Change search
ReferencesLink to record
Permanent link

Direct link
Variability in target delineation for cavernous sinus meningioma and anaplastic astrocytoma in stereotactic radiosurgery with Leksell Gamma Knife Perfexion
Stockholm University, Faculty of Science, Department of Physics. Karolinska Institutet, Sweden.
Elekta Instrument AB, Sweden.
Elekta Instrument AB, Sweden.
Elekta Instrument AB, Sweden.
Show others and affiliations
2014 (English)In: Acta Neurochirurgica, ISSN 0001-6268, E-ISSN 0942-0940, Vol. 156, no 12, 2303-2313 p.Article in journal (Refereed) Published
Abstract [en]

Background: Radiosurgery clinical practice relays on empirical observations and the experience of the practitioners involved in determining and delineating the target and therefore variability in target delineation might be expected for all the radiosurgery approaches, independent of the technique and the equipment used for delivering the treatment. The main aim of this study was to quantify the variability of target delineation for two radiosurgery targets expected to be difficult to delineate. The secondary aim was to investigate the dosimetric implications with respect to the plan conformity. The primary aim of the study has therefore a very general character, not being bound to one specific radiosurgery technique.

Materials and methods: Twenty radiosurgery centers were asked to delineate one cavernous sinus meningioma and one astrocytoma and to plan the treatments for Leksell Gamma Knife Perfexion. The analysis of the delineated targets was based on the calculated 50% agreement volume, AV50. The AV50 was compared to each delineated target by the concordance index and discordance index. The differences in location, size, and shape of the delineated targets were also analyzed using the encompassing volume compared to the common volume, i.e., the AV100, of all delineated structures.

Results: Target delineation led to major differences between the participating centers and therefore the AV50 was small in comparison to each delineated target volume. For meningioma, the AV50 was 5.90 cm3, the AV100 was 2.60 cm3, and the encompassing volume was 13.14 cm3. For astrocytoma, the AV50 was 2.06 cm3 while the AV100 was extremely small, only 0.05 cm3, and the encompassing volume was 43.27 cm3. These variations translate into corresponding discrepancies in plan conformity.

Conclusions: Significant differences in shape, size, and location between the targets included in this study were identified and therefore the clinical implications of these differences should be further investigated.

Place, publisher, year, edition, pages
2014. Vol. 156, no 12, 2303-2313 p.
Keyword [en]
Leksell Gamma Knife Perfexion; Gamma Knife radiosurgery; Radiosurgery; Target delineation; Astrocytoma; Meningioma; Inter-observer variability
National Category
Cancer and Oncology
URN: urn:nbn:se:su:diva-107221DOI: 10.1007/s00701-014-2235-1ISI: 000345097700012OAI: diva2:744115
Available from: 2014-09-06 Created: 2014-09-06 Last updated: 2015-06-15Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textOpen Access PDF (2440 kB)

Search in DiVA

By author/editor
Sandström, HelenaJokura, HidefumiToma-Dasu, Iuliana
By organisation
Department of Physics
In the same journal
Acta Neurochirurgica
Cancer and Oncology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 38 hits
ReferencesLink to record
Permanent link

Direct link