The goal of this observational study is to evaluate the efficacy and safety of stereotactic body radiotherapy (SABR) in patients with oligometastatic or oligoprogressive cancer.
The main questions it aims to answer are:
1. oncologic outcomes (progression-free survival, local failure rate), 2. patient-reported outcomes, 3. physician-assessed toxicity, and 4. dynamics of circulating tumor DNA (ctDNA) for biomarker analysis.
Performance status (ECOG PS) 0-2
Diagnosed with metastatic disease
Confirmed to have oligometastatic/oligoprogressive cancer on imaging performed within 4 weeks (up to 5 lesions)
Patient with a history of prior radiotherapy to the site planned for SABR
Patients with concomitant brain metastases