To validate a simulation environment for virtual planning of percutaneous cryoablation of renal tumors.
Prospectively collected data from 19 MR-guided procedures were used for validation of the simulation model. Volumetric overlap of the simulated ablation zone volume (Σ) and the segmented ablation zone volume (S; assessed on 1-month follow-up scan) was quantified. Validation metrics were DICE Similarity Coefficient (DSC; the ratio between twice the overlapping volume of both ablation zones divided by the sum of both ablation zone volumes), target overlap (the ratio between the overlapping volume of both ablation zones to the volume of S; low ratio means S is underestimated), and positive predictive value (the ratio between the overlapping volume of both ablation zones to the volume of Σ; low ratio means S is overestimated). Values were between 0 (no alignment) and 1 (perfect alignment), a value > 0.7 is considered good.
Mean volumes of S and Σ were 14.8 cm3 (± 9.9) and 26.7 cm3 (± 15.0), respectively. Mean DSC value was 0.63 (± 0.2), and ≥ 0.7 in 9 cases (47%). Mean target overlap and positive predictive value were 0.88 (± 0.11) and 0.53 (± 0.24), respectively. In 17 cases (89%), target overlap was ≥ 0.7; positive predictive value was ≥ 0.7 in 4 cases (21%) and < 0.6 in 13 cases (68%). This indicates S is overestimated in the majority of cases.
The validation results showed a tendency of the simulation model to overestimate the ablation effect. Model adjustments are necessary to make it suitable for clinical use.
Cardiovascular and interventional radiology. 2020 Sep 15 [Epub ahead of print]
Tim J van Oostenbrugge, Jan Heidkamp, Michael Moche, Phil Weir, Panchatcharam Mariappan, Ronan Flanigan, Mika Pollari, Stephen Payne, Marina Kolesnik, Sjoerd F M Jenniskens, Jurgen J Fütterer
Department of Urology, Radboud University Medical Center, P.O. box 9101, 6500 HB, Nijmegen, The Netherlands. ., Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands., Department of Diagnostic and Interventional Radiology, University Hospital, Leipzig, Germany., NUMA Engineering Services Ltd, Dublin, Ireland., Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland., Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, UK., Fraunhofer - FIT - Institute for Applied Information Technology, Sankt-Augustin, Germany.