ESTRO 36 Abstract Book

S697 ESTRO 36 2017 _______________________________________________________________________________________________

Results Between July 2011 and January 2015, 891 pts were evaluable at 24 months. Mean age was 74.1±8.7 years. Indications for ADT were: biochemical relapse after local treatment (21.4%), adjuvant to radiotherapy (RT) (31.6%), metastases (24.2%) and locally advanced tumour without local treatment (20.6%). Gleason score was >7, 7(4+3), 7 (3+4) and <7 in 33.6%, 23.1%, 26% and 17.3%, respectively. For the subgroup treated with ADT adjuvant to RT (279 pts), mean age was 71.4±6.9 yrs, and 72.8% had at least one comorbidity. Gleason score was >7, 7(4+3), 7 (3+4) et <7 in 28.2%, 23.5%, 32.5% and 15.9% of pts respectively. At 24 months, modification of ADT was reported by 43.8% of the whole population and by 37.6% of the subgroup treated with ADT adjuvant to RT. The main types of modification (% of whole population) concerned the formulation (molecule or duration of action) (61.3%), duration of ADT (10.5%), switch to intermittent treatment (10.0%), addition of chemotherapy (5.6%) or second line hormonal manipulation (9.0%). Modifications of ADT according to indications are summarized in table below. Clear explanation for adaptations was given for only 110 patients (whole population): disease progression: 55.5% ; patient request: 26.4%, tolerance: 12.7% and failure of castration: 7.3%. Conclusion Change of initial modality of ADT is frequent in the first 24 months of treatment (43.8%) and numerically more frequent in presence of metastases or biochemical relapse than when ADT is added to RT. Surprisingly, the main type of modification is formulation. The main reported reason for modification is disease progression . EP-1315 Prostate cancer lymph nodal disease: SBRT only or extensive prophylactic irradiation and boost? A. Fodor 1 , C. Sini 2 , C.L. Deantoni 1 , C. Fiorino 2 , C. Cozzarini 1 , B. Noris Chiorda 1 , I. Dell'Oca 1 , M. Picchio 3 , P. Mangili 2 , E. Incerti 3 , R. Calandrino 2 , L. Gianolli 3 , N.G. Di Muzio 1 1 San Raffaele Scientific Institute, Department of Radiation Oncology, Milan, Italy 2 San Raffaele Scientific Institute, Medical Physics, Milan, Italy 3 San Raffaele Scientific Institute, Department of Nuclear Medicine, Milan, Italy Purpose or Objective Sensitivity and specificity of choline PET/CT is high on a per patient basis, but not on a per lesion basis (positive lymph nodes may be underdiagnosed). We report the outcome of salvage radiotherapy, delivered with TomoTherapy®(TT), in prostate cancer (PCa) patients (pts) previously submitted to radical prostatectomy and presenting persistent/ relapsing PSA and positive(+) lymph-nodes(LN) at 11 C-choline PET/CT(PET), treated with prophylactic TT on LN areas (pelvic/lombo-aortic, LA) and simultaneous integrated boost(SIB) on PET+ LN. Material and Methods From March 2007-May 2013, 36 PCa pts treated with radical prostatectomy (RP) +/- pelvic/LA LN dissection(LND), and presenting +LN at PET, were treated with TT. Analysis was restricted to oligometastatic treatment-naïve PCa pts satisfying published selection criteria for SBRT (Ost et al, Eur Urol 2016), including also

The outcomes of 42 completed NaF PET/CT studies are outlined in Table 1. One patient underwent a NaF PET/CT for staging of an unknown primary.

Conclusion Accurate staging by way of adjunctive imaging is important in the newly diagnosed patient cohort to aid decisions regarding suitability for prostatectomy or radical radiotherapy. Advanced staging beyond CT TAP and bone scan is becoming more important in the metastatic setting as more treatments become available. Determining the burden of metastatic disease to direct treatment is also of great importance. Our figures showed that NaF PET CT changed the management of 60% of patients overall. A recurring theme, particularly in groups with first suspected osseous metastases or suspected progression of known osseous metastases, was that although NaF PET CT was successful in finding more osseous metastases, oftentimes patients were either not fit for, or refused, further treatment. In addition a number of patients had already commenced chemotherapy, ADT or hormonal therapy prior to NaF PET CT, often based on rising PSA level. In a significant number of cases also patients did not have up to date standard staging i.e. bone scan and/or CT thorax abdomen pelvis within three months of NaF PET, which may have sufficed instead of advanced imaging in certain cases. NaF PET/CT is a useful additional imaging investigation in clarifying the presence or absence of bone metastases in scenarios of diagnostic uncertainty and it aided the decision-making process regarding further therapeutic strategies. However, care needs to be taken to use advanced imaging in those where there is diagnostic uncertainty and where treatment options still exist. EP-1314 Changes in hormonal therapy during the first 24 months of treatment: a longitudinal cohort study C. Hennequin 1 , D. Rossi 2 , M. Zerbib 3 , J.L. Moreau 4 , A. Ruffion 5 , Y. Neuzillet 6 , T. Lebret 6 1 Hôpital Saint-Louis, Department of Radiation Oncolgy, Paris, France 2 Hôpital Nord, Urology department, Marseille, France 3 Hopital Cochin, Urology Department, Paris, France 4 Centre d'Urology, Urology department, Nancy, France 5 Centre Hospitalier Lyon Sud, Urology Department, Lyon, France 6 Hôpital Foch, Urology department, Suresnes, France Purpose or Objective Data are limited showing changes in patients’ use of androgen deprivation therapy (ADT) in routine clinical practice. The objective of the study was to describe the number and type of modifications of ADT during the first 24 months of treatment. Material and Methods In this non-interventional, longitudinal cohort study, we assessed the number and type of modifications of ADT during the first 24 months of treatment in France. At baseline and every 6 months, we collected clinical, biological and therapeutic data and any changes of ADT modality.