ESTRO 2025 - Abstract Book

S1568

Clinical – Mixed sites & palliation

ESTRO 2025

3838

Digital Poster Stereotactic body radiotherapy combined with immunotherapy or targeted therapy: a screenshot from Italy Giulia Marvaso 1,2 , Giulia Corrao 1 , Mattia Zaffaroni 1 , Maria Giulia Vincini 1 , Serena Badellino 3 , Paolo Borghetti 4 , Francesco Cuccia 5 , Manuela Federico 6 , Giampaolo Montesi 7 , Antonio Pontoriero 8 , Ciro Franzese 9,10 , Mauro Loi 11 , Barbara Alicja Jereczek-Fossa 1,2 , Marta Scorsetti 9,10 1 Division of Radiation Oncology, IEO European Institute of Oncology IRCCS, Milan, Italy. 2 Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy. 3 Radiation Oncology, University of Turin, Turin, Italy. 4 Radiation Oncology Department, ASST Spedali Civili and University of Brescia, Brescia, Italy. 5 Radiation Oncology, ARNAS Civico Hospital, Palermo, Italy. 6 Radiation Therapy Unit, Clinica Macchiarella, Palermo, Italy. 7 Radiation Oncology Unit, Santa Maria della Misericordia Hospital, Rovigo, Italy. 8 Radiation Oncology Unit, University of Messina, Messina, Italy. 9 Radiotherapy and Radiosurgery Department, IRCCS Humanitas Research Hospital, Milan, Italy. 10 Department of Biomedical Sciences, Humanitas University, Milan, Italy. 11 Department of Radiation Oncology, Azienda Universitaria Ospedaliera Careggi, Florence, Italy Purpose/Objective: Despite the widespread use of immunotherapy (IO) and target therapy (TT) in clinical practice, data on toxicity in combination with SBRT are lacking, largely based on retrospective studies and case reports. The present survey, conducted within the Italian Association of Clinical Oncology and Radiotherapy (AIRO) Oligometastatic Study Group, was developed for radiation oncologists to investigate the current clinical practice in Italy regarding SBRT in cancer patients using IO and TT. Material/Methods: The online survey, composed of 19 questions, was developed using the cloud-based platform SurveyMonkey® and was sent to all registered AIRO members using the association's mailing list and was administered online and in anonymous form. Results: 68 AIRO members from different Italian regions completed the proposed survey. 59% stated that there is sufficient knowledge within their institute regarding the potential interaction between SBRT and TT/IO. According to 76% of the pool, a multidisciplinarily protocol is available in their institute. However, 50% of participants report that interdisciplinary consultation with a radiation oncologist did not always take place. Only 6% of the radiation oncologists stated that they lacked sufficient knowledge to adequately consider the treatment of these patients, while 81% of them felt confident in deciding whether or not to combine SBRT and IO/TT. Results of questions regarding combination of SBRT and IO/TT are reported in Table 1 . The 26% and the 37% answered that TT and IO respectively should be stopped during RT administration. Preferences of the responders on whether or not to combine hypofractionated radiotherapy and IO/TT are reported in Figure 1 . Regarding which drug types would be of concern when patients are referred for SBRT, the majority of the answers regarded ALK inhibitors (21%), BRAF inhibitors (25%), EGFR inhibitors (26%), immune checkpoint inhibitors (25%) and PARP inhibitors (25%). Only 5% did not consider any of these classes of drugs. Particularly, many radiation oncologists (19%) did not expect a real risk of tumor flare upon discontinuation of TT or IO.