ESTRO 2020 Abstract book

S129 ESTRO 2020

1 University of Manchester, School of Medicine, Manchester, United Kingdom ; 2 University of Manchester, Division of Cancer Sciences, Manchester, United Kingdom ; 3 University of Manchester, School of Pharmacy, Manchester, United Kingdom ; 4 University of Manchester, Division of Cancer Science, Manchester, United Kingdom ; 5 Christie NHS Foundation Trust, Clinical Oncology, Manchester, United Kingdom Purpose or Objective Management of inoperable non-small cell lung cancer (NSCLC) patients with severe chronic obstructive pulmonary disease (COPD) and lung fibrosis is complex. We investigated outcomes of curative-intent thoracic radiotherapy in these patients. Material and Methods A retrospective real world dataset of 587 NSCLC patients with COPD and 34 with lung fibrosis treated with curative- intent thoracic radiotherapy at The Christie NHS Foundation Trust (Manchester, UK) from January 2015 to December 2016 were analysed. COPD severity was graded using Global Initiative for Chronic Obstructive Lung Disease classification (GOLD I-IV), dependent on forced expiratory volume in 1 second (FEV1). The primary endpoint was overall-survival (OS). The longitudinal use of oxygen therapy and Medical Research Council (MRC) dyspnoea scores were evaluated in a patient subset. Demographic and clinical characteristics, baseline lung function and radiotherapy and dosimetric lung parameters were evaluated for association with OS. Results The characteristics for the whole cohort are shown in table 1. 148 (25%) COPD patients received stereotactic ablative body radiotherapy (SABR). Median OS was 20 months (95% CI: 17-21) for GOLD I (mild COPD; n=194), 19 months (95% CI 17-21) for GOLD II (moderate COPD; n=255) and 20 months for GOLD III/ IV (severe and very severe COPD; n=138) patients, respectively (fig1A). FEV1 and GOLD category did not correlate with OS (p≥0.05). Median OS was significantly shorter for patients with lung fibrosis (12 months, 95% CI: 4-18) compared to patients without lung fibrosis (21 months, 95% CI: 19-23); p<0.001 (fig1B). Treatment type (fractionated radiotherapy worse compared to SABR), larger tumour volume, higher dosimetric lung parameters (mean dose, V20 and V5), advanced tumour stage and squamous histology all correlated with poor OS (p<0.05). MRC dyspnoea scores and oxygen therapy data were available in 21 (62%) and 14 (41%) fibrosis patients and 92 (67%) and 40 (30%) GOLD III/ IV COPD patients, respectively. MRC dyspnoea scores were not significantly different before and after radiotherapy in fibrosis and GOLD III/ IV patients (p≥0.05). Oxygen therapy increased after radiotherapy in GOLD III/ IV patients (n=12 before vs n=28 after) and in fibrosis patients (n=4 before vs n=10 after).

Oncology- West German Cancer Center- University Hospital Essen- Division of Thoracic Oncology- University Medicine Essen – Ruhrlandklinik- Essen- Germany- German Cancer Consortium DKTK- Partner Site University Hospital Essen- Germany, Dep, ; 8 Department of Pulmonary Medicine- Section of Interventional Pneumology- Ruhrlandklinik- West German Lung Transplantation Center- University Hospital Essen- Germany, Department of Pulmonary Medicine- Section of Interventional Pneumology- Ruhrlandklinik-, ; 9 Department of Radiotherapy- West German Cancer Center- University Hospital Essen- Germany- German Cancer Consortium DKTK- Partner Site University Hospital Essen- Germany, Department of Radiotherapy- West German Cancer Center- University Hospital Essen-, Germany Purpose or Objective [ 18 F]FDG-PET/CT-imaging has proven to be a highly sensitive and specific diagnostic element in lung cancer. It presents an obligatory diagnostic imaging technique for radiation treatment planning in patients with locally advanced non-small-cell lung cancer (NSCLC). The purpose of this study was to examine whether the accuracy of the target volume can be improved by adding endobronchial ultrasound transbronchial needle aspiration (EBUS TBNA) information to standard [ 18 F]FDG PET/CT imaging for mediastinal lymph node staging and its impact on clinical Consecutive patients (pts) with primary NSCLC who underwent [ 18 F]FDG-PET/CT-imaging and EBUS TBNA prior to radiotherapy treatment planning of the primary tumor and lymph nodes at risk were analyzed in this study in the time period from 12/2011 to 12/2018. SUV max values were measured in lymph node stations which were sampled by EBUS TBNA. All lymph node stations were assessed by an expert radiologist and nuclear medicine physician. The clinical target volume (CTV) delineated for the clinical treatment plans was evaluated whether it covers a given lymph node station in dependence of the EBUS and PET A total of 919 lymph node stations were biopsied in 264 patients, of which 322 were positive for tumor cells. The treatment plan and target coverage of a lymph node station was significantly dependent on the EBUS result, the SUV max value and the rating by the specialist (p<0.0001 for each factor, logistic regression). EBUS positivity was significantly predicted by the SUV max value in that lymph node station (Receiver operator characteristic Area under curve =0.917, p<0.0001). 10,3% of all involved biopsied lymph nodes would not be included in the clinical radiation volume according to the [ 18 F]FDG PET/CT report alone (false negative rate). The positive predictive value of [ 18 F]FDG PET/CT ratings by the specialist was 66.4%, and the negative predictive value of the [ 18 F]FDG PET/CT rating was 93.1%. Conclusion [ 18 F]FDG-PET -imaging and EBUS TBNA prove to be both a valuable instrument for primary diagnosis and treatment planning in lung cancer. At the prevalence of lymph node involvement in a radiotherapy cohort, the positive predictive value of PET CT is rather low and the false negative rate is high. Hence, we recommend EBUS-TBNA for each patient with primary diagnosis of lung cancer prior to radiotherapy. OC-0228 Curative-intent radiotherapy outcomes in NSCLC patients with severe/very severe COPD & lung fibrosis C. Tang 1 , G. Price 2 , H. Mistry 3 , J. Kennedy 4 , L. Pemberton 5 , D. Woolf 5 , N. Bayman 5 , D. Cobben 2 , C. Chan 5 , C. Faivre-Finn 4 , M. Harris 5 , H. Sheikh 2 , J. Coote 5 , A. Salem 2 target volume (CTV). Material and Methods results. Results