Improving the consistency in cervical esophageal target volume definition by special training.
OBJECTIVE
Three-dimensional conformal radiation therapy requires the precise definition of the target volume. Its potential benefits could be offset by the inconsistency in target definition by radiation oncologists. In a previous survey of radiation oncologists, a large degree of variation in target volume definition of cervical esophageal cancer was noted for the boost phase of radiotherapy. The present study evaluated whether special training could improve the consistency in target volume definitions.


METHODS
A pre-training survey was performed to establish baseline values. This was followed by a special one-on-one training session on treatment planning based on the RTOG 94-05 protocol to 12 radiation oncologists. Target volumes were redrawn immediately and at 1-2 months later. Post-training vs. pre-training target volumes were compared.


RESULTS
There was less variability in the longitudinal positions of the target volumes post-training compared to pre-training (p < 0.05 in 5 of 6 comparisons). One case had more variability due to the lack of a visible gross tumor on CT scans. Transverse contours of target volumes did not show any significant difference pre- or post-training.


CONCLUSIONS
For cervical esophageal cancer, this study suggests that special training on protocol guidelines may improve consistency in target volume definition. Explicit protocol directions are required for situations where the gross tumor is not easily visible on CT scans. This may be particularly important for multicenter clinical trials, to reduce the occurrences of protocol violations.
Tai
Patricia
P
Department of Oncology, London Regional Cancer Center, London, Ontario, Canada. ptai@scf.sk.ca
Van Dyk
Jake
J
Battista
Jerry
J
Yu
Edward
E
Stitt
Larry
L
Tonita
Jon
J
Agboola
Olusegun
O
Brierley
James
J
Dar
Rashid
R
Leighton
Christopher
C
Malone
Shawn
S
Strang
Barbara
B
Truong
Pauline
P
Videtic
Gregory
G
Wong
C Shun
CS
Wong
Rebecca
R
Youssef
Youssef
Y
D004502:Education, Medical, Continuing / Q000379:methods; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D006801:Humans; D021621:Imaging, Three-Dimensional; D055585:Physical Phenomena; D010825:Physics; D018787:Radiation Oncology / Q000193:education*; D020266:Radiotherapy, Conformal; D014057:Tomography, X-Ray Computed