Results of robotic radiotherapy in rare brain 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: Rare tumors of the central nervous system (CNS) occur in 30 out of 100,000 adults annually. They are categorized in the World Health Organization's 2021 classification, and there is no complete consensus on treatment. Treatment of these rare CNS tumors involves observation, surgical excision, and radiotherapy (RT). The decision to use RT requires a multidisciplinary approach due to potential neurocognitive side effects. In this study, we aimed to evaluate the outcomes of 20 cases treated with robotic RT in our clinic. Materials-Methods: Twenty cases that underwent stereotactic radiotherapy (SRT) with the CyberKnife-M6 (CK-M6) device between 2019 and 2025 were evaluated in January 2026 after a 35-month (8- 81) follow-up. Results: The median age was 52 (20- 70). The most common diagnoses were hemangioma (n: 4) and hemangioblastoma (n: 3) (Table 1). The symptom duration was 12 months (1- 240), and 17 cases underwent surgery (macroscopic total excision= 9, subtotal excision= 7, biopsy= 1), two of which had a history of adjuvant stereotactic radiosurgery (SRS). Two patients underwent surgery 5 and 6 times, respectively. The median interval between surgery and SRT was 16 months (3- 192). A median of 13 Gy (10- 16)/1 fx was applied to 5 cases receiving SRS, and a median of 25 Gy (19- 30)/5 fx (5- 8) was applied to 15 cases receiving hypofractionated SRT (hSRT) (Fig 1). The median BED3 and BED10 values were 66,67 Gy (43,07- 101,33) and 37,5 Gy (26,22- 48,00), respectively (Table 2). In three cases, 3, 10, and 14 lesions were irradiated simultaneously, respectively. The median treatment duration was 19 minutes (15- 41). In 17 cases evaluated at a median of 3 months (3- 4) after SRT, 2 partial responses, 14 stable responses, and 1 progression were observed. Another case showed local progression at 9 months. A patient diagnosed with hemangiopericytoma developed a distant recurrence after 8 months. Radionecrosis was observed in three cases at a median of 13 months (3- 29). At the last follow-up, 5 cases were responsive, 12 cases were stable, and cases with local or distant progression were stable with surgical and/or systemic treatment. All patients were alive at the last control. The mean local progression-free survival (LRPFS) was 73 months (± 5.16), and progression-free survival (PFS) was 69.63 months (± 6.04), respectively. The 3-year overall survival, LRPFS, and PFS were 100%, 89,7%, and 84,7%, respectively. Organs at risk (OAR) doses were not exceeded in any case (Table 3). Of the 16 patients with neurological deficits before RT, 2 regressed after RT, and no new deficits were observed. Conclusion: Modern RT techniques aim to provide maximum protection to OAR and minimize side effects. In our study, CK-M6-based SRT was found to be effective, comfortable, and safe in the treatment of rare brain tumors.