ESTRO 2021 Abstract Book

S1684

ESTRO 2021

fatigue post-radiotherapy. Materials and Methods

From the REQUITE database, we retrospectively analysed 23 prostate cancer patients who received EBRT. The bone marrow volume was defined as the inner cavity of the whole pelvic bone (WPB) and the contour process used the following steps: 1) manual WPB segmentation from L5 to the inferior border of the femoral head, 2) upload the pelvic contouring to the structure template management, 3) import the template structure through ATLAS-initialization in all patients, 4) manual correction applied if necessary, 5) automatic BM contouring using contraction tool, negative 0.4mm from the whole pelvic contorting in all direction as shown in figure 1. The integral dose was defined as Body-PTV to calculate the following: ID [Gy ⋅ l]=D [Gy] ⋅ V [l]. The mean dose, V 10 , and V 20 were calculated for both the Body-PTV and each BM PTV volumes. Fatigue was scored 1= patient-reported fatigue or 0= did not report fatigue based on self-reported questionnaires that included EORTC QLQ-C30, QLQ PR25, and MFI. Statistical analysis used descriptive statistics, t-tests and boxplots, and bee swarm graphs.

Results The mean ID for patients with fatigue scores of 1 was 121.6 Gy.l, versus 104.5 Gy.l for patients with scores of 0 (p < 0.05) see figure 2. The mean dose, V 10 , and V 20 , of the BM structure for patients with fatigue scores of 1 were 10 Gy, 36.7%, and 18.7% respectively. For patients with fatigue scores of 0 the mean dose, V 10 , and V 20 were 8.8 Gy, 33.3%, and 16.2%. None of which demonstrated significant differences ( p = 0.136, p = 0.108, and p = 0.205 respectively).

Conclusion We found Atlas-based auto segmentation (ABAS) is a reliable method in WPB contouring which can be a practical tool in a large cohort. To our knowledge, this is the first study investigating BM dose and fatigue in PC patients. ID was found to be the most discriminatory dosimetric parameter correlated to fatigue. Higher doses to BM were not associated with increased fatigue reports. This could be further investigated in a larger cohort. PO-1980 Use of Patient Reported Outcome (PRO) to facilitate patient-centered communication in radiotherapy A. Kristensen 1 , D. Winther 2 , R. Baltzer 1 1 Aarhus University Hospital, Danish Centre for Particle Therapy, Aarhus, Denmark; 2 Aarhus University Hospital, Dansih Centre for Particle Therapy, Aarhus, Denmark Purpose or Objective In a Danish radiotherapy clinic, we explored the use of a PRO questionnaire in patients with brain tumors to monitor acute toxicity to radiotherapy as well as mental well-being during treatment. The aim was to support patient-centered communication in weekly consultations with a multidiciplinary team of healthcare professionals based on the completed PRO questionnaire. Materials and Methods The PRO questionnaire was based on literature on acute toxicity to radiotherapy in patients with brain tumors; 17 items were selected in the EORTC Item Library. Patients and healthcare professionals evaluated the questionnaire and participated in a dialogue meeting exploring experiences on patient involvement during the course of treatment. Throughout 2020, 50 adult patients (>18 years) with brain tumors completed the electronic questionnaire weekly during their treatment with radiotherapy. The completed PRO questionnaire was available for health professionals before consultations. To assess the potential of the PRO questionnaire to support the dialogue during consultations, the participating patients' medical records were reviewed. The consistency between information in the completed PROs and medical records was