ESTRO 36 Abstract Book

S276 ESTRO 36 _______________________________________________________________________________________________

Purpose or Objective SBRT is a safe and effective treatment which could postpone androgen deprivation therapy (ADT) in oligorecurrent PC. Despite that, in literature there is a lack of data about the role of SBRT in patients (pts) with oligoprogressive castrate resistant PC (oligo-CRPC). Our aim is to assess the feasibility and efficacy of SBRT in the treatment of oligorecurrent PC in terms of biochemical progression-free survival (BPFS) and ADT-free survival (ADT-FS) and also in pts with oligo-CRPC, in terms of distant progression free survival (DPFS) and second line systemic-treatment-free survival (STFS). Material and Methods non-castrate pts with oligorecurrent disease detected with Choline-PET or CT+Scintigraphy following biochemical recurrence were treated with SBRT. BPFS and ADT-FS were the primary endpoint. Secondary endpoints were local control and toxicity. On the other hand, oligo- CRPC pts detected with choline-PET or CT+scintigraphy after PSA rise during ADT were enrolled in the analysis. Primary endpoint were DPFS and STFS. Univariate analysis was performed in order to assess factors influencing outcome in both categories. Results 100 pts with oligorecurrent PC (139 lesions; lymph nodes 84.2%, bones 15.8%) were treated from 03/2010 to 02/2016. After a median follow up of 20.4 months, 1yr- and 2yrs-BPFS were 58.1% and 38.3%. 15 pts underwent a second course of SBRT for a further oligoprogression: this result in a median ADT-FS of 20.9 months with 1-, 2-, 3- yrs ADT-FS of 67.4%, 47.3% and 31%. At univariate analysis, low PSA-DT is related with a worse ADT-FS. LC rate was 88,2% at two years. No G3 toxicity was reported. 41 pts with oligo-CRPC (70 lesions) were treated from 01/2010 to 04/2016. After a median follow up of 23.43 months, 1yr- and 2yrs-DPFS were 43.2% and 21.6% with a median DPFS of 11 months. 10 pts underwent a second course of SBRT. At the time of analysis, 20 patients had started systemic treatment (10 pts with Abiraterone or Enzalutamide and 10 pts with Docetaxel): median STFS was 22 months with 1-, 2-, 3-yrs STFS of 74.8%, 41.3% and 29.5%. No significant correlations were found at univariate analysis. No toxicity was registered. Conclusion SBRT for oligorecurrent PC is an effective treatment and postpones palliative ADT for almost 2 yrs without toxicity. SBRT has proven effective even in oligoprogressive CRPC with a capacity to delay the start of systemic second line therapies for almost 2 yrs. OC-0522 Extracranial stereotactic Radiotherapy for lymph nodal recurrences: a dose escalation trial F. Deodato 1 , G. Macchia 1 , M. Ferro 1 , M. Ferro 1 , G. Torre 1 , v. Picardi 1 , M. Nuzzo 1 , S. Cilla 2 , A. Ianiro 2 , G. Tolento 3 , S. Cammelli 3 , F. Romani 4 , A. Arcelli 3,5 , R. Frakulli 3 , L. Giaccherini 3 , G. Siepe 3 , G.P. frezza 5 , A. Farioli 6 , S. Mignona 7 , V. Valentini 8 , A.G. morganti 3 1 Fondazione di Ricerca e Cura “Giovanni Paolo II”, Radiotherapy Unit, Campobasso, Italy 2 Fondazione di Ricerca e Cura “Giovanni Paolo II”, Medical Physic Unit, Campobasso, Italy 3 University of Bologna, Department of Experimental- Diagnostic and Specialty Medicine - DIMES, Bologna, Italy 4 University of Bologna- S. Orsola-Malpighi Hospital, Medical Physic Unit, Bologna, Italy 5 Ospedale Bellaria, Radiotherapy Department, Bologna, Italy 6 University of Bologna, Department of Medical and Surgical Sciences - DIMEC, Bologna, Italy 7 Fondazione di Ricerca e Cura “Giovanni Paolo II”, Oncology Unit, Campobasso, Italy 8 Policlinico Universitario “A. Gemelli”- Università Cattolica del Sacro Cuore, Department of Radiotherapy, Rome, Italy

techniques does improve data collection but for some patient populations and studies this approach is not as effective or financially possible. Furthermore, missing PRO data may influence the ability to detect difference within long term data. Missing data is rarely random with participants from the poorest outcomes or highest vulnerability not returning questionnaires so most likely to create conclusions biased to complete cases [4]. Longer term monitoring of radiotherapy effects requires innovative ways of collecting data from patients. PROs produce large data sets which need to be summarized and or transformed. Multiple tools can provide an overlap in items and domains scores. Clustering of symptoms across tools and looking at change in symptoms over time rather than cross sectional analysis approaches can be of benefit [5]. Using data sharing and linkage approaches to access and link PROs to wider data sets such as primary health care records and resources used by patients may help in addressing some of the knowledge gaps. Lack of consistency in analysis techniques, volume of data and missing values are challenges for researchers. Failure to address these challenges and standardize PROs assessment during clinical trials risks the introduction of bias and devalues the importance of patient reported outcomes within studies. References 1 1. Cella, D. and A. Stone (2015). "Health-related quality of life measurement in oncology." American Psychologist 70(2): 175-185. 2. Faithfull, S., et al. (2015). "Patient-reported outcome measures in radiotherapy: clinical advances and research opportunities in measurement for survivorship." Clinical Oncology 27: 679-685. 3. Kyte, D., et al. (2016). "Current practices in patient- reported outcome (PRO) data collection in clinical trials: a cross sectional survey of UK trial staff and management." BMJ Open(December). 4. Gomes, M., et al. (2016). "Addressing missing data in patient reported outcome measures (PROMS): implications for the use of PROMS for comparing provider performance." Health Economics 25: 515-528. 5. Lemanska A, et al. (2014). "Predictive Modelling of Patient Reported Radiotherapy-Related Toxicity by the Application of Symptom Clustering and Autoregression." 412-422. OC-0521 The role of SBRT in oligorecurrent and oligoprogressive prostate cancer: a multi-institutional study L. Triggiani 1 , S. Magrini 1 , A. Bruni 2 , F. Alongi 3 , A. Magli 4 , A. Bonetta 5 , L. Livi 6 , R. Santoni 7 , P. Borghetti 1 , M. Maddalo 1 , M.D. Rolando 8 , G. Ingrosso 7 , N. Pasinetti 1 , M. Buglione 1 1 Spedali Civili di Brescia, Department of Radiation Oncology- University of Brescia, Brescia, Italy 2 AOU Policlinico di Modena, U.O. Radioterapia Oncologica, Modena, Italy 3 Ospedale Sacro Cuore Don Calabria, Radioterapia Oncologica, Negrar, Italy 4 Ospedale Santa Maria della Misericordia, S.O.C. di Radioterapia Oncologica-, Udine, Italy 5 Ospedale di Cremona, U.O. Radioterapia-, Cremona, Italy 6 A.O.U Careggi- Università di Firenze, SODc Radioterapia Oncologica- DAI Oncologia-, Firenze, Italy 7 Policlinico Tor Vergata- Università di Roma2, U.O.C. di Radioterapia-, Roma, Italy 8 Campus Biomedico, Radioterapia Oncologica, Roma, Italy Proffered Papers: Oligometastatic disease