Here is the design of a clinical trial:

Official Title: Comparing of Modified Wet Suction Technique and Dry Suction Technique for Endoscopic Ultrasound -Guided Fine Needle Aspiration (EUS-FNA) of Solid Occupying Lesions: a Prospective Multi-center,Randomized,and Controlled Trial

Included conditions:
- Pancreas Neoplasms
- Lymphatic Metastasis
- Neoplasm Metastases
- Unknown Primary Neoplasm Metastasis
- Infection
- Inflammation
- Sarcoid
- Lymphadenopathy

Study Armgroups:
- {'label': 'Arm A', 'type': 'OTHER', 'description': 'the first pass is made with 5ml suction technique', 'interventionNames': ['Procedure: the first pass is made with 5ml suction technique']}
- {'label': 'Arm B', 'type': 'OTHER', 'description': 'the first pass is made with modified wet suction technique', 'interventionNames': ['Procedure: the first pass is made with modified wet suction technique']}

Interventions:
- {'type': 'PROCEDURE', 'name': 'the first pass is made with 5ml suction technique', 'description': 'the first pass is made with 5ml suction technique, then modified wet suction technique / 5ml suction technique/ modified wet suction technique is operated successively.', 'armGroupLabels': ['Arm A']}
- {'type': 'PROCEDURE', 'name': 'the first pass is made with modified wet suction technique', 'description': 'the first pass is made with modified wet suction technique, then 5ml suction technique/ modified wet suction technique/ 5ml suction technique is operated successively.', 'armGroupLabels': ['Arm B']}

Primary Outcomes:
- {'measure': 'the overall diagnostic accuracy of modified wet suction technique and 5ml dry suction technique to the solid occupying lesions', 'description': "The investigators' primary outcome measure is to compare the overall diagnostic accuracy of modified wet suction technique and dry suction technique to the solid occupying lesions.", 'timeFrame': '18 months'}

Please estimate the sample size based on the assumption: 
Power of 80%, two-sided significance level of 5%, 20% dropout or withdrawal rate, statistically significant for P < 0.05, using a two-tailed distribution.
Sample size and statistical analysis
        Based on a literature review of suction techniques for heterogeneous indications [12, 14], we expected a difference between DRST and wet suction technique on diagnostic yields of 75% vs. 85% after four needle passes. The calculation yielded target sample sizes of 248 for 5 ml DRST and 248 for MWST, with a power of 80% and a two-sided significance level of 5%. Each group should have 124 patients following the 2âÃâ2 cross-over design. Assuming a 20% dropout or withdrawal rate, we calculated a final sample size of 296 patients (148 per group).
        The safety set comprises all the randomized subjects who will receive at least one trial treatment. The full analysis set should be as close as possible to the intention-to-treat set. The standards and population of the per-protocol set will be finalized after data blinding verification. The direct deletion method will be used to treat missing data.
        A two-tailed distribution will be used and statistically significance will be considered for Pâ<â0.05. All category variables will be described in terms of the count and percentage using the Ï2 test, whereas continuous variables will be described as meanâÂ±âstandard deviation using t tests or Wilcoxon rank-sum tests. Sensitivity, specificity, positive predictive value, negative predictive value, receiver operating characteristic curve, and diagnostic accuracy will be computed using a 2âÃâ2 table and Ï2 test for DRST and MWST. The blood contamination and cellularity in specimens will be divided into three levels (Grade A, Grade B, and Grade C), and McNemarâs test for correlated proportions will be used. All analyses will be performed using SAS version 9.2.