ESTRO 38 Abstract book

S899 ESTRO 38

A second course of radiotherapy was required in 44 cases (63%), obtaining response in 36 cases (81%) in the early analysis and response was maintained in 28 cases (77%) after 3 or more months. Conclusion Low-dose radiotherapy is an effective and well-tolerated approach for painful inflammatory periarticular disorders, achieving acceptable rates of pain control that seem to be maintained during follow-up and thus contributing to improve the quality of life of these patients. Further follow-up is required for ensuring these promising results. EP-1672 Multimodality treatment in thymic tumors:a retrospective analysis and accordance with ESMOguidelines A. Carnevale 1 , C. Greco 1 , M. Fiore 1 , E. Ippolito 1 , S. Silipigni 1 , C.G. Rinaldi 1 , A. Di Donato 1 , S. Gentile 1 , P. Trecca 1 , P. Zuccoli 1 , G. Petrianni 1 , S. Palizzi 1 , R.M. D'Angelillo 1 , L. Trodella 1 , S. Ramella 1 1 University Campus BioMedico of Rome, Radiation Oncolgy, Rome, Italy Purpose or Objective Surgery represents the mainstay treatment for Thymic Epitelial Tumors. Due to the lack of prospective randomized studies, the role of postoperative radiotherapy (PORT) is not supported by high levels of evidence. We retrospectively assessed whether the decision regarding the postoperative radiotherapy at Campus Bio-Medico University has been taken according to the new ESMO guidelines. Material and Methods All consecutive patients with Thymic Tumors from 2005 to 2018 were analyzed and a complete review of medical records was performed. Results 51 patients underwent surgery up-front. Median age at diagnosis was 64 years (range 33-82). Tumors histology was thymoma (A-AB-B3) in 47 (92%) patients or thymic carcinoma in 4 (8%) patients. Complete resection (R0) was achieved in 35 (67%) patients. Other patients had R1 resection. Applying 8° TNM system edition, 1 patients with Masaoka stage III was reclassified to stage II and I stage and one IV A. Decision of delivering PORT was in accordance with ESMO guidelines in 94% of the 51 patients. Two patients with R1 resection, with B1 and B2 thymoma and negative postoperative CT scan, did not receive radiotherapy for excessive delay after surgery. Median total dose was 46 Gy and was variable depending of radical resection: median total dose was 45 Gy after R0 resection and 54 Gy after R1 resection. Only G1-2 acute esophageal and G1 acute lung toxicities were reported. No in-field local recurrences were reported; four patients had pleural and distance metastases.With a median follow up of 47 months (range 7.2-155 months), median overall survival was 9.7 years. Conclusion Our data suggest that PORT is a safe and effective treatment for Thymic Epitelial Tumors in patients with stage II (B2-B3), Stage III Masaoka-Koga, R1 resection and Thymic carcinoma, in accordance with ESMO guidelines. EP-1673 Implementation of a Collaborative Fast Access Radiotherapy Program for Benign Disease M. Rolfo 1 , R. Shaffer 1 1 Genesiscare Uk, Radiation Oncology, Berkshire, United Kingdom Purpose or Objective Benign diseases and non-malignant conditions may cause pain, loss of function and other symptoms that can impact on quality of life. Radiation may not be sought as first line treatment for benign conditions, but some studies have suggested the efficacy of RT as a valid treatment option for specific patient cohorts. Genesis Care Australia, Spain

treatment. In 51 cases, a second course was needed to achieve better response, accomplishing it in 44 of them with a stable response in all except 2 cases. 55% of the cases were followed for more than 6 months and 90% of these patients maintained partial or total response after long follow-up. Conclusion Low doses of radiotherapy achieve significant pain relief in patients with osteoarthritis disorders, as well as subjective functional improvement and decrease in daily requirements of analgesia. All in all, this improvement can be translated in a better quality of life accomplished. EP-1671 Radiotherapy: promising alternative treatment for painful enthesopathies and inflammatory diseases B. Álvarez Rodríguez 1 , Á. Montero 1 , F. Aramburu 2 , E. Calvo 2 , J. Palma 1 , J. Valero 1 , J. García 3 , J. Martí 3 , R. Ciérvide 1 , E. Sánchez 1 , S. Rodríguez 2 , M.Á. De la Casa 3 , M. García-Aranda 1 , X. Chen 4 , O. Hernando 4 , R. Alonso 4 , M. López 1 , P. García de la Peña 2 , C. Rubio 1 1 Hospital Universitario HM Sanchinarro, Radiation Oncology, Madrid, Spain ; 2 Hospital Universitario HM Sanchinarro, Rheumatology, Madrid, Spain ; 3 Hospital Universitario HM Sanchinarro, Radiophysics, Madrid, Spain ; 4 Hospital Universitario HM Puerta del Sur, Radiation Oncology, Madrid, Spain Purpose or Objective Efficacy of low-dose radiotherapy for periarticular inflammatory diseases has been largely probed. We present the results after analyzing a series of patients enrolled in our protocol consisting of a prospective non- randomized study. Material and Methods From April 2015 to May 2018, 44 patients were enrolled in our protocol, including 32 women (70%) and 12 men (30%), with a median age of 59 y/o (range 30-89 y/o). The analysis was based on the number of treatments delivered, which were 70 because some patients referred pain at different locations. Most patients (77%) presented with bursitis, specifically trochanteritis (70.5%), followed by sacroiliitis (13%) and epicondylitis (6%). Pre-treatment and post-treatment evaluation of the pain was based on the visual analogue pain scale (VAS), requirements of oral analgesic intake and the modified von Pannewitz pain score (MVPPS). Clinical response was evaluated 6 weeks after treatment and each 3 months thereafter. If less than major response was achieved, a second course was delivered 6-8 weeks after finishing the first course. Treatment comprised low-dose radiation up to a total dose of 6 Gy (1 Gy/fraction) every other day. All patients underwent CT-based simulation. This was, sometimes, fused with the corresponding magnetic resonance image if available. Planning target volume (PTV) was contoured on CT scan including the painful periarticular soft tissue. Treatment was delivered in a LINAC and daily verified with orthogonal X-ray. Results Before treatment, 81% of the patients referred VAS equal or greater than 7, while only 7% of the patients maintained this VAS after treatment. On the other hand, no patients referred VAS equal or under 3 before treatment, but 66% of the patients did achieved it after radiotherapy; what is more, 13% of all cases referred complete response (VAS 0) after treatment. The median follow-up was 8 months (range 1-29), and 54% of the patients were monitored for more than 6 months. In these cases, 89% maintained VAS < and 37% showed VAS < 3 after long follow-up. Regarding functionality, 87% of the cases referred MVPPS 1-3 and 44% of patients referred less intake of analgesia.