Yeo SY, Elevelt A, Donato K, van Rietbergen B, Ter Hoeve ND, van Diest PJ, Grüll H
Eindhoven University of Technology, High Tech Campus, The Netherlands
Bone pain resulting from cancer metastases reduces a patient's quality of life. Magnetic Resonance-guided High Intensity Focused Ultrasound (MR-HIFU) is a promising alternative palliative thermal treatment technique for bone metastases that has been tested in a few clinical studies. Here, we describe a comprehensive pre-clinical study to investigate the effects, and efficacy of MR-HIFU ablation for the palliative treatment of osteoblastic bone metastases in rats.
MATERIALS AND METHODS:
Prostate cancer cells (MATLyLu) were injected intra-osseously in Copenhagen rats. Upon detection of pain, as determined with a dynamic weight bearing (DWB) system, a MR-HIFU system was used to thermally ablate the bone region with tumor. Treatment effect and efficacy were assessed using magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT) with technetium-99m medronate (99mTc-MDP), micro-computed tomography (?CT) and histology.
DWB analysis demonstrated that MR-HIFU-treated animals retained 58.6±20.4% of limb usage as compared to 2.6±6.3% in untreated animals (P=0.003). MR-HIFU delayed tumor specific growth rates (SGR) from 29±6 to 13±5%/day (P<0.001). Untreated animals (316.5±78.9mm3) had a greater accumulation of 99mTc-MDP than HIFU-treated animals (127.0±42.7mm3, P=0.004). The total bone volume increase for untreated and HIFU-treated animals was 15.6±9.6% and 3.0±4.1% (P=0.004), respectively. Histological analysis showed ablation of nerve fibers, tumor, inflammatory and bone cells.
Our study provides a detailed characterization of the effects of MR-HIFU treatment on bone metastases, and provides fundamental data, which may motivate and advance its use in the clinical treatment of painful bone metastases with MR-HIFU.
BIOSEB Instruments Used:
Dynamic Weight Bearing 2.0 (BIO-DWB-DUAL)