Impact of beam-hardening corrections on proton relative stopping power estimates from single- and dual-energy CT.

A major contributing factor to proton range uncertainty is the conversion of computed tomography (CT) Hounsfield units (HU) to proton relative stopping power (RSP). This uncertainty is heightened in the presence of X-ray beam-hardening artifact (BHA), which has two manifestations: cupping and streaking, especially in and near bone tissue. This uncertainty can affect the accuracy of proton RSP calculation for treatment planning in proton radiotherapy.

Accuracy of proton stopping power estimation of silicone breast implants with single and dual-energy CT calibration techniques.

A major contributing factor to proton range uncertainty is the conversion of computed tomography (CT) Hounsfield Units (HU) to proton relative stopping power (RSP). This uncertainty is elevated with implanted devices, such as silicone breast implants when computed with single energy CT (SECT). In recent years, manufacturers have introduced implants with variations in gel cohesivity.

Characterization of penumbra sharpening and scattering by adaptive aperture for a compact pencil beam scanning proton therapy system.

Purpose: To quantitatively access penumbra sharpening and scattering by adaptive aperture (AA) under various beam conditions and clinical cases for a Mevion S250i compact pencil beam scanning proton therapy system.

Methods: First, in-air measurements were performed using a scintillation detector for single spot profile and lateral penumbra for five square field sizes (3 × 3 to 18 × 18 cm ), three energies (33.04, 147.

Performance evaluation of adaptive aperture's static and dynamic collimation in a compact pencil beam scanning proton therapy system: A dosimetric comparison study for multiple disease sites.

A compact pencil beam scanning (PBS) proton therapy system, Mevion S250i with Hyperscan, is equipped with adaptive aperture (AA) to collimate the beam with 2 different techniques: Static aperture (SA) and dynamic aperture (DA). SA (single aperture) collimates the outermost contour of the target and DA (multi-layer aperture) collimates each energy layer of the proton beam. This study evaluates dosimetric performance of SA and DA for different disease sites.

Prediction of the output factor using machine and deep learning approach in uniform scanning proton therapy.

Purpose: The purpose of this work is to develop machine and deep learning-based models to predict output and MU based on measured patient quality assurance (QA) data in uniform scanning proton therapy (USPT).

Methods: This study involves 4,231 patient QA measurements conducted over the last 6 years. In the current approach, output and MU are predicted by an empirical model (EM) based on patient treatment plan parameters.