Gamma knife radiosurgery in patients with Cushing's Disease: Is it a curative option?

Background The first line of treatment of Cushing's disease (CD) is surgery. However, surgical resection is not amenable in all cases and the role of radiosurgical management of residual tumors or upfront treatment has been reported. Our study highlights the effectiveness and safety of Gamma Knife Radiosurgery for the treatment of Cushing's disease. Methods This was an ambidirectional descriptive cohort study on 16 consecutive patients with a confirmed Cushing's disease that underwent Gamma Knife Radiosurgery (GKR) before July 2014 and assessed for outcome during the study period between January 2014 and June 2016 (30 Months). We included patients with a minimum of two years follow up. The main outcomes were biochemical remission and tumor volume control. Secondary outcomes were visual field changes and morbidity. Results Sixteen cases with CD were included into the study. The Mean age +/- SD was 34.81 +/- 10.10 years. The male to female sex ratio was 1:3. Six cases (37.5%) were de novo. Normalization of hypersecretion at 2 years was achieved in 13 cases (81.3%).The median hormone normalization time was 23 months. Tumor volume control was achieved in all the cases, whereas tumor shrinkage was achieved in (10 cases) 62.5%. The median shrinkage time was 13 months. Of the 12 eyes with pre-Gamma Knife visual affection, 8 (75%) normalized, 4 (25%) improved, and none deteriorated. No patient developed new hypopituitarism after GK radiosurgery. One case developed diplopia at 24 months follow up from abducens palsy. No mortality occurred in our series. Conclusion Gamma Knife Stereotactic Radiosurgery is an effective and safe treatment option for Cushing's disease. It can be used as a complementary therapeutic procedure to classic surgery or as a first line treatment in selected number of patients.