Radiosurgery with a Linear Accelerator

Abstract

Based on the concepts of Leksell and on recommendations of different Swedish physicists on the use of linear accelerator for radiosurgical use, we developed a new methodology coupling the Talairach stereotactic System with a commercial linac. Anatomical facts encouraged us to use coronal angles of irradiation employing the angular displacement of the linac above the horizontal plane. Different coronal planes are obtained by rotation of the stereotactic frame. The center of the irradiated target coincides with the irradiation and rotation center of the linear accelerator. Multiple targets can be irradiated in the same session. We use as recommended a secondary collimator in heavy alloy. Special software was prepared after different dosimetric controls. The use of a PC allows us to employ 1–6 targets and different collimators to displace the isocenters in order to obtain geometrical isodose modification, and to change the value of each irradiation arc or portions of each arc in some minutes. Simple or sophisticated neurosurgical strategies can be applied in the treatment of frequently irregular shape and volume AVMs.

Brain Metastases: Biology and Comprehensive Strategy from Radiotherapy to Metabolic Inhibitors and Hyperthermia

“…In this case the limiting size of this device are brain metastases with a major diameter = 18 mm or tumor volume ranged from 0.5 to 33 cm 3 (Alexander et al 1995, Lunsford et al 1990. Following the same principle several authors (Betti et al 1991, Colombo et al 1985, Hartman et al 1985, Giller and Berger 2005, Shoshan et al 2005, Sperduto 2003, Valk and Dillon 1991 in the late 1980 developed LINAC based radiosurgical method. Linac radiosurgical treatment relies upon the following aspects: a) a collimated X-ray is directed stereotactically to the target area; b) the gentry of the linear accelerator rotates over the patient producing an arc of radiation oriented on the target.…”

The Emerging Role of Stereotactic Radiosurgery in the Treatment of Glioblastoma Multiforme

“…An alternative to GKS was developed in the mid-1980s using the conventional linear accelerators (LINAC) available in most large hospitals [11][12][13][14][15]. Unlike the radioactive cobalt-based GKS, these LINAC-based systems use generated x-ray beams which do not require or generate any radioactive material.…”

Robotics and its applications in stereotactic radiosurgery

“…In the early 1980s LINAC radiosurgery was introduced by Betti et al [4][5][6] and Colombo et al 12 This procedure utilizes x-rays, which are photon beams produced by electron acceleration. This concept of multiple noncoplanar arc therapy has been complemented in the last decade with the development of multileaf and micromultileaf collimators.…”