Program Information
Verification Study of Monaco 5.0 Treatment Planning System
J Sutherland*, E Vandervoort , D La Russa , M MacPherson , J Belec , The Ottawa Hospital, Ottawa, ON
Presentations
TU-C1-GePD-TT-5 (Tuesday, August 1, 2017) 9:30 AM - 10:00 AM Room: Therapy ePoster Theater
Purpose: The Monaco treatment planning system was upgraded (v5.0) to include forward planning capabilities for photon and electron treatments. The inverse planning internal parameters were also modified by the manufacturer to improve treatment delivery and optimization efficiency. Verification results are presented and include an assessment of dose calculation accuracy and inverse planning modifications.
Methods: Elekta Infinity photon collapsed cone and electron Monte-Carlo beam models were evaluated through a series of measurements and calculations in water for a range of field shapes. The impact of inverse planning modifications were also assessed for five types of treatment plans by comparing parameters such as treatment time, Mu per control point, plan quality metrics.
Results: Analysis of absolute dose distributions was based on a local / normalized gamma 2 % / 2 mm for depth dose and off-axis profiles respectively. Deviations for photon beam models are mostly for small fields (< 3x3cm²) and off-axis position at large depth (> 20 cm radius, > 20 cm depth). Deviations for electron beam model are mostly located at extended SSD (115 cm) for small applicators (6x6 and 10x10 cm²). MLC dynamic properties required modifications to maintain similar inverse plan quality as in the previous Monaco version: minimum MU per dynamic control point changed from 2.0 to 1.0; and minimum gantry degree per control point changed from 2.0 to 1.5. Impact of those changes on treatment time and sensitivity to leaf calibration errors was found to be less than 10% and 0.4 % respectively.
Conclusion: Monaco 5.0 upgrade requires new beam models for forward planning of electron and photon treatments. The beam models were verified and found to be acceptable except for the 6x6 cm² electron applicator at extended SSD. The inverse planning parameters required modifications to maintain the same treatment plan quality as in previous Monaco version.
Funding Support, Disclosures, and Conflict of Interest: Elekta Research Agreement
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