ESTRO 2023 - Abstract Book

S1838

Digital Posters

ESTRO 2023

Conclusion Statistical analysis reveals some behaviors connected to target location and size. Paddick Index: Since PI is defined <1, the higher the ITV volume the better tends to be PI according to an average slope of 0.0018 cm-3 (p-value<0.0001). Gradient Index: Conversely, increasing ITV volume seem to display a negative association with GI (p-value<0.0001), defined as the ratio of volume isodose of 50% and 100%, that is, the higher the ITV volume the steeper the dose distribution in our study. GI associated with ‘Others’ category exhibits a lower value when comparing to GI linked to CW (p-value=0.017), with an averaged difference of 0.250 and hence a better dosimetric fall-off.

PO-2062 Automating the simulations of IMRT, DCA and VMAT plans with the PRIMO Monte Carlo software

M. Hermida López 1 , J.F. Calvo-Ortega 2,3

1 Hospital Universitari Vall d'Hebron, Física i Protecció Radiològica, Barcelona, Spain; 2 Hospital Quirónsalud Barcelona , Radiation Oncology, Barcelona, Spain; 3 Hospital Quirónsalud Málaga, Radiation Oncology, Málaga, Spain Purpose or Objective The PRIMO Monte Carlo software [Strahlenther Onkol. 2013;189:881-886] allows the simulation of clinical IMRT and VMAT plans for Varian linacs. PRIMO relies on the general-purpose Monte Carlo code PENELOPE and the fast Monte Carlo code DPM. The setup of a plan simulation in PRIMO takes 5-10 min, as several manual steps are needed: project creation, selection of phase-space file (PSF), import of DICOM files, etc. After the simulation, a manual import of the DICOM dose file from the treatment planning system (TPS) is also needed to compare PRIMO and TPS dose distributions. PRIMO provides an advanced macro mode to speed up the process, but the macro file creation is also manual. Hence, the simulation of plans on a routine basis can be very time-consuming. We aimed to automate the simulation setup of clinical plans, including IMRT, dynamic conformal arc (DCA), and VMAT techniques. Materials and Methods A set of scripts ( PRIMO WatchDog v. 1.08, Feb. 23, 2022) was developed in Python 3.7 to automate the simulation setup: • The scripts run in background monitoring a specified folder. Plan DICOM files can be pasted in this folder or manually exported from the TPS to the folder. The following steps proceed automatically. • When the DICOM files are detected, the patient and plan ID, linac ID, beam energy, and MLC model, among other parameters, are read from the DICOM files. • The scripts create a PRIMO macro file to setup the simulation and the gamma index analyses. At this point, the scripts are ready to manage a new plan in a parallel process. • The scripts start PRIMO with the macro file, and the simulation begins. • Once the simulation and the gamma index analyses are done, the scripts store the results in a CSV text file for further analysis. The scripts were tested with the following hardware and software: • PRIMO v. 0.3.1.1816 under Windows 7 and Windows 10. • Varian PSF for 6 MV and 6 MV FFF photon beams from a TrueBeam linac. • IMRT and VMAT plans from Varian Eclipse 15.6/16.1, for TrueBeam linacs with Millennium 120 and HD MLC models. • VMAT plans from Brainlab Elements Cranial SRS 3.0, and DCA plans from Brainlab Elements Multiple Metastases 3.0, for a TrueBeam linac with HD MLC.