Figure 4.

Controlled Dox release from TSL-Dox with closed-loop MRgFUS hyperthermia in a F98 rat brain tumor. (A) Data from a representative experiment during FUS-induced mild hyperthermia in healthy rats using MR thermometry-based closed-loop controller (42.5 ± 1 °C). The controller was able to reach the threshold temperature (42.5 °C) within few seconds and remain at it for several minutes (±1 °C). It was found that cooling the water below 15 °C can eliminate brain damage due to skull-heating. (B) Top: representative contrast enhanced MRI (T₁ weighted) image of the F98 tumor in rat. Bottom: representative MR thermometry image during the application of closed-loop FUS-induced mild hyperthermia the F98 tumor in rat. (C) Comparison of average fluorescence intensities between different treatment groups: i) Control - No Drug, ii) TSL-Dox - No Heat, iii) TSL-Dox + Heat at 42.5 °C) (p ≤ 0.05). The number of rats used per group was 4.