Author ORCID Identifier
0000-0001-9720-8059
Date of Graduation
12-2023
Document Type
Dissertation (PhD)
Program Affiliation
Medical Physics
Degree Name
Doctor of Philosophy (PhD)
Advisor/Committee Chair
Stephen F. Kry, PhD
Committee Member
Rebecca M. Howell, PhD
Committee Member
Eugene Koay, MD, PhD
Committee Member
Christopher Peeler, PhD
Committee Member
Christine Peterson, PhD
Committee Member
Alfredo Mirandola, MS
Abstract
Carbon ion therapy is available at over a dozen institutions around the world and is being employed for treatment of cancer. The increased biological effect of carbon compared to conventional photon-based radiotherapy holds promise for the therapeutic benefit in historically radioresistant tumors. While ion chamber dosimetry has been used for day-to-day clinical measurements of absorbed dose, there are few options for remote dosimetry. The availability of such tools would support the development of a robust remote audit program for carbon ion therapy.
The Imaging and Radiation Oncology Core (IROC) conducts remote audits of photon and proton therapy. These audits are used to ensure comparability and consistency among radiotherapy clinics and are an important peer-review tool to ensure accurate dose delivery. The most common detectors used for these audits are thermoluminescent dosimeters (TLD) and optically-stimulated luminescent dosimeters (OSLD) and GafChromic film.
The aim of this work will be to characterize dosimeters and materials for use in carbon radiotherapy and combine these tools to create an end-to-end anthropomorphic phantom audit. The absorbed dose corrections factors for TLD and OSLD will be characterized in a therapeutic carbon beam, as will a variety of plastics typically used in phantom dose measurements. An anthropomorphic phantom, mimicking pancreatic cancer, will be designed, and field-tested at a clinical carbon facility. A realistic carbon treatment plan will be created for the pancreas phantom and delivered using a therapeutic carbon beam at the Centro Nazionale di Adroterapia Oncologica (CNAO) in Pavia, Italy. The phantom dosimetry will be measured using film and one of the luminescent dosimeters characterized by this project.
This work will lay the foundation for remote audits of carbon ion radiotherapy centers. This will be an important step in developing a framework for clinical trial credentialing for carbon therapy randomized trials. These tools will help ensure that carbon ion radiotherapy treatment around the world is accurate and consistent.
Keywords
carbon therapy, particle therapy, radiation dosimetry, quality assurance, anthropomorphic phantoms, audits, medical physics, radiation therapy