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.