Magnetic resonance imaging as predictor of functional outcome in craniopharyngiomas

Quality of life of craniopharyngioma patients can be severely impaired by derangement of hypothalamic function. A classification, taking into account preoperative hypothalamic damage, evaluated by magnetic resonance imaging (MRI), and correlating it with postoperative weight change is still missing in the literature. The aim of our study is to identify objective radiological criteria as preoperative prognostic factors for hypothalamic damage. Pre- and post-operative MRI and clinical data of 47 patients, treated at our Institution for craniopharyngioma, were retrospectively analyzed, based on radiological variables, identified as prognostic factor for hypothalamic involvement. Main factors associated with postoperative obesity were hypothalamic hyperintensity in T2-weighted/FLAIR imaging (p < 0.033), mammillary body involvement according to Müller classification (p < 0.020), unidentifiable pituitary stalk (p < 0.001), dislocated chiasm (p < 0.038), either not visible infundibular recess (p < 0.019) or unrecognizable supra-optic recess (p < 0.004), and retrochiasmatic tumor extension (p < 0.019). Accordingly, postoperative hypothalamic syndrome was associated with peritumoral edema in T2-weighted/FLAIR images (p < 0.003), unidentifiable hypothalamus (p < 0.024), hypothalamic compression (p < 0.006), fornix displacement (p < 0.032), and unrecognizable supra-optic recess (p < 0.031). Ultimately, variables identified as predictive factors of postoperative hypothalamic syndrome were the degree of hypothalamic involvement according to the classification described by Sainte-Rose and Puget (p < 0.002; grade 0 vs 2 p < 0.001), Van Gompel (p < 0.002; grade 0 vs 1, p < 0.027; and grade 0 vs 2, p < 0.002), and Muller (p < 0.006; grade 0 vs 1, p < 0.05; and grade 0 vs 2, p < 0.004). The identification of these predictive factors will help to define and score the preoperative hypothalamic involvement in craniopharyngioma patients.