Stereotactic surgery is a minimally invasive form of surgical intervention that makes use of a three-dimensional coordinate system to locate small targets inside the body and to perform on them some action such as ablation, biopsy, lesion, injection, stimulation, implantation, radiosurgery (SRS), etc. In theory, any organ system inside the body can be subjected to stereotactic surgery. However, difficulties in setting up a reliable frame of reference (such as bone landmarks, which bear a constant spatial relation to soft tissues) mean that its applications have been, traditionally and until recently, limited to brain surgery. Besides the brain, biopsy and surgery of the breast are done routinely to locate, sample (biopsy), and remove tissue. Plain X-ray images (radiographic mammography), computed tomography, and magnetic resonance imaging can be used to guide the procedure. Another accepted form of "stereotactic" is "stereotaxic". The word roots are stereo-, a prefix derived from the Greek word στερεός (stereos, "solid"), and -taxis (a suffix of New Latin and ISV, derived from Greek taxis, "arrangement", "order", from tassein, "to arrange"). Uses The surgery is used to treat various brain cancers, benign, and functional disorders of the brain. This is sometimes combined with whole brain radiotherapy, and a 2021 systematic review found this combination led to the greatest improvement of survival for those with single brain metastasis. Amongst the malignant brain disorders are: brain metastasis and glioblastoma. The benign brain disorders are: meningioma, cerebral arteriovenous malformation, vestibular schwannoma, and pituitary adenoma. Functional disorders are: trigeminal neuralgia, Parkinson's disease, and epilepsy. Procedure Stereotactic surgery works on the basis of three main components: A stereotactic planning system, including atlas, multimodality image matching tools, coordinates calculator, etc. A stereotactic device or apparatus A stereotactic localization and placement procedure Modern stereotactic planning systems are computer based. The stereotactic atlas is a series of cross sections of anatomical structure (for example, a human brain), depicted in reference to a two-coordinate frame. Thus, each brain structure can be easily assigned a range of three coordinate numbers, which will be used for positioning the stereotactic device. In most atlases, the three dimensions are: latero-lateral (), dorso-ventral () and rostro-caudal (). The stereotactic apparatus uses a set of three coordinates (, and ) in an orthogonal frame of reference (cartesian coordinates), or, alternatively, a cylindrical coordinates system, also with three coordinates: angle, depth and antero-posterior (or axial) location. The mechanical device has head-holding clamps and bars which