title: Is there a clinical benefit with a smooth compensator design compared with a plunged compensator design for passive scattered protons?
abstract: In proton therapy, passive scattered proton plans use compensators to conform the dose to the distal surface of the planning volume. These devices are custom made from acrylic or wax for each treatment field using either a plunge-drilled or smooth-milled compensator design. The purpose of this study was to investigate if there is a clinical benefit of generating passive scattered proton radiation treatment plans with the smooth compensator design. We generated 4 plans with different techniques using the smooth compensators. We chose 5 sites and 5 patients for each site for the range of dosimetric effects to show adequate sample. The plans were compared and evaluated using multicriteria (MCA) plan quality metrics for plan assessment and comparison using the Quality Reports [EMR] technology by Canis Lupus LLC. The average absolute difference for dosimetric metrics from the plunged-depth plan ranged from -4.7 to +3.0 and the average absolute performance results ranged from -6.6% to +3%. The manually edited smooth compensator plan yielded the best dosimetric metric, +3.0, and performance, + 3.0% compared to the plunged-depth plan. It was also superior to the other smooth compensator plans. Our results indicate that there are multiple approaches to achieve plans with smooth compensators similar to the plunged-depth plans. The smooth compensators with manual compensator edits yielded equal or better target coverage and normal tissue (NT) doses compared with the other smooth compensator techniques. Further studies are under investigation to evaluate the robustness of the smooth compensator design.
authors.affiliation: University of Texas School of Allied Health-Medical Dosimetry, Houston, TX. Electronic address: art.tabibian@gmail.com.
authors.forename: Art A
authors.initials: AA
authors.lastname: Tabibian
authors.affiliation: University of Texas School of Allied Health-Medical Dosimetry, Houston, TX.
authors.forename: Adam
authors.initials: A
authors.lastname: Powers
authors.affiliation: University of Texas School of Allied Health-Medical Dosimetry, Houston, TX.
authors.forename: Keith
authors.initials: K
authors.lastname: Dolormente
authors.affiliation: University of Texas School of Allied Health-Medical Dosimetry, Houston, TX.
authors.forename: Sneha
authors.initials: S
authors.lastname: Oommen
authors.affiliation: University of Texas School of Allied Health-Medical Dosimetry, Houston, TX.
authors.forename: Akhil
authors.initials: A
authors.lastname: Tiwari
authors.affiliation: MD Anderson Department of Radiation Oncology, Houston, TX.
authors.forename: Matt
authors.initials: M
authors.lastname: Palmer
authors.affiliation: MD Anderson Department of Radiation Physics, Houston, TX.
authors.forename: Xiaorong R
authors.initials: XR
authors.lastname: Zhu
authors.affiliation: MD Anderson Department of Radiation Physics, Houston, TX.
authors.forename: Heng
authors.initials: H
authors.lastname: Li
authors.affiliation: MD Anderson Department of Radiation Physics, Houston, TX.
authors.forename: Narayan
authors.initials: N
authors.lastname: Sahoo
authors.affiliation: MD Anderson Department of Radiation Physics, Houston, TX.
authors.forename: Paul
authors.initials: P
authors.lastname: Wisdom
authors.affiliation: Radiation Oncology Resources, Goshen, IN.
authors.forename: Kyle
authors.initials: K
authors.lastname: Velasco
authors.affiliation: Decimal, Inc, Sanford, FL.
authors.forename: Kevin
authors.initials: K
authors.lastname: Erhart
authors.affiliation: Decimal, Inc, Sanford, FL.
authors.forename: Henry
authors.initials: H
authors.lastname: Stanley
authors.affiliation: MD Anderson Department of Radiation Oncology, Houston, TX.
authors.forename: Bao-Ngoc T
authors.initials: BN
authors.lastname: Nguyen
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D009369:Neoplasms / Q000532:radiotherapy*; D061766:Proton Therapy; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D011882:Radiotherapy, High-Energy / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D011522:Protons
chemical_list: D011522:Protons
keywords: Compensator; Passive scattered proton; Plunge-drilled; Plunged-depth compensator; Proton; Smooth compensator; Smooth-milled