ESTRO 2023 - Abstract Book

S851

Digital Posters

ESTRO 2023

Materials and Methods A cross-sectional questionnaire was disseminated via social media, Facebook, Twitter, Instagram, and LinkedIn between January and March 2022 using Microsoft Forms. Twenty-one questions were selected from a previously published questionnaire to measure the extent of knowledge and misconceptions surrounding RT. Respondents were divided into groups – A - Those who previously received RT/had a cancer diagnosis, B – Those with a family member/close friend who had RT, C – no exposure to RT, D – healthcare worker not working in oncology. Data were analysed using Microsoft Excel; Chi-squared and Student t-tests were used to assess the statistical significance of the results. Ethical approval was obtained from the University College Cork’s Social Research Ethics Committee (SREC). Results Of the 332 responders, 280 were deemed usable (84%). The majority of respondents were in group B (63%, 176/280). 30% of answers demonstrated certain misconceptions about the use, benefit, and risks associated with RT. However, responders with experience of cancer had a statistically higher aggregate score than those without cancer experience (p=0.05). Furthermore, healthcare workers performed statistically better than the public (P = 0.002) but showed wide variation in answers to individual questions. Conclusion There is an ongoing need for accurate informational resources, support services, and educational interventions for healthcare workers and the public, focusing on those undergoing RT treatment. The crucial role of the practitioner in guiding patients through treatment is highlighted, emphasising the duty of care involved in caring for those who may have limited understanding or inherent misconceptions surrounding their treatment. S.A. Koerber 1 , M. Roehrich 2 , L. Walkenbach 2 , C. Fink 1 , C. Schroeter 2 , C. Kratochwil 2 , J. Liermann 1 , K. Herfarth 1 , J. Debus 1 , U. Haberkorn 2 , F.L. Giesel 3 1 Heidelberg University Hospital, Radiation Oncology, Heidelberg, Germany; 2 Heidelberg University Hospital, Nuclear Medicine, Heidelberg, Germany; 3 University Hospital Duesseldorf, Nuclear Medicine, Duesseldorf, Germany Purpose or Objective For radiotherapy planning, 18F-FDG-PET/CT is commonly used for several tumors such as lung cancer. However, the tracer has been partially challenging due to physiological brown fat uptake, inflammation or low glucose transporter and hexokinase activity in certain tumor types. Since the introduction of PET imaging of the fibroblast activation protein (FAP), novel and promising FAP-specific tracers with high diagnostic performance were introduced. The current study evaluated the impact of 68Ga-FAPI-PET/CT on tumor stage and (radio)oncological management in a large cohort of patients with various cancers. Materials and Methods A total of 227 patients with 25 different kinds of cancer were included in this retrospective study. Most common tumor types were pancreatic (n = 78), head and neck (n = 29) and lung cancer (n = 23). Tracer uptake was quantified by standardized uptake values (SUV)max and (SUV)mean. After comparison with standard imaging, changes in tumor stage and (radio)oncological management were recorded. Results After FAPI-imaging, a high tumor-to-background ratio of more than 3 in most lesions was observed due to a low background activity in normal tissue. For more than 50% of all patients, there was a change of TNM stage. Upstaging was more frequent than downstaging considering results from the novel imaging probe (55.6%). With regard to (radio)oncological management, a change occurred for 56.0% of all patients after 68Ga-FAPI-PET/CT. The most common reason was an improvement for target volume delineation, however, major changes (e.g. change of therapy modality) were observed for almost 15% of the group. Conclusion This large study with different kinds of cancer demonstrated promising results particularly among cancers less suitable for conventional PET imaging such as pancreatic cancer. Nevertheless, prospective trials including histopathological verification are mandatorily required to confirm the increasing importance of 68Ga-FAPI-PET/CT and finally assess the impact on radiation oncology. PO-1064 Impact of novel PET-imaging on (radio)oncological management in a large cohort with various tumors

PO-1065 Incidental findings in non-patient, volunteer MR imaging: a single centre experience

L. McDaid 1 , A. Datta 1 , J. O'Connor 2 , P. Manoharan 3 , S. Bonington 3 , A. Choudhury 1 , P. Hoskin 2 , R. Huddart 4 , C. Eccles 1

1 The Christie NHS Foundation Trust, Radiotherapy, Manchester, United Kingdom; 2 University of Manchester, Radiotherapy Related Research, Manchester, United Kingdom; 3 The Christie NHS Foundation Trust, Radiology, Manchester, United Kingdom; 4 Institute of Cancer Research, Clinical Academic Radiotherapy, London, United Kingdom Purpose or Objective Novel magnetic resonance imaging (MRI) protocols require optimisation on healthy volunteers prior to being implemented for use in patients. Though the acquired images may not be of optimal diagnostic quality, it is possible to identify abnormalities. Therefore, it is appropriate that the rate, and types of incidental findings are audited and compared with literature standards.