ESTRO 2021 Abstract Book

S1185

ESTRO 2021

Conclusion This retrospective single-center study confirmed the efficacy of SRS in the treatment of BM, with a good toxicity profile.

PO-1443 PRECISION ANALYSIS OF THE “TEACHH” MODEL FOR DECISION-MAKING IN PALLIATIVE PATIENTS C. Escuin 1 , M. Cerrolaza 1 , V. Navarro 1 , A. Lanuza 1 , A. Campos 1 , S. Flamarique 1 , C. García 1 , J.M. Ponce 1 , R. Ibañez 1 1 University Hospital Miguel Servet, Radiation oncology, Zaragoza, Spain Purpose or Objective Radiation therapy is an established local treatment option within the multidisciplinary treatment of palliative care for cancer patients. This treatment provides effective relief in uncontrolled bleeding, neurological symptoms, or metastatic bone pain. Estimating life expectancy is essential to establish the most appropriate decision-making, thus carrying out the most optimal treatment. We intend to assess the efficacy of the TEACHH prognostic scale after its introduction into our routine clinical practice. This scale divides patients into life expectancy groups (1.7, 5, and 19.9 months), according to patient parameters and disease progression. Materials and Methods 410 patients were studied between May 2017 and December 2020 and the life expectancy estimated by “TEACHH” was compared with the actual survival in deceased patients at the time of analysis. Results Of the 344 deceased patients (83.9% of the total patients assessed by the TEACHH scale); 92 patients (26.7%) had a life expectancy of 1.7 months group, 241 (70.05%) of 5 months group and 11 (3.19) of 19.9 months group. Patients with an estimate of survival by “TEACHH” of 1.7 months had a mean real survival of 2.03 months, those with an estimate of 5 months had a mean of real survival of 3.52 months, and patients with an estimate of “TEACHH” of 19.9 months, and the actual median survival was 14.53 months. Conclusion "TEACHH” model is an effective prognostic tool to support decision-making, being especially useful in those cases with estimates of life expectancy of less than 2 months. PO-1444 Determinants of radioresistance and progression-free interval in SBRT-treated spinal metastases M. Aquilano 1 , S. Lucidi 1 , L. Mauro 2 , G. Francolini 3 , G. Simontacchi 2 , D. Greto 2 , I. Desideri 4 , P. Bonomo 2 , A.G. Allegra 1 , M. Mariotti 1 , L. Masi 5 , R. Doro 5 , I. Bonucci 6 , V. Di Cataldo 6 , M. Mangoni 1 , L. Livi 1 1 University of Florence, Department of Experimental and Clinical Biomedical Sciences "M. Serio", Florence, Italy; 2 Azienda Ospedaliero-Universitaria Careggi, Department of Radiation Oncology, Florence, Italy; 3 Azienda Ospedaliero-Universitaria Careggi, Department of Radiation Oncology, Florence, Italy; 4 University of Florence, Department of Experimental and Clinical Biomedical Sciences "M. Serio" , Florence, Italy; 5 Radiation Oncology IFCA, Department of Medical Physics, Florence, Italy; 6 Radiation Oncology IFCA, Department of Radiation Oncology, Florence, Italy Purpose or Objective Stereotactic Body Radiotherapy (SBRT) is increasingly used in uncomplicated spine metastases to palliate symptoms and prolong disease control. However, criteria for patient selection are not available. The aim of this study is to identify determinants of local failure and progression-free interval in patients treated with SBRT to spinal metastases. Materials and Methods Data from consecutive patients treated with Cyberknife-based spine SBRT between January 2019 and March 2020 were retrospectively collected. Dose was expressed as Biological Effective Dose for α/β=10 (BED 10 ). Kaplan-Meyer method was used to calculate Local Control (LC) and Disease Progression-free Survival (DPFS) from date of SBRT to event. Univariate (UVA) and Multivariate analysis (MVA) were performed using log-rank and Cox model, respectively. Results Sixty-two patients accounting for 70 spinal metastases were included. Median age was 66 (range 32-87) years. Disease was metastatic at diagnosis in 21 patients (34%) : an active primary tumor was present in 17 patients (27%). Among treated sites, most represented primary malignancies were prostate (n=28, 40%) and breast (n=21, 30%). SBRT was delivered to cervical, thoracic, lumbar and sacral vertebrae in respectively 15(21%), 21(30%), 29(41%), and 5(8%) cases. Dose regimens consisted of 25-30 Gy in 5 fractions and 21-30 Gy in 3 fractions in respectively 61 (87%) and 9 (13%) cases, resulting in a median BED of 43.2 (range 37.5-60) Gy 10 . Concurrent chemotherapy (including cytotoxic or targeted agents) was administered in 43% of cases (n=30). After a median follow up of 10 months (range 1-24 months), 9 local relapses and 40 distant progressions were observed. One year LC was 87% (Fig.1A): non-prostate primary tumor ( p=0.003, Fig.1B) and concurrent chemotherapy (p=0.006, Fig.1C) were associated to poorer LC at UVA, and an independent correlation was confirmed at MVA (respectively p=0.017 and p=0.024). One-year DPFS was 43% (Fig.1D). UVA showed a correlation between impaired DPFS and active primary tumor (p=0.003), metastatic dissemination at diagnosis (p=0.02) and non-prostate primary tumor (p=0.009), although only an active primary tumor site was independently associated to DPFS at MVA (p=0.007, Fig.1E). Acute toxicity consisted of G2 pain flare and G2 nausea in respectively 5 (7%) and 4 (6%) cases: no clinical variable was significantly correlated with increased acute toxicity. No late toxicity, in particular vertebral fracture, was reported