Cyberknife radio-neurosurgery for secreting pituitary adenomas treated with single fraction radio-neurosurgery: A systematic review and<i> meta</i>-analysis

Introduction: Stereotactic radiosurgery (SRS) is one of the treatment options for the management of residual or recurrent secreting pituitary adenomas (PA). While the role of radiosurgery (RS) by Gamma Knife (GK) has been clearly established, Cyberknife (CK) RS has been evaluated in fewer series. Material and methods: To perform a systematic review of the literature and meta-analysis, with the aim of focusing on the effect of CK RS on secreting PA. Using PRISMA guidelines, we reviewed articles published between January 1994 and January 2024. The inclusion criteria contained: single fraction RS, biochemical remission, tumor control and complication appearance (hypopituitarism). Results: Were incorporated 8 studies including 152 secreting PA. Vast majority were treated in single fraction 115 (75.6 %), with an overall rate of 59.9 % (p < 0.001). Total remission was encountered in 44/108 patients, for an overall rate of 50.2 % (p < 0.001). Partial remission was inconsistently reported among studies for 25/55 patients, for an overall rate of 38.8 % (p = 0.003). Uncontrolled disease was encountered in 36/108 patients, for an overall rate of 32.7 % (p < 0.001). Tumor control was not separately reported for secreting or non-secreting PA, but attained overall high rates. Conclusion: Single fraction CK radiosurgery is common practice for secreting PA. Our meta-analysis suggests high rates of both total and partial remission (as high as 89 % if both taken together), with a complete remission rate of 50.2 %. These results encourage the use of single fraction CK RS for secreting PA. To reach high rates of biochemical control, high doses of irradiation should be used.