Findings recently reported by Lili Chen, Ph.D., Associate Professor and medical physicist in the Radiation Oncology Department of Fox Chase Cancer Center in Philadelphia, indicate that MR-guided focused ultrasound has the potential to increase the efficacy of docetaxel in treating prostate cancer.
Supported by a Foundation research award totaling $102,324, Chen set out to answer two key questions:
1) Would high intensity focused ultrasound increase the cellular uptake of the chemotherapy drug, docetaxel, in vivo?
2) Would increased uptake of docetaxel combined with radiotherapy enhance tumor growth inhibition?
To obtain answers, Chen and her colleagues had to first determine technical parameters for optimal ultrasound output. These parameters included frequency, acoustic power and pulse width that are adequate to enhance the efficacy of chemotherapy in mice. Next, they developed an optimal MR imaging protocol so MR guidance could be used for the focused ultrasound treatment.
Once technical parameters had been established, Chen and colleagues conducted two in vivo experiments. In the first, they treated one cohort with pulsed MR-guided focused ultrasound and docetaxel; treated a second with the drug only; and, used a third cohort as a control group. Results of that experiment showed that the cohort receiving MR-guided focused ultrasound tolerated it well. That cohort also had a higher uptake of docetaxel than the drug-only group.
Chen’s second in vivo experiment investigated if docetaxel plus MR-guided focused ultrasound improved prostate tumor control. Four study cohorts were used. The first was treated with a combination of focused ultrasound and docetaxel once a week for two consecutive weeks. The second received docataxel only, and the third received focused ultrasound only. The fourth cohort served as a control group.
