Dosimetric validation of Monaco treatment planning system on an Elekta VersaHD linear accelerator

Abstract

The purpose of this study is to perform dosimetric validation of Monaco treatment planning system version 5.1. The Elekta VersaHD linear accelerator with high dose rate flattening filter‐free photon modes and electron energies was used in this study. The dosimetric output of the new Agility head combined with the FFF photon modes warranted this investigation into the dosimetric accuracy prior to clinical usage. A model of the VersaHD linac was created in Monaco TPS by Elekta using commissioned beam data including percent depth dose curves, beam profiles, and output factors. A variety of 3D conformal fields were created in Monaco TPS on a combined Plastic water/Styrofoam phantom and validated against measurements with a calibrated ion chamber. Some of the parameters varied including source to surface distance, field size, wedges, gantry angle, and depth for all photon and electron energies. In addition, a series of step and shoot IMRT, VMAT test plans, and patient plans on various anatomical sites were verified against measurements on a Delta4 diode array. The agreement in point dose measurements was within 2% for all photon and electron energies in the homogeneous phantom and within 3% for photon energies in the heterogeneous phantom. The mean ± SD gamma passing rates of IMRT test fields yielded 93.8 ± 4.7% based on 2% dose difference and 2 mm distance‐to‐agreement criteria. Eight previously treated IMRT patient plans were replanned in Monaco TPS and five measurements on each yielded an average gamma passing rate of 95% with 6.7% confidence limit based on 3%, 3 mm gamma criteria. This investigation on dosimetric validation ensures accuracy of modeling VersaHD linac in Monaco TPS thereby improving patient safety.

Modeling Elekta VersaHD using the Varian Eclipse treatment planning system for photon beams: A single‐institution experience

“…Absolute percent point dose differences were <2% for all studied cases. Another study on VersaHD model validation in Monaco found an average gamma pass rate of (93.8% ± 4.7%) based on 2%global/2mm criteria for eight types of IMRT test field plans, and an average gamma pass rate of 95% based on 3%global/3 mm criteria for eight re‐planned patient cases . Absolute percent point dose differences measured in a homogeneous phantom were <2% for all cases in the same study.…”

“…A commercial DICOM‐RT‐based plan and delivery verification system Mobius (Mobius Medical Systems, Houston, TX, acquired by Varian recently) was commissioned to provide routine IMRT QA and to independently validate Eclipse model in addition to the ionization chamber and film measurements. The feasibility and accuracy of using Mobius for second dose check was reported in previous studies . The commissioning was a similar iterative process involving Mobius DLG adjustments through plan recalculation for Mobius and Eclipse dose comparisons.…”

“…Varian Medical Systems and Elekta Instruments are two major vendors of medical linear accelerators (LINACs) for cancer radiation therapy. The latest generation of LINAC platforms, including TrueBeam/VitalBeam from Varian and VersaHD from Elekta, represent cutting edge technological advancements in radiotherapy treatment delivery. Both vendors also offer proprietary trademarked treatment planning systems: Varian Eclipse and Elekta Monaco for beam modeling, treatment dose calculation and plan design.…”

“…The latest generation of LINAC platforms, including TrueBeam/VitalBeam from Varian and VersaHD from Elekta, represent cutting edge technological advancements in radiotherapy treatment delivery. Both vendors also offer proprietary trademarked treatment planning systems: Varian Eclipse and Elekta Monaco for beam modeling, treatment dose calculation and plan design. In radiation oncology departments with a multivendor LINAC setting, utilization of more than one treatment planning system (TPS) creates another layer of complexity for data flow and systems communications, plan evaluations and comparisons, plan dose summations, and resource sharing.…”

Sistemas de Planejamento em Radioterapia

“…Existem diversos sistemas comercias para planejamento para teleterapia, tais como: iPlan RT (BrainLAB A.G., Heimstetten, Germany) 23 , XiO (Elekta AB, Stockholm, Sweden) 24,25 , Monaco (Elekta AB, Stockholm, Sweden) [26][27][28] , Pinnacle (Philips Radiation Oncology Systems, Fitchburg, WI) 29,30 , Eclipse (Varian Medical Systems, Palo Alto, CA, USA) 31,32 , RayStation 33,34 e Panther 3D 35,36 .…”