PMID- 16641422
OWN - NLM
STAT- MEDLINE
DCOM- 20060824
LR  - 20161124
IS  - 1748-880X (Electronic)
IS  - 0007-1285 (Linking)
VI  - 79
IP  - 944
DP  - 2006 Aug
TI  - Optimizing localization accuracy in head and neck, and brain radiotherapy.
PG  - 672-80
AB  - 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.
FAU - McJury, M
AU  - McJury M
AD  - Department of Radiotherapy Physics, Weston Park Hospital, Whitham Road, 
      Sheffield, UK.
FAU - Dyker, K
AU  - Dyker K
FAU - Nakielny, R
AU  - Nakielny R
FAU - Conway, J
AU  - Conway J
FAU - Robinson, M H
AU  - Robinson MH
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20060426
PL  - England
TA  - Br J Radiol
JT  - The British journal of radiology
JID - 0373125
SB  - IM
MH  - Brain Neoplasms/diagnostic imaging/*radiotherapy
MH  - Head and Neck Neoplasms/diagnostic imaging/*radiotherapy
MH  - Humans
MH  - Observer Variation
MH  - Radiotherapy, Conformal/*methods/standards
MH  - Sensitivity and Specificity
MH  - Tomography, X-Ray Computed/methods/*standards
EDAT- 2006/04/28 09:00
MHDA- 2006/08/25 09:00
CRDT- 2006/04/28 09:00
PHST- 2006/04/28 09:00 [pubmed]
PHST- 2006/08/25 09:00 [medline]
PHST- 2006/04/28 09:00 [entrez]
AID - 14663755 [pii]
AID - 10.1259/bjr/14663755 [doi]
PST - ppublish
SO  - Br J Radiol. 2006 Aug;79(944):672-80. doi: 10.1259/bjr/14663755. Epub 2006 Apr 
      26.