ESTRO 2024 - Abstract Book

S5221

Radiobiology - Microenvironment

ESTRO 2024

1957

Digital Poster

Proton Therapy for Glioblastoma: Insights into Tumor Evolution and Microenvironment Remodeling

Richard Lu

Cincinnati Children's Hospital Medical Center, EHCB/Oncology, Cincinnati, USA

Purpose/Objective:

Proton therapy is an innovative radiation therapy that limits radiation exposure to healthy tissue while maintaining tumor control. However, the impact of proton therapy on glioblastoma (GBM) is not fully defined. We hypothesize that understanding tumor evolution and response to radiotherapy is critical for developing new interventions.

Material/Methods:

In this study, we compared conventional proton therapy to standard photon therapy in a syngeneic orthotopic GBM model throughout treatment. We analyzed tumor tissues at early, regressing, and relapse stages after irradiation using a multifaceted approach combining single-cell transcriptomics, bulk RNA sequencing, and histology.

Results:

We found that proton therapy initially reduced tumor volume before an eventual recurrence. Both proton and photon therapies showed equivalent tumor control. Single-cell analyses revealed that proton radiation remodeled the tumor microenvironment, notably impacting T-cell and macrophage populations during regression and relapse.

Conclusion:

Our study offers valuable insights into the effects of proton therapy on tumor growth and the dynamics of the tumor microenvironment.

Keywords: Proton therapy, glioblastoma, tumor progression

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