Comprehensive geometry-based plan quality score for lung VMAT

Brand J, Szkitsak J, Lobão R, Axer BN, Pieper L, Ott O, Haderlein M, Putz F, Fietkau R, Corradini S, Bert C, Speer S (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Zeitschrift für Medizinische Physik Elsevier Science B.v; Amsterdam

DOI: 10.1016/j.zemedi.2026.03.014

Abstract

Volumetric-modulated arc therapy (VMAT) treatment planning for lung tumors requires balancing adequate planning target volume (PTV) coverage with optimal organ-at-risk (OAR) sparing. However, plan quality varies due to differences in planner expertise, preferences, and especially patient anatomy. This study introduces a Comprehensive Plan Score (CPS) for lung VMAT plans, integrating geometry-based OAR quality indices derived from overlap volume histograms (OVH) and overlap-z-histograms (OZH). CPS was developed by combining normalized target and OAR scores, including geometry-based metrics derived from OVH and OZH. Relative weights were learned from blinded pairwise plan comparisons performed by four senior radiation oncologists (ROs). A total of 35 manual versus automated lung VMAT plan pairs were evaluated, with 20 cases used for training and 15 for independent testing. Across all comparisons, ROs expressed a clear preference in 81% of cases, while 19% were judged equivalent. Inter-observer agreement was fair (Fleiss’ κ = 0.36), with pairwise Cohen's κ ranging from 0.13 to 0.71. In the independent test cohort, CPS using the preference-trained weighting set matched the ROs consensus in 11/15 cases. Applying an equivalence threshold (ΔCPS = 0.01) increased agreement to 13/15 cases (86%). In conclusion, the CPS provides a more objective and geometry-based measure of lung VMAT plan quality. By quantifying achievable OAR sparing based on prior data, it supports consistent and standardized plan evaluation, potentially improving the reproducibility and overall quality of radiotherapy planning.

Authors with CRIS profile

Johann Brand Department of Radiation Oncology Juliane Szkitsak Department of Radiation Oncology Rafael Cerqueira Lobão Professur für Med. Strahlenphysik Bernd-Niklas Axer Department of Radiation Oncology Lucas Pieper Department of Radiation Oncology Oliver Ott Department of Radiation Oncology Marlen Haderlein Department of Radiation Oncology Florian Putz Department of Radiation Oncology Rainer Fietkau Lehrstuhl für Strahlentherapie Stefanie Corradini Department of Radiation Oncology Christoph Bert Department of Radiation Oncology Stefan Speer Department of Radiation Oncology

How to cite

APA:

Brand, J., Szkitsak, J., Lobão, R., Axer, B.-N., Pieper, L., Ott, O.,... Speer, S. (2026). Comprehensive geometry-based plan quality score for lung VMAT. Zeitschrift für Medizinische Physik. https://doi.org/10.1016/j.zemedi.2026.03.014

MLA:

Brand, Johann, et al. "Comprehensive geometry-based plan quality score for lung VMAT." Zeitschrift für Medizinische Physik (2026).

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