ABSTRACT
<p><b>OBJECTIVE</b>To investigate complication features following gamma knife radiosurgery (GKR), and to assess factors causing complications.</p><p><b>METHODS</b>A retrospective analysis was conducted for 253 patients with intracranial arteriovenous malformation (AVMs), meningiomas, glial neoplasms, germinomas and metastatic cancer, respectively, which were treated with GKR.The incidences of acute, subacute and late complications following GKR were evaluated. Meanwhile, risk factors inducing subacute complications, such as the cell proliferative population of target tissues and location of target in AVM and meningioma, were evaluated, respectively.</p><p><b>RESULTS</b>The subacute complications are the prominent reactions in all the five diseases. There is a significant difference in the incidence rate of subacute complications between early responding tissues and slow responding tissues, central and peripheral AVM, basal and non-basal meningioma.</p><p><b>CONCLUSIONS</b>Subacute complications are the prominent reactions after GKR, and the reactions are almost always reversible. The risk of subacute complications following GKR treatment is correlated to the proliferative cell population in the target tissues and the target location (AVM, meningioma).</p>