• Int. J. Radiat. Oncol. Biol. Phys. · May 2018

    Determination of Intrafraction Prostate Motion During External Beam Radiation Therapy With a Transperineal 4-Dimensional Ultrasound Real-Time Tracking System.

    • Dwi Seno Kuncoro Sihono, Michael Ehmann, Sigrun Heitmann, Sandra von Swietochowski, Mario Grimm, Judit Boda-Heggemann, Frank Lohr, Frederik Wenz, and Hansjörg Wertz.
    • Department of Radiation Oncology, Universitaetsmedizin Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany; Department of Physics, Faculty of Mathematics and Sciences, University of Indonesia, Kampus UI Depok, Indonesia. Electronic address: sihono@stud.uni-heidelberg.de.
    • Int. J. Radiat. Oncol. Biol. Phys. 2018 May 1; 101 (1): 136-143.

    Purpose/ObjectiveTo determine intrafraction prostate motion during volumetric modulated arc therapy (VMAT) using transperineal ultrasound (US) real-time tracking.Methods And Materials770 US monitoring sessions in 38 prostate cancer patients' VMAT treatment series were retrospectively evaluated. Intrafraction motion assessment of the prostate was based on continuous position monitoring with a 4-dimensional US system along the 3 directions: left-right (LR), anterior-posterior (AP), and inferior-superior (SI). The overall mean values and standard deviations (SD) along with random and systematic errors were calculated.ResultsThe mean duration of each monitoring session was 254 s. The mean (μ), the systematic error (Σ), and the random error (σ) of intrafraction prostate displacement were μ = (0.01, -0.08, 0.15) mm, Σ = (0.30, 0.34, 0.23) mm, and σ = (0.59, 0.73, 0.64) mm in the LR, AP and SI directions, respectively. The percentage of treatments for which prostate displacement was ≤2 mm was 97.01%, 92.24%, and 95.77% in the LR, AP, and SI directions, respectively. At 60 s, a vector length of prostate displacement >2 mm was present in 0.67% of the data. The percentage increased to 2.42%, 6.14%, and 9.35% at 120 s, 180 s, and 240 s, respectively.ConclusionsThe magnitudes of intrafraction prostate motion along the SI and AP directions were comparable. On average, the smallest motion was in the LR direction and the largest in AP direction. Most of the prostate displacements were within a few millimeters. However, with increasing treatment time (eg, during hypofractionation), larger 3-dimensional prostate displacements up to 18.30 mm could be observed. Shortening treatment time can reduce the impact of intrafraction motion and potentially allows smaller safety margins.Copyright © 2018 Elsevier Inc. All rights reserved.

      Pubmed     Full text   Copy Citation     Plaintext  

      Add institutional full text...

    Notes

     
    Knowledge, pearl, summary or comment to share?
    300 characters remaining
    help        
    You can also include formatting, links, images and footnotes in your notes
    • Simple formatting can be added to notes, such as *italics*, _underline_ or **bold**.
    • Superscript can be denoted by <sup>text</sup> and subscript <sub>text</sub>.
    • Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens - or asterisks *.
    • Links can be included with: [my link to pubmed](http://pubmed.com)
    • Images can be included with: ![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
    • For footnotes use [^1](This is a footnote.) inline.
    • Or use an inline reference [^1] to refer to a longer footnote elseweher in the document [^1]: This is a long footnote..

    hide…