During the past ten years, radiosurgery has moved from an obscure radiation treatment modality practiced in only a few specialized centers in the world, to a mainstream radiotherapeutic technique practiced in most major radiotherapy centers. Currently, the main thrust of development in radiosurgery is aimed at conformal dose delivery to irregular intracranial targets. This thesis deals with theoretical and practical aspects of the use of static, non-coplanar, conformal fields in radiosurgery. / For a typical radiosurgical case involving an irregular target, a comparison was made between treatment plans using the dynamic technique with one and two isocenters and a treatment plan using 7 fixed, non-coplanar, irregularly shaped beams. The static conformal fields plan achieved a target-dose conformation similar to the 2-isocenter dynamic plan, treating 2 to 3 times less healthy tissue to intermediate and high doses that did the 1-isocenter dynamic plan, while delivering a much more uniform dose to the target volume. / A comparison was also made between treatment plans using a varying number of static conformal fields. While the degree of tissue sparing and target-dose homogeneity were both shown to increase with the number of static fields, this increase was found to become smaller and smaller as the number of fields was successively raised from 5 to 7, from 7 to 9 and, ultimately, from 9 to 11. A conclusion is reached that a number of fields between 7 and 9 represents a reasonable compromise between the degree of tissue sparing and target-dose homogeneity achieved, and the ease with which the radiosurgical procedure is planned and delivered.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.27499 |
| Date | January 1997 |
| Creators | Bourque, Daniel. |
| Contributors | Podgorsak, Ervin B. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Medical Radiation Physics.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001601600, proquestno: MQ37097, Theses scanned by UMI/ProQuest. |
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