ESTRO 2024 - Abstract Book

S941

Clinical - CNS

ESTRO 2024

primary and recurrent tumors associated with early recurrence. In early relapsed tumors, immune interactions involving TAM 1 were more activated, whereas those involving TAM 2 were more pronounced in late recurrent tumors. Additionally, the hypoxia-inducible factor 1 signaling pathway was found to be enriched in both primary and recurrent tumors associated with outfield failure. Active immune interactions mediated by BTLA on TAM 1 and CCR1 on TAM 2 were observed.

Conclusion:

We showed that differentially enriched pathways and immune-cell interactions in terms of primary vs recurrence, recurrence interval, and failure pattern, using matched primary and recurrent glioblastoma RNA sequencing dataset. These findings contribute to our understanding of GBM recurrence and its implications for prognosis. Further validation of these findings using additional datasets is warranted.

Keywords: Glioblastoma

2689

Digital Poster

First clinical results after proton therapy in patients with aggressive pituitary macroadenomas

Birgit Flechl, Eugen Hug, Antonio Carlino, Maciej Pelak, Petra Mozes, Ulrike Mock, Slavisa Tubin, Christoph Hajdusich, Piero Fossati, Carola Lütgendorf-Caucig

MedAustron, radiation oncology, Wiener Neustadt, Austria

Purpose/Objective:

In general, pituitary adenomas are classified as benign tumors. However, in case of locally aggressive tumor characteristics, therapy is indicated. Due to the proximity to the brain and brainstem, to optical structures and/or skull base infiltration, surgical as well as radiation therapy is challenging. In comparison to conventional photon therapy, proton therapy (PT) offers a steeper dose drop and is therefore used in order to reduce the risk of acute and chronic side effects.

Material/Methods:

In this study, we report on patients diagnosed with pituitary adenomas and treated with fractionated PT at MedAustron facility. From 2017 – 2023, 21 patients were identified. Median age was 52 years ranging from 30-77 years. The majority of patients had surgeries before PT whereas most of them underwent one resection (67%; n=14), 9.5% (n=2) had 4 surgeries and 24% (n=5) did not have any tumor resection. 76% (n=16) revealed benign tumors (69%, n=11 null cell adenomas; 31%, n=5 hormone- active) and 25% (n=5) higher grade histology (Ki67 ≥10%).