Cyberknife® hypofractionated stereotactic radiosurgery (CK-hSRS) as salvage treatment for brain metastases

• Published in: Journal of cancer research and clinical oncology 2021-09, Vol.147 (9), p.2765-2773
• Main Authors: Telentschak, Sergej, Ruess, Daniel, Grau, Stefan, Goldbrunner, Roland, von Spreckelsen, Niklas, Jablonska, Karolina, Treuer, Harald, Kocher, Martin, Ruge, Maximilian
• Format: Article
• Language: English
• Subjects: Adverse events; Brain cancer; Cancer Research; Hematology; Internal Medicine; Medical prognosis; Medicine; Medicine & Public Health; Metastases; Metastasis; Oncology; Original Article – Clinical Oncology; Original – Clinical Oncology; Patients; Prognosis; Radiation therapy; Radiosurgery; Survival; Terminology; Tumors
• ISSN: 0171-5216; 1432-1335
• DOI: 10.1007/s00432-021-03564-z

Purpose The introduction of hypofractionated stereotactic radiosurgery (hSRS) extended the treatment modalities beyond the well-established single-fraction stereotactic radiosurgery and fractionated radiotherapy. Here, we report the efficacy and side effects of hSRS using Cyberknife ® (CK-hSRS) for the treatment of patients with critical brain metastases (BM) and a very poor prognosis. We discuss our experience in light of current literature. Methods All patients who underwent CK-hSRS over 3 years were retrospectively included. We applied a surface dose of 27 Gy in 3 fractions. Rates of local control (LC), systemic progression-free survival (PFS), and overall survival (OS) were estimated using Kaplan–Meier method. Treatment-related complications were rated using the Common Terminology Criteria for Adverse Events (CTCAE). Results We analyzed 34 patients with 75 BM. 53% of the patients had a large tumor, tumor location was eloquent in 32%, and deep seated in 15%. 36% of tumors were recurrent after previous irradiation. The median Karnofsky Performance Status was 65%. The actuarial rates of LC at 3, 6, and 12 months were 98%, 98%, and 78.6%, respectively. Three, 6, and 12 months PFS was 38%, 32%, and 15%, and OS was 65%, 47%, and 28%, respectively. Median OS was significantly associated with higher KPS, which was the only significant factor for survival. Complications CTCAE grade 1–3 were observed in 12%. Conclusion Our radiation schedule showed a reasonable treatment effectiveness and tolerance. Representing an optimal salvage treatment for critical BM in patients with a very poor prognosis and clinical performance state, CK-hSRS may close the gap between surgery, stereotactic radiosurgery, conventional radiotherapy, and palliative care.