Safety and Efficacy of Primary Hypofractionated Gamma Knife Radiosurgery for Giant Hypothalamic Hamartoma.

Objective: To describe the feasibility, safety, efficacy, and complication profile of primary hypofractionated gamma knife radiosurgery (GKRS), and practical nuances of performing the same in pediatric patients.
Methods: Three pediatric patients (age range 17-65 mo) underwent primary hypofractionated GKRS in 2-3 consecutive days with interfraction interval of 24 h. All patients had precocious puberty and were on GnRH analogue. Frame based GKRS done with 8.1-9.2 Gy radiation per fraction at 50% isodose in 2-3 fractions targeting the entire hamartoma volume. The mean target volume was 5.67 cc (4.45-7.39 cc). The authors followed these patients for clinical and endocrinological assessment at every 6 mo interval while the repeat MRI done at 6 mo and then annually. The seizure outcome analysis was done using Engel scale.
Results: At a mean follow up of 27 mo (24-30 mo), 2 patients became Engel class 3 while one achieved Engel class 1 control. 2 patients showed halted pubertal growth with no additional hormonal aberration. 2 patients showed significant volumetric reduction (48% and 32%) and patchy necrosis inside the hypothalamic hamartoma (HH). There was no deficit in visual function, memory and cognition. One patient showed reduction in aggressiveness.
Conclusion: Giant HH are exceptionally difficult neurological diseases. Primary hypofractionated GKRS may be an alternative approach as mono/multitherapy with promising results and minimal complication.
(© 2021. Dr. K C Chaudhuri Foundation.)