Session Item

Poster (digital)
Radiosurgery in her2-breast cancer brain metastasis:local control and overall survival in 32 women
Samantha Dicuonzo, Italy


Radiosurgery in her2-breast cancer brain metastasis:local control and overall survival in 32 women

Samantha Dicuonzo1, Francesca Colombo2, Luca Bergamaschi2, Gaia Piperno1, Annamaria Ferrari1, Maria Cristina Leonardi1, Mattia Zaffaroni1, Maria Alessia Zerella1, Damaris Patricia Rojas1, Marianna Alessandra Gerardi1, Anna Morra1, Elena Rondi3, Sabrina Vigorito3, Federica Cattani3, Roberto Orecchia4, Barbara Alicja Jereczek-Fossa1, Samuele Frassoni5, Vincenzo Bagnardi5

1European Institute of Oncology IRCCS, Department of Radiotherapy, Milan, Italy; 2University of Milan/European Institute of Oncology IRCCS, Department of Oncology and Hemato-Oncology/Department of Radiotherapy, Milan, Italy; 3European Institute of Oncology IRCCS, Unit of Medical Physic, Milan, Italy; 4European Institute of Oncology IRCCS, Scientific Directorate, Milan, Italy; 5University of Milan-Bicocca, Department of Statistics and Quantitative Methods, Milan, Italy

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Purpose or Objective

Outcomes of patients with HER2-breast cancer brain metastasis (BCBM) remain suboptimal. To evaluate the effectiveness of local therapy (stereotactic radiosurgery [SRS]) we analyzed local control (LC), distant intra-cranial control (DBC) and overall survival (OS) in patients with metachronous HER2-BCBM

Material and Methods

Data of consecutive patients who underwent SRS with CyberKnife (Accuray, USA) from February 2012 to November 2020 were retrospectively analysed. Parameters included demographics, histology and primary tumour characteristics, presence and control of extracranial disease, number of lesions, single and total gross target volume (GTV). Preliminary results of OS, LC and DBC at the last follow up were evaluated. This retrospective study was notified to our Ethical Committee (IEO N93/11)


Thirty-two consecutive patients for a total of 82 metachronous HER2- BCBM treated with CyberKnife were included in this preliminary analysis.

Median follow up from primary surgery and SRS was 113 months (range 42-241) and 17 months (range 0-101).

Median time to brain-progression from initial diagnosis of breast cancer was 78 months (range: 15-215) with 17/32 (53%) patients with both cranial and controlled-extracranial disease at the time of of SRS.

Patients were treated for all brain lesions they presented, with a median of 2 lesions for each patient (range, 1 – 9). Total median SRS dose was 21 Gy (range, 18 -24 Gy) given in 1 to 3 fractions, in alternate days. Median single lesion GTV was 0.29 cm3 (range, 0.02 – 13.22). 

At the last follow up available, 17/32 patients were alive (OS=53% ; 16 patients with both cranial and extracranial disease).

LC was reported in 56 of the 82 treated lesions (68%; 1 and 3-years LC : 65% and 45%, respectively-Fig 1), while DBC (no appearance of any new intracranial lesions) was observed in 10/32 patients (31%).

Univariate and multivariate analysis for correlation with demographics, tumour and treatment characteristics are ongoing.

No patients experienced severe neurotoxicity (Grade 4-5 in the Common Terminology Criteria for Adverse Events) with only 5 asymptomatic radionecrosis recorded.


Our results showed OS  in line with literature and a satisfactory 1 and 3-years LC rates with almost one third of our patients alive with no appearance of any new intracranial lesions after SRS and no severe neurotoxicity in the entire population. Ongoing-statistically analysis are needed to correlate outcome with prognostic factors