Abstract Book

S876

ESTRO 37

Material and Methods Sixty patients presenting high grade recurrent STS of extremities or trunk treated with surgery and perioperative BRT followed by adjuvant EBRT +/- chemotherapy (CHT) were retrospectively analyzed. Local recurrences occurred after a median of 41.3 months after the first surgery (range: 5-268 months). Patient outcomes during FU as well as prognostic factors of patients outcome in terms of local control (LC), metastasis-free survival (MFS), disease-free survival (DFS) and overall survival (OS) were investigated. BRT delivered dose was 20 Gy (Low Dose-Rate or Pulsed Dose-Rate technique). EBRT was delivered with 3D-technique using multiple beams. The prescribed dose was 46 Gy to the planning target volume (PTV), delivered over 23 daily fractions. Neoadjuvant and adjuvant chemotherapy was used in patients with potentially chemosensitive histological subtypes. Univariate analysis was estimated according to Kaplan-Meier method and the log-rank test. Results Sixty patients (median age 53.5 years, range: 9-79), treated from January 2000 to January 2011 for high grade recurrent STS were included in this retrospective analysis. Median follow-up was 60.9 months (range: 15- 114), starting from the second surgery, performed for the late local recurrence. Thirteen patients out of 60 (21.7%) relapsed during FU, fifteen (25.0%) developed metastases and thirteen (21.7%) died. One-year LC, MFS, DFS and OS were 93.2%, 90.0%, 86.4% and 100.0%, respectively. 5- year LC, MFS, DFS and OS were 76.7%, 74.3%, 62.2% and 74.6%. An improved 5-year DFS was recorded in patients with lower arm versus upper arm and trunk tumors: 82.2% versus 53.8% and 66.7%, respectively; p: 0.034. The worse results recorded in upper limb STS may depend on the greater difficulty of radical surgery in this dimensionally smaller and richer of neurovascular bundles district. Patients not receiving CHT showed an higher 5- year MFS, DFS and OS (p: 0.055, 0.091 and 0.070, respectively); no statistical difference according to histology was detected. Conclusion The combination of BRT and EBRT is able to obtain satisfactory results and should therefore be taken into consideration in the case of recurrent tumors, to ensure a greater local control compared to surgery alone. Prospective studies on combination treatment modalities in the adjuvant treatment of relapsing STS are still necessary to improve these results. EP-1629 Are SIB-VMAT and SIB-IMRT good techniques for extremity soft tissue sarcoma radiotherapy treatment? I. Ortiz González 1 , D. Morera 2 , L. Valencia 1 , P. Mateos 3 , R. Roncero 1 , M. Vidal 1 , N. Aymar 1 , J. Gadea 1 , J.C. Font 2 , J. Pardo 1,4,5 1 Hospital Universitari Son Espases, Radiation Oncology, Palma de Mallorca, Spain 2 Hospital Universitari Son Espases, Medical Physics, Palma de Mallorca, Spain 3 Grupo Juaneda, Radiation Oncology, Ibiza, Spain 4 Hospital General de Catalunya, Quironsalud, Sant Cugat del Vallès, Spain 5 Institut d’Investigació Sanitaria de Illes Balears, IdisBa, Balearic Islands, Spain Purpose or Objective Recent data suggest intensity-modulated radiation therapy (IMRT) may improve local control in extremity soft tissue sarcoma (STS) treatment after limb-sparing

primary tumors (n=10; 58%). Size of primary tumor ranged between 5.9 – 17.4 cm. Majority of them had oligo metastatic disease [≤3 bone metastasis = 5 (29.4%); ≤3 marrow metastasis = 4 (23.5%); lung + marrow +/- bone/node = 4 (23.5%); >3 marrow metastasis = 1 (5.9%); lung + bone = 1 (5.9%); node = 1 (5.9%); soft tissue = 1 (5.9%)]. Single and multiple site of metastasis was present in 9 (53%) and 8 (47%) patients respectively. Complete response based on whole body FDG PET CT was present in 5 patients post induction chemotherapy. After local radiation, complete response at primary and metastatic site was seen in 11 (64.7%) and 13 (76.5%) patients respectively. At a median follow up of 28 months (range 5 - 70 months) none of the patients had died due to disease. Two patients (11.8%) had died of chemotherapy-related toxicity. Relapse was seen in 2 out of 11 patients (18.2%) with complete response post local radiation and in 4 out of 5 patients (80%) who did not have complete response. Relapse was seen in 3 out of 9 patients (33.3%) with single site of metastasis and 3 out of 8 patients (37.5%) with multiple site of metastasis. The 3-year Event Free Survival (EFS) and Overall Survival (OS) was 55.5% and 86.9% respectively. Conclusion This study shows that in Ewing sarcoma patients with limited metastatic disease at presentation curative intent treatment with multiagent chemotherapy and local radiation leads to a good clinical outcome with majority having complete response at both primary and metastatic site. The patients with complete response have a relatively better outcome compared to those who don’t. Longer follow up is required in this select group of patients to ascertain the above finding. A. Cortesi 1,2 , A. Galuppi 1 , A. Romeo 2 , G. Ghigi 2 , D.M. Donati 3 , A. Righi 4 , M.E. Abate 5 , G. Bianchi 6 , E. Garofalo 1 , A. Sambri 6 , G. Macchia 7 , F. Deodato 7 , S. Cilla 8 , A.G. Morganti 1 , S. Cammelli 1 1 Radiation Oncology Center- Department of Experimental- Diagnostic and Specialty Medicine - DIMES, University of Bologna- S.Orsola-Malpighi Hospital, Bologna, Italy 2 Radiotherapy Department, Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori IRST- IRCCS, Meldola, Italy 3 Orthopaedic Service- Musculoskeletal Oncology Department-, Rizzoli Orthopaedic Institute, Bologna, Italy 4 Department of Pathology, Rizzoli Orthopaedic Institute, Bologna, Italy 5 Muscolo-Skeletal Oncology Department, Rizzoli Orthopaedic Institute, Bologna, Italy 6 Orthopaedic Service- Musculoskeletal Oncology Department, Rizzoli Orthopaedic Institute, Bologna, Italy 7 Radiotherapy Unit, Fondazione di Ricerca e Cura “Giovanni Paolo II”, Campobasso, Italy 8 Medical Physics Unit, Fondazione di Ricerca e Cura “Giovanni Paolo II”, Campobasso, Italy Purpose or Objective To evaluate clinical outcome during follow-up (FU) in patients with late recurrent soft tissue sarcomas (STS) after adequate surgery, treated with perioperative brachytherapy (BRT) and adjuvant external radiation therapy (EBRT). EP-1628 Radiotherapy for high grade late recurrent soft tissue sarcomas: follow up and outcomes