Stereotactic radiosurgery (SRS) delivers a precisely shaped, high dose of radiation to a defined intracranial target in a single or small number of sessions. Despite its name, it is non-incisional: the therapeutic effect comes from converging many radiation beams on the target while surrounding brain receives a much lower dose.
Delivery systems
- Gamma-based systems use many fixed cobalt sources focused on a single point, well suited to small, well-defined targets.
- Linear-accelerator systems shape and deliver beams from multiple arcs, offering flexibility across target sizes.
- Robotic systems use a compact linear accelerator on a robotic arm with image guidance for frameless treatment.
Technique
Treatment relies on rigid or image-guided immobilization, high-resolution planning imaging (MRI fused with CT), and inverse planning that optimizes dose conformity and steep gradients. Quality assurance of targeting accuracy is fundamental, because the therapeutic ratio depends on millimeter precision.
Clinical applications
SRS is used for brain metastases, benign tumors such as vestibular schwannoma and meningioma, arteriovenous malformations, and functional targets in selected disorders. It is often integrated with surgery, whole-brain radiotherapy, or systemic therapy within a multidisciplinary plan, chosen by lesion number, size, location, and patient status.
Outcomes and considerations
Reported local control rates are high for appropriately sized targets, with the advantage of short, non-invasive treatment. Target size is a key limitation, and larger lesions may require staged or fractionated approaches. Follow-up imaging distinguishes treatment response from radiation effect over time.
INVAMED technologies in this space
INVAMED develops neurosurgical and cranial instrumentation supporting the broader neuro-oncology pathway; explore the neuro, spine and cranial category.
Device availability and approved indications vary by country. This content is prepared for healthcare professionals and does not replace clinical judgment or the instructions for use.