First experience and clinical results using a new non-coplanar mono-isocenter technique (HyperArc™) for Linac-based VMAT radiosurgery in brain metastases

J Cancer Res Clin Oncol. 2019 Jan;145(1):193-200. doi: 10.1007/s00432-018-2781-7. Epub 2018 Oct 31.


Introduction: Radiosurgery (SRS) or stereotactic fractionated radiotherapy (SFRT) is increasing in the treatment of brain metastases (BMs). Aim of the present study was to evaluate the safety and effectiveness of SRS/SFRT for BMs, using a new mono-isocenter non-coplanar solution (HyperArc™ Varian Medical System).

Methods: BMs patients with a diameter inferior to 3 cm, a life expectancy of more than 3 months and a good performance status, were eligible for Linac-based volumetric modulated arc therapy (VMAT) SFRT/SRS with HyperArc™. A retrospective analysis of patients and BMs was performed.

Results: From August 2017 to May 2018, 381 BMs in 64 patients were treated and 246 BMs (43 patients, median number of BMs: 5) of them were suitable for analysis. With a median FU time of 6 months, 244 out 246 (99%) BMs were controlled (18% complete response; 41% partial response, 40% stable disease), 2 BMs showed a progression, at the first control. No acute or late toxicities were reported. Median overall survival (OS) has not yet been achieved, while median time to progression was 5 months. In univariate analysis, statistically negative prognostic factors for OS were histology of primary tumor (p = 0.009): lung/breast cancer had better survival rates as compared to others. Cumulative intracranial volume disease ≥ 15 cc and systemic progression disease were independent prognostic factors for OS at univariate (p = 0.04; p = 0.005) and multivariate (p = 0.04; p = 0.009) analysis, respectively.

Conclusion: The present first clinical data show that SFRT/SRS with HyperArc™ is safe and effective for BMs patients. The utilization of SFRT/SRS for BMs is promising and should be further explored in randomized trials.

Keywords: Brain metastases; HyperArc; Linac-based VMAT; Radiosurgery; Radiotherapy; Stereotactic fractionated radiotherapy.

MeSH terms

  • Adult
  • Aged
  • Brain Neoplasms / radiotherapy*
  • Brain Neoplasms / secondary*
  • Disease Progression
  • Female
  • Humans
  • Male
  • Middle Aged
  • Prognosis
  • Radiosurgery / adverse effects
  • Radiosurgery / instrumentation
  • Radiosurgery / methods*
  • Retrospective Studies
  • Survival Analysis
  • Treatment Outcome
  • Tumor Burden