Interobserver variability in target definition for stereotactic arrhythmia radioablation

Martijn H. van der Ree, Phillip S. Cuculich, Marcel van Herk, Geoffrey D. Hugo, Jippe C. Balt, Matthew Bates, Gordon Ho, Etienne Pruvot, Claudia Herrera-Siklody, Wiert F. Hoeksema, Justin Lee, Michael S. Lloyd, Michiel J.B. Kemme, Frederic Sacher, Romain Tixier, Joost J.C. Verhoeff, Brian V. Balgobind, Clifford G. Robinson, Coen R.N. Rasch, Pieter G. Postema

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


Background: Stereotactic arrhythmia radioablation (STAR) is a potential new therapy for patients with refractory ventricular tachycardia (VT). The arrhythmogenic substrate (target) is synthesized from clinical and electro-anatomical information. This study was designed to evaluate the baseline interobserver variability in target delineation for STAR. Methods: Delineation software designed for research purposes was used. The study was split into three phases. Firstly, electrophysiologists delineated a well-defined structure in three patients (spinal canal). Secondly, observers delineated the VT-target in three patients based on case descriptions. To evaluate baseline performance, a basic workflow approach was used, no advanced techniques were allowed. Thirdly, observers delineated three predefined segments from the 17-segment model. Interobserver variability was evaluated by assessing volumes, variation in distance to the median volume expressed by the root-mean-square of the standard deviation (RMS-SD) over the target volume, and the Dice-coefficient. Results: Ten electrophysiologists completed the study. For the first phase interobserver variability was low as indicated by low variation in distance to the median volume (RMS-SD range: 0.02–0.02 cm) and high Dice-coefficients (mean: 0.97 ± 0.01). In the second phase distance to the median volume was large (RMS-SD range: 0.52–1.02 cm) and the Dice-coefficients low (mean: 0.40 ± 0.15). In the third phase, similar results were observed (RMS-SD range: 0.51–1.55 cm, Dice-coefficient mean: 0.31 ± 0.21). Conclusions: Interobserver variability is high for manual delineation of the VT-target and ventricular segments. This evaluation of the baseline observer variation shows that there is a need for methods and tools to improve variability and allows for future comparison of interventions aiming to reduce observer variation, for STAR but possibly also for catheter ablation.

Original languageEnglish
Article number1267800
JournalFrontiers in Cardiovascular Medicine
StatePublished - 2023


  • cardiac radioablation
  • interobserver variability
  • stereotactic arrhythmia radioablation
  • stereotactic arrhythmia radiotherapy
  • ventricular tachycardia


Dive into the research topics of 'Interobserver variability in target definition for stereotactic arrhythmia radioablation'. Together they form a unique fingerprint.

Cite this