title: Intercomparison of dose distribution between gamma knife and C-arm-mounted linac.
abstract: Although the Gamma Knife is widely used as a standard tool of radiosurgery for intracranial diseases, recent innovations in medical accelerators have actualized equivalent dose distribution. Most commonly, multiple non-coplanar arc beams through a combination of gantry and couch rotations are used in linac-based radiosurgery, but beam entry geometry is different from that with the Gamma Knife. We have developed a C-arm-mounted medical accelerator and realized conical beam entry without couch rotation. A combination of several conical rotation beams with different C-arm angles comprises multi-orbit dynamic conical radiation therapy (MODCRT) and resembles radiation beam entry with the Gamma Knife. Intercomparison of dose distributions and dose-volume histograms for the same brain tumor demonstrated that MODCRT delivers a similar dose fall-off pattern to that obtained with the Gamma Knife, though the low-dose spread patterns differ.
mesh_terms: D001932:Brain Neoplasms / Q000601:surgery; D006801:Humans; D011829:Radiation Dosage; D016634:Radiosurgery / Q000295:instrumentation*