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71. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC)
9. Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

21.06. - 24.06.2020

Reduction of radiation dosage of intraoperative computed tomography and its effect on localisation accuracy of a stereotactic frame

Reduzierung der Strahlendosis und deren Auswirkungen auf die Genauigkeit der Lokalisierung eines rahmengestützten Stereotaxie-Systems

Meeting Abstract

Suche in Medline nach

  • presenting/speaker Miriam Bopp - Universitätsklinikum Gießen und Marburg, Klinik für Neurochirurgie, Marburg, Deutschland
  • Noel Kröncke - Universitätsklinikum Gießen und Marburg, Klinik für Neurochirurgie, Marburg, Deutschland
  • Barbara Carl - Universitätsklinikum Gießen und Marburg, Klinik für Neurochirurgie, Marburg, Deutschland
  • Christopher Nimsky - Universitätsklinikum Gießen und Marburg, Klinik für Neurochirurgie, Marburg, Deutschland

Deutsche Gesellschaft für Neurochirurgie. 71. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), 9. Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie. sine loco [digital], 21.-24.06.2020. Düsseldorf: German Medical Science GMS Publishing House; 2020. DocP224

doi: 10.3205/20dgnc510, urn:nbn:de:0183-20dgnc5103

Veröffentlicht: 26. Juni 2020

© 2020 Bopp et al.
Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). Lizenz-Angaben siehe http://creativecommons.org/licenses/by/4.0/.


Gliederung

Text

Objective: To perform deep brain stimulation (DBS) an accurate localization of anatomical target structures as well as the precise placement of the electrodes within the target structures is required. To map high-resolution preoperative data to the patient’s anatomy stereotactic frame-based techniques are applied. Due to less geometric distortion often computed tomography (CT) imaging is used, especially when intraoperative CT systems are available. Nevertheless, standard CT protocols together with increased scan length due to the stereotactic frame and attached localizer box, resulting in high radiation dosage. To overcome this issue while keeping high accuracy of frame localization in this study various scan protocols raging from high to ultra-low radiation were evaluated.

Methods: To analyze the accuracy of frame localization related to different scanning protocols, a stereotactic frame (Zamorano-Duchovny) including a CT localizer box was attached to a head phantom. The stereotactic system was aligned straight in the iso-center of the CT scanner (AIRO® iCT, Brainlab, Munich, Germany). Start and end of each scan was defined equally covering the localizer box and the stereotactic frame. Six protocols (helical acquisition) were used: Head, Orbit, Sinus, Sinus-50%, Sinus-80%, Newborn. Frame localization was performed using Brainlab Elements Stereotaxy (Brainlab, Munich, Germany). The radiation dosage and deviation of slice-by-slice detected points along each of the eleven rods from the given model was evaluated.

Results: Overall deviation from the underlying model of the localizer box was 0.18 ± 0.05 mm (Head), 0.17 ± 0.05 mm (Orbit), 0.17 ± 0.04 mm (Sinus), 0.17 ± 0.04 mm (Sinus-50%), 0.17 ± 0.04 mm (Sinus-80%) and 0.16 ± 0.04 mm (Neonate) revealing no significant difference in localization accuracy. With a scan length of about 20 cm the dose length product was 1624.37 mGy*cm (Head), 583.19 mGy*cm (Orbit), 358.41 mGy*cm (Sinus), 178.22 mGy*cm (Sinus-50%), 71.45 mGy*cm (Sinus-80%) and 12.84 mGy*cm (Newborn) showing a significant decrease, while keeping all relevant structures (localizer box, bony structures for image fusion) sufficiently available.

Conclusion: For frame-based stereotactic procedures applying CT imaging for frame localization as well as image fusion with high-resolution preoperative data to map frame, image and patient space, also ultra-low dosage scanning protocols can be applied without any loss of localization accuracy.