La radiologia medica

, Volume 122, Issue 9, pp 676–682 | Cite as

Stereotactic ablative radiation therapy for brain metastases with volumetric modulated arc therapy and flattening filter free delivery: feasibility and early clinical results

  • Alba Fiorentino
  • Niccolò Giaj-Levra
  • Umberto Tebano
  • Rosario Mazzola
  • Francesco Ricchetti
  • Sergio Fersino
  • Gioacchino Di Paola
  • Dario Aiello
  • Ruggero Ruggieri
  • Filippo Alongi



For selected patients with brain metastases (BMs), the role of stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (SFRT) is well recognized. The recent introduction of flattening filter free (FFF) delivery during linac-based SRS or SFRT allows shorter beam-on-time, improving patients’ comfort and facility workflow. Nevertheless, limited experiences evaluated the impact of FFF linac-based SRS and SFRT in BMs treatment. Aim of the current study was to analyze SRS/SFRT linac-based FFF delivery for BMs in terms of dosimetric and early clinical results.

Materials and methods

Patients with life expectancy >3 months, number of BMs <5, diameter <3 cm, and controlled or synchronous primary tumor received SRS/SFRT. The prescribed total dose and fractionation, based on BMs size and proximity to organs at risk, ranged from 15 Gy in 1 fraction to 30 Gy in 5 fractions. A FFF volumetric modulated arc therapy (VMAT) plan was generated with one or two coplanar partial arcs. Toxicity was assessed according to CTCAE v4.0.


From April 2014 to February 2016, 45 patients (89 BMs) were treated with SRS/SFRT linac-based FFF delivery. The mean beam-on-time was 140 s for each lesion (range 90–290 s) and the average brain Dmean was 1 Gy (range 0.1–4.8 Gy). At the time of analysis, local control was reported in 93.2% (83/89 BMs). With a median follow-up time of 12 months (range 1–27 months), the median overall survival was 14 months and the 6-month overall survival was 77%. Finally, the median intracranial disease control was 11 months. Acute and late toxicities were acceptable without severe events (no adverse events ≥G2 were recorded).


These preliminary results highlighted the feasibility and safety of linac-based SRS/SFRT with FFF mode for BMs patients. A longer follow-up is necessary to confirm the efficacy of this treatment modality in BM patients.


Brain metastases Radiotherapy Stereotactic radiotherapy Stereotactic fractionated radiotherapy 


Compliance with ethical standards

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Conflict of interest

The authors declare that they have no conflict of interest. Informed consent was obtained from all individual participants included in the study.

Ethical approval

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.


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Copyright information

© Italian Society of Medical Radiology 2017

Authors and Affiliations

  • Alba Fiorentino
    • 1
  • Niccolò Giaj-Levra
    • 1
  • Umberto Tebano
    • 1
  • Rosario Mazzola
    • 1
  • Francesco Ricchetti
    • 1
  • Sergio Fersino
    • 1
  • Gioacchino Di Paola
    • 2
  • Dario Aiello
    • 1
  • Ruggero Ruggieri
    • 1
  • Filippo Alongi
    • 1
  1. 1.Radiation OncologySacro Cuore Don Calabria Cancer Care CenterVeronaItaly
  2. 2.Statistic Science FacultyUniversity of PalermoPalermoItaly

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