Quantification of Imrt Severity Scores For Improvement of Fmea Results

<p>Accurate delivery of intensity modulation radiation therapy (IMRT) requires perfect execution of a long, complicated chain of events; failure of any component of this process may contribute to dose delivery errors, compromising treatment quality and, more importantly, patient safety. Prospective, process-wide risk mitigation techniques are becoming more prevalent in radiotherapy to establish comprehensive quality management (QM) programs, such as failure modes and effects analysis (FMEA). The subjective nature of the ordinal scores used for FMEA leads questionable reliability and validity of the results. Additionally, physics components are commonly grouped together, leaving out valuable details important to physics QM. While the process of performing an FMEA is beneficial, it does not guarantee accurate assessment of failure modes. The objective of this project was to provide quantitative severity scores for IMRT delivery failure modes to decrease variability and increase the validity and applicability of FMEA results for improvement of physics QM. The hypothesis of this proposed work was that quantified IMRT physical failure mode severity scores were significantly more likely to describe the true severity compared to conventional qualitative scores. To test this hypothesis, physical failure modes were simulated in clinical IMRT patient treatment plans and the ability of qualitative subjective scores and quantitative scores to accurately describe the magnitude of the resultant dose discrepancies in clinical plans were compared. Qualitative subjective scores were obtained through an online survey of the medical physicist community. Quantitative scores were obtained through phantom treatment planning studies and measurements. Each set of severity data for the identified failure modes were compared to the true clinical severities in ten oropharyngeal patient treatment plans using Wilcoxon Signed Rank Tests. 8/11 failure mode true severity scores were predicted by quantitative approaches and 6/11 were predicted by qualitative approaches (p</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation (PhD)

Year dc:date.available

2015

Author dc:creator

• Faught, Jacqueline T

Contributors dc:contributor

• David S. Followill, PhD
• Peter A. Balter, PhD
• Laurence E. Court, PhD

• FMEA
• severity score
• IMRT
• IMRT errors
• failure modes and effects analysis
• quantitative severity score
• Medicine and Health Sciences
• Oncology
• Other Physics

Repository record dc:identifier

https://digitalcommons.library.tmc.edu/utgsbs_dissertations/617

OAI identifier oai:identifier

oai:digitalcommons.library.tmc.edu:utgsbs_dissertations-1647