Effect of hydrogen peroxide on the sustained release of 99mTc-labeled cytarabine in melanoma of C57 mice by ECT imaging pharmacology.

e15569 Background: To investigate the residence time of 99mTc-labeled cytarabine in mouse tumors under ECT imaging. Methods: The subcutaneous solid tumor model of mice was established by injection of melanoma cell suspension into the left forelimb of C57 mice. The tumor-bearing mice were divided into treatment group and control group when the longest diameter of the tumor was 5-8 mm. Group 3 only. The mice in the control group were given intratumoral injection of 0.1 ml of 99mTc-labeled cytarabine solution, and the mice in the treatment group were given intratumoral injection 0.1 ml 99mTc labeled cytarabine combined with hydrogen peroxide solution at 0.25 h, 0.5 h, 1 h. After 2 hours and 19 hours of administration, the radioactivity intensity values were observed by SPECT Apx-409 ECT phenomenon equipment. Results: The T/W values of ECT imaging in 3 mice in the treatment group were higher than those in the control group at 0.25 h, 0.5 h, 1 h, 2 h and 19 h. The T/W values of ECT imaging decreased in the treatment group at different time points. The amplitude was lower, and the T/W values in each period were higher than those in the control group. Conclusions: The sustained release agent hydrogen peroxide can significantly increase the residence time of 99mTc-labeled cytarabine in the tumor. It is speculated that hydrogen peroxide has a positive effect on prolonging the drug action time of cytarabine and improving the effect of killing tumor cells. It showed that H2O2 can hold the Ara-C for a long time in tumor.