Bronchoscopic Microwave Ablation Group Inclusion Criteria

1. Adults aged ≥18 years
2. Histologically or cytologically confirmed stage IA NSCLC (T1N0M0, tumor ≤3 cm)
3. Determined by multidisciplinary evaluation to be an appropriate candidate for bronchoscopic ablation as part of standard clinical care, and the patient agrees to a lung-preserving treatment approach
4. Tumour size less than 2.5 cm in maximum diameter as measured on thin-slice chest CT
5. Tumour located in the middle or peripheral third of the lung parenchyma
6. Imaging and clinical evaluation indicate no lymph node involvement, and lymph node dissection for staging is not required
7. Medically fit for bronchoscopic procedure under standard institutional anaesthesia protocols
8. Pulmonary function results or clinical assessment indicate significant benefit from preserving lung tissue, such as predicted FEV1 or DLCO less than 40%, or clinician judgment that lung preservation is critical for quality of life
9. Eastern Cooperative Oncology Group (ECOG) performance status of 0-2

Exclusion Criteria

1. Presence of lymph node involvement (N1 or higher) or distant metastases (M1)
2. Centrally located tumours within the inner third of the lung or those requiring ablation near major airways
3. Tumours adjacent to heat-sensitive structures (e.g., main bronchi, oesophagus, pericardium, aorta, or pulmonary artery) where adequate ablation margins cannot be safely achieved
4. Rapidly enlarging lesions or those with high metabolic activity on PET-CT that warrant surgical resection and lymph node evaluation
5. Imaging findings suggesting possible nodal involvement that necessitate surgical dissection for accurate staging
6. Pregnant or breastfeeding women
7. Inability or unwillingness to comply with study procedures
8. Presence of electronic implants (e.g., pacemaker or defibrillator) at risk of interference from microwave energy
9. Active pulmonary infection, uncorrectable coagulopathy, or ASA score ≥4
10. Patients with multiple lesions requiring both surgery and ablation who cannot represent a single treatment strategy within the study

Surgical Resection Group Inclusion Criteria

1. Adults aged ≥18 years
2. Histologically or cytologically confirmed stage IA NSCLC (T1N0M0, tumor ≤3 cm)
3. Determined by multidisciplinary evaluation to have surgical resection as the preferred standard treatment option, and patient agrees to surgical resection.
4. Tumour size between 2.5 and 3.0 cm, or smaller lesions for which surgery is considered the more appropriate option based on tumour features or safety concerns.
5. Tumour located in the central third of the lung, or in proximity to heat-sensitive structures where surgery offers better oncologic and safety margins.
6. Imaging findings suggest possible lymph node involvement or a clinical indication for systematic nodal dissection and pathological staging.
7. Rapidly growing or high-SUV lesions on PET-CT requiring complete resection and full histologic staging.
8. Medically fit for general anaesthesia and surgical resection, with capability for intraoperative frozen-section margin assessment

Exclusion Criteria

1. Presence of lymph node involvement (N1 or higher) or distant metastases (M1)
2. High surgical risk or limited pulmonary reserve where a lung-preserving strategy is preferred.
3. Tumours clearly suitable for ablation (≤2.5 cm, located in the middle or peripheral third, and safely ablatable with adequate margins).
4. Active pulmonary infection, uncorrectable coagulopathy, or unfit for general anaesthesia or lung resection.
5. Patients with multiple lesions, some requiring surgery and others ablation, who cannot be assigned to a single treatment strategy within the study.
6. Pregnant or breastfeeding women
7. Inability or unwillingness to comply with study procedures