LAT for Oligoprogressive NSCLC Treated With First-line OSImertinib

To determine whether in patients with EGFR mutated advanced NSCLC and osimertinib as first-line treatment, the (repeated) use of LAT to 3 OP lesions and continuation of first-line osimertinib, improves the median progression-free survival by more than 3 months (i.e. PFS2-PFS1 = >3 months).