“A MAP IS NOT THE TERRITORY”: EVALUATION OF HARDWARE MODIFICATION, EDUCATIONAL INTERVENTION, AND SOFTWARE FEEDBACK FOR RADIOTHERAPY TARGET VOLUME DELINEATION
Creators: name: Fuller, Clifton
Publisher: name: figshare
Year: 2022
Subjects: Radiation therapy
Cancer therapy (excl. chemotherapy and radiation therapy)
Medical physics
Radiology and organ imaging

description: <b>A Dissertation Presented to the Faculty of The University of Texas Health Science Center at San Antonio Graduate School of Biomedical Sciences in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy </b><b>by Clifton David Fuller, MD</b><br>Supervising Professor:<br>Niko Papanikolaou, Ph.D.<br><br>Thesis Committee Members:Sotirios Stathakis, Ph.D.Geoffrey D. Clarke, Ph.D.Richard Crownover, Ph.D., M.D.Charles R. Thomas, Jr., MD<br>Presented in Public Defense &amp; Examination inSan Antonio, Texas, on April 29th, 2011.<br><b>Thesis Abstract</b>The advent of conformal radiotherapy, as well as the developing paradigm of image-guided radiotherapy, affords delivery of tumoricidal radiation doses to user-definedtarget volumes while minimizing dose to proximal organs-at-risk. This exactitude of radiation delivery allows exceptional dose-volume matching capability; nonetheless, the steep dosimetric gradients involved necessitate that even minor geometric uncertainties mayresult in substantial dose deviations, which may in turn reduce dose to tumor or increaseexposure to radiosensitive tissues. Target volumes and organs-at-risk for treatment planning are defined by human users, introducing possible geometric variability due to variation in target delineation. While uniformly recognized as a critical step in image-guided radiotherapy treatment planning, little data has been developed regarding standardization and evaluation of the task of target volume delineation. In the pre-conformal radiotherapy era, standardized fields were utilized to ensure uniformity of treated regions. However, in the era of volume-based delineation, data suggest that considerable operator-dependent variation exists in target volume delineation and consequent dose distribution. This variabilitycomplicates clinical trial quality assurance and prevents ready comparison of treatment protocols. To date however, little data has been reported regarding quantitative metrics toevaluate inter- and intra-user variability in delineation tasks. Furthermore, the effects of modification of either hardware/interface devices or educational interventions are poorly understood.Consequently, the primary specific aims of this study include:<br>1. Examination of distinct human-computer interfaces on target delineation efficiency, suitability, and reproducibility, and target volume variability2. Determination of the impact of atlas-based curricular interventions on target volume delineation concordance with expert-derived target structures.3. Development and refinement of software for automated/semi-automated inter- and intra-user target volume delineation comparison."<br><br>This is a deposition of the Thesis version presented for Public Defense and Examination, and preliminarily approved by the Thesis Committee on 2022-03-30; a finalized version was deposited to ProQuest upon formal Graduate School administrative approval, proofing/formatting, and doctoral degree conferral on 2011-08-01. This version, formatted by the author, is deposited for FAIR use, given that "ProQuest’s author agreement for dissertations and theses is non-exclusive. Authors have the full right to make their works available to other commercial services or for open access outside of the ProQuest service."<br>The public Defense presentation slide deck (2011-04-29) is deposited as a PowerPoint and PDF version.