Implementation of Sphinx/Lynx as daily QA equipment for scanned proton and carbon ion beams

Abstract

Purpose Reporting on the first implementation of a proton dedicated commercial device (IBA Sphinx/Lynx) for daily Quality Assurance (QA) of scanned proton and carbon ion beams. Methods Daily QA trendlines over more than 3 years for protons and more than 2 years for carbon ions have been acquired. Key daily QA parameters were reviewed, namely the spot size and position, beam range, Bragg peak width, coincidence (between beam and imaging system isocenters), homogeneity and dose. Results The performance of the QA equipment for protons and carbon ions was evaluated. Daily QA trendlines allowed us to detect machine performance drifts and changes. The definition of tolerances and action levels is provided and compared with levels used in the literature. Conclusion The device has been successfully implemented for routine daily QA activities in a dual particle therapy facility for more than 2 years. It improved the efficiency of daily QA and provides a comprehensive QA process.

Proton dosimetry in a magnetic field: Measurement and calculation of magnetic field correction factors for a plane‐parallel ionization chamber

“…3, 128.4, 153.1, 223.4, and 252.7 MeV with 2 mm spot spacing in both orthogonal directions and a constant spot weighting. The homogeneity of proton spots fields at MedAustron was currently reported by Grevillot et al, 32 showing a variation within a 7 × 4 cm 2 rectangle of 0.9% ± 0.2%. In contrast to the work of Fuchs et al, 25 a set of laterally shifted 10 × 10 cm 2 single-layer quasi mono-energetic irradiation fields was created by employing horizontal shifts in positive x-direction to compensate for the laterally shifted proton beam path in the MF and, thereby, to re-center the irradiation field at the measurement depth at the reference point of the PPIC.…”

“…The effect of this correction itself on the determination of $$k_{\vec{B},M,Q}$$ is expected to be minimal. Grevillot et al 32 . used the same beamline and observed only minor fluctuations in the proton field homogeneity for a shifted field.…”

“…The effect of this correction itself on the determination of k ⃗ B,M,Q is expected to be minimal. Grevillot et al 32 used the same beamline and observed only minor fluctuations in the proton field homogeneity for a shifted field. In addition, Gebauer et al 15 reported minimal relative shifts (<0.5 mm) of proton pencil beams within the central 5 × 5 cm 2 region of a proton field measured in a 0.32 T MRI machine.…”

Commissioning and clinical implementation of an independent dose calculation system for scanned proton beams

“…18 The reader is further invited to refer to the work of Grevillot et al for details about the measurement equipment and methodology. 23,24 Some of the commissioning measurements were used for TPS and myQA iON beam modeling, others were used for validation. myQA iON commissioning set-ups were prepared in the TPS.…”

A comprehensive pre‐clinical treatment quality assurance program using unique spot patterns for proton pencil beam scanning FLASH radiotherapy

“…Several studies 23–28 have established daily QA checks and jigs procedures following AAPM TG‐224 recommendations 29 . However, a quantitative evaluation of the performance of the UHDR delivery system remains lacking.…”