tumor chemoresistance and could potentially identify nonresponding patients early during NAC. For breast functional imaging using 99m Tc-sestamibi, several modalities, such as scintimammography (SMG), breast-specific gimaging (BSGI), and single photon emission computed tomography (SPECT)/computed tomography (CT) have been validated.…”