ESTRO 37 Abstract book

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ESTRO 37

Quantitative assessment was performed by maximum standardized uptake values (SUV MAX ) calculation of predefined regions of interest (ROIs) in tumor, morphologically changed lymph nodes and/or detected distal metastatic lesions. PET/MR disease staging (TNM) was performed separately by two nuclear medicine specialists and one radiologist. The (SUV max) of 2,5 was used for the differentiation of malignant from benign focal uptake. FDG-PET/MR was compared to CT and clinical findings to evaluate od additional value of the former study. Results FDG-PET/MRI confirmed metabolically active disease in the all lesions localized by CT in all pts. HNC was staged as T1-4 N0-1 M0-1 . Increased FDG uptake in FDG-PET/MR study was observed, with SUV MAX of 2,6-22,3 - in primary tumors of volume of 1,36-48 cm 3 , with SUV MAX of 3,2-14,3 in the lymph nodes of volume of 0,91-11,29 cm 3 in 16 pts. New additional metabolically active foci compared to CT were detected as follows: primary tumor in 1 case, lymph nodes in 5 pts (22,73%), distant metastases were detected in n=2 (9,1%) pts. Interestingly, in 1 patient 3 simultaneous primary foci were diagnosed with FDG- PET/MR, which were missed with physical and CT examinations. FDG-PET/MR contributed to the change of the decision of the treatment in 2 pts (9,1%). Both FDG- PET and MR, which were fused with planning CT allowed for better target volume delineation in known from CT and clinical findings anatomic regions, as well as additionally – of precise contouring of newly visualized, primary and lymphatic regions. Follow-up FDG-PET/MR examinations are continuously performed and will be a subject of future analysis. Conclusion FDG-PET/MRI enables much more precise anatomic and metabolic localization and characterization of HNC and is very valuable diagnostic and planning treatment tool especially in sophisticated RT planning in HNC pts. EP-1180 Public involvement in design of a phase III trial comparing IMPT and IMRT for oropharyngeal cancer C. Hague 1 , B. Foran 2 , E. Hall 3 , L. Lee 1 , R. Mackay 4 , A. McPartlin 1 , C. Nutting 5 , M. Ofuya 3 , S. Parsons 6 , R. Prestwich 7 , N. Slevin 1 , C. West 8 , D. Thomson 1 1 The Christie NHS Foundation Trust, Clinical Oncology, Manchester, United Kingdom 2 Weston Park Hospital, Clinical Oncology, Sheffield, United Kingdom 3 The Institute of Cancer Research, Clinical Trials and Statistics Unit, London, United Kingdom 4 The Christie NHS Foundation Trust, Division of Cancer Science, Manchester, United Kingdom 5 The Royal Marsden NHS Foundation Trust, Clinical Oncology, London, United Kingdom 6 The University of Manchester, Public Programmes Team, Manchester, United Kingdom 7 St James' University Hospital, Clinical Oncology, Leeds, United Kingdom 8 The University of Manchester, Division of Cancer Science, Manchester, United Kingdom Purpose or Objective The Christie Hospital, Manchester and University College London Hospital are developing the UK's high energy proton beam service. This NHS service is due to open in August 2018 and shall treat patients from all UK centres. Here we report the results of public and patient involvement in the design of the first UK trial of Intensity Modulated Proton Therapy (IMPT) versus Intensity Modulated Radiotherapy (IMRT) for low risk

proton beam therapy, randomisation within the trial, willingness to travel and stay in Manchester for treatment and the trial design and endpoints. Fifteen consecutive patients previously treated by IMRT for low risk oropharyngeal cancer from each of the three centres were invited. The focus groups consisted of presentations and discussions centred around the questions shown in Table 1. Information was recorded manually on pre prepared laminates, patient questionnaires, audio recordings and by telephone or email contact with a sample of patients after each meeting. Data were analysed using thematic analysis.

Results Thirty three patients and six relatives attended the focus groups between September and October 2017. Existing public knowledge of protons and the differences between the two treatments was good. Most people perceived IMPT as a more targeted therapy. Beliefs about randomisation included disappointment if not receiving IMPT. Some expressed willingness to participate to help future patients. The feedback regarding travelling to the proton beam centre and staying away from home for treatment was generally positive, accepting need for adequate support from family, clinical and nursing staff. The patient pathway and proposed trial outcomes were viewed favourably. Conclusion This was an important piece of work to understand people's perceptions on the proton trial. The feedback received on the trial design and logistics has been encouraging. This has helped provide input into the trial design. The trial grant application is in process and due to be submitted in the near future. EP-1181 Prognostic value of lymph node and tumor necrosis in nasopharyngeal carcinoma W. Siala 1 , N. Sallemi 1 , W. Mnejja 1 , N. Toumi 2 , K. Ben Mahfoudh 3 , A. Ghorbel 4 , M. Frikha 2 , J. Daoud 1 1 CHU Habib Bourguiba, Radiotherapy oncology, Sfax, Tunisia 2 CHU Habib Bourguiba, medical oncology, Sfax, Tunisia 3 CHU Habib Bourguiba, Radiology, Sfax, Tunisia 4 CHU Habib Bourguiba, ENT, Sfax, Tunisia Purpose or Objective Necrosis is the final step in the biological evolution of the tumor resulting in a chronic hypoxia. This hypoxia is not only responsible for chemo and radioresistance but it has also been proven to induce the transcription of many genes that promote tumor progression. The objective of our work was therefore to study the prognostic value of this lymph node and tumor necrosis in nasopharyngeal carcinomas (NPC). Material and Methods This is a retrospective study that included 508 patients treated for non-metastatic nasopharyngeal carcinoma in our institution between 1993 and 2014. Computed

oropharyngeal cancer. Material and Methods

Focus groups were held in Manchester, Sheffield and Leeds. These aimed to understand patients' views of