Minimally invasive thermal brain treatment
From a reading of recent neurosurgical literature with a search focus on intracranial applications, a list of thermal agents and related minimally invasive techniques was drawn; this list was supplemented by our own research experience. Thermal agents which are either implemented in clinical practice or undergoing active research include: Radioffequency current, laser light, microwave electromagnetic radiation, ultrasound and cryogens. Therapies include percutaneous coagulation of small targets which are less than half of one cubic centimeter as for rhizotomy for trigeminal neuralgia and pallidotomy for kinetic disorders, as well as interstitial hyperthermia and/or coagulation of large tumors which range up to centimeters in diameter. Implementation of a thermal agent for therapy evolves in a dynamic interaction between the specific technology and an understanding cf the tissue properties governing the agent's therapeutic effect. Minimally invasive techniques require methods to define, visualize and approach targeted tissue, and to monitor (and thereby control) the extent of the thermal âlesion.' Over the twentieth century, concomitant with advances in neurosurgery and radiology, technologies have been developed with which to approach the twenty-first century in pursuit of these minimally invasive thermal interventions which are, as of yet, new and underdeveloped.