Date of Graduation
8-2018
Document Type
Dissertation (PhD)
Program Affiliation
Medical Physics
Degree Name
Doctor of Philosophy (PhD)
Advisor/Committee Chair
Laurence E. Court
Committee Member
Peter Balter
Committee Member
Beth Beadle
Committee Member
David Followill
Committee Member
Christopher Nelson
Committee Member
Christine Peterson
Abstract
Millions of people in low- and middle- income countries (LMICs) are without access to radiation therapy and as rate of population growth in these regions increase and lifestyle factors which are indicative of cancer increase; the cancer burden will only rise. There are a multitude of reasons for lack of access but two themes among them are the lack of access to affordable and reliable teletherapy units and insufficient properly trained staff to deliver high quality care. The purpose of this work was to investigate to two proposed efforts to improve access to radiotherapy in low-resource areas; an upright radiotherapy chair (to facilitate low-cost treatment devices) and a fully automated treatment planning strategy.
A fixed-beam patient treatment device would allow for reduced upfront and ongoing cost of teletherapy machines. The enabling technology for such a device is the immobilization chair. A rotating seated patient not only allows for a low-cost fixed treatment machine but also has dosimetric and comfort advantages. We examined the inter- and intra- fraction setup reproducibility, and showed they are less than 3mm, similar to reports for the supine position.
The head-and-neck treatment site, one of the most challenging treatment planning, greatly benefits from the use of advanced treatment planning strategies. These strategies, however, require time consuming normal tissue and target contouring and complex plan optimization strategies. An automated treatment planning approach could reduce the additional number of medical physicists (the primary treatment planners) in LMICs by up to half. We used in-house algorithms including mutli-atlas contouring and quality assurance checks, combined with tools in the Eclipse Treatment Planning System®, to automate every step of the treatment planning process for head-and-neck cancers. Requiring only the patient CT scan, patient details including dose and fractionation, and contours of the gross tumor volume, high quality treatment plans can be created in less than 40 minutes.
Keywords
Radiation Therapy, Automation, Low Resource Solutions, Cancer