Gross tumor delineation in esophageal cancer on MRI compared with F-18-FDG-PET/CT

Vollenbrock, S.E.; Nowee, M.E.; Voncken, F.E.M.; Kotte, A.N.T.J.; Goense, L.; Rossum, P.S.N. van; ... ; Nijkamp, J. (2019)

Article / Letter to editor

Purpose: Current delineation of the gross tumor volume (GTV) in esophageal cancer relies on computed tomography (CT) and combination with F-18-fluorodeoxyglucose (FDG) positron emission tomography (PET). There is increasing interest in integrating magnetic resonance imaging (MRI) in radiation treatment, which can potentially obviate CT- or FDG-PET/CT-based delineation. The aim of this study is to evaluate the feasibility of target delineation on T2-weighted (T2W) MRI and T2W including diffusion-weighted MRI (T2W + DW-MRI) compared with current-practice FDG-PET/CT.Methods: Ten observers delineated primary esophageal tumor GTVs of 6 patients on FDG-PET/ CT, T2W-MRI, and T2W DW-MRI. GTVs, generalized conformity indices, in-slice delineation variation (root mean square), and standard deviations in the position of the most cranial and caudal delineated slice were calculated.Results: Delineations on MRI showed smaller GTVs compared with FDG-PET/CT-based delineations. The main variation was seen at the cranial and caudal border. No differences were observed in conformity indices (FDG-PET/CT, 0.68; T2W-MRI, 0.66; T2W + DW-MRI, 0.68) and in-slice variation (root mean square, 0.13 cm on FDG-PET/CT; 0.10 cm on T2W-MRI; 0.14 cm on T2W + DW-MRI). In the 2 tumors involving the gastroesophageal junction, addition of DW-MRI to T2W-MRI significantly decreased caudal border variation.Conclusions: MRI-based target delineation of the esophageal tumor is feasible with interobserver variability comparable to that with FDG-PET/CT, despite limited experience with delineation on MRI. Most variation was seen at cranial-caudal borders, and addition of DW-MRI to T2W-MRI may reduce caudal delineation variation of gastroesophageal junction tumors. (C) 2019 The Authors. Published by Elsevier Inc. on behalf of American Society for Radiation Oncology.

• All authors: Vollenbrock, S.E.; Nowee, M.E.; Voncken, F.E.M.; Kotte, A.N.T.J.; Goense, L.; Rossum, P.S.N. van; Lier, A.L.H.M.W. van; Heijmink, S.W.; Bartels-Rutten, A.; Wessels, F.J.; Aleman, B.M.P.; Dewit, L.; Kerkmeijer, L.G.W.; Jansen, E.P.M.; Intven, M.; Lips, I.M.; Meijer, G.J.; Nijkamp, J.
• Date: 2019-10-01
• Journal: Advances in Radiation Oncology
• Volume: 4
• Issue: 4
• Pages: 596 - 604
• DOI: doi:10.1016/j.adro.2019.04.004
• Link: https://www.sciencedirect.com/science/article/pii/S2452109419300521?via%...