ESTRO 2025 - Abstract Book

S2850

Physics - Dose prediction, optimisation and applications of photon and electron planning

ESTRO 2025

Conclusion: The application of inverse planning using the HIPO algorithm to calculate needle dwell times produces plans comparable to those generated with forward optimization. However, the Wilcoxon signed-rank test revealed statistically significant dosimetric differences between the two methods for specific parameters, including CTV_HR D98, DNR, and the ratio of needle dwell time to total dwell time. HIPO optimization offers the potential to reduce planning time, making it a valuable tool for improving efficiency in treatment workflows. References: Fröhlich G, Gyula Geszti, Júlia Vízkeleti, Péter Ágoston, Csaba Polgár, Major T. Dosimetric comparison of inverse optimisation methods versus forward optimisation in HDR brachytherapy of breast, cervical and prostate cancer. 2019 Sep 3;195(11):991–1000. Pötter R, Tanderup K, Kirisits C, de Leeuw A, Kirchheiner K, et al. The EMBRACE II study: The outcome and prospect of two decades of evolution within the GEC-ESTRO GYN working group and the EMBRACE studies. Clinical and Translational Radiation Oncology [Internet]. 2018 Jan 11;9:48–60. Kirisits C, Rivard MJ, Baltas D, Ballester F, et al. Review of clinical brachytherapy uncertainties: Analysis guidelines of GEC-ESTRO and the AAPM. Radiotherapy and Oncology. 2014 Jan 1;110(1):199–212. Digital Poster Three year experience of clinical Implementation of an Automated VMAT Treatment Planning Script for Head and Neck Cancer Patients Nataliya Kovalchuk, Peng Dong, Michael Xiang, Everett Moding, Michael Gensheimer, Beth Beadle, Quynh Thu Le, Lei Xing, Yong Yang Radiation Oncology, Stanford University, Stanford, USA Purpose/Objective: This study aimed to assess the impact of implementing an in-house automated VMAT treatment planning script for patients with head and neck (HN) cancer. Material/Methods: The automated planning script, developed using Eclipse Scripting Application Programming Interface (ESAPI), was introduced in 2020 for HN cancer patients. To evaluate its efficacy, dosimetric indices for 1000 patients treated between 2017 and 2023 were compared, with 500 patients planned manually and 500 patients planned using the automated script. Differences in target and organ-at-risk metrics were analyzed using a t-test, with p < 0.05 Keywords: Brachytherapy, HIPO, cervical cancer 3086