ESTRO 2022 - Abstract Book

S1060

Abstract book

ESTRO 2022

Conclusion SBRT is superior to conventional RT in terms of pain control and local disease control. It is important to notice that accurate and uniform radiological assessment is complicated in retrospective setting. SBRT could represent the standard of care for oligometastatic patients with good performance status and a longer life expectancy.

PO-1255 Retrospective analysis of synchronous NSCLC stage IV oligometastatic treated with local treatments

D. Jornet 1 , A. Botticella 2 , B. Besse 3 , P. Lavaud 3 , S. Mussot 4 , C. Roux 5 , P. Pradère 6 , D. Planchard 3 , A. Levy 7 , C. Le Péchoux 7

1 Centre International des Cancers Thoraciques (CICT), Gustave Roussy, Radiation Oncology Department, F-94805, Villejuif, France; 2 Centre International des Cancers Thoraciques (CICT), Gustave Roussy, Radiation Oncology, F-94805, Villejuif, France; 3 Centre International des Cancers Thoraciques (CICT), Gustave Roussy, Oncology Department, F-94805, Villejuif, France; 4 Marie-Lannelongue Hospital, Thoracic and Vascular Surgery and Heart-Lung Transplantation Department, F-92350, Le Plessis Robinson, France; 5 Centre International des Cancers Thoraciques (CICT), Gustave Roussy, Interventional Radiology, F-94805, Villejuif, France; 6 Marie-Lannelongue Hospital, Pneumology Department, F-92350, Le Plessis Robinson, France; 7 Centre International des Cancers Thoraciques (CICT), Gustave Roussy, Radiation Oncology Department, F-94805, Villejuif, France Purpose or Objective Our aim was to assess the impact of any local treatments of the primary lesion and of all metastases in synchronous oligometastatic (SOM) NSCLC. Materials and Methods Patients diagnosed with a SOM NSCLC at a single Institution between 2009 and 2020 were retrospectively analyzed if they presented <3 involved organs and <5 metastasis in total. All patients underwent a staging 18 F-PET-CT scan and a brain MRI. Primary tumor was managed with curative-intent surgery or radiotherapy. Local ablative treatments (stereotactic radiotherapy [SRT]/radiosurgery (SRS), surgery, radiofrequency ablation [RFA]) were delivered on all visible metastases. Systemic treatment was not mandatory, in particular if brain was the only metastatic site. No response to previous systemic treatments was required. Frontline/consolidation immunotherapy was not delivered. Results Sixty-four patients (25 females, 39 males) with 108 lesions were identified. Mean age was 62 years (SD: 12.10). Thirty-one patients (48.4%) had T1/T2 stage and 41 patients (64%) presented a N2/N3 stage. Not counting the metastatic sites, 45 patients (69%) presented a thoracic stage 3 disease. Thirty-eight patients (59%) had one metastatic site (17 patients (26%) and 9 patients (14%) had 2 and >3 metastatic sites, respectively). Main metastatic sites were: brain (34/64 patients, 53% of patients), bone (19/64 patients, 29%) and lung (4/64, 6%). Most patients (84%) received platinum-based chemotherapy. Primary thoracic tumor was managed with concurrent chemo- radiation in 53 patients (83%), stereotactic body radiotherapy (SBRT) in 8 patients (12%) and surgery in 3 (5%). The treatment of the metastatic sites was SRS in 21/64 patients (33%), surgery followed by post-operative SRS in 11/64 patients (17%), SBRT in 10/64 patients (15%) and conformal RT in 14/64 patients (21%). The median follow-up was 27 months [range: 4-132 months]. The median OS was 36.6 months [CI 95% : 23.5-50.2] and 1-, 2- and 5-years OS rates were respectively of 95%, 65% and 31%. The median PFS was 10.5 months [CI 95% : 8.6-14.7] and 1-, 2- and 5-years PFS rates were respectively of 44%, 23% and 15%. The median time to initiation of a novel systemic therapy was 28.13 months [95% CI: 26.2-not reached]. The multivariate analysis suggested that the T stage (T1-2 versus T3-4) was an independent predictor of OS (HR= 1.03, IC 95% :1-1.08 p= 0.02), whereas the thoracic stage (stage I-II versus III-IV) was an independent predictor on PFS (HR= 1.04, CI 95% :1.003-1.07, p=0.05). Among the 54 patients who relapsed, 39 were oligo-recurrent, and 24 of them (24/39, 62%) subsequently received a subsequent local treatment only.

Conclusion