Microbeam Radiation Therapy Bio-Dosimetry Enhanced by Novel Radiosensitiser Combinations in the Treatment of Brain Cancer.

: Brain cancer is notoriously resistant to traditional treatments, including radiotherapy. Microbeam radiation therapy (MRT), arrays of ultra-fast synchrotron X-ray beams tens of micrometres wide (called peaks) and spaced hundreds of micrometres apart (valleys), is an effective alternative to conventional treatments. MRT's advantage is that normal tissues can be spared from harm whilst maintaining tumour control.

Impact of robust optimization on patient specific error thresholds for high dose rate prostate brachytherapy source tracking.

Purpose: The purpose of this study was to compare the effect of catheter shift errors and determine patient specific error thresholds (PSETs) for different high dose rate prostate brachytherapy (HDRPBT) plans generated by different forms of inverse optimization.

Methods: Three plans were generated for 50 HDRPBT patients and PSETs were determined for each of the 3 plans. Plan 1 was the original Oncentra Prostate (v4.

Comparative study of a microdosimetric biological weighting function for RBEmodeling in particle therapy with a solid state SOI microdosimeter.

the recently developed V79-RBEbiological weighting function (BWF) model is a simple and robust tool for a fast relative biological effectiveness (RBE) assessment for comparing different exposure conditions in particle therapy. In this study, the RBEderived by this model (through the particle and heavy ion transport code system (PHITS) simulatedspectra) is compared with values of RBEusing experimentally derivedspectra from a silicon-on-insulator (SOI) microdosimeter.experimentally measuredspectra are used to calculate an RBEvalue utilizing the V79-RBEBWF model as well as the modified microdosimetric kinetic model (MKM) to produce an RBE-vs-trend for a wide range of ions.

Simulation of cell cycle effects on DNA strand break induction due to α-particles.

Purpose: Understanding cell cycle variations in radiosensitivity is important for α-particle therapies. Differences are due to both repair response mechanisms and the quantity of initial radiation-induced DNA strand breaks. Genome compaction within the nucleus has been shown to impact the yield of strand breaks.

Targeted alpha therapies using At: A Geant4 simulation of dose and DNA damage.

Introduction: Targeted alpha therapies show great potential for cancer treatment due to their high linear energy transfer (LET) and low range. At is currently employed in clinical trials. Targeted alpha therapies (TAT) are effective as an adjuvant treatment for cancer or to treat micrometastases and diffuse cancers.

A radiation therapy platform to enable upright cone beam computed tomography and future upright treatment on existing photon therapy machines.

Background: The conventional lying down position for radiation therapy can be challenging for patients due to pain, swallowing or breathing issues. To provide an alternative upright treatment position for these patients, we have developed a portable rotating radiation therapy platform which integrates with conventional photon treatment machines. The device enables cone-beam computed tomography (CBCT) imaging of patients in an upright position, and the future delivery of therapeutic radiation.

Towards melanoma in situ vaccination with multiple ultra-narrow X-ray beams.

Despite the recent progress, current treatment modalities are not able to eradicate cancer. We show that Microbeam Radiotherapy (MRT), an innovative type of Spatially Fractionated Radiotherapy, can control murine melanoma by activating the host's own immune system. The beneficial effects are very pronounced in comparison to uniform radiotherapy traditionally employed in the clinic.

A novel approach to double-strand DNA break analysis through γ-H2AX confocal image quantification and bio-dosimetry.

DNA damage occurs in all living cells. γ-H2AX imaging by fluorescent microscopy is widely used across disciplines in the analysis of double-strand break (DSB) DNA damage. Here we demonstrate a method for the quantitative analysis of such DBSs.

Inter-center comparison of proton range verification prototypes with an anthropomorphic head phantom.

. To compare in reproducible and equalized conditions the performance of two independent proton range verification systems based on prompt gamma-ray detectors from two different proton therapy centers..

Verification of linear energy transfer optimized carbon-ion radiotherapy.

Linear energy transfer (LET) verification was conducted using a silicon-on-insulator (SOI) microdosimeter during the commissioning of LET-optimized carbon-ion radiotherapy (CIRT). This advanced treatment technique is expected to improve local control rates, especially in hypoxic tumors.An SOI microdosimeter with a cylindrical sensitive volume of 30m diameter and 5m thickness was used.

Effects of spot size errors in DynamicARC pencil beam scanning proton therapy planning.

Spot size stability is crucial in pencil beam scanning (PBS) proton therapy, and variations in spot size can disrupt dose distributions. Recently, a novel proton beam delivery method known as DynamicARC PBS scanning has been introduced. The current study investigates the dosimetric impact of spot size errors in DynamicARC proton therapy for head and neck (HNC), prostate, and lung cancers.

Mobility Gaps of Hydrogenated Amorphous Silicon Related to Hydrogen Concentration and Its Influence on Electrical Performance.

This paper presents a comprehensive study of hydrogenated amorphous silicon (a-Si)-based detectors, utilizing electrical characterization, Raman spectroscopy, photoemission, and inverse photoemission techniques. The unique properties of a-Si have sparked interest in its application for radiation detection in both physics and medicine. Although amorphous silicon (a-Si) is inherently a highly defective material, hydrogenation significantly reduces defect density, enabling its use in radiation detector devices.

A review of whole gland prostate brachytherapy with focal dose escalation to intra-prostatic lesions: Clinical efficacy and technical aspects.

Focal boost to intra-prostatic lesions (IPLs) in radiotherapy could enhance treatment efficacy. Brachytherapy (BT), delivering highly conformal dose with sharp dose gradients emerges as a potentially optimal approach for precise dose escalation to IPLs. This study aims to consolidate clinical and planning studies that implemented whole gland prostate BT and focal dose escalation to IPLs, with the view to synthesize evidence on the strategy's effectiveness and variability.

Adapting outside the box: Simulation-free MR-guided stereotactic ablative radiotherapy for prostate cancer.

Background And Purpose: Magnetic resonance (MR)-guided radiotherapy (MRgRT) enhances treatment precision and adaptive capabilities, potentially supporting a simulation-free (sim-free) workflow. This work reports the first clinical implementation of a sim-free workflow using the MR-Linac for prostate cancer patients treated with stereotactic ablative radiotherapy (SABR).

Materials And Methods: Fifteen patients who had undergone a prostate-specific membrane antigen positron emission tomography/CT (PSMA-PET/CT) scan as part of diagnostic workup were included in this work.

Opportunities and challenges of upright patient positioning in radiotherapy.

Upright positioning has seen a surge in interest as a means to reduce radiotherapy (RT) cost, improve patient comfort, and, in selected cases, benefit treatment quality. In particle therapy (PT) in particular, eliminating the need for a gantry can present massive cost and facility footprint reduction. This review discusses the opportunities of upright RT in perspective of the open challenges.

3D printed heterogeneous paediatric head and adult thorax phantoms for linear accelerator radiotherapy quality assurance: from fabrication to treatment delivery.

. This study aims to design and fabricate a 3D printed heterogeneous paediatric head phantom and to customize a thorax phantom for radiotherapy dosimetry..

Automated lattice radiation therapy treatment planning personalised to tumour size and shape.

Purpose: Lattice radiation therapy (LRT) alternates regions of high and low doses inside the tumour. Whilst this technique reported positive results in tumour size reduction, optimal lattice parameters are still unknown. We introduce an automated LRT planning method personalised to tumour shape and designed to allow investigation of lattice geometry.

Potential anatomical triggers for plan adaptation of cervical cancer external beam radiotherapy.

This study aimed to identify potential anatomical variation triggers using magnetic resonance imaging for plan adaption of cervical cancer patients to ensure dose requirements were met over an external beam radiotherapy course. Magnetic resonance images (MRIs) acquired before and during treatment were rigidly registered to a pre-treatment computerised tomography (CT) image for 11 retrospective cervix cancer datasets. Target volumes (TVs) and organs at risk (OARs) were delineated on both MRIs and propagated onto the CT.

Quantifying the Dosimetric Impact of Proton Range Uncertainties on RBE-Weighted Dose Distributions in Intensity-Modulated Proton Therapy for Bilateral Head and Neck Cancer.

Background: In current clinical practice, intensity-modulated proton therapy (IMPT) head and neck cancer (HNC) plans are generated using a constant relative biological effectiveness (cRBE) of 1.1. The primary goal of this study was to explore the dosimetric impact of proton range uncertainties on RBE-weighted dose (RWD) distributions using a variable RBE (vRBE) model in the context of bilateral HNC IMPT plans.

Dosimetry of microbeam radiotherapy by flexible hydrogenated amorphous silicon detectors.

Detectors that can provide accurate dosimetry for microbeam radiation therapy (MRT) must possess intrinsic radiation hardness, a high dynamic range, and a micron-scale spatial resolution. In this work we characterize hydrogenated amorphous silicon detectors for MRT dosimetry, presenting a novel combination of flexible, ultra-thin and radiation-hard features.Two detectors are explored: an n-type/intrinsic/p-type planar diode (NIP) and an NIP with an additional charge selective layer (NIP + CSC).