Radiosurgical

Radiosurgical refers to noninvasive medical procedures that use precisely focused radiation to treat abnormalities or functional disorders with a level of precision comparable to surgical excision. The term is often used interchangeably with stereotactic radiosurgery (SRS), and can describe both the treatment modality and the equipment or planning approaches used to deliver high-dose radiation to a targeted volume while sparing surrounding tissue.

Radio surgical methods originated with the development of stereotactic techniques in the mid-20th century and were popularized by the Gamma Knife in the 1960s. Modern radiosurgery employs several platforms, including gamma-based systems (Gamma Knife), linear accelerator–based systems (linac SRS), and robotic delivery systems (CyberKnife). Some centers also offer proton or heavy-particle radiosurgery, though these are less common. Treatments are used for intracranial targets and, in several forms, for extracranial sites as part of stereotactic body radiotherapy (SBRT).

Indications include benign tumors such as meningiomas and vestibular schwannomas, malignant brain tumors, and metastatic lesions, as well as vascular abnormalities such as arteriovenous malformations and functional disorders like trigeminal neuralgia. Extracranial applications include spine, liver, lung, and pancreatic lesions, depending on lesion size and proximity to critical structures.

Procedure and planning involve immobilization of the patient, high-resolution imaging, and sophisticated treatment planning to delineate the target and nearby organs at risk. Radiation is delivered in one or a few sessions (fractions), with dose regimens chosen to maximize tumor control while minimizing adverse effects.

Outcomes are variable by condition but often include strong local control and symptom relief for suitable lesions. Risks include radiation-induced edema or necrosis, fatigue, and rarely neurological deficits. Careful patient selection and multidisciplinary review are essential to maximize benefit and minimize risk.