Extent of resection and craniopharyngioma recurrence: a volumetric analysis

The optimal extent of resection (EOR) required to minimize recurrence risk in craniopharyngioma remains unclear. The objective of this study was to quantitatively evaluate postoperative tumor volume and EOR as determinants of progression-free survival (PFS) in surgically treated adamantinomatous craniopharyngiomas.

We retrospectively measured pre- and post-surgical tumor volumes in 60 patients using manual MRI-based segmentation. None received planned adjuvant radiotherapy. The median follow-up duration was 5 years. Clinical and volumetric variables were analyzed using Cox proportional hazards regression. Time-dependent receiver operating characteristic analysis at 3 years was also performed.

Tumor progression/recurrence occurred in 60% of patients. On univariable analysis, EOR was associated with improved PFS (HR 0.981 per 1% increase; 95% CI 0.966-0.997; p = 0.018), whereas increasing TV^solid (HR 1.178 per 1 cc increase; 95% CI 1.041-1.334; p = 0.010), residual cystic disease (HR 3.600; 95% CI 1.788-7.249; p < 0.001), and preoperative tumor volume (HR 1.006 per 1 cc increase; 95% CI 1.000-1.013; p = 0.044) were associated with increased progression risk. Given collinearity between EOR and TV^solid, separate multivariable models were constructed. EOR and TV^solid remained significantly associated with progression in their respective models, and residual cystic disease was associated with progression in both models. Optimism-corrected AUCs were 0.777 (95% CI, 0.649-0.927) for EOR and 0.813 (95% CI, 0.691-0.953) for TV^solid.

EOR, TV^solid and the presence of residual cystic disease are independently associated with progression after craniopharyngioma resection. Risk stratification using tumor volumetry may help individualize postoperative decision-making in terms of surveillance versus adjuvant radiotherapy.