ESTRO-EPTN radiation dosimetry guidelines for the acquisition of proton pencil beam modelling data.

Proton therapy (PT) is an advancing radiotherapy modality increasingly integrated into clinical settings, transitioning from research facilities to hospital environments. A critical aspect of the commissioning of a proton pencil beam scanning delivery system is the acquisition of experimental beam data for accurate beam modelling within the treatment planning system (TPS). These guidelines describe in detail the acquisition of proton pencil beam modelling data.

Optically stimulated luminescence dosimeters for simultaneous measurement of point dose and dose-weighted LET in an adaptive proton therapy workflow.

Purpose: To demonstrate the suitability of optically stimulated luminescence detectors (OSLDs) for accurate simultaneous measurement of the absolute point dose and dose-weighted linear energy transfer (LET) in an anthropomorphic phantom for experimental validation of daily adaptive proton therapy.

Methods: A clinically realistic intensity-modulated proton therapy (IMPT) treatment plan was created based on a CT of an anthropomorphic head-and-neck phantom made of tissue-equivalent material. The IMPT plan was optimized with three fields to deliver a uniform dose to the target volume covering the OSLDs.

Optically stimulated luminescence detectors for dosimetry and LET measurements in light ion beams.

This work investigates the use of AlO:C and AlO:C,Mg optically stimulated luminescence (OSL) detectors to determine both the dose and the radiation quality in light ion beams. The radiation quality is here expressed through either the linear energy transfer (LET) or the closely related metric, which depends on the particle's speed and effective charge. The derived LET andvalues are applied to improve the dosimetry in light ion beams.

Detailed Monte-Carlo characterization of a Faraday cup for proton therapy.

Background: Experiments with ultra-high dose rates in proton therapy are of increasing interest for potential treatment benefits. The Faraday Cup (FC) is an important detector for the dosimetry of such ultra-high dose rate beams. So far, there is no consensus on the optimal design of a FC, or on the influence of beam properties and magnetic fields on shielding of the FC from secondary charged particles.

Comparing radiolytic production of HO and development of Zebrafish embryos after ultra high dose rate exposure with electron and transmission proton beams.

The physico-chemical and biological response to conventional and UHDR electron and proton beams was investigated, along with conventional photons. The temporal structure and nature of the beam affected both, with electron beam at ≥1400 Gy/s and proton beam at 0.1 and 1260 Gy/s found to be isoefficient at sparing zebrafish embryos.

Improved simultaneous LET and dose measurements in proton therapy.

The objective of this study was to improve the precision of linear energy transfer (LET) measurements using [Formula: see text] optically stimulated luminescence detectors (OSLDs) in proton beams, and, with that, improve OSL dosimetry by correcting the readout for the LET-dependent ionization quenching. The OSLDs were irradiated in spot-scanning proton beams at different doses for fluence-averaged LET values in the (0.4-6.

Beam properties within the momentum acceptance of a clinical gantry beamline for proton therapy.

Purpose: Energy changes in pencil beam scanning proton therapy can be a limiting factor in delivery time, hence, limiting patient throughput and the effectiveness of motion mitigation techniques requiring fast irradiation. In this study, we investigate the feasibility of performing fast and continuous energy modulation within the momentum acceptance of a clinical beamline for proton therapy.

Methods: The alternative use of a local beam degrader at the gantry coupling point has been compared with a more common upstream regulation.

Commissioning of a clinical pencil beam scanning proton therapy unit for ultra-high dose rates (FLASH).

Purpose: The purpose of this work was to provide a flexible platform for FLASH research with protons by adapting a former clinical pencil beam scanning gantry to irradiations with ultra-high dose rates.

Methods: PSI Gantry 1 treated patients until December 2018. We optimized the beamline parameters to transport the 250 MeV beam extracted from the PSI COMET accelerator to the treatment room, maximizing the transmission of beam intensity to the sample.

AlO:C optically stimulated luminescence dosimeters (OSLDs) for ultra-high dose rate proton dosimetry.

The response of AlO:C optically stimulated luminescence detectors (OSLDs) was investigated in a 250 MeV pencil proton beam. The OSLD response was mapped for a wide range of average dose rates up to 9000 Gy s, corresponding to a ∼150 kGy sinstantaneous dose rate in each pulse. Two setups for ultra-high dose rate (FLASH) experiments are presented, which enable OSLDs or biological samples to be irradiated in either water-filled vials or cylinders.

Characterization of a Low-Cost Plastic Fiber Array Detector for Proton Beam Dosimetry.

The Pencil Beam Scanning (PBS) technique in proton therapy uses fast magnets to scan the tumor volume rapidly. Changing the proton energy allows changing to layers in the third dimension, hence scanning the same volume several times. The PBS approach permits adapting the speed and/or current to modulate the delivered dose.

Commissioning and quality assurance of a novel solution for respiratory-gated PBS proton therapy based on optical tracking of surface markers.

We present the commissioning and quality assurance of our clinical protocol for respiratory gating in pencil beam scanning proton therapy for cancer patients with moving targets. In a novel approach, optical tracking has been integrated in the therapy workflow and used to monitor respiratory motion from multiple surrogates, applied on the patients' chest. The gating system was tested under a variety of experimental conditions, specific to proton therapy, to evaluate reaction time and reproducibility of dose delivery control.

Characterization of a MLIC Detector for QA in Scanned Proton and Carbon Ion Beams.

Purpose: Beam energy validation is a fundamental aspect of the routine quality assurance (QA) protocol of a particle therapy facility. A multilayer ionization chamber (MLIC) detector provides the optimal tradeoff between achieving accuracy in particle range determination and saving operational time in measurements and analysis procedures. We propose the characterization of a commercial MLIC as a suitable QA tool for a clinical environment with proton and carbon-ion scanning beams.

Range resolution and reproducibility of a dedicated phantom for proton PBS daily quality assurance.

Purpose: Wedge phantoms coupled with a CCD camera are suggested as a simple means to improve the efficiency of quality assurance for pencil beam scanning (PBS) proton therapy, in particular to verify energy/range consistency on a daily basis. The method is based on the analysis of an integral image created by a pencil beam (PB) pattern delivered through a wedge. We have investigated the reproducibility of this method and its dependence on setup and positional beam errors for a commercially available phantom (Sphinx, IBA Dosimetry) and CCD camera (Lynx, IBA Dosimetry) system.