Intrafractional 6D head movement increases with time of mask fixation during stereotactic intracranial RT-sessions

Autor: Peter Lukas, Ute Ganswindt, Georg Goebel, Christoph Reinhold Arnold, Julian Mangesius, Thomas Seppi, Rocco Weigel, Meinhard Nevinny-Stickel, Danijela Vasiljevic
Rok vydání: 2019
Předmět:
Organs at Risk
lcsh:Medical physics. Medical radiology. Nuclear medicine
Hypofractionated Radiotherapy
Movement
lcsh:R895-920
Treatment duration
Radiosurgery
lcsh:RC254-282
Patient Positioning
Intrafractional accuracy
030218 nuclear medicine & medical imaging
Stereotactic radiotherapy
Immobilization
ExacTrac
03 medical and health sciences
0302 clinical medicine
X-ray position monitoring
Image Processing
Computer-Assisted
Humans
Medicine
Radiology
Nuclear Medicine and imaging
Thermoplastic mask head fixation
Fixation (histology)
Frameless stereotactic radiation therapy
Phantoms
Imaging
business.industry
Research
Radiotherapy Planning
Computer-Assisted
Masks
Radiotherapy Dosage
lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens
Oncology
Head and Neck Neoplasms
Head Movements
030220 oncology & carcinogenesis
Random error
Head (vessel)
Head movements
Radiotherapy
Intensity-Modulated
Treatment time
Tomography
X-Ray Computed
business
Nuclear medicine
Zdroj: Radiation Oncology, Vol 14, Iss 1, Pp 1-8 (2019)
Radiation Oncology (London, England)
ISSN: 1748-717X
Popis: Background The present study investigates the intrafractional accuracy of a frameless thermoplastic mask used for head immobilization during stereotactic radiotherapy. Non-invasive masks cannot completely prohibit head movements. Previous studies attempted to estimate the magnitude of intrafractional inaccuracy by means of pre- and postfractional measurements only. However, this might not be sufficient to accurately map also intrafractional head movements. Materials and methods Intrafractional deviation of mask-fixed head positions was measured in five patients during a total of 94 fractions by means of close-meshed repeated ExacTrac measurements (every 1.4 min) conducted during the entire treatment session. A median of six (range: 4 to 11) measurements were recorded per fraction, delivering a dataset of 453 measurements. Results Random errors (SD) for the x, y and z axes were 0.27 mm, 0.29 mm and 0.29 mm, respectively. Median 3D deviation was 0.29 mm. Of all 3D intrafractional motions, 5.5 and 0.4% exceeded 1 mm and 2 mm, respectively. A moderate correlation between treatment duration and mean 3D displacement was determined (rs = 0.45). Mean 3D deviation increased from 0.21 mm (SD = 0.26 mm) in the first 2 min to a maximum of 0.53 mm (SD = 0.31 mm) after 10 min of treatment time. Conclusion Pre- and post-treatment measurement is not sufficient to adequately determine the range of intrafractional head motion. Thermoplastic masks provide both reliable interfractional and intrafractional immobilization for image-guided stereotactic hypofractionated radiotherapy. Greater positioning accuracy may be obtained by reducing treatment duration ( Trial registration Clinicaltrials.gov, NCT03896555, Registered 01 April 2019 - retrospectively registered.
Databáze: OpenAIRE
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