Plan Complexity Analyser Authors: Esa Kuusela, Varian Medical Systems. Filippo Cozzi. Liceo Scientifico A. Sereni, Luino, Italy
The script executes an analysis of the plan complexity for IMRT and VMAT on a field per field basis and extracts some quantitative metrics from the MLC sequences. NOTE: the tool currently works only for c-arm linacs (e.g. TrueBeam) and it is not intended for dual layer MLC based machines like Halcyon. It will be upgraded soon.
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Average aperture area (in mm2). It is the MLC defined open field averaged over all the control points in the field. It is provided with its standard deviation.
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Average aperture per leaf couple (in mm), ALPO: it is the per-leaf-pair aperture averaged per each control point and over all the control points in the field. It is provided with its standard deviation.
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BA: it is the beam area weighted on the MU per control point. BA is defined as:
Where AAj is the aperture area and j is extended to all the control points.
- BI: beam irregularity. BI is defined as:
Where AIj is the aperture irregularity defined as:
And APj is the aperture perimeter per each control point
- BM: beam modulation. BM is efined as:
Detailed descriptions and discussion of BA, BI and BM can be found in Du et al [1] and a more general overview in the chapter 8 of [2].
References:
[1] Du W, Cho S H, Zhang X, Hoffman K E and Kudchadker R J 2014 Quantification of beam complexity in intensity-modulated radiation therapy treatment plans Med. Phys. https://aapm.onlinelibrary.wiley.com/doi/abs/10.1118/1.4861821
[2]. Das. I. , Sanfilippo N, Fogliata A, Cozzi L. Intensity modulated radiation therapy. A clinical overview. IOP Publishing, Bristol, UK, 2020 https://store.ioppublishing.org/page/detail/Intensity-Modulated-Radiation-Therapy//?k=9780750313360