Intensity-modulated radiation therapy (IMRT) is an advanced mode of high-
precision radiation therapy that utilizes computer-controlled x-ray accelerators to
deliver precise radiation doses to malignant tumors. The radiation dose is designed to
conform to the three-dimensional (3-D) shape of a tumor by modulating the intensity
of the radiation beam to focus a higher radiation dose to the tumor while minimizing
radiation exposure to surrounding normal tissue. One form of IMRT is known as
tomotherapy. Tomotherapy achieves dose conformity to a tumor by modulating the
intensity of a fan beam of radiation as the source revolves about a patient.
Current available tomotherapy machines use x-ray linear accelerators (linacs)
as a source of radiation. However, since linacs are technologically complex, the world-
wide use of linac-based tomotherapy is limited. This thesis involves an investigation
of Cobalt 60 (Co-60) based tomotherapy. The inherent simplicity of Co-60 has the
potential to extend the availability of this technique to clinics throughout the world.
The goal of this thesis is to generate two-dimensional (2-D) Co-60 tomotherapy con-
formal dose distributions with a computer program and experimentally validate them
on ¯lm using a ¯rst generation bench-top tomotherapy apparatus.
The bench-top apparatus consists of a rotation-translation stage that can
mimic a 2-D tomotherapy delivery by translating the phantom across a thin, "pencil-
like" photon beam from various beam orientations. In this thesis, several random and
clinical patterns are planned using an in-house inverse treatment planning system and
are delivered on ¯lm using the tomotherapy technique. The delivered dose plans are
compared with the simulated plans using the gamma dose comparison method. The
results show a reasonably good agreement between the plans and the measurements,
suggesting that Co-60 tomotherapy is indeed capable of providing state-of-the-art
conformal dose delivery. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2008-04-25 02:20:56.102 / Canadian Institutes of Health Research (CIHR) and the ORDCF’s Ontario Consortium for Image-guided Therapy and Surgery.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/1182 |
| Date | 28 April 2008 |
| Creators | Dhanesar, Sandeep Kaur |
| Contributors | Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Format | 1980937 bytes, application/pdf |
| Rights | This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
| Relation | Canadian theses |
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