scholarly journals Reducing radiation dose and enhancing imaging quality of 4DCT for radiation therapy using iterative reconstruction algorithms

2017 ◽  
Vol 2 (3) ◽  
pp. 515-521 ◽  
Author(s):  
George Noid ◽  
An Tai ◽  
Guang-Pei Chen ◽  
Jared Robbins ◽  
X. Allen Li
Keyword(s):  
Radiation Therapy ◽  
Radiation Dose ◽  
Iterative Reconstruction ◽  
Reconstruction Algorithms ◽  
Imaging Quality

scholarly journals The influence of model iterative reconstruction on image quality in standard and low-dose computer tomography of the chest. experimental study.

2020 ◽  
Author(s):  
Антон Yu. Silin ◽  
Ivan S. Gruzdev ◽  
Sergey P. Morozov
Keyword(s):  
Radiation Dose ◽  
Dose Reduction ◽  
Spatial Resolution ◽  
Iterative Reconstruction ◽  
Low Dose ◽  
Reconstruction Algorithms ◽  
Anthropomorphic Phantom ◽  
Pulmonary Lesions ◽  
Calibration Phantom

Background: One of the ways to reduce the radiation dose in CT is to improve image reconstruction algorithms. The latest offer from scanner manufacturers is Model Iterative Reconstruction (MIR). Aims: To compare the quality of visualization of the structures of the organs of the chest and to prove the effectiveness of the low-dose protocol with iterative model reconstruction. Materials and methods: A calibration phantom with a spatial resolution module and an anthropomorphic phantom of the upper body of an adult with nodules in the lungs was scanned on two CT scanners of different manufacturers using the standard dose protocol (SDCT) with algorithms of hybrid iterative reconstruction (HIR) of images and MIR and low-dose protocol (LDCT) and MIR algorithm. The quality of the obtained images was evaluated by the parameters: noise (SD), the contrast-to-noise ratio (CNR), spatial resolution and visualization of pulmonary nodules. The radiation dose was calculated according to the scanner data, the data of individual dosimeters placed on the anthropomorphic phantom, and using a dosimetric phantom. Results: The average SD was 11.5; 24.4 and 21.6; CNR 85.47; 40.6 and 45.6; spatial resolution 2 mm; 2 mm and 3 mm for SDCT with MIR, SDCT with HIR and LDCT with MIR, respectively. Visualization of pulmonary lesions remained excellent in all cases. The radiation dose in case of SDCT was 2.7, and in case of LDCT - 0.67 mSv. The dose reduction was confirmed by dosimeter data. Similar results were obtained by repeating the experiment on a second scanner. Conclusions: The average SD was 11.5; 24.4 and 21.6; CNR 85.47; 40.6 and 45.6; spatial resolution 2 mm; 2 mm and 3 mm for SDCT with MIR, SDCT with HIR and LDCT with MIR, respectively. Visualization of pulmonary lesions remained excellent in all cases. The radiation dose in case of SDCT was 2.7, and in case of LDCT - 0.67 mSv. The dose reduction was confirmed by dosimeter data. Similar results were obtained by repeating the experiment on a second scanner.

Reducing CT radiation dose with iterative reconstruction algorithms: The influence of scan and reconstruction parameters on image quality and CTDIvol

2014 ◽  
Vol 83 (9) ◽  
pp. 1645-1654 ◽  
Author(s):  
Thorsten Klink ◽  
Verena Obmann ◽  
Johannes Heverhagen ◽  
Alexander Stork ◽  
Gerhard Adam ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Iterative Reconstruction ◽  
Reconstruction Algorithms ◽  
Ct Radiation

scholarly journals Personal innovative approach in radiation therapy of lung cancer- functional lung avoidance SPECT-guided (ASPECT) radiation therapy: a study protocol for phase II randomised double-blind clinical trial

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Azza Ahmed Khalil ◽  
Eric Hau ◽  
Val Gebski ◽  
Cai Grau ◽  
Harriet Gee ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Lung Cancer ◽  
Clinical Trial ◽  
Radiation Therapy ◽  
Radiation Dose ◽  
Pulmonary Toxicity ◽  
Double Blind ◽  
Curative Intent ◽  
Radiation Induced

Abstract Background Radiation therapy (RT) plays a key role in curative-intent treatment for locally advanced lung cancer. Radiation induced pulmonary toxicity can be significant for some patients and becomes a limiting factor for radiation dose, suitability for treatment, as well as post treatment quality of life and suitability for the newly introduced adjuvant immunotherapy. Modern RT techniques aim to minimise the radiation dose to the lungs, without accounting for regional distribution of lung function. Many lung cancer patients have significant regional differences in pulmonary function due to smoking and chronic lung co-morbidity. Even though reduction of dose to functional lung has shown to be feasible, the method of preferential functional lung avoidance has not been investigated in a randomised clinical trial. Methods In this study, single photon emission computed tomography (SPECT/CT) imaging technique is used for functional lung definition, in conjunction with advanced radiation dose delivery method in randomised, double-blind trial. The study aims to assess the impact of functional lung avoidance technique on pulmonary toxicity and quality of life in patients receiving chemo-RT for lung cancer. Eligibility criteria are biopsy verified lung cancer, scheduled to receive (chemo)-RT with curative intent. Every patient will undergo a pre-treatment perfusion SPECT/CT to identify functional lung. At radiation dose planning, two plans will be produced for all patients on trial. Standard reference plan, without the use of SPECT imaging data, and functional avoidance plan, will be optimised to reduce the dose to functional lung within the predefined constraints. Both plans will be clinically approved. Patients will then be randomised in a 2:1 ratio to be treated according to either the functional avoidance or the standard plan. This study aims to accrue a total of 200 patients within 3 years. The primary endpoint is symptomatic radiation-induced lung toxicity, measured serially 1–12 months after RT. Secondary endpoints include: a quality of life and patient reported lung symptoms assessment, overall survival, progression-free survival, and loco-regional disease control. Discussion ASPECT trial will investigate functional avoidance method of radiation delivery in clinical practice, and will establish toxicity outcomes for patients with lung cancer undergoing curative chemo-RT. Trial registration Clinicaltrials.gov Identifier: NCT04676828. Registered 1 December 2020.

scholarly journals The Biological Basis for Enhanced Effects of Proton Radiation Therapy Relative to Photon Radiation Therapy for Head and Neck Squamous Cell Carcinoma

2021 ◽  
Vol 8 (1) ◽  
pp. 3-13
Author(s):  
Li Wang ◽  
Piero Fossati ◽  
Harald Paganetti ◽  
Li Ma ◽  
Maura Gillison ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Squamous Cell Carcinoma ◽  
Radiation Therapy ◽  
Radiation Dose ◽  
Cell Carcinoma ◽  
Head And Neck ◽  
Squamous Cell ◽  
Proton Radiation ◽  
X Ray

Abstract Head and neck squamous cell carcinomas (HNSCCs) often present as local-regionally advanced disease at diagnosis, for which a current standard of care is x-ray–based radiation therapy, with or without chemotherapy. This approach provides effective local regional tumor control, but at the cost of acute and late toxicity that can worsen quality of life and contribute to mortality. For patients with human papillomavirus (HPV)–associated oropharyngeal squamous cell carcinoma (SCC) in particular, for whom the prognosis is generally favorable, de-escalation of the radiation dose to surrounding normal tissues without diminishing the radiation dose to tumors is desired to mitigate radiation-related toxic effects. Proton radiation therapy (PRT) may be an excellent de-escalation strategy because of its physical properties (that eliminate unnecessary radiation to surrounding tissues) and because of its biological properties (including tumor-specific variations in relative biological effectiveness [RBE] and linear energy transfer [LET]), in combination with concurrent systemic therapy. Early clinical evidence has shown that compared with x-ray–based radiation therapy, PRT offers comparable disease control with fewer and less severe treatment-related toxicities that can worsen the quality of life for patients with HNSCC. Herein, we review aspects of the biological basis of enhanced HNSCC cell response to proton versus x-ray irradiation in terms of radiation-induced gene and protein expression, DNA damage and repair, cell death, tumor immune responses, and radiosensitization of tumors.

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