A novel phantomless, EPID-based method of measuring the beam focal spot offset of a linear accelerator was proposed and validated for Varian machines. In this method, one set of jaws and the MLC were utilized to form a symmetric field and then a 180 collimator rotation was utilized to determine the radiation isocenter defined by the jaws and the MLC, respectively. The difference between these two isocentres is directly correlated with the beam focal spot offset of the linear accelerator. In the current work, the method has been considered for Elekta linacs. An Elekta linac with the Agility head does not have two set of jaws, therefore, a modified method is presented making use of one set of diaphragms, the MLC and a full 360 collimator rotation. The modified method has been tested on two Elekta Synergy linacs with Agility heads and independently validated. A practical guide with instructions and a MATLAB code is attached for easy implementation.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6036348PMC
http://dx.doi.org/10.1002/acm2.12344DOI Listing

Publication Analysis

Top Keywords

beam focal
12
focal spot
12
elekta linac
8
linac agility
8
agility head
8
practical guide
8
spot offset
8
offset linear
8
linear accelerator
8
set jaws
8

Similar Publications

Background: Magnetic resonance-guided transurethral ultrasound ablation (MR-TULSA) is a new focal therapy for treating localised prostate cancer that is associated with fewer adverse effects (AEs) compared with established treatments. To support large-scale clinical implementation, information about cost-effectiveness is required.

Objective: To evaluate the cost-utility of MR-TULSA compared with robot-assisted radical prostatectomy (RARP), external beam radiation therapy (EBRT) and active surveillance (AS) for patients with low- to favourable intermediate-risk localised prostate cancer.

View Article and Find Full Text PDF

Purpose/objective(s): While definitive chemoradiation (CRT) with 5-FU/MMC remains the standard of care for localized anal cancer, treatment is associated with significant acute and late toxicity. Proton radiation therapy (RT) may potentially reduce such toxicity. Here, we assess the long-term outcomes of anal cancer patients treated with CRT using proton RT in two prospective pilot studies.

View Article and Find Full Text PDF

Objective: To investigate the reparative effect of hypoxia pretreated hAMSCs on radiation-induced damage to salivary gland function in mice.

Methods: hAMSCs were separated from human amniotic tissues by mechanical and enzymatic digestion methods and a 15 Gy electron beam was used to locally irradiate the neck of mouse to create a salivary gland injury model. The mouse models were randomly divided into four groups: control group, IR+PBS group, IR+Nor group and IR+HP group.

View Article and Find Full Text PDF

Purpose: Minibeam radiotherapy (MBRT) uses small parallel beams of radiation to create a highly modulated dose pattern. The aim of this study is to develop an optical radioluminescence imaging (RLI) approach to perform real-time dose measurement for MBRT.

Methods: MBRT was delivered using an image-guided small animal irradiator equipped with a custom collimator.

View Article and Find Full Text PDF

Background: Proton beam therapy (PBT) has been gradually introduced for treating choroidal melanoma. This study systematically reviewed clinical reports to evaluate the efficacy and safety of PBT in choroidal melanoma patients.

Methods: This systematic review included all the primary studies involving PBT for choroidal melanoma patients through April 2024.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!