Lung cancer showdown: surgery vs. radiation in High-Risk patients

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Age ≥ 18 years * Biopsy-proven NSCLC * Diagnostic codes: DC34, DC 34.1, DC 34.2, DC 34.3 or DC 34.9 * Clinical stage I NSCLC according to the 9th edition of TNM * Performed diagnostic PET-CT and supplementary invasive procedures for staging purposes in accordance with the Danish national reference program for the staging and treatment of lung cancer (30) * 9th edition TNM staging: cT1aN0M0, cT1b-cN0M0, cT1cN0M0 and cT2aN0M0 (clinical stage I) * Tumor is localized in the outer third of the lung and considered technically resectable by SWR, as well as treatable with peripheral SBRT when assessed during MDT conference * Eastern Cooperative Oncology Group (ECOG) performance status (PS) = 0-2. * Preoperative pulmonary function test according to national guidelines performed within 6 weeks before the MDT conference * Patient fulfills the "high-risk patient" criteria outlined: A high-risk patient is a patient that fulfills at minimum one of the main-risk criteria and/or two of the secondary criteria: Main criteria: * FEV-1 ≤ 50% and/or * DLCO ≤ 50% Secondary criteria: * Age ≥ 80 * FEV-1 = 51-60% and/or DLCO = 51-60% * Known pulmonary hypertension with PAP ≥40 mm Hg diagnosed \< 6 months before inclusion * Known LVEF ≤ 40% diagnosed \< 6 months before inclusion Exclusion Criteria: * Declared terminally ill or life expectancy shorter than one year. * Multifocal disease * PS ≥ 3 * Centrally located tumors not eligible to SBRT * Previous ipsilateral lung surgery * Pregnancy or breastfeeding. * Inability to understand oral and written informed consent * Intravenous substance abuse or severe alcohol abuse (\> 25 units per week) * Not amendable for surgery in general anesthetic * Previous radiotherapy to the thorax, which may limit the feasibility or increase the risk of stereotactic reirradiation due to cumulative dose constraints and potential toxicity * Diagnosed with Interstitial lung disease (ILD)