Assessment of a conventional volumetric-modulated arc therapy knowledge-based planning model applied to the new Halcyon© O-ring linac in locoregional breast cancer radiotherapy. (June 2021)

• Record Type: Journal Article
• Authors: Costa, Emilie; Richir, Thomas; Robilliard, Magalie; Bragard, Christel; Logerot, Christelle; Kirova, Youlia; Fourquet, Alain; De Marzi, Ludovic
• Is Part Of: Physica medica. Volume 86(2021)
• Page Start: 32
• Page End: 43
• Publication Date: 2021-06
• Subjects: Breast cancer -- Radiation therapy -- Knowledge-based planning -- Halcyon©; Medical physics -- Periodicals; Biophysics -- Periodicals; Biophysics -- Periodicals; Imagerie médicale -- Périodiques; Radiothérapie -- Périodiques; Rayons X -- Sécurité -- Mesures -- Périodiques; Physique -- Périodiques; Médecine -- Périodiques; 610.153
• DOI: 10.1016/j.ejmp.2021.05.022
• Languages: English
• ISSNs: 1120-1797

Abstract

Highlights: Knowledge base planning (KBP) for loco-regional breast cancer with VMAT. KBP method trained on a conventional linac was tested on a new Halcyon system. High quality plans performed with 6MV FFF beams on the new Halcyon O-ring linac can be obtained. Abstract: Introduction: The aim of this study was to evaluate the performance of a knowledge-based planning (KBP) model for breast cancer trained on plans performed on a conventional linac with 6 MV FF (flattening filter) beams and volumetric-modulated arc therapy (VMAT) for plans performed on the new jawless Halcyon© system with 6 MV FFF (flattening filter-free) beams. Materials and methods: Based on the RapidPlan© (RP) KBP optimization engine, a DVH Estimation Model was first trained using 56 VMAT left-sided breast cancer treatment plans performed on a conventional linac, and validated on another 20 similar cases (without manual intervention). To determine the capacity of the model for Halcyon©, an additional cohort of 20 left-sided breast cancer plans was generated with RP and analyzed for both TrueBeam© and Halcyon© machines. Plan qualities between manual vs RP (followed by manual intervention) Halcyon© plans set were compared qualitatively by blinded review by radiation oncologists for 10 new independent plans. Results: Halcyon© plans generated with the VMAT model trained with conventional linac plans showed comparable target dose distribution compared to TrueBeam© plans. Organ sparing was comparable between the 2 devices with a slight decrease in heart dose for Halcyon© plans. Nine out of ten automatically generated Halcyon© plans were preferentially chosen by the radiation oncologists over the manually generated Halcyon© plans. Conclusion: A VMAT KBP model driven by plans performed on a conventional linac with 6 MV FF beams provides high quality plans performed with 6 MV FFF beams on the new Halcyon© linac.