ESTRO 2024 - Abstract Book

S791

Clinical - CNS

ESTRO 2024

The estimated 5-year local control (LC) rate was 87% for the entire cohort, 98% for WHO I and non-surgical patients, and 51% for WHO II-III meningiomas and hemangiopericytomas.

Distant relapse (DR) occurred in 15 patients (8.5%), among these 4 experienced local recurrences. The DR median time was 40 months.

The estimated 5-year DR-free survival rate was 89% for the entire cohort, 94% for WHO I and non-surgical patients, and 70% for WHO II-III meningiomas and hemangiopericytomas. Overall, 12 patients died during follow-up, with 4 having non-benign meningiomas and succumbing to disease progression. The 5-year OS was 93% for the entire cohort. LC was found to be influenced by WHO grade. One WHO I patient had local failure, while most patients with local relapse had WHO II- III lesions (p<0.0001). Additionally, patients with an age ≤ 55 years showed a significant association (p=0.04) with better LC. No significant associations were observed between LC and gender (p=0.44), volume of GTV (p=0.30), or timing of proton therapy (p=0.88).

Similar results were obtained in the univariable analysis correlating OS and DRFS with WHO grade (I-unknown vs. II III) with p-values of 0.004 and 0.0004, respectively. While age did not reach statistical significance about OS (p=0.06).

WHO grade emerged as the most notable prognostic factor in OS, LC, and DR.