ESTRO 2021 Abstract Book

S241

ESTRO 2021

reimbursement issues (29%), technical limitations (20%), and lack of patient referral (13%). Interestingly, limited treatment capacity was the least reported factor (3%) for not treating a specific tumour type with PT (Figure 2).

Conclusion Across European PT centres, CNS tumours and HNC are the most frequently treated tumour types. Most centres use indication protocols. Interestingly, some countries are more conservative in the number of cancers treated with PT than others. Lack of evidence for PT and reimbursement issues are the most commonly reported reasons for not treating specific tumour types with PT rather than limited treatment capacity. PH-0329 Feasibility and outcome of bridging RT pre CAR-T in DLBCL in one centre with a wide referral network J. Brady 1 , I. Vasiliadou 1 , V. Potter 2 , R. Benjamin 2 , P. Patten 2 , M. Cuadrado 2 , O. Evans 3 , E. Alexander 4 , C. Gillham 5 , J. Summers 6 , T. Ajithkumar 7 , A. Bates 8 , R. Sanderson 2 , A. Kuhnl 2 , N. Mikhaeel 1,9 1 Guy's and St Thomas' NHS Foundation Trust, Guy's Cancer Centre, London, United Kingdom; 2 King's College Hospital NHS Foundation Trust, Department of Haematology, London, United Kingdom; 3 Belfast City Hospital, Belfast Health and Social Care Trust, Department of Clinical Oncology, Belfast, United Kingdom; 4 Royal Marsden NHS Foundation Trust, Department of Clinical Oncology, Sutton , United Kingdom; 5 St James' Hospital, St Luke's Radiation Oncology Network, Dublin, Ireland; 6 Maidstone and Tunbridge Wells NHS Trust, Kent Oncology Centre, Maidstone, United Kingdom; 7 Cambridge University Hospitals, Department of Oncology, Cambridge, United Kingdom; 8 University Hospital Southampton NHS Foundation Trust, Southampton Oncology Centre, Southampton, United Kingdom; 9 King's College London, School of Cancer and Pharmaceutical Sciences, London, United Kingdom Purpose or Objective CD19 CAR-T therapy is the most effective salvage treatment for relapsed/refractory DLBCL. However the manufacture of CAR-T cells takes several weeks and patients (pts) are at risk of progression during this time and usually require some form of bridging therapy to contain their disease. Radiotherapy (RT) is an attractive bridging option, as the chance of response to further conventional cytotoxic therapy is low. RT is generally delivered in the window between apheresis and infusion and requires careful scheduling. The aim of this study is to evaluate the feasibility, toxicity and early outcome of bridging RT in a cohort of pts undergoing CAR-T therapy for DLBCL. Materials and Methods This was a prospective analysis of pts receiving bridging RT since the start of CAR-T programme at our institution. We collected data on pt demographics, disease and RT details, as well as outcomes including early response, relapse, survival and toxicity. Results