Neurosurgeons are involved in "stereotactic radiosurgery" along with radiation oncologists in tumor and AVM treatment. The system is designed for stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT). In 2004, Stoddard began treating patients using stereotactic radiosurgery. Noninvasive stereotactic radiosurgery is, , being compared to standard surgery for certain types of epilepsy. Forms used include stereotactic radiosurgery, such as Gamma knife, Cyberknife or Novalis Tx radiosurgery. During this time Leksell pursued his work on stereotactic radiosurgery and refinement of stereotactic methods. In 1993, Brainlab developed a linear accelerator-based system for stereotactic radiosurgery using micromultileaf collimators. Treatment options include surgery, radiotherapy, radiosurgery, and chemotherapy. Linear accelerators are also widely used in medicine, for radiotherapy and radiosurgery. In addition, pharmacotherapy, radiotherapy, and radiosurgery have been utilized accompanying a surgical procedure. These options are observation, microsurgical removal and radiation (radiosurgery or radiotherapy). AVM-specific treatment may also involve endovascular embolization, neurosurgery or radiosurgery. Treatments for cerebral cavernous hemangiomas include radiosurgery or microsurgery. Experimental treatments include targeted therapy, gamma knife radiosurgery, boron neutron capture therapy and gene therapy. Gamma-knife radiation is the favored mechanism of radiosurgery.