First experience and clinical results using a new non-coplanar mono-isocenter technique (HyperArc™) for Linac-based VMAT radiosurgery in brain metastases
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).
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.
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.
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.
KeywordsBrain metastases Radiotherapy Radiosurgery Stereotactic fractionated radiotherapy Linac-based VMAT HyperArc
No funding or financial interests for this study.
Compliance with ethical standards
For this type of study formal consent is not required. However, all procedures were in accordance with the ethical standards and the Helsinki declaration.
A specific informed consent was obtained from all individual participants included in the study.
Conflict of interest
FA acts as Varian Consultant and he had Speacker Onoraria. Remaining authors (AF, FG, SC, NGL, LR, MR, FR, AB, GL, RM, RR) declare no conflict of interests.
- De Mattos-Arruda L, Nag C, Piscuoglio S et al (2018) Genetic heterogeneity and actionable mutations in HER2-positive primary breast cancers and their brain metastases. Oncotarget 9(29):20617–20630Google Scholar
- NCCN Central Nervous System Cancers (2018) Version 1.2018 guidelines. https://www.nccn.org/professionals/physician_gls/pdf/cns.pdf. Accessed Sept 2018