BJR
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
First published online April 26, 2006
British Journal of Radiology (2006) 79, 672-680
© 2006 British Institute of Radiology
doi: 10.1259/bjr/14663755
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by McJury, M
Right arrow Articles by Robinson, M H
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by McJury, M
Right arrow Articles by Robinson, M H

Full paper

Optimizing localization accuracy in head and neck, and brain radiotherapy

M McJury, PhD1, K Dyker, MBChB, MRCP, FRCR2, R Nakielny, MA(Cantab), BM BCh, FRCR3, J Conway, PhD1 and M H Robinson, MD, FRCP, FRCR2

Departments of 1Radiotherapy Physics 2YCR Clinical Oncology, Weston Park Hospital, Whitham Road, Sheffield 3Department of Radiology, Royal Hallamshire Hospital, Glossop Road, Sheffield, UK

The purpose of this study was to investigate the impact on localization of utilizing contrast-enhanced CT scans and the formal input of a radiologist in the planning process. 25 head and neck/brain patients had pre- and post-contrast CT scans in the treatment position. Radiotherapy treatment was planned on the unenhanced CT images as per standard practice. Retrospectively, their scans (unenhanced and enhanced) were re-contoured by two oncologists and a radiologist. These new contours were compared with the original unenhanced treatment contours and differences in contour volume, geographical isocentre position and tolerance coverage of the associated planning target volumes (PTVs) were evaluated using the original plans. The use of contrast enhanced CT data during localization by the oncologist shows little change in gross tumour volumes (GTVs) or PTVs, geographical position or tolerance coverage for the targets in the brain studied here. Larger changes in mean volume are seen for the head and neck cases alone. Changes are greater and statistically significant (p<0.05, Wilcoxon signed rank test) for localization by the radiologist. Furthermore, when comparing the original PTV marked by the oncologist with a new PTV re-contoured by the oncologist, but based on a GTV marked-up by the radiologist, again statistically significant (p<0.01) changes in percentage volume are noted. Intraoperator precision is good, percentage volume differences being of the order 3–6%. PTVs also show improved standard deviations compared with GTVs. Geographic shifts are generally within our departmental tolerance levels for daily patient setup. Comparing precision of unenhanced data with enhanced, mean percentage volume changes are smaller, but not statistically significant. The use of enhanced scan data for localization has little effect on size, geographical position or tolerance coverage of PTVs marked up by the oncologists in this study. However, more important is the input from a radiologist. Statistically significant differences due to mark-up on enhanced scans by the radiologist are shown. Furthermore, significant differences are also seen between PTVs based on oncologist-generated GTVs, and those based on radiologist-generated GTVs.




This article has been cited by other articles:


Home page
 Br. J. Radiol.Home page
BJR review of the year - 2006
Br. J. Radiol., March 1, 2007; 80(951): 147 - 151.
[Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
BJR DMFR IMAGING  ALL BIR JOURNALS 
Copyright © 2006 by the British Institute of Radiology.