ESTRO 2020 Abstract Book

S661 ESTRO 2020

cm3 (p = 0.005) while smaller lesions showed a 3-y LC > 92% . No patients in our series experienced severe neurotoxicity (Grade 4-5 in the Common Terminology Criteria for Adverse Events).

Toxicity Grades of 65 patients in this study

Grade 0

Grade 1

Grade 2

Grade 3

Grade 4

phase 1 phase 2

54 54 59 52 33 21 12

0 0 4 2 0 0 0

9 5 0 2 4 3 2

1 3 0 0 0 0 0

1 2 0 0 0 0 0

2nd month 3rd month 6th month 9th month 12th month

Conclusion In patients with cancers of the head and neck not suitable for curative treatment and with limited life expectancy, the QUAD SHOT regimen with concurrent radiosensitizing chemotherapy offers an overall high palliative response rate and is well tolerated. It is an effective palliative approach that minimizes the burden of longer protracted courses of treatment. The short duration of the treatment was favored by the outstation patients and their attendants. It may be concluded that this short course of therapy is an effective tool for palliation of symptoms, improving quality of life with acceptable toxicity and merits a larger randomized trial. PO-1255 Prognostic factors in brain metastases from breast cancer treated with Cyberknife G. Riva 1 , A. Ferrari 1 , I. Cavallo 1 , L. Bergamaschi 1 , S. Durante 1 , G. Piperno 1 , S. Vigorito 2 , F. Cattani 2 , R. Orecchia 3 , B.A. Jereczek-Fossa 1 1 Istituto Europeo di Oncologia - IEO, Radiotherapy, MIlan, Italy ; 2 Istituto Europeo di Oncologia - IEO, Medical Physics, MIlan, Italy ; 3 Istituto Europeo di Oncologia - IEO, Scientific Directorate, MIlan, Italy Purpose or Objective The objective of this study was to explore factors associated with local control (LC), distant intra-cranial control (DBC) and overall survival (OS) in a mono institutional experience in the stereotactic radiosurgery (SRS) of patients with brain metastases from breast cancer. Material and Methods Data of 95 consecutive patients (190 lesions treated) affected by brain metastases from breast cancer who underwent SBS with CyberKnife (Accuray, USA) from January 2012 to December 2017 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). OS, LC and DBC at 3 years were evaluated. Results Total median SRS dose was 21 Gy (range, 15 -25 Gy) given in 1 to 5 fractions, in alternative days. After a median follow-up of 18 months (range 1-82), at least one radiological evaluation was available for 79 patients (156 lesions). LC was reported in 136 of 156 treated lesions (87%) while DBC was observed in 58 of 79 patients (26%). Thirty-four patients are still alive and 3-y OS was globally 31.5 %. Univariate analysis showed that the absence or controlled systemic disease at the time of SRS were associated better DBC (p = 0.013) and OS (p = <0.0001). The correlation between OS and controlled systemic disease was confirmed also by a multivariate analysis (p = 0.0003). In a multivariate analysis, older age ( > 60 years) and presence of 2-3 metastatic brain lesions were significantly negatively correlated to OS (p = 0.005 and 0.033, respectively). Single lesion GTV influenced LC, most of local recurrence occurred to lesions with GTV ≥ 0.80

Conclusion SRS is safe and efficacious treatment for brain metastases from breast cancer. Local control reaches 90% at 3 years with predominant distant intracranial pattern of failures, especially for lesions < 0.80 cm 3 . The state of systemic disease at time of SRS, age and number of lesions were major prognostic factors in OS. Further investigation is warranted in order to define the optimal patient selection criteria and treatment parameters. PO-1256 Feasibility and initial results of Linac-based Stereotactic Body Radiotherapy in spinal metastases N. Giaj Levra 1 , M. Niyazi 2,3 , V. Figlia 1 , G. Napoli 1 , R. Mazzola 1 , L. Nicosia 1 , S. Corradini 2 , R. Ruggieri 1 , G. Minniti 4 , F. Alongi 1,5 1 IRCCS Ospedale Sacro Cuore-Don Calabria, Radiation Oncology, Negrar, Italy ; 2 University Hospital- LMU Munich, Department of Radiation Oncology, Munich, Germany ; 3 German Cancer Consortium DKTK, German Cancer Consortium DKTK, Munich, Germany ; 4 San Pietro Hospital FBF, Radiation Oncology Unit- UPMC Hillman Cancer Center, Roma, Italy ; 5 University of Brescia, University of Brescia, Brescia, Italy Purpose or Objective Stereotactic radiosurgery (SRS) and stereotactic body radiotherapy (SBRT) are well established local treatment