Stereotactic multiple arc radiotherapy.

A radiotherapy technique is presented for delivering a concentrated pattern of absorbed dose to intracranial lesions. Treatment takes place on a conventional, isocentrically mounted linear accelerator, rotated in several planes around a single target site. A new, relocatable stereotactic frame is used which enables fractionated radiotherapy to be administered if required. Calculations of the absorbed dose distribution in three orthogonal planes are performed using specially prepared software on a computer used for standard treatment planning. In this way, the need for excessive computing power is avoided.