Dosimetric Parameters Associated with the Long-Term Oncologic Outcomes of Gamma Knife Surgery for Sellar and Parasellar Tumors in Pediatric Patients [post]

Eun Jung Lee, Ji Yeoun Lee, Jin-Wook Kim, Ji-Hoon Phi, Yong Hwy Kim, Seung-Ki Kim, Hyun-Tai Chung, Kyu-Chang Wang, Dong Gyu Kim
2021 unpublished
Purpose We aimed to investigate the dosimetric parameter and the minimally required dose associated with long-term control of sellar and parasellar tumors after gamma knife surgery (GKS) in children. Methods A retrospective analysis was performed on pediatric patients under the age of 19 who were diagnosed with sellar and parasellar tumors and received GKS in our institution from 1998 to 2019. Cox proportional hazards regression analyses were used to investigate the dosimetric parameters
more » ... ted with treatment outcome. The Kaplan-Meier method was used to analyze tumor control rates after GKS. Results Thirty-seven patients with 40 sellar and parasellar tumors, including 22 craniopharyngiomas and 12 pituitary adenomas, were followed up for a mean of 85.8 months. The gross target volume was 0.05 − 15.28 cm3, and the mean marginal dose was 15.8 Gy (range, 9.6–30.0 Gy). Ten patients experienced treatment failure at 28.0 ± 26.7 months. The actuarial 5- and 10-year tumor control rates were 79.0% and 69.8%, respectively. D98% was an independent predictive factor of tumor control (p = 0.007, hazard ratio 0.846, 95% confidence interval 0.749–0.956), with cutoff values of 11.5 Gy in the entire cohort and 10 Gy in the craniopharyngioma group. Visual deterioration occurred in two patients with the maximum point dose of 10.1 Gy and 10.6 Gy to the optic apparatus. Conclusion D98% is a reliable index of the minimum required dose for long-term control of sellar and parasellar tumors after GKS. The optimal D98% value for each diagnosis needs to be elucidated in the future.
doi:10.21203/rs.3.rs-495870/v1 fatcat:rgvsvri4zfcelp75asjkz4emuy