Protect the pituitary stalks in craniopharyngioma resection by endoscopic endonasal approach.

Objectives: Craniopharyngiomas are benign tumors originating from Rathke's pouch, typically located near the pituitary stalk. Preservation of the pituitary stalk is critical for maintaining pituitary function. We aimed to assess whether preoperative MRI, including diffusion tensor imaging (DTI), can accurately predict the tumor-stalk relationship to guide surgical planning.

Methods: This study included 82 patients with primary craniopharyngiomas. All patients underwent MRI, including conventional imaging and DTI, to assess the tumor-stalk relationship. Clinical data, including demographics, clinical presentation, extent of tumor resection, pituitary stalk preservation, endocrine outcomes, and postoperative complications were collected.

Results: In this study, the stalk was preserved in 50 patients (61%) and sacrificed in 32 patients (39%). The results showed that pituitary stalk preservation did not significantly increase the risk of tumor recurrence but was associated with a reduced risk of permanent diabetes insipidus (DI) (36% vs. 87.5%, P<0.01) and hypopituitarism (56% vs. 75%, P<0.01) during a mean follow-up period of 58.8 months. Male gender, elevated preoperative prolactin levels, and preoperative DI were factors associated with stalk sacrifice. Stalk preservation was more frequently achieved in peripheral-type tumors compared to central-type tumors. DTI, in combination with conventional MRI, provided greater accuracy in predicting the tumor-stalk relationship than conventional MRI alone. Successful preservation was linked to ≥ 22 stalk fibers (AUC = 0.783, P < 0.01) and ≥ 8.5 mm fiber length (AUC = 0.708, P < 0.01) on DTI.

Conclusions: Preoperative MRI, particularly DTI, effectively predicts tumor-stalk topography for surgical planning. Peripheral-type tumors or those with higher stalk fiber counts/lengths are more amenable to preservation, reducing permanent DI risk. These findings support tailored approaches to optimize endocrine outcomes while maintaining oncological safety.