Efficacy, Safety, and Dosing Protocols of Intracystic Bleomycin for Cystic Craniopharyngioma: A Scoping Review of Case Reports and Case Series

Abstract Background: Craniopharyngiomas are rare, benign, yet locally aggressive tumors of the sellar region. Their cystic nature and proximity to critical neuroendocrine structures complicate complete surgical excision and increase recurrence risk. Consequently, intracystic bleomycin (ICB) serves as an alternative therapy when safe surgical excision is unachievable. Materials and Methods: A scoping review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines. Electronic databases including PubMed, Scopus, Cochrane, and ScienceDirect were searched. Case reports, series, and retrospective cohorts describing ICB dosing, safety, and efficacy were included. Data extraction covered patient demographics, tumor morphology, dosing regimens, leakage verification, and clinical outcomes. Results: Eighteen studies were included, spanning diverse geographic regions. Populations ranged from infants to elderly adults, with a predominance of pediatric cases. Administration protocols varied widely, with cumulative doses between 15 and 150 mg. Outcomes demonstrated significant cyst regression, with reductions exceeding 90% in some cases and sustained clinical improvement in up to 73% of patients. Adverse events included catheter-related complications, leakage, and neurotoxicity, occasionally resulting in hypothalamic injury or fatal cerebral edema. Gadolinium-enhanced magnetic resonance imaging proved superior for leakage detection and monitoring. Conclusion: ICB offers meaningful tumor control and reduced morbidity compared with aggressive surgery, particularly in pediatric populations. However, heterogeneity in dosing strategies and adverse event profiles underscores the need for standardized protocols. Future directions emphasize national registries, improved diagnostic monitoring, and prospective evaluation of long-term outcomes. Overall, ICB represents a valuable adjunct in multimodal management of cystic craniopharyngiomas, balancing efficacy with safety.