ESTRO 2024 - Abstract Book

S860

Clinical - CNS

ESTRO 2024

We report a single-centre experience on patients with newly diagnosed BM treated with radical surgery followed by SRS with the aim to evaluate patterns of local recurrence.

Material/Methods:

We retrospectively collected data from consecutive patients treated with SRS to the surgical cavity in our centre between November 2018 and February 2023.

Patients who experienced intracranial disease progression from surgery to initiation of SRS were excluded.

Local (in field) and distant (out of field) treatment failures were defined based on magnetic resonance. Kaplan-Meier curves were generated for local, distant, and leptomeningeal recurrence free survival (LRFS, DRFS, LeRFS).

Results:

Twenty-five patients for a total of 35 cavities were treated with either Gamma Knife (GK) or CyberKnife (CK) after surgical resection.

Patients’ baseline characteristics are summarized in Table 1.

Eight out of 25 patients received concomitant SRS to synchronous BM for a total of 10 lesions. The median prescription dose was 19 Gy (range 12-25) at a median isodose line (IDL) of 70% (range 50-83.5) with a median of 1 fraction (range 1-5).

Local, distant, or leptomeningeal recurrence occurred in 3, 6 and 3 patients, respectively. Nine patients died, for a median PFS and OS of 11 and 14 months, respectively.

After a median follow up of 11 months, median LRFS, DRFS and LeRFS were 11, 9 and 11 months, respectively. No significant association between surgical cavity volume and LRFS, DRFS and LeRFS was detected. No significant impact of primary tumour histology (melanoma, ovarian cancer and renal cell carcinoma vs others) on LRFS or DRFS was found.