Impact of beam complexity on plan delivery accuracy verification of a transmission detector in volumetric modulated arc therapy. in Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB) / Phys Med. 2024 Jun;122:103387. doi: 10.1016/j.ejmp.2024.103387. Epub 2024 May 25.

2024
ASL Torino 4

Tipo pubblicazione

Journal Article

Autori/Collaboratori (6)Vedi tutti...

Radici L
Medical Physics Department, ASL TO4, Ivrea, Italy.
Petrucci E
Medical Physics Department, ASL TO4, Ivrea, Italy.
Casanova Borca V
Medical Physics Department, ASL TO4, Ivrea, Italy.

et alii...

Abstract

OBJECTIVE: To study the effect of beam complexity on VMAT delivery accuracy evaluated by means of a transmission detector, together with the possibility of scoring plan complexity. METHODS: 43 clinical VMAT plans delivered by a TrueBeam linear accelerator to both Delta(4) Discover and Delta(4) Phantom+ for patient-specific quality assurance were evaluated. Global Dose-? analysis, MLC-? analysis, percentage of leaves with a deviation between planned and measured leaf tip position lower than 1 mm (LD) were computed. Modulation complexity score (MCS(v)), average leaf travel (LT), a multiplicative combination of LT and MCS(v) (LTMCS), percentage of leaves with speed lower than 5 mm/s (LS), from 5 to 20 mm/s (MS), higher than 20 mm/s (HS) and the average value of leaf speed (MLCS(av)) were evaluated by means of an home-made Matlab script. RESULTS: Dose-? passing rate showed a moderate correlation with MCS(v,) LT, MLCS(av), LS and HS, while a stronger positive correlation was found with LTMCS. A strong correlation was observed between LD and both LT and leaves speed, while a weak correlation was observed with MCS(v). A correlation between MLC-? pass rate and plan complexity parameters was found except for MCS(v); a moderate correlation with LS was observed, while all other parameters showed weak correlations. CONCLUSIONS: The study confirmed the possibility to establish correlations between plan complexity indices versus dose distribution and MLC parameters measured by a transmissive detector. Further investigation is necessary to define specific values of the complexity indices to evaluate whether a VMAT plan is deliverable as intended.

Accesso banca dati bibliografica

PMID : 38797025

DOI : 10.1016/j.ejmp.2024.103387

Keywords

Radiotherapy, Intensity-Modulated/methods/instrumentation; Radiotherapy Planning, Computer-Assisted/methods; Phantoms, Imaging; Humans; Radiotherapy Dosage; Particle Accelerators; Complexity plan indices; Transmission detector; Volumetric modulated arc therapy;