An online adaptive plan library approach for intensity modulated proton therapy for head and neck cancer

Michelle Oud; Sebastiaan Breedveld; Marta Giżyńska; Michiel Kroesen; Stefan Hutschemaekers; Steven Habraken; Steven Petit; Zoltán Perkó; Ben Heijmen; Mischa Hoogeman

doi:10.1016/j.radonc.2022.09.011

An online adaptive plan library approach for intensity modulated proton therapy for head and neck cancer

Radiother Oncol. 2022 Nov:176:68-75. doi: 10.1016/j.radonc.2022.09.011. Epub 2022 Sep 20.

Authors

Affiliations

¹ Erasmus MC Cancer Institute, Department of Radiation Oncology, University Medical Center Rotterdam, PO Box 2040, 3000 CA, Rotterdam, The Netherlands. Electronic address: m.oud@erasmusmc.nl.
² Erasmus MC Cancer Institute, Department of Radiation Oncology, University Medical Center Rotterdam, PO Box 2040, 3000 CA, Rotterdam, The Netherlands.
³ Holland Proton Therapy Center, Department of Medical Physics & Informatics, Delft, The Netherlands.
⁴ Erasmus MC Cancer Institute, Department of Radiation Oncology, University Medical Center Rotterdam, PO Box 2040, 3000 CA, Rotterdam, The Netherlands; Holland Proton Therapy Center, Department of Radiation Oncology, Delft, The Netherlands.
⁵ Holland Proton Therapy Center, Department of Radiation Oncology, Delft, The Netherlands.
⁶ Erasmus MC Cancer Institute, Department of Radiation Oncology, University Medical Center Rotterdam, PO Box 2040, 3000 CA, Rotterdam, The Netherlands; Holland Proton Therapy Center, Department of Medical Physics & Informatics, Delft, The Netherlands.
⁷ Delft University of Technology, Faculty of Applied Sciences, Department of Radiation Science and Technology, The Netherlands.

PMID: 36150418
DOI: 10.1016/j.radonc.2022.09.011

Abstract

Background and purpose: In intensity modulated proton therapy (IMPT), the impact of setup errors and anatomical changes is commonly mitigated by robust optimization with population-based setup robustness (SR) settings and offline replanning. In this study we propose and evaluate an alternative approach based on daily plan selection from patient-specific pre-treatment established plan libraries (PLs). Clinical implementation of the PL strategy would be rather straightforward compared to daily online re-planning.

Materials and methods: For 15 head-and-neck cancer patients, the planning CT was used to generate a PL with 5 plans, robustly optimized for increasing SR: 0, 1, 2, 3, 5 mm, and 3% range robustness. Repeat CTs (rCTs) and realistic setup and range uncertainty distributions were used for simulation of treatment courses for the PL approach, treatments with fixed SR (fSR₃) and a trigger-based offline adaptive schedule for 3 mm SR (fSR₃OfA). Daily plan selection in the PL approach was based only on recomputed dose to the CTV on the rCT.

Results: Compared to using fSR₃ and fSR₃OfA, the risk of xerostomia grade ≥ II & III and dysphagia ≥ grade III were significantly reduced with the PL. For 6/15 patients the risk of xerostomia and/or dysphagia ≥ grade II could be reduced by > 2% by using PL. For the other patients, adherence to target coverage constraints was often improved. fSR₃OfA resulted in significantly improved coverage compared to PL for selected patients.

Conclusion: The proposed PL approach resulted in overall reduced NTCPs compared to fSR₃ and fSR₃OfA at limited cost in target coverage.

Keywords: Daily adaptive radiotherapy; Head and neck cancer; Intensity modulated proton therapy; Inter-fraction motion; Plan library; Proton therapy.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Deglutition Disorders*
Head and Neck Neoplasms* / radiotherapy
Humans
Organs at Risk
Proton Therapy* / adverse effects
Proton Therapy* / methods
Radiotherapy Dosage
Radiotherapy Planning, Computer-Assisted / methods
Radiotherapy, Intensity-Modulated* / adverse effects
Radiotherapy, Intensity-Modulated* / methods
Xerostomia*