Therapeutic ultrasound for tumours
Reviewed by Guari Mankekar

This review article provides details about the potential applications of transcranial focused ultrasound (FUS), its mechanism of action and the studies that have set the basis for its use in neuro-oncology. FUS is an emerging modality of therapy for various diseases of the brain. Despite the fact that focused ultrasound was described more than 50 years ago, technological challenges prevented it from being introduced in medical practice. Using transducers or arrays, FUS delivers focused energy. The high rate of energy deposited in one focused area leads to heat generation with lethal and sublethal effects such as tumour ablation especially ablating deep seated tumours inaccessible surgically. FUS has been used extensively in research animals for ablative treatment, opening the blood brain barrier for targeted drug delivery and immunomodulation. Currently clinical trials are being conducted to investigate the applications and safety of FUS. Sonodynamic therapy, radiosensitisation, enhanced local drug delivery and other roles of FUS have therefore not yet been established. The role of MR guided FUS (MRgFUS) has been extensively studied for drug delivery to brain tumours. MRgFUS mechanically opens the blood brain barrier in a targeted, focused area transiently to deliver drugs like liposome encapsulated doxorubicin. FUS and MRgFUS offer exciting and innovative technology for the management of not only brain tumours but potentially also for deep seated tumors located in the head–neck region.

Emerging applications of therapeutic ultrasound in neuro-oncology: moving beyond tumor ablation.
Hersh DS, Kim AJ, Winkles JA, et al.
NEUROSURGERY
2016;79(5):643-54.