It is known that slight variations in total dose delivered to the patient in external beam photon radiotherapy can significantly alter the probability of tumour control. For this reason, ICRU has recommended a goal of $ pm$5% precision in the dose delivery to the target volume. Several investigators have analyzed the degree of precision routinely achieved and have come to the conclusion that ICRU's goal can be attained, but in practice this is just barely so. / We have measured the degree of precision which exists in our institution by examining each step of the radiotherapy process on a cobalt unit and a 10 MV linear accelerator. Our study finds beam intensity uncertainties of $ pm$3.8% (one standard deviation) and beam positional uncertainties of $ pm$5.5 mm (one standard deviation). The effect of these uncertainties on the dose to the patient is illustrated for a typical case.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.22856 |
| Date | January 1995 |
| Creators | Curtin-Savard, Arthur |
| 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: 001468150, proquestno: MM08006, Theses scanned by UMI/ProQuest. |
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