Physical Aspects Of Modern Stereotactic Radiosurgery (review)Andreas Mack1, Schneider Uwe1, Weltz Dirk1, Paddick Ian2, Scheib Stefan3, Mindermann Thomas1, Curschmann Jürgen1, von Briel Christian1, Wolff Robert4, Seifert Volker51Klinik Hirslanden 2 Cromwell Hospital 3 Varian 4 Gamma Knife Centre 5 University Hospital Keywords: gamma knife, physics, radiosurgery, linear accelerator, proton beam
Developments in previous years have lead to a variety of decent treatment devices to be used for either radiosurgery or fractionated stereotactic radiotherapy.
A comparison of the main techniques in the market is given. Following the preliminary results given in Quebec, we have now finished our voluminous work.
Common methods and techniques are introduced and compared with regard to their specific parameters. Classical devices as the Gamma Knife and Linacs as well as younger techniques such as Cyber Knife and Tomotherapy are looked at thoroughly concerning their physical parameters.
Comparisons clearly demonstrate the individual characteristics of the different machines. The Gamma Knife techniques uses mechanical precision and steep dose gradients to offer the maximum conformity for radiosurgical treatments, while the Linac based technologies concentrate on tools such as IMRT, IGRT. Both of these beam modulation techniques can be used for stereotactic fractionated radiotherapy and the treatment of the body. The CyberKnife offers precise tracking methods especially for targeting outside the skull (Xsightspine, Synchrony). In practice this requires precise synchrony being realized on the basis of changing field shape (MLC), controlling the position of the target (x-rays, triggered cameras) and by online measurements of the applied dose.
This is a retrospective study.
Whereas most of the technologies have improved their equipment in terms of delivered accuracy and comfort, the ideal radiosurgery site would be an interdisciplinary filled centre offering dedicated machines for pure radiosurgery on the one hand and an all purpose machine covering the rest of the body on the other.
At present, therapy with protons is still on an absolutely experimental level. It could however function as a preliminary stage, leading to therapy with heavy ions which have the advantages of a higher ionisation density and superior biological effect. Project Roles:
A. Mack (), S. Uwe (), W. Dirk (), P. Ian (), S. Stefan (), M. Thomas (), C. Jürgen (), v. Christian (), W. Robert (), S. Volker ()