Thermal ablation of brain tumors
Development of image-guided interstitial probes for the characterization and minimally invasive treatment of brain tumours (SIGI project)
Conventional treatments for both primary and secondary metastatic brain tumors involve surgical resection of the lesion in combination with chemotherapy or radiotherapy. Although these treatment strategies are effective in many patients, up to 20% of patients fail such treatments.
In this project, an alternative treatment approach using a newtherapeutic ultrasound device is being developed for treating brain tumors.The ultrasound devices we are developing are miniaturized interstitial devices that are MR compatible. These devices can be inserted through a small burr hole in the skull and be used to thermally ablate tumors. Precise temperature maps and predictions of cell death can be made in real-time during treatments with a magnetic resonance imaging (MRI) system. Temperatures in the tumor can reach greater than 50°C after several minutes of heating, which is sufficient to achieve cell death. Furthermore, interstitial devicescan be built with many independent ultrasound elements and a broad frequency range for additional shaping of the geometry of the heated region to conform to the tumor volume. This novel interstitial ultrasound approach may yield a new treatment strategy for patients who fail conventional brain tumor treatments.
Fig1: A prototype MRI-compatible ultrasound transducer with a 4-mm diameter that can be used for performing interstitial thermal ablation of tumors.
Fig2: Temperature maps obtained using MR monitoring during four minutes of heating in a tissue-mimicking phantom with a prototype interstitial ultrasound probe. The maximum temperature rise is shown in the upper left hand corner.