Diss. (sammanfattning) Umeå : Umeå universitet, 2006. / Härtill 4 uppsatser.

Thesis (M.Sc.). / Written for the Medical Physics Unit. Title from title page of PDF (viewed 2008/05/29). Includes bibliographical references.

Thesis (M.Sc.). / Written for the Medical Physics Unit. Title from title page of PDF (viewed 2008/07/29). Includes bibliographical references.

Thesis (M.S.)--University of Toledo, 2008. / "In partial fulfillment of the requirements for the degree of Master of Science in Biomedical Sciences." Title from title page of PDF document. Bibliography: p. 153-155.

Thesis (Ph.D.). / Written for the Dept. of Physics. Title from title page of PDF (viewed 2009/11/06). Includes bibliographical references.

Thesis (M.S.)--Medical University of Ohio, 2005. / "In partial fulfillment of the requirements for the degree of Master of Science in Biomedical Sciences." Major advisor: E. Ishmael Parsai. Includes abstract. Document formatted into pages: 144 p. Title from title page of PDF document. Title at ETD Web site: Development of Graphical User Interfaces (GUI) software and databases for radiation therapy applications. Bibliography: page 65.

Advanced-stage nasopharyngeal carcinoma (NPC) presents very difficult scenarios for radiation therapy (RT) planning. The infiltration of tumor to the skull base and beyond means that the tumor is very close to critical normal organs (organs at risk, OARs). Despite the advent of intensity-modulated radiotherapy (IMRT) treatment technique---the state-of-art RT technique, conflicting requirements between organ protection and target dose conformity is still problematic. The objectives of the present research are (1) to investigate the dosimetry properties of IMRT treatment in advanced-stage NPC in respect of its dosimetric limitations and planning problems, (2) to develop new methods and tools to resolve such problems, in particular to improve the quality of treatment plans and efficiency of the dose planning and optimization process. A series of four inter-linked studies were conducted to address these issues. / In conclusion, the solutions to several major problems in IMRT planning for advanced-stage NPC were investigated and established. It has been demonstrated in this research that, by applying these methods and tools, significant improvement in the dosimetry and efficiency of IMRT treatment planning can be accomplished as compared with conventional IMRT planning techniques. It is expected that such would translate into an improvement in treatment throughput, better tumor control and reduction in normal tissues complications. The methods developed have potential to be applied to all stages of NPC and to other tumor sites. / The first study was to improve the efficacy in target coverage and organs sparing using an "organ-splitting" approach. The OARs which overlapped with targets were split into target-overlapping and non-overlapping segments and each segment was assigned with different constraints parameters to increase the degree of flexibility during optimization. As a result, a steep gradient in the dose distribution at the regions of interface between the targets and normal critical organs could be achieved and treatment quality was improved. In the second study, a thorough dosimetric comparison between conventional 2-dimensional (2D) RT and IMRT plans was conducted to determine, with reference to outcome of 2D treatments, the extended tolerance dose limits for the critical organs, especially that of the brainstem and spinal cord, and their planning organ at risk volume. Such data could then serve as reference in IMRT planning when the dose of critical organs need be exceeded in order to allow adequate dose to a very close by target. In the third study, the feasibility of using interpolated contours for segmentation of targets and OARs in IMRT planning was investigated. The result indicated that the use of interpolated contours in IMRT planning could significantly reduce the contouring time by about 50% without degrading the target coverage and OARS sparing. In the final study, an array of dose constraint templates that could accommodate different degrees of overlap between the targets and OARs, together with a template selection program, were developed to improve the efficiency of IMRT planning. By applying the methods and tools developed, IMRT treatment planning of advanced NPC could become more efficient and less dependent on planner's experience. / Chau, Ming Chun. / Adviser: Anthony Chan Tak Cheung. / Source: Dissertation Abstracts International, Volume: 69-02, Section: B, page: 0948. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 118-128). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / School code: 1307.

This research demonstrates that a 3D printed bolus can be customized for electron radiation therapy. Both extruder and powder based printers were used, along with, paraffin wax, super stuff, and H20. The plan dose coverage and conformity for the planning target volume (PTV), was such that the distal side of the PTV was covered by the 90% isodose line. The structure is read, and converted into an STL file. The file is sent to a slicer to print. The object was filled with parafin wax, superstuff or water and sealed. Materials Hounsfield units were analyzed, along with the structure stability. This method is evaluated by scanning the 3D printed bolus. The dose conformity is improved compared to that with no bolus. By generating a patient specific 3D printed bolus there is an in improvement in conformity of the prescription isodose surface while sparing immediately adjacent normal tissues. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

The purpose of this study is to verify and validate the dose at various points of interest in accelerated partial breast irradiation (APBI) treated with the Strut Adjusted Volume Implant (SAVI) applicator using Thermoluminescent Dosimeters (TLDs). A set of CT images were selected from a patient’s data who had received APBI using the SAVI applicator. The images were used to make 3D models. TLDs were calibrated for Brachytherapy. Various points of interest were marked out and slots were carved in the 3D models to fit the TLDs. CT scans were taken of the 3D models with expanded SAVI applicator inserted. A plan was made following B-39 protocol. The TLDs were read and the absorbed doses were calculated and compared to the delivered doses. The results of this study show that the overall average reading of the TLDs is within expected value. The TPS shows overestimated dose calculations for brachytherapy. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

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