ESTRO 2021 Abstract Book

S1240

ESTRO 2021

escalation cases. The whole treatment currently takes about 36 minutes per fraction.

PO-1513 Radiation-induced cardiac toxicity for oesophageal or oesophagogastric junctional adenocarcinoma L. Pelari 1 , F. López 2 , V.J. Duque 2 , P. Retorta 3 , A. Hernandez 2 , M. Valero 2 , S. Sancho 2 1 Ramon y Cajal Hospital, Radiation Oncology, Madrid, Spain; 2 Ramón y Cajal Hospital, Radiation Oncology, Madrid, Spain; 3 Ramón y Cajal Hospital, Medical physicist, Madrid, Spain Purpose or Objective Radiation-induced cardiac toxicity is a rare, but relevant sequelae in oesophageal or oesophagogastric junctional cancer treated with chemoradiotherapy CROSS-protocol. Recent studies have demonstrated that left anterior descending (LAD) coronary V15 Gy ≥10% and left ventricle V15 Gy >1% in patients with pre- existing coronary heart disease (CHD) were associated with increased risk of major cardiac adverse events (MACEs)The aim of this study was to demonstrate the relevance of a correct delineation of cardiac substructures in order to reduce possible MACEs. Materials and Methods We retrospectively evaluated patients with locally advanced oesophageal or oesophagogastric junctional adenocarcinoma (T1-T4, N0-N2, M0 according to the TNM classification, AJCC 8th edition) who received neoadjuvant chemoradiotherapy according to CROSS protocol. Cardiac substructures were manually delineated. Radiotherapy dose parameters (LAD V15 Gy and VI V15 Gy) were calculated and history of pre-existing cardiovascular disease and MACEs (unstable angina, heart failure hospitalization or urgent visit, myocardial infarction, coronary revascularization and cardiac death) during follow-up were analysed. Results From December 2015 to July 2020, 16 patients were treated by the reported schedule. Median age was 62 years (range 41-72 years). Median follow-up was 14 months (range 2-48 months). All patients had histologically confirmed oesophageal adenocarcinoma and were treated using IMRT (intensity modulated radiotherapy) technique up to 41,4-50,4 Gy. Three patients (18,75%) suffered from pre-existing CHD. Median LAD V15 Gy was 15,69% and median VI V15 Gy was 42,75%. No MACEs were reported. Conclusion It seems appropriate to pay special attention to cardiac substructures contouring due to significant radiation doses received during treatment. Longer term follow-up and prospective studies should be designed to validate our results. PO-1514 Prospective assessment of employees stress during the COVID-19 pandemic M. Guckenberger 1 , N. Andratschke 1 , P. Balermpas 2 , M. Denner 3 , B. Hilty 3 , S. Tanadini-Lang 3 , L. Wilke 1 , S. Perryck 1 1 University Hospital Zürich, University of Zürich, Department of Radiation Oncology, Zurich, Switzerland; 2 University Hospital Zürich, University of Zürich, Department of Radiation Oncology, Zurich, Switzerland; 3 University Hospital Zürich, University of Zürich , Department of Radiation Oncology, Zurich, Switzerland Purpose or Objective The COVID-19 pandemic has required rapid and repetitive adjustment of radiotherapy practice, hospital and department organization and hygienic measures. This has been in parallel with significant changes in everyone’s private life. In the Department of Radiation Oncology, University Zurich, all employees were invited to participate in weekly assessments of their stress levels, aiming to rapidly and precisely implement Starting from March 31 st 2020, weekly anonymized surveys were distributed to all employees (n=134) of the Department of Radiation Oncology, University of Zurich. Survey Monkey was used, and distribution was performed via email. The survey asked about the profession (clinician, medical physics and dosimetry, RTT, nurse, administration and research) and whether work in the last week was performed in hospital with or without patient contact or in home office. Global stress level during the last week was assessed on a 10-point scale. Additionally, stress was assessed in the sub-categories: concerns about own health; concerns about health of family & friends; concerns about patients` health. Results Between March 31 st 2020 and February 17 th 2021, a total of 47 surveys resulted in 1733 responses, 37 responses on average (range 26 and 54). Response rate was 28% on average and did not change over time, overall and in each profession. Averaged over all responses, the global stress level varied substantially between professions, ranging between 2.8 for administration and 6.8 for RTTs. The global stress level was highest for in-hospital work with patient contact with an average of 4.7, whereas stress was similar for in-hospital work without patient contact and home-office with 3.5 and 3.8, respectively. Concerns about health were highest about family & friends with 4.0 on average compared to concerns about the own health and of the patients with average values of 3.1 and 3.5, respectively. Changes of global stress level over the 47 weeks were strongly associated with development of the pandemic (figure). Averaged over all employees, the global stress level stated with 4.8 on average in March 2020 and dropped continuously in the spring and summer months until the second COVID-19 wave started in September 2020 with two peaks in November and December with 5.5 and 5.7 on average, respectively. Interventions against high stress levels were performed for all professions and especially the RTT subgroup with highest stress levels (workshops; meditation room; detailed information about hospital-specific infection rates; information about hospital wide possibilities for coping mechanisms, effectiveness of PPE; team meetings). anti-stress measures. Materials and Methods