ESTRO 2024 - Abstract Book

S819

Clinical - CNS

ESTRO 2024

the time of the first sRT was not a significant prognostic factor for mOS (1 vs. 2-10 BM with mOS of 16.5 vs. 10.8, p = 0.07) with patients receiving TT surviving longer independent of the number of BM (1 vs. 2-10 BM with mOS of 28.7 vs. 17.1, p = 0.82). The timing of ICI/TT and sRT was not prognostic. In the NSCLC subgroup not receiving ICI or TT, progression within the first 3 months after sRT was prognostic for mOS (57.7 vs. 5.3 months, p < 0.0001). In contrast, for patients receiving ICI or TT, progression within 3 months did not seem to affect overall survival (24.6 vs. 15.0 months, p = 0.21).

Conclusion:

Aside from the number of BM, the overall survival of patients after sRT for BM and cavities was significantly associated with the PTV size and cerebral progression after sRT. In the NSCLC subgroup, the suitability for and administration of ICI or TT is a relevant prognostic factor of OS, whereas the number of BM was not significantly associated with OS. In patients receiving TT, the number of irradiated BM and the time to cerebral progression may have a lesser impact on OS.

Keywords: targeted therapy, checkpoint inhibition, SRS

1052

Digital Poster

Linac-based Stereotactic Radiosurgery for Arteriovenous Malformation - A noninvasive alternative

Mariya Deputy, Sanjay Hunugundmath, Sammed Upadhye, Amit Nirhali, Vishram Naik, Sharad Gadhave

Sahyadri superspeciality hospital, Radiation Oncology, Pune, India

Purpose/Objective:

To evaluate the obliteration rates of arteriovenous malformation (AVM) with Linac-based radiosurgery.

Material/Methods:

We retrospectively analyzed 30 patients diagnosed with AVM treated between 2020 to 2023. The median age at presentation was 31 years (range – 20 to 54 years). Median planning target volume (PTV) was 9.5 cc (range – 1.5 to 46 cc). The median dose prescribed was 18 Gy (14 -24Gy). We calculated modified radiosurgery based AVM grading score for all patients ((0.1) (volume, mL) + 0.02 (age, years) + 0.5 (location)) prior to treatment and its impact on obliteration of AVM was analyzed.

Results: