Early chemotherapy response evaluation in tumors by 99mTc-DTPA-DG.

Abstract

PURPOSE:

The aim of this study was to evaluate the utility of 99mTc-diethylenetriaminepentaacetic acid-deoxyglucose (DTPA-DG) for monitoring the early response of tumors to chemotherapy.

METHOD:

To evaluate the role of 99mTc-DTPA-DG in vitro chemotherapy, the uptake ratios assays were conducted using A549 lung cancer and MCF-7 breast cancer cells after the 2 tumor cell types had been treated with cisplatin and paclitaxel chemotherapeutic agents, respectively. Apoptosis in the 2 cell types, an indicator of chemotherapeutic action, was assessed by inverted fluorescence microscope and flow cytometry. The assessment of 99mTc-DTPA-DG in vivo was performed by scintigraphic imaging studies of 99mTc-DTPA-DG in MCF-7 mammary tumor cell xenografts at timed intervals after treatment. The animals were randomly assigned to 5 groups: group A, saline injection; group B, low-dose cisplatin; group C, high-dose cisplatin; group D, low-dose combination chemotherapy; and group E, high-dose combination chemotherapy. Imaging findings were correlated with the effectiveness of chemotherapy.

RESULTS:

The uptake rates of 99mTc-DTPA-DG by A549 lung cancer cells and MCF-7 breast cancer cells in the chemotherapeutic groups were all significantly lower than those in the controls (p < 0.01). The apoptotic ratios in the control groups were significantly lower than the apoptotic ratios in the chemotherapeutic treatment groups in the 2 tumor cell types. The uptake ratios and the apoptosis ratios are inverse correlation, which suggested that we could evaluate the chemotherapy response by the uptake of 99mTc-DTPA-DG in vitro. Scintigraphy in MCF-7 mammary tumor xenografts mice demonstrated that tumor could be clearly visualized by 99mTc-DTPA-DG. The efficacy of combined chemotherapy treatment in this xenograft model was assessed by scintigraphy of tumor/muscle ratios.

CONCLUSIONS:

99mTc-DTPA-DG is a targeted molecular imaging agent, promising in the evaluation of early response of tumors to chemotherapy.

• Authors: Jie Liang, Yue Chen, Zhanwen Huang, Yanling Zhao, Ling He
• Journal: Cancer biotherapy & radiopharmaceuticals (Cancer Biother Radiopharm) Vol. 23 Issue 3 Pg. 363-70 (Jun 2008) ISSN: 1557-8852 [Electronic] United States
• PMID: 18593369 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antineoplastic Agents
• Radiopharmaceuticals
• technetium 99m diethylenetriaminepentaacetate-deoxyglucose
• Technetium Tc 99m Pentetate

Topics

• Animals
• Antineoplastic Agents (pharmacology)
• Apoptosis
• Cell Line, Tumor
• Cell Nucleus (metabolism)
• Flow Cytometry
• Humans
• Lung Neoplasms (diagnosis, drug therapy)
• Mammary Neoplasms, Animal (diagnosis, drug therapy)
• Mice
• Mice, Nude
• Microscopy, Fluorescence
• Neoplasm Transplantation
• Radiopharmaceuticals (pharmacology)
• Technetium Tc 99m Pentetate (analogs & derivatives, pharmacology)
• Time Factors