Assessment of Radiotherapy Planning Efficacy Based on Brain Tumor Shape Analysis

Assessment of Radiotherapy Planning Efficacy Based on Brain Tumor Shape Analysis

Funded by Bogazici BAP Grant 19482 (2022-2023) 

Principal Investigator: Esin Öztürk Işık

Researchers:  Esra Sümer

Project Summary: The primary goal of Gamma Knife (GK) dose planning is to cover any shape irregularities of target that strongly affect dose distribution inside and outside the target. However, there is currently no clinically practical tool for estimating the effect of shape irregularity of target on dose plan efficiency. In this study, the main aims are to measure tumor shape irregularity and analyze its effect on GK plan efficiency and treatment outcomes. In the present study, GK treatment plans created by Perfection/ICON platform for vestibular schwannoma. Tumor shape irregularity will be measured using radiomic shape features from segmented magnetic resonance (MR) images. Dose planning efficiency will be measured using the selectivity index (SI), gradient index (GI), Paddick conformality index (PCI), and efficacy index (EI). Correlation and linear regression analyses will be applied between the shape irregularity features and the dose plan indices. Then, machine learning algorithms will be used to identify the best-performing shape feature to predict dose plan efficiency. Finally, treatment outcomes at year 2 will be investigated, including tumor growth control and functional hearing preservation using Cox regression analyses to determine whether tumor shape irregularity has any effect on GK plan efficiency and treatment outcomes. Among the various shape irregularity metrics, the one with the highest predictive performance will be selected. It is expected that the irregularity of tumor shape will provide useful information to the clinician with the initial estimation of treatment efficacy and the comparisons of tumors.

Keywords: Gamma knife radiosurgery, shape irregularity, radiomics, machine learning


  1. Sümer, E., Tek, E., O. Türe, A., Şengöz, M., Dincer, A., Ozcan, A., et al.. (2022). The effect of tumor shape irregularity on Gamma Knife treatment plan quality and treatment outcome: an analysis of 234 vestibular schwannomas. Scientific Reports, 12(1), 21809

Conference Proceedings

  1. Sümer E, Türe OA, Şengöz M, Pamir MN, Dinçer A, Özduman K, Ozturk-Isik E. Correlation of MRI Radiomics Features and Recurrence After Gamma Knife Treatment in Parasagittal and Falx Meningiomas. International Society for Magnetic Resonance in Medicine. Toronto, Canada, June 3-8, 2023 (digital poster)
  2. Sümer E, Ozturk-Isik E, A radiomics pipeline for neuro-oncological research. GliMR 3rd Annual Meeting. Kuşadası, Turkey, September 28-30, 2022 (oral presentation)