BACKGROUND: The influence of the surgeon's preoperative goal regarding the extent of tumor resection on patient outcomes has not been carefully studied among patients with nonfunctioning pituitary adenomas.

OBJECTIVE: To analyze the relationship between surgical tumor removal goal and patient outcomes in a prospective multicenter study.

METHODS: Centrally adjudicated extent of tumor resection (gross total resection [GTR] and subtotal resection [STR]) data were analyzed using standard univariate and multivariable analyses.

RESULTS: GTR was accomplished in 148 of 171 (86.5%) patients with planned GTR and 32 of 50 (64.0%) patients with planned STR (P = .001). Sensitivity, specificity, positive predictive value, and negative predictive value of GTR goal were 82.2, 43.9, 86.5, and 36.0%, respectively. Knosp grade 0-2, first surgery, and being an experienced surgeon were associated with surgeons choosing GTR as the goal (P < .01). There was no association between surgical goal and presence of pituitary deficiency at 6 mo (P = .31). Tumor Knosp grade (P = .004) and size (P = .001) were stronger predictors of GTR than was surgical goal (P = .014). The most common site of residual tumor was the cavernous sinus (29 of 41 patients; 70.1%).

CONCLUSION: This is the first pituitary surgery study to examine surgical goal regarding extent of tumor resection and associated patient outcomes. Surgical goal is a poor predictor of actual tumor resection. A more aggressive surgical goal does not correlate with pituitary gland dysfunction. A better understanding of the ability of surgeons to meet their expectations and of the factors associated with surgical result should improve prognostication and preoperative counseling.