TY - JOUR
T1 - Localised hyperthermia in rodent models using an MRI-compatible high-intensity focused ultrasound system
AU - Bing, Chenchen
AU - Nofiele, Joris
AU - Staruch, Robert
AU - Ladouceur-Wodzak, Michelle
AU - Chatzinoff, Yonatan
AU - Ranjan, Ashish
AU - Chopra, Rajiv
N1 - Funding Information:
Financial support for this study was provided by the Cancer Prevention and Research Initiative of Texas, grant nos. R1308, 1R01CA199037-01 and generous donation from the M.R. and Evelyn Hudson Foundation. R.S. is an employee of Philips Research. R.C. is a co-founder of FUS Instruments, the company that manufactured the preclinical focused ultrasound system that was adapted in this study for hyperthermia exposures. The company provided no financial support for this study. The other authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
Publisher Copyright:
© 2015 Taylor & Francis.
PY - 2015/11/17
Y1 - 2015/11/17
N2 - Purpose: Localised hyperthermia in rodent studies is challenging due to the small target size. This study describes the development and characterisation of an MRI-compatible high-intensity focused ultrasound (HIFU) system to perform localised mild hyperthermia treatments in rodent models. Material and methods: The hyperthermia platform consisted of an MRI-compatible small animal HIFU system, focused transducers with sector-vortex lenses, a custom-made receive coil, and means to maintain systemic temperatures of rodents. The system was integrated into a 3T MR imager. Control software was developed to acquire images, process temperature maps, and adjust output power using a proportional-integral-derivative feedback control algorithm. Hyperthermia exposures were performed in tissue-mimicking phantoms and in a rodent model (n = 9). During heating, an ROI was assigned in the heated region for temperature control and the target temperature was 42 °C; 30 min mild hyperthermia treatment followed by a 10-min cooling procedure was performed on each animal. Results: 3D-printed sector-vortex lenses were successful at creating annular focal regions which enables customisation of the heating volume. Localised mild hyperthermia performed in rats produced a mean ROI temperature of 42.1 ± 0.3 °C. The T10 and T90 percentiles were 43.2 ± 0.4 °C and 41.0 ± 0.3 °C, respectively. For a 30-min treatment, the mean time duration between 41-45 °C was 31.1 min within the ROI. Conclusions: The MRI-compatible HIFU system was successfully adapted to perform localised mild hyperthermia treatment in rodent models. A target temperature of 42 °C was well-maintained in a rat thigh model for 30 min.
AB - Purpose: Localised hyperthermia in rodent studies is challenging due to the small target size. This study describes the development and characterisation of an MRI-compatible high-intensity focused ultrasound (HIFU) system to perform localised mild hyperthermia treatments in rodent models. Material and methods: The hyperthermia platform consisted of an MRI-compatible small animal HIFU system, focused transducers with sector-vortex lenses, a custom-made receive coil, and means to maintain systemic temperatures of rodents. The system was integrated into a 3T MR imager. Control software was developed to acquire images, process temperature maps, and adjust output power using a proportional-integral-derivative feedback control algorithm. Hyperthermia exposures were performed in tissue-mimicking phantoms and in a rodent model (n = 9). During heating, an ROI was assigned in the heated region for temperature control and the target temperature was 42 °C; 30 min mild hyperthermia treatment followed by a 10-min cooling procedure was performed on each animal. Results: 3D-printed sector-vortex lenses were successful at creating annular focal regions which enables customisation of the heating volume. Localised mild hyperthermia performed in rats produced a mean ROI temperature of 42.1 ± 0.3 °C. The T10 and T90 percentiles were 43.2 ± 0.4 °C and 41.0 ± 0.3 °C, respectively. For a 30-min treatment, the mean time duration between 41-45 °C was 31.1 min within the ROI. Conclusions: The MRI-compatible HIFU system was successfully adapted to perform localised mild hyperthermia treatment in rodent models. A target temperature of 42 °C was well-maintained in a rat thigh model for 30 min.
KW - Heat-targeted drug delivery
KW - MR-HIFU
KW - mild hyperthermia
KW - nanoparticles
KW - non-invasive thermometry
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U2 - 10.3109/02656736.2015.1094833
DO - 10.3109/02656736.2015.1094833
M3 - Article
C2 - 26540488
AN - SCOPUS:84953355035
SN - 0265-6736
VL - 31
SP - 813
EP - 822
JO - International Journal of Hyperthermia
JF - International Journal of Hyperthermia
IS - 8
ER -