ESTRO 2024 - Abstract Book

S1767

Clinical - Lung

ESTRO 2024

The data will also be interrogated in several other ways. This includes dividing up time periods to look at trends of radiotherapy delivery, extracting other data to allow a greater depth of analysis, including age, gender, deprivation frailty score, patient reported quality of life, pathology, systemic therapies and additional radiotherapy details, such as GTV. This will be achieved by cross-referencing the data with other structured forms found on the EPR such as radiotherapy and chemotherapy prescriptions. This will allow patients who received induction chemotherapy to be separated from the radical radiotherapy cohort and to look at those patients who received concurrent chemoradiotherapy +/- consolidation durvalumab. 346 (11%), 66 (2%) and 709 (24%) patients were documented as PS 3-4, having stage IV disease at diagnosis and severe co-morbidity as per ACE score respectively. The overall survival for these patients was higher than expected and despite small numbers in the poor PS and stage IV disease group, these patients warrant further analysis to understand treatment decisions and their overall trajectory.

This data is a proof-of-concept analysis that large volumes or real-world data can be extracted from structured data within EPRs and forms a benchmark for future comparisons.

Keywords: Radiotherapy, real-world evidence, lung cancer

2642

Digital Poster

Comparing Dosimetry and RT pneumonitis risk between carbon ion radiotherapy and SABR in lung cancer

Hyejo Ryu 1,2 , Bitbyeol Kim 1 , Jaeman Son 1,2 , Seongmoon Jung 1,2 , Hyeongmin Jin 1,2 , Hong Gyun Wu 1,2 , Jong Min Park 1,2 , Kyung Su Kim 1,2 1 Seoul National University Hospital, Radiation Oncology, Seoul, Korea, Republic of. 2 Seoul National University College of Medicine, Radiation Oncology, Seoul, Korea, Republic of

Purpose/Objective:

To identify the indications for carbon ion Radiotherapy (CIRT) and photon-based Stereotactic Ablative Radiotherapy (photon SABR) for lung tumors by analyzing dosimetric parameters and the risk of radiation pneumonitis (RP).

Material/Methods:

We generated photon and carbon-based treatment plans for 20 lung lesions treated by SABR or hypofractionated radiotherapy at our institution. A gating technique was employed, and all plans were prescribed a dose of 60 Gy [RBE] delivered in 4 fractions. Parameters were collected including gross target volume (GTV), planning target volume (PTV), mean lung dose (MLD), and lung V20Gy. The tumor diameter was estimated from GTV, assuming a spherical shape. The Lyman-Kutcher Burman (LKB) model was used to assess the risk of RP.