ESTRO 38 Abstract book

S739 ESTRO 38

esophagitis grade 1, 2, 3 in 18%, 53% , 2% of the patients, respectively. No acute toxicity grade 4 or 5 occurred. In 2 patients with central tumors and close vicinity to great vessels, a treatment relationship to lethal haemorrhages, 7 and 9 months after the end of radiotherapy, cannot be excluded. Besides that, no late toxicity >grade 1 was observed. Conclusion This accelerated, differentiated dose-intensified approach yields encouraging results for survival and tumor control; along with in general low toxicity up to now. EP-1351 Long-term survival with FDG-PET directed therapy in NSCLC with synchronous solitary brain metastasis S.J. Newman 1 , N. Bucknell 1 , M. Bressel 1 , P. Tran 1 , B. Campbell 1 , N. Haghighi 1 , D. Kok 1 , M. MacManus 1 , C. Phillips 1 , M. Shaw 1 , A. Wirth 1 , G. Wheeler 1 , D. Ball 1 , S. Siva 1 1 Peter MacCallum Cancer Centre, Radiation Oncology, Melbourne, Australia Purpose or Objective At diagnosis, approximately 10% of all patients with NSCLC have intracranial metastases, and 1% have synchronous solitary brain metastasis (SSBM). In similar cohorts treated radically to both sites published 5-year overall survival (OS) is 11-21%. Use of FDG-PET can significantly alter staging, treatment choices and intent. We investigate the outcomes of patients diagnosed with NSCLC and SSBM and treated with radical local therapies in the FDG-PET era. Material and Methods In this retrospective study, eligible patients had histologically-confirmed NSCLC and SSBM staged with FDG- PET and received radical treatment from 1/2/1999 to 31/12/2017. A lung-molecular graded prognostic assessment (lung-molGPA) score was assigned for each patient using age, ECOG score, and, if performed, molecular status. Overall survival (OS) and progression free survival (PFS) were calculated using Kaplan-Meier methods. Cox proportional hazard models determined prognostic factors for PFS. Results Forty-nine patients were eligible. Median age was 63 years (range: 34–76). Thirty (61%) were male. Nineteen patients (39%) were ECOG 0, 26 (53%) ECOG 1 and 4 (8%) ECOG 2. Sixty-seven percent were ≥T2 and 47% were ≥N2 (Table 1). Forty-six of 48 patients (1 unknown) (96%) had MRI brain. For intrathoracic disease, 10 patients (20%) had surgery, surgery and RT in 1 (2%), surgery and adjuvant chemoRT in 2 (4%), surgery and adjuvant chemotherapy in 2 (4%), chemoRT in 29 (59%), SABR in 4 (8%) and fractionated RT in 1 (2%). For intracranial disease, 20 patients (41%) had surgery, 7 (14%) definitive SRS and 22 (45%) had adjuvant RT. For adjuvant RT, 20 had whole brain RT and 2 had SRS cavity boost. Median follow up of all patients was 3.9 years. Median time to first relapse was 6 months (95%CI: 5–11). At 2 years, 45% of first failures were intracranial only (95%CI: 30–59). At 2 years PFS was 13% (95%CI: 6–28). At 2 and 5 years, OS was 56% (95%CI: 43–73) and 30% (95%CI: 18–51), respectively (Figure 1). In ≥N1 disease, 5 year OS was 34% (95%CI: 18–63). On univariable analysis, lower ECOG (HR 2.28, 95%CI: 1.17–4.43, p=0.014) and higher lung-molGPA scores (HR 0.26, 95%CI: 0.11–0.61, p=0.002) were associated with significantly longer OS. Higher lung-molGPA was associated with significantly longer PFS (HR 0.47, 95%CI: 0.24–0.94, p=0.031). On multivariable analysis, lung-molGPA (HR 0.33, 95%CI: 0.15–0.71, p=0.005) and N-stage (HR 1.56, 95%CI: 1.13– 2.15, p=0.007) were significant positive and negative prognostic factors, respectively, for PFS.

Conclusion Patients with NSCLC and SSBM staged with FDG-PET had a 5 year OS of 30% when treated radically to both sites. This is greater than previously reported outcomes. For ≥N1 patients, the 5 year OS was 34%, which to our knowledge is thelongest reported survival in similar populations. These results suggest that such patients should be treated with aggressive local therapy, as this can be associated long-term OS and possible cure. EP-1352 Locally advanced NSCLC: performance status based eligibility for adjuvant check point inhibitor G. Persson 1,2,3 , T. Schytte 4,5 , A.L. Appelt 6,7 , S. Borissova 1 , C. Brink 5,8 , T.S. Hansen 9 , L. Hoffmann 10 , M. Josipovic 3 , A.A. Khalil 11 , M.M. Knap 11 , M.D. Lund 12 , C.M. Lutz 10 , D.S. Møller 10 , T.B. Nielsen 8 , M. Nielsen 8 , W. Ottosson 1 , M. Pøhl 3 , J.B. Thomsen 3 , O. Hansen 4,5 1 Herlev Hospital- University of Copenhagen, Department of Oncology, Herlev, Denmark ; 2 Faculty of Health and Medical Sciences- University of Copenhagen, Department of Clinical Medicine, Copenhagen, Denmark ; 3 Rigshospitalet- University of Copenhagen, Department of Oncology, Copenhagen, Denmark ; 4 Odense University Hospital, Department of Oncology, Odense, Denmark ; 5 University of Southern Denmark, Institute of Clinical Research, Odense, Denmark ; 6 St. James's University Hospital, Leeds Cancer Centre, Leeds, United Kingdom ; 7 University of Leeds, Leeds Institute of Cancer and