TY - JOUR
T1 - Reduced inter-observer and intra-observer delineation variation in esophageal cancer radiotherapy by use of fiducial markers
AU - Machiels, M. lanie
AU - Jin, Peng
AU - van Hooft, Jeanin E.
AU - Gurney-Champion, Oliver J.
AU - Jelvehgaran, Pouya
AU - Geijsen, Elizabeth D.
AU - Jeene, Paul M.
AU - Willemijn Kolff, M.
AU - Oppedijk, Vera
AU - Rasch, Coen. R. N.
AU - van Herk, Marcel B.
AU - Alderliesten, Tanja
AU - Hulshof, Maarten C. C. M.
PY - 2019
Y1 - 2019
N2 - Objective: Delineation variation of esophageal tumors remains a large source of geometric uncertainty. In the present study, we investigated the inter- and intra-observer variation in esophageal gross tumor volume (GTV) delineation and the impact of endoscopically implanted fiducial markers on these variations. Material/Methods: Ten esophageal cancer patients with at least two markers endoscopically implanted at the cranial and caudal tumor borders and visible on the planning computed tomography (pCT) were included in this study. Five dedicated gastrointestinal radiation oncologists independently delineated GTVs on the pCT without markers and with markers. The GTV was first delineated on pCTs where markers were digitally removed and next on the original pCT with markers. Both delineation series were executed twice to determine intra-observer variation. For both the inter- and intra-observer analyses, the generalized conformity index (CI gen ), and the standard deviation (SD) of the distances between delineated surfaces (i.e., overall, longitudinal, and radial SDs) were calculated. Linear mixed-effect models were used to compare the without and with markers series (α = 0.05). Results: Both the inter- and intra-observer CI gen were significantly larger in the series with markers than in the series without markers (p <.001). For the series without markers vs. with markers, the inter-observer overall SD, longitudinal SD, and radial SD was 0.63 cm vs. 0.22 cm, 1.44 cm vs. 0.42 cm, and 0.26 cm vs. 0.18 cm, respectively (p <.05); moreover, the intra-observer overall SD, longitudinal SD, and radial SD was 0.45 cm vs. 0.26 cm, 1.10 cm vs. 0.41 cm, and 0.22 cm vs. 0.15 cm, respectively (p <.05). Conclusion: The presence of markers at the cranial and caudal tumor borders significantly reduced both inter- and intra-observer GTV delineation variation, especially in the longitudinal direction. Our results endorse the use of markers in GTV delineation for esophageal cancer patients.
AB - Objective: Delineation variation of esophageal tumors remains a large source of geometric uncertainty. In the present study, we investigated the inter- and intra-observer variation in esophageal gross tumor volume (GTV) delineation and the impact of endoscopically implanted fiducial markers on these variations. Material/Methods: Ten esophageal cancer patients with at least two markers endoscopically implanted at the cranial and caudal tumor borders and visible on the planning computed tomography (pCT) were included in this study. Five dedicated gastrointestinal radiation oncologists independently delineated GTVs on the pCT without markers and with markers. The GTV was first delineated on pCTs where markers were digitally removed and next on the original pCT with markers. Both delineation series were executed twice to determine intra-observer variation. For both the inter- and intra-observer analyses, the generalized conformity index (CI gen ), and the standard deviation (SD) of the distances between delineated surfaces (i.e., overall, longitudinal, and radial SDs) were calculated. Linear mixed-effect models were used to compare the without and with markers series (α = 0.05). Results: Both the inter- and intra-observer CI gen were significantly larger in the series with markers than in the series without markers (p <.001). For the series without markers vs. with markers, the inter-observer overall SD, longitudinal SD, and radial SD was 0.63 cm vs. 0.22 cm, 1.44 cm vs. 0.42 cm, and 0.26 cm vs. 0.18 cm, respectively (p <.05); moreover, the intra-observer overall SD, longitudinal SD, and radial SD was 0.45 cm vs. 0.26 cm, 1.10 cm vs. 0.41 cm, and 0.22 cm vs. 0.15 cm, respectively (p <.05). Conclusion: The presence of markers at the cranial and caudal tumor borders significantly reduced both inter- and intra-observer GTV delineation variation, especially in the longitudinal direction. Our results endorse the use of markers in GTV delineation for esophageal cancer patients.
UR - https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85063574041&origin=inward
UR - https://www.ncbi.nlm.nih.gov/pubmed/30905243
U2 - https://doi.org/10.1080/0284186X.2019.1588991
DO - https://doi.org/10.1080/0284186X.2019.1588991
M3 - Article
C2 - 30905243
SN - 0284-186X
SP - 1
EP - 8
JO - Acta oncologica (Stockholm, Sweden)
JF - Acta oncologica (Stockholm, Sweden)
ER -