ESTRO 2021 Abstract Book

S835

ESTRO 2021

SUVmax, TLR max, TBR max between the 3 different segmentation methods. TLG, SUVmax, Total SUVbw, TLRmax, TBRmax, SUVpeak, volume features had an excellent intraclass correlation (ICC >0.80) whereas number of voxel and MTV parameters had a good ICC with values ranging between 0.61 and 0.80. Conclusion Nine FDG PET features extracted from pretherapeutic 18FDG PET/CT (volume, TLG, SUVmax, SUVpeak, number of voxel, MTV, total of SUVbw, TLRmax, TBRmax) seem to be robust parameters despite segmentation method, and could be used as potential biomarkers in future studies. PO-1003 Implementation of the routine collection of PROMs for patients with Head and Neck cancer L. Pascal 1,2 , M. Van Hemelrijck 1 , T. Guerrero Urbano 1,3 , M. Lei 1,4 1 King's College London, School of Cancer & Pharmaceutical Sciences, London, United Kingdom; 2 Guy's and St Thomas' NHS Foundation Trust , Clinical Oncology, London, United Kingdom; 3 Guy's and St Thomas' NHS Foundation Trust , Clinical Oncology , London, United Kingdom; 4 Guy's at St Thomas' NHS Foundation Trust , Clinical Oncology, London, United Kingdom Purpose or Objective Head and neck cancer (HNC) and its treatment can have considerable functional consequences and impair quality of life (QoL). The integration of patient reported outcome measures (PROMS) during a course of radiotherapy (RT) enables close monitoring, early identification and management of significant issues. Using PROMs in clinical practice provides a platform for patients to self-report symptoms and enable close monitoring throughout their cancer journey. The use of PROMs has been shown to reduce the number of hospitalisations, improve quality of care delivered and improve patient satisfaction. A service evaluation is currently being conducted at a tertiary cancer centre to assess the feasibility and acceptability of delivering a PROMs programme to patients with HNC. This interim analysis aimed to assess feasibility and optimal time points for collection. Materials and Methods Eligible patients were approached at their initial oncology consultation and consented to take part. Patients completed paper PROMs of the University of Washington QOL 4.1(UWQOL) and MD Anderson Dysphagia Inventory (MDADI) questionnaires at baseline and weekly during RT. The RT period was divided into 2 time frames for analysis: weeks 1 -3 and weeks 4 – 6. Inclusion criteria: >18 years, English speakers and confirmed HNC treated with curative intent. Questionnaire responses were entered into a database and analysed using descriptive statistics. Results Between September 2020 and January 2021, 17 patients completed weekly PROMS during radiotherapy . 68% of PROMS questionnaires were completed. Median time taken to complete PROMs was 10 minutes (4 – 45) for both time periods. Compliance at weeks 1 - 3 was 71% and fell to 57% between weeks 4 -6. Conversely, for UWQOL, report of significant issues was highest at weeks 4 - 6 (21%) and lowest at weeks 1 - 3 (11%) . For MDADI, the total mean composite score first showed a clinically significant 10 point drop from the baseline score of 76.03 to 66.23 at week 3. At week 6, the score had fallen further compared to baseline by 15.88 points, to 60.15. Conclusion Most patients completed the entire PROMs programme. However, during weeks 4 – 6, compliance was lowest and the proportion of significant issues reported doubled. From this analysis, PROMs collection appears to be feasible. A lower frequency of PROM collection may increase compliance. Ongoing data collection will help to identify the optimal time points for PROMs collection during RT. PO-1004 Prevalence and distribution of cervical lymph node metastases in HPV+ and HPV- oropharyngeal cancer L. Bauwens 1 , V. Gregoire 2 1 Centre Léon Bérard, Radiation Oncology Department, Lyon, France; 2 Centre Léon Bérard, Radiation oncology department, Lyon, France Purpose or Objective In oropharyngeal squamous cell carcinoma (OP-SCC), the prevalence and distribution of clinical and pathological lymph node metastasis in the neck have been extensively reported. It served as the basis for consensus recommendations on the selection of the lymph node levels in the neck requiring a treatment. The objective of the study is to compare the prevalence and distribution of neck node metastases in HPV+ and HPV- OP-SCC from a large series of patients with OP-SCC who underwent a cervical lymph-node dissection (LND) as part of their treatment. Materials and Methods The study concentrated on OP-SCC patients treated by various neck node dissection (LND) procedures from January 2014 to December 2018 in 3 French institutions. Patients with prior head and neck cancer, prior neck surgery, the use of induction chemotherapy, or patients with carcinoma of unknown primary were excluded. HPV-status was assessed by p16 immunohistochemistry. For each patient, the clinical and the pathological nodal status, as well as the distribution of the positive nodes in each neck level (from Ia to V) were reported. Results Two hundred and sixty-three patients were included (126 p16-negative (p16-), and 137 p16-positive (p16+). The rate of clinical positive node (cN+) reached 54% and 88.3% in the p16- and p16+ groups, respectively (p < 0.001); the corresponding rate of pathological positive node (pN+) reached 61.9% and 91.2%, respectively (p< 0.001). Regarding the clinical lymph node distribution, in p16+ patients, more positive nodes were observed in the ipsilateral level IV (p=0.003), and less positive nodes were observed in the contralateral levels III and IV