Interobserver variability of radiation therapists aligning to fiducial markers for prostate radiation therapy

Deegan, Timothy, Owen, Rebecca, Holt, Tanya, Roberts, Lisa, Biggs, Jennifer, McCarthy, Alicia, Parfitt, Matthew, & Fielding, Andrew (2013) Interobserver variability of radiation therapists aligning to fiducial markers for prostate radiation therapy. Journal of Medical Imaging and Radiation Oncology, 57(4), pp. 519-523.

View at publisher


As the use of fiducial markers (FMs) for the localisation of the prostate during external beam radiation therapy (EBRT) has become part of routine practice, radiation therapists (RTs) have become increasingly responsible for online image interpretation. The aim of this investigation was to quantify the limits of agreement (LoA) between RTs when localising to FMs with orthogonal kilovoltage (kV) imaging.

Methods Six patients receiving prostate EBRT utilising FMs were included in this study. Treatment localisation was performed using kV imaging prior to each fraction. Online stereoscopic assessment of FMs, performed by the treating RTs, was compared with the offline assessment by three RTs. Observer agreement was determined by pairwise Bland-Altman analysis.

Results Stereoscopic analysis of 225 image pairs was performed online at the time of treatment, and offline by three RT observers. Eighteen pairwise Bland-Altman analyses were completed to assess the level of agreement between observers. Localisation by RTs was found to be within clinically acceptable 95% LoAs.

Conclusions Small differences between RTs, in both the online and offline setting, were found to be within clinically acceptable limits. RTs were able to make consistent and reliable judgements when matching FMs on planar kV imaging.

Impact and interest:

5 citations in Scopus
Search Google Scholar™
3 citations in Web of Science®

Citation counts are sourced monthly from Scopus and Web of Science® citation databases.

These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.

Citations counts from the Google Scholar™ indexing service can be viewed at the linked Google Scholar™ search.

ID Code: 59126
Item Type: Journal Article
Refereed: Yes
Keywords: fiducial marker, observer variability, radiation therapy
DOI: 10.1111/1754-9485.12055
ISSN: 1754-9485
Subjects: Australian and New Zealand Standard Research Classification > PHYSICAL SCIENCES (020000) > OTHER PHYSICAL SCIENCES (029900) > Medical Physics (029903)
Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > ONCOLOGY AND CARCINOGENESIS (111200) > Radiation Therapy (111208)
Divisions: Past > QUT Faculties & Divisions > Faculty of Science and Technology
Current > Institutes > Institute of Health and Biomedical Innovation
Past > Schools > Physics
Current > QUT Faculties and Divisions > Science & Engineering Faculty
Deposited On: 17 Apr 2013 22:23
Last Modified: 27 Sep 2013 00:34

Export: EndNote | Dublin Core | BibTeX

Repository Staff Only: item control page