Functional avoidance-based intensity modulated proton therapy with 4DCT derived ventilation imaging for lung cancer

• Type of Material: Article
• Authors: Jingjing M Dougherty, Mayo Clinic, Jacksonville; Edward Castillo, Rice University; Richard Castillo, Emory University; Austin M Faught, St. Jude Children's Research Hospital; Mark Pepin, Mayo Clinic, Rochester; Sean S Park, Mayo Clinic, Rochester; Chris J Beltran, Mayo Clinic, Rochester; Thomas Guerrero, Beaumont Health System; Inga Grills, Beaumont Health System; Yevgeniy Vinogradskiy, University of Colorado Aurora
• Language: English
• Date: 2021-06-22
• Publisher: WILEY
• Publication Version: Final Published Version
• Copyright Statement: © 2021 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals LLC on behalf of American Association of Physicists in Medicine.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1002/acm2.13323
• Title of Journal or Parent Work: JOURNAL OF APPLIED CLINICAL MEDICAL PHYSICS
• Volume: 22
• Issue: 7
• Start Page: 276
• End Page: 285
• Keywords: MONTE-CARLO; radiation pneumonitis; CONCURRENT CHEMOTHERAPY; lung toxicity; REGIONAL VENTILATION; Radiology, Nuclear Medicine & Medical Imaging; lung ventilation; MOTION; Science & Technology; TRIAL; proton motion interplay; 4DCT; functional lung imaging; OUTCOMES; PARAMETERS; SIMULATION; proton therapy; INTERPLAY; IMPT; STRATEGIES; Life Sciences & Biomedicine
• Research Categories: Biology, Radiation; Health Sciences, Oncology

Abstract

The primary objective is to evaluate the potential dosimetric gains of performing functional avoidance-based proton treatment planning using 4DCT derived ventilation imaging. 4DCT data of 31 patients from a prospective functional avoidance clinical trial were evaluated with intensity modulated proton therapy (IMPT) plans and compared with clinical volumetric modulated arc therapy (VMAT) plans. Dosimetric parameters were compared between standard and functional plans with IMPT and VMAT with one-way analysis of variance and post hoc paired student t-test. Normal Tissue Complication Probability (NTCP) models were employed to estimate the risk of two toxicity endpoints for healthy lung tissues. Dose degradation due to proton motion interplay effect was evaluated. Functional IMPT plans led to significant dose reduction to functional lung structures when compared with functional VMAT without significant dose increase to Organ at Risk (OAR) structures. When interplay effect is considered, no significant dose degradation was observed for the OARs or the clinical target volume (CTV) volumes for functional IMPT. Using fV20 as the dose metric and Grade 2+ pneumonitis as toxicity endpoint, there is a mean 5.7% reduction in Grade 2+ RP with the functional IMPT and as high as 26% in reduction for individual patient when compared to the standard IMPT planning. Functional IMPT was able to spare healthy lung tissue to avoid excess dose to normal structures while maintaining satisfying target coverage. NTCP calculation also shows that the risk of pulmonary complications can be further reduced with functional based IMPT.