Clinical evaluation for the difference of absorbed doses calculated to medium and calculated to water by Monte Carlo method.

Radiat Oncol

Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, No. 651, Dongfeng Road East, Guangzhou, 510060, China.

Published: July 2018

Background: To evaluate the difference of absorbed doses calculated to medium and to water by a Monte Carlo (MC) algorithm based treatment planning system (TPS), and to assess the potential clinical impact to dose prescription.

Methods: Thirty patients, 10 nasopharyngeal cancer (NPC), 10 lung cancer and 10 bone metastases cases, were selected for this study. For each case, the treatment plan was generated using a commercial MC based TPS and dose was calculated to medium (D). The plan was recalculated for dose to water (D) using the same Monitor Units (MU) and control points. The differences between D and D were qualitatively evaluated by dose-volume parameters and by the plan subtraction method. All plans were measured using the MapCheck2, and gamma passing rates were calculated.

Results: For NPC and Lung cases, the mean differences between D and D for the targets were less than 2% and the maximum difference was 3.9%. The maximum difference of D for the organs at risk (OARs) was 6.7%. The maximum differences between D and D were as high as 10% in certain high density regions. For bone metastases cases, the mean differences between D and D for the targets were more than 2.2% and the maximum difference was 7.1%. The differences between D and D for the OARs were basically negligible. At 3%&3 mm criterion, the gamma passing rate of D plan and D plan were close (> 94%).

Conclusion: The differences between D and D has little clinical impact for most clinical cases. In bony structures the differences may become clinically significant if the target/OAR is receiving doses close to its tolerance limit which can potentially influence the selection or rejection of a particular plan.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6064144PMC
http://dx.doi.org/10.1186/s13014-018-1081-3DOI Listing

Publication Analysis

Top Keywords

calculated medium
12
maximum difference
12
difference absorbed
8
absorbed doses
8
doses calculated
8
water monte
8
monte carlo
8
clinical impact
8
npc lung
8
bone metastases
8

Similar Publications

In the current investigation, the efficiency inhibition of two newly synthesized bi-pyrazole derivatives, namely 2,3-bis[(bis((1 H-pyrazol-1-yl) methyl) amino)] pyridine (Tetra-Pz-Ortho) and 1,4-bis[(bis((1 H-pyrazol-1-yl) methyl) amino)] benzene (Tetra-Pz-Para) for corrosion of carbon steel (C&S) in 1 M HCl medium was evaluated. A Comparative study of inhibitor effect of Tetra-Pz-Ortho and Tetra-Pz-Para was conducted first using weight loss method and EIS (Electrochemical Impedance Spectroscopy) and PDP (Potentiodynamic Polarisation) techniques. Tetra-Pz-Ortho and Tetra-Pz-Para had a maximum inhibition efficacy of 97.

View Article and Find Full Text PDF

Objectives: Artificial intelligence (AI) software including Brainomix "e-CTA" which detect large vessel occlusions (LVO) have clinical potential. We hypothesised that in real world use where prevalence is low, its clinical utility may be overstated.

Methods: In this single centre retrospective service evaluation project, data sent to Brainomix from a medium size acute National Health Service (NHS) Trust hospital between 1/3/2022-1/3/2023 was reviewed.

View Article and Find Full Text PDF

Implicit solvation models permit the approximate description of solute-solvent interactions, where water is the most often considered solvent due to its relevance in biological systems. The use of other solvents is less common but is relevant for applications such as in nuclear magnetic resonance (NMR) or chromatography. As an example, chloroform is commonly used in anisotropic NMR to measure residual dipolar couplings (RDCs) of chiral analytes weakly aligned by an alignment medium.

View Article and Find Full Text PDF

An original approach to characterize electrochemical interfaces at the atomic level, a challenging topic toward the understanding of electrochemical reactivity, is reported. We employed surface resonant X-ray diffraction experiments combined with their simulation using first-principle density functional theory calculations and were thus able to determine the molecular and electronic structures of the partially ionic layer facing the electrode surface, as well as the charge distribution in the surface metal layers. Pt(111) in an acidic medium at an applied potential excluding specific adsorption was studied.

View Article and Find Full Text PDF

Background: Low back pain (LBP) is the leading cause of disability worldwide. Contrary to clinical guidelines, opioids are frequently prescribed early in the management of LBP in primary care, leading to potential harm and downstream healthcare costs. The objective of this study was to model the one-year impacts of strategies that reduce opioid prescribing for low back pain (LBP) in primary care on healthcare costs and overdose deaths Australia-wide and explore the potential for such strategies to be cost-neutral.

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!