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ORIGINAL RESEARCH article

Front. Oncol.
Sec. Radiation Oncology
Volume 14 - 2024 | doi: 10.3389/fonc.2024.1445166

A multi-institutional trial evaluating the use of an integrated quality assurance phantom for frameless single-isocenter multitarget stereotactic radiosurgery

Provisionally accepted
Dante P. Capaldi Dante P. Capaldi 1Lawrie Skinner Lawrie Skinner 2Daniel W. Pinkham Daniel W. Pinkham 3Sergei Zavgorodni Sergei Zavgorodni 4Olga (. Stafford Olga (. Stafford 5Maryam Shirmohammad Maryam Shirmohammad 6Jason E. Matney Jason E. Matney 7Piotr Dubrowski Piotr Dubrowski 2Paul De Jean Paul De Jean 8Elliot M. Grafil Elliot M. Grafil 8Amy Yu Amy Yu 2*
  • 1 University of California, San Francisco, San Francisco, United States
  • 2 Stanford Cancer Institute, School of Medicine, Stanford University, Stanford, California, United States
  • 3 School of Medicine, Yale University, New Haven, Connecticut, United States
  • 4 British Columbia Cancer Agency, Victoria, Canada
  • 5 Alta Bates Summit Medical Center, Oakland, California, United States
  • 6 Department of Radiation Oncology, School of Medicine, Michigan Medicine, University of Michigan, Ann Arbor, Michigan, United States
  • 7 Department of Radiation Oncology, School of Medicine, University of California, Davis, Sacramento, California, United States
  • 8 Other, Palo Alto, United States

The final, formatted version of the article will be published soon.

    Background: Brain radiosurgery treatments require multiple quality-assurance (QA) procedures to ensure accurate and precise treatment delivery of ablative doses. As single-isocenter multitarget radiosurgery treatments become more popular for treating patients with multiple brain metastases, quantifying off-axis accuracy of linear accelerators is crucial. In this study, we developed a novel brain radiosurgery integrated phantom and validated this phantom at multiple institutions to enable radiosurgery QA with a single phantom to facilitate implementation of a frameless singleisocenter, multitarget radiosurgery program. The phantom combines multiple independent verification system tests including the Winston-Lutz test, off-axis accuracy evaluation (i.e., offaxis Winston-Lutz), as well as dosimetric measurements utilizing both point dose and film measurement.A novel 3D-printed phantom, coined OneIso, was designed with a movable insert which can switch between Winston-Lutz test targets and dose measurement without moving the phantom itself. In total, four phantoms were printed, and eight institutions participated in this study, which included both Varian TrueBeam (n=6) and Elekta Versa (n=2) linear accelerators. For off-axis Winston-Lutz measurements, a row of off-axis ball-bearings (BBs) was integrated into the OneIso. To quantify the spatial accuracy versus distance from isocenter, twodimensional displacements were calculated between the planned and delivered BB locations relative to their respective MLC-defined field borders. For dose verification, brain radiosurgery clinical treatment plans previously treated were delivered at multiple cancer centers (six of eight centers). Radiochromic film and pinpoint ion chamber comparison measurements were obtained with OneIso.

    Keywords: Frontiers in Oncology 3251/12,000 Figures/Tables Limit: 10/15 3D printing, Quality Assurance, Stereotactic radiosurgery, Frameless Brain Radiosurgery Treatment, off-Axis Winston-Lutz, Single Isocenter Multi-Target R1, Response 3

    Received: 06 Jun 2024; Accepted: 03 Oct 2024.

    Copyright: © 2024 Capaldi, Skinner, Pinkham, Zavgorodni, Stafford, Shirmohammad, Matney, Dubrowski, De Jean, Grafil and Yu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Amy Yu, Stanford Cancer Institute, School of Medicine, Stanford University, Stanford, CA 94305-5456, California, United States

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.