Here is the design of a clinical trial:

Official Title: Effects of Intraoperative Goal-directed Fluid Therapy (GDFT) on the Postoperative Brain Edema in Neurosurgical Patients With Malignant Supratentorial Gliomas

Included conditions:
- Fluid Therapy
- Brain Edema
- Brain Tumor

Study Armgroups:
- {'label': 'GDFT group', 'type': 'EXPERIMENTAL', 'description': 'The patients will receive fluid therapy under goal directed.', 'interventionNames': ['Other: GDFT']}
- {'label': 'Routine group', 'type': 'SHAM_COMPARATOR', 'description': 'The patients will receive routine fluid therapy.', 'interventionNames': ['Other: traditional fluid therapy']}

Interventions:
- {'type': 'OTHER', 'name': 'GDFT', 'description': 'Target parameter will be titrated with fluid bolus, and thus individual amount varied depending on the parameter value at that time. Maintenance of oxygenation, hemoglobin, blood glucose, core temperature and hemodynamics, such as mean arterial pressure and heart rate, will be applied according to the same standard for each patient.', 'armGroupLabels': ['GDFT group']}
- {'type': 'OTHER', 'name': 'traditional fluid therapy', 'description': 'Fluid therapy will be done without goal directed. Maintenance of oxygenation, hemoglobin, blood glucose, core temperature and hemodynamics, such as mean arterial pressure and heart rate, will be applied according to the same standard for each patient.', 'armGroupLabels': ['Routine group']}

Primary Outcomes:
- {'measure': 'Quantitative analysis of brain edema', 'description': 'Postoperative brain edema is defined as edema surrounding the surgical resection cavity, which will be evaluated through CT images.Image evaluators will manually delineate region of interest (ROI) and operative cavity on each slice. The area will be calculated automatically by PACS system. The total volume will be acquired by multiplying area and slice thickness. The volume of edema will be calculated by the totoal volume of edema plus cavity minus the volume of cavity.', 'timeFrame': 'Within 24 hours postoperatively'}

Please estimate the sample size based on the assumption: 
A two-tailed significance level of 0.05 and a power of 80% were used. A drop-out rate of 5% was considered. Descriptive statistics will be reported as means with standard deviation and medians with inter-quartile range (IQR) for normally distributed and skewed continuous data, respectively. Statistical tests include Student's t-test, Mann-Whitney U test, X2 analysis, Fisher's exact test, and repeated measurements of variance analysis with Bonferroni correction. Missing data will be imputed using inverse probability weighting and worst-case imputation scenarios. Statistical significance will be declared at a type I error of 0.05.
Sample size calculation and statistical plan
        We used the PASS 2011 software (NCSS LLC, USA) for Windows to calculate the sample size. According to the pilot study we conducted, the sample size of 450 will find the difference in postoperative brain edema volume of 4 cm3 with a standard deviation of 18 and 16 in the two groups. Considering the drop-out rate of 5%, we calculated the sample size of 480. In addition, we also estimated the sample size based on previous studies reporting the incidence of brain edema varying from 6.8 to 50% after malignant brain tumor resection. The sample size of 480 patients (240 for each group) will be sufficient to detect the difference of 13% at a two-tailed significant level of 0.05 and a power of 80% using the Studentâs t-test, with a drop-out rate of 5%. Our medical center completed about 800 high-grade glioma resection surgeries each year, which could ensure enough participants.
        Descriptive statistics will be reported as means with standard deviation and medians with inter-quartile range (IQR) for normally distributed data and skewed continuous data, respectively, and counts (percentage) for categorical data. Normally distributed continuous variables will be compared with Studentâs t-test, while skewed variables will be compared using the Mann-Whitney U test. The categorical variables will be compared with X2 analysis or Fisherâs exact test. The repeated measurement data will be analyzed by repeated measurements of variance analysis with Bonferroni correction. The primary outcome, brain edema volume, will be compared between groups using the Studentâs t-test on intention to treat and per protocol, and the conclusion will be drawn according to the intention-to-treat analysis.
        The intention-to-treat analysis will depend on the allocated population while the per-protocol analysis will depend on the actual fluid therapy the population receives. Furthermore, subgroup analysis is required in this study, and patients will be analyzed according to preoperative ASA physical status, KPS score, and WHO classification given by postoperative pathology. In addition, missing data will be imputed using inverse probability weighting and the worst-case imputation scenarios for sensitivity analysis will be performed for missing values of primary outcomes. SPSS 16.0 for windows will be used for all statistical analyses. The statistical significance will be declared at a type I error of 0.05.