Pituitary adenomas originate from the endocrine tissue of the adenohypophysis and are the most common sellar lesions (accounting for up to 80% of them) *[1], [2], [3], [4]. Symptoms from pituitary adenomas can either arise from local compression of nearby structures, such as the anterior optic pathway, or can be related to hypersecretion of pituitary hormones. Acromegaly is a chronic condition generated by a growth hormone (GH)-secreting pituitary adenoma which involves excess in circulating levels of GH and insulin-like growth factor 1 (IGF-1) [5]. Treatment of acromegaly is aimed at normalizing biochemical parameters as well as improving well-being controlling signs and symptoms. It can be challenging and therefore often requires a multimodal approach, including surgery, medical therapy, radiosurgery or radiation therapy [6].

Surgery, more specifically transsphenoidal approach, is commonly the primary treatment for acromegaly allowing for histopathological analysis, complete or partial tumor resection and decompression of neurological structures *[6], *[7], [8]. Radical surgical removal and IGF-1 normalization, even in experienced hands, are achieved in about 60-70% of cases [7]. Patients with larger and invasive tumors (macroadenomas) are therefore often not in remission postoperatively. Medical therapies, including somatostatin receptor ligands, cabergoline, and pegvisomant can be recommended to patients with persistent disease after surgery. Medical treatment can also be offered before surgery, but current data deal contradictory information regarding an improvement of surgical outcomes and postoperative complications [9]. Stereotactic radiosurgery (SRS) more and more frequently gains a place in the treatment algorithm of acromegaly and is usually recommended as third-line or second-line therapeutic approach and rarely as a first-line treatment when surgery is contraindicated [9], [10]. Compared to conventional radiotherapy, large doses of radiation are accurately delivered in a three-dimensional setting, targeting the tumor and reducing the risk of hypopituitarism, radiation induced optic neuropathy (RION), and the incidence of secondary tumors [11], [12], [13], [14]. SRS is usually given in a single fraction or, less frequently, in a reduced number of fractions (from 2 to a maximum of 5); in the latter case, it is called hypofractionated SRS [15]. The techniques mainly used include Gamma Knife (GKRS) or a modified linear accelerator (LINAC)-based radiosurgical systems. Several retrospective case series on different SRS techniques for acromegaly, including GKRS, LINAC, Cyber Knife (CK), have been reported over the years [16]. In this paper, we provide a systematic review of the literature and meta-analysis from the last two decades on SRS for acromegaly with the aim of describing efficacy and safety of this technique.