Abstract
Introduction:
Despite the adoption of a fully endoscopic transsphenoidal surgery technique by many pituitary centers, no prospective studies compare the extent of tumor resection (EOR) of this technique to microscopic transsphenoidal surgery. We propose a prospective, multicenter study that compares EOR in patients with nonfunctioning pituitary macroadenomas undergoing microscopic tumor removal to patients undergoing fully endoscopic tumor removal.
Methods:
A Protocol Development Committee consisting of pituitary neurosurgeons and a biostatistician was established to design the clinical trial. The committee developed the study hypothesis and established the patient population, end points, and data elements to be collected. A biostatistician reviewed the protocol and performed sample size calculations using dichotomous extent of resection estimates derived from quantitative meta-analyses.
Results:
We propose that EOR in nonfunctioning macroadenomas achieved using a fully endoscopic technique is superior to that achieved using a microscopic technique. The study design is a prospective, multicenter, cohort study. The study will consist of two groups: patients with nonfunctioning pituitary macroadenomas undergoing either (1) fully endoscopic transsphenoidal surgery or (2) microscopic transsphenoidal surgery. The study is powered to detect a 6% absolute difference in gross total resection (GTR) rate (medium effect size estimate). A total of 350 patients will be enrolled in each group. The primary end point will be percentage of patients with GTR based on a centrally scored 3-month postoperative MRI. Secondary end points include volumetric EOR at 3 months, endocrine outcomes, and visual outcomes. A secondary analysis will examine differences in EOR for tumors stratified by size. An interim analysis will be performed after 100 patients have been enrolled in each group to determine if reaching the primary end point is feasible. Statistical analysis will be performed by a biostatistician.
Conclusion:
We have developed a protocol for a multicenter study comparing EOR in nonfunctioning pituitary macroadenomas between two commonly performed transsphenoidal surgical techniques. We anticipate that the trial protocol will continue to be modified as more surgeons review the protocol. The study is expected to open enrollment in 2015.