Salvage re-irradiation in patients with recurrent high-grade glial tumors
iARTIST-International Advanced Radiotherapy Techniques Symposium, İstanbul, Türkiye, 11 - 14 Haziran 2026, (Tam Metin Bildiri)
- Yayın Türü: Bildiri / Tam Metin Bildiri
- Basıldığı Şehir: İstanbul
- Basıldığı Ülke: Türkiye
- Bursa Uludağ Üniversitesi Adresli: Evet
Özet
Background: High-grade glial tumors (HGGs) are the most common malignant brain tumors in adults and almost inevitably recur after standard therapy. After recurrence, treatment options include repeat surgery, systemic therapy, and, in selected cases, salvage re-irradiation (re-RT). This study investigated the clinical outcome of recurrent patients (rHGG) treated with salvage re-RT. Materials-Methods: Thirty-five patients underwent salvage re-RT between 2016 and 2025 and were evaluated in January 2026 after a 10-month follow-up (range, 1 73 months). The median age was 53 years (23-70), including 69% of glioblastoma multiforme, and 31% of patients with grade 3-4 gliomas (Table 1). All received prior RT at a median dose of 60 Gy (35- 60,9) in 30 fraction (14-33) with concurrent and/or adjuvant systemic therapy.. Results: The median time to first recurrence was 12 months (2- 127), with the majority occurring in-field (94%). Salvage re-RT given to 18 patients with conventional RT using the linear accelerator device, and 17 patients with hypofractionated stereotactic RT (hSRT) using the CyberKnife-M6 device (Fig 1). Salvage surgery was performed in 51% of cases. Salvage re-RT doses were 30 Gy (22,5- 40,05) in 15 fractions (5- 22) with a median interval of 20 (3- 131) months between RT courses. Salvage systemic treatment included concurrent (3%), concurrent and adjuvant (11%), adjuvant (69%) of patients, respectively. For salvage re-RT, the CTV and PTV margin was applied as 5 and 3 mm for conventional RT and PTV margin 3 mm for hSRT. The median GTV and PTV volumes were 26,26 cc (0,52- 278) and 87,04 cc (1,11- 513), respectively. For salvage re-RT, the median BED10α/β=10 and EQD2 α/β=10 were 45 Gy (31.86- 50.74) and 37.5 Gy (26.46- 42.28), respectively. For 33 cases with in-field recurrence, the cumulative BED10α/β=10 and EQD2 α/β=10 were 116.6 Gy (91.75- 122.74) and 97.04 Gy (76.19- 102.28), respectively. The disease control rate following salvage re-RT was 55% (18/33) of cases, with a median of 6 (1- 73) months. Radionecrosis (RN) developed in 15 cases (43%) after the first RT at a median of 4 months (2- 32), while it developed in 15 cases (43%) after re-RT at a median of 5 months (2- 16), two of which had a previous RN. No significant difference was found between RN and salvage re-RT dose and PTV. The median overall survival (OS) was 17 months (± 1.54) and progression-free survival (PFS) was 12 months (± 4.46) after salvage re-RT. 2-year OS and PFS were 30.2% and 22.1%, respectively. In univariate analysis, salvage systemic treatment was significantly associated with OS (median 18 vs 5 months, p= 0.007) and PFS (median 17 vs 5 months, p= 0.029) (Fig 2). Presence of RN was favorable factor for OS (median 22 vs 10 months, p= 0.027) and PFS (22 vs 10 months, p= 0.037). Conclusion: We observe favorable survival rates following salvage re-RT, and identified prognostic factors, such as salvage systemic therapy and presence of RN. Technological advances and image-guided RT allow delivery of higher RT doses more safely in rHGG provide favorable outcomes