Related Experiment Video
Updated: Nov 21, 2025

Characterization of Recombination Effects in a Liquid Ionization Chamber Used for the Dosimetry of a Radiosurgical Accelerator
Published on: May 9, 2014
An uncertainty metric to evaluate deformation vector fields for dose accumulation in radiotherapy
Akihiro Takemura1, Akira Nagano2, Hironori Kojima3,4
1Faculty of Health Sciences, Institution of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa 920-0942, Japan.
Background And Purpose:
In adaptive radiotherapy, deformable image registration (DIR) is used to propagate delineations of tumors and organs into a new therapy plan and to calculate the accumulated total dose. Many DIR accuracy metrics have been proposed. An alternative proposed here could be a local uncertainty (LU) metric for DIR results.
Materials And Methods:
The LU represented the uncertainty of each DIR position and was focused on deformation evaluation in uniformly-dense regions. Four cases demonstrated LU calculations: two head and neck cancer cases, a lung cancer case, and a prostate cancer case. Each underwent two CT examinations for radiotherapy planning.
Results:
LU maps were calculated from each DIR of the clinical cases. Reduced fat regions had LUs of 4.6 ± 0.9 mm, 4.8 ± 1.0 mm, and 4.5 ± 0.7 mm, while the shrunken left parotid gland had a LU of 4.1 ± 0.8 mm and the shrunken lung tumor had a LU of 3.7 ± 0.7 mm. The bowels in the pelvic region had a LU of 10.2 ± 3.7 mm. LU histograms for the cases were similar and 99% of the voxels had a LU < 3 mm.
Conclusions:
LU is a new uncertainty metric for DIR that was demonstrated for clinical cases. It had a tolerance of <3 mm.
More Related Videos
10:33Expedited Radiation Biodosimetry by Automated Dicentric Chromosome Identification ADCI and Dose Estimation
Published on: September 4, 2017
06:20Irradiator Commissioning and Dosimetry for Assessment of LQ α and β Parameters, Radiation Dosing Schema, and in vivo Dose Deposition
Published on: March 11, 2021
Related Concept Videos
Biological Effects of Radiation
Deformation of Member under Multiple Loadings
In the case of a member with a variable cross-section, the strain is not constant but depends on the position. The deformation of an...
Propagation of Uncertainty from Systematic Error
Uncertainty: Overview
Dose Size and Dosing Frequency: Determination Methods
Propagation of Uncertainty from Random Error