Here is the design of a clinical trial:

Official Title: Targeted Axillary Dissection Using Carbon Marking for Patients With Node-positive Breast Cancer Following Neoadjuvant Therapy (TADCOM): a Prospective, Multicenter, Randomized Controlled Trial

Included conditions:
- Breast Cancer
- Surgery
- Lymph Node Metastases

Study Armgroups:
- {'label': 'Group 1: CG-TAD Group', 'type': 'ACTIVE_COMPARATOR', 'description': 'US-guided clip insertion into suspicious ALNs pre-NAC Post-NAC, TAD removing SLNs and clipped LNs', 'interventionNames': ['Device: Tissue Marker Clip']}
- {'label': 'Group 2: CN-LNM Group', 'type': 'EXPERIMENTAL', 'description': 'US-guided CNSI injection to tattoo suspicious ALNs pre-NAC Post-NAC, TAD removing SLNs and carbon-marked LNs', 'interventionNames': ['Drug: Carbon Nanoparticle Suspension Injection']}
- {'label': 'Group 3: PCN-MAP Group', 'type': 'EXPERIMENTAL', 'description': 'US-guided CNSI injection around primary tumor pre-NAC, additional US-guided clip placement for metastatic LN Post-NAC, TAD removing SLNs, carbon-marked LNs, and clipped LNs', 'interventionNames': ['Drug: Carbon Nanoparticle Suspension Injection']}

Interventions:
- {'type': 'DEVICE', 'name': 'Tissue Marker Clip', 'description': 'Tissue Marker Clip to be Placed in Metastatic Axillary Lymph Node (Before Neoadjuvant Chemotherapy for Breast Cancer)', 'armGroupLabels': ['Group 1: CG-TAD Group']}
- {'type': 'DRUG', 'name': 'Carbon Nanoparticle Suspension Injection', 'description': 'Carbon Nanoparticle Suspension Injection to be Placed in Metastatic Axillary Lymph Node (Before Neoadjuvant Chemotherapy for Breast Cancer)', 'armGroupLabels': ['Group 2: CN-LNM Group']}
- {'type': 'DRUG', 'name': 'Carbon Nanoparticle Suspension Injection', 'description': 'Carbon Nanoparticle Suspension Injection to be Placed around Primary Tumor (Before Neoadjuvant Chemotherapy for Breast Cancer)', 'armGroupLabels': ['Group 3: PCN-MAP Group']}

Primary Outcomes:
- {'measure': 'Lymph node retrieval rate marked', 'description': 'The proportion of successfully retrieved marked lymph nodes will be calculated and compared among the study groups to evaluate the effectiveness of each marking technique.', 'timeFrame': 'Up to 2 months'}
- {'measure': 'Number of sentinel and marked lymph nodes', 'description': 'The mean, median, and range of the number of sentinel and marked lymph nodes harvested during surgery will be recorded and compared to assess the efficacy of the marking techniques in identifying lymph nodes of interest.', 'timeFrame': 'Up to 2 months'}
- {'measure': 'Concordance between marked and sentinel lymph nodes', 'description': 'The consistency between marked lymph nodes and intraoperatively identified sentinel lymph nodes will be evaluated by calculating the percentage of marked nodes that are also sentinel nodes and vice versa.', 'timeFrame': 'Up to 2 months'}
- {'measure': 'Complication rate', 'description': 'All surgery-related complications, including but not limited to hemorrhage, lymphedema, infection, pain, tissue damage, clip displacement, clip loss, absence of CNSI staining, and excessive CNSI staining, will be recorded and analyzed. The overall complication rate and rates for specific types of complications will be reported. The severity of complications will be assessed using the Clavien-Dindo classification to provide a standardized evaluation of complication severity.', 'timeFrame': 'Up to 60 months'}

Please estimate the sample size based on the assumption: 
Calculations were based on achieving a Type I error rate (Î±) of 0.05 and a statistical power (1-Î²) of 80%. An anticipated dropout rate of 10% was also considered.
Sample size calculation
      To ensure sufficient statistical power for detecting the predefined non-inferiority margin in this study, we performed sample size calculations. The non-inferiority margin was set at 10%, which represents the maximum allowable difference in effect size between the carbon marking and the conventional tissue marker clip methods. Calculations were based on achieving a Type I error rate (Î±) of 0.05 and a statistical power (1-Î²) of 80%. Initial calculations indicated a need for 112 participants to meet these criteria. Considering an anticipated dropout rate of 10%, we adjusted the sample size to 126 participants to maintain the necessary statistical power throughout the study. This adjustment results in approximately 42 participants per treatment arm. These calculations were conducted using Python (version 3.8.5) with the SciPy stats module (version 1.5.2).
      
        Neoadjuvant chemotherapy regimens
        NAC regimens for breast cancer will be customized based on the patientâs ECOG performance status, molecular subtype, and relevant biomarkers such as HER2 overexpression. Treatment durations range from 3 to 6 months, following the latest evidence-based guidelines. Anti-HER2 therapies are added for cases with HER2 overexpression to enhance efficacy. During NAC, patient response is closely monitored via ultrasound, mammography, and MRI before and after chemotherapy cycles, adjusting treatments based on individual tolerance and effectiveness. This personalized approach ensures optimal safety and outcomes, incorporating patient and clinical input in decision-making.