Here is the design of a clinical trial:

Official Title: Mediastinal Lymph Node Dissection Versus Spared Mediastinal Lymph Node Dissection in Stage IA Non-small Cell Lung Cancer Presented as Ground-glass Nodules: Study Protocol of a Phase III, Randomized, Multi-center Trial (MELDSIG) in China

Included conditions:
- Lung Neoplasms
- Lymph Node Excision

Study Armgroups:
- {'label': 'Mediastinal lymph node dissection group', 'type': 'EXPERIMENTAL', 'description': 'A', 'interventionNames': ['Procedure: Systemic mediastinal lymph node dissection']}
- {'label': 'Spared mediastinal lymph node dissection group', 'type': 'ACTIVE_COMPARATOR', 'description': 'B', 'interventionNames': ['Procedure: Spared mediastinal lymph node dissection']}

Interventions:
- {'type': 'PROCEDURE', 'name': 'Systemic mediastinal lymph node dissection', 'description': 'Systematic hilar and mediastinal lymph node dissection.', 'armGroupLabels': ['Mediastinal lymph node dissection group']}
- {'type': 'PROCEDURE', 'name': 'Spared mediastinal lymph node dissection', 'description': 'Mediastinal lymph node is spared in this group.', 'armGroupLabels': ['Spared mediastinal lymph node dissection group']}

Primary Outcomes:
- {'measure': 'Overall survival', 'description': 'Overall survival is defined as days from randomization to death from any cause, and it was censored at the last day when the patient was alive.', 'timeFrame': '5 years'}

Please estimate the sample size based on the assumption: 
One-sided significance level of 5%, power of 80%, drop-out rate of 5%, accrual time of 2 years, follow-up time of 5 years
Sample size
        According to previous studies on stage IA subsolid and pure GGNs, the 5-year survival rate is 87.6%â100%.10 11 We assumed an expected 5-year OS rate of 90% in the mediastinal LND group and an anticipated accrual time of 2 years and a follow-up time of 5 years. Based on a one-sided significance level of 5%, a power of 80%, a non-inferiority margin of 5% for 5-year OS rate and a drop-out rate of 5%, the total sample size was set at 1362 patients (681 per arm) by PASS V.11.0 software.