{"entity":{"id":"stereotactic-radiosurgery","kind":"term","name":"Stereotactic radiosurgery (SRS)","aka":["SRS","radiosurgery","Gamma Knife","gamma knife","fractionated stereotactic radiotherapy"],"tldr":"A single high dose of radiation delivered to a brain tumour or metastasis by beams converging from all sides, so the target gets a destructive dose while the surrounding brain gets little; no scalpel is involved despite the name. It treats metastases up to about 3-4 cm and has replaced whole-brain radiotherapy for limited disease because it spares cognition.","summary":"Gamma Knife, CyberKnife and linac-based SRS treat brain metastases up to about 3-4 cm (or several at once) with local control above 80% and have replaced whole-brain radiotherapy for limited disease because they spare cognition (N0574, JLGK0901). Larger cavities after surgery get fractionated stereotactic radiotherapy in 3-5 sessions. Modern practice combines SRS with CNS-active drugs (osimertinib, tucatinib, T-DXd), and trials now test whether upfront SRS can be deferred when such drugs are available.","asOf":"2026-09-09","wikipedia":"https://en.wikipedia.org/wiki/Radiosurgery","links":[{"label":"Wikipedia","url":"https://en.wikipedia.org/wiki/Radiosurgery"}],"tags":[],"related":["brain-metastases","wbrt","sbrt-term"],"cancers":[],"sections":["radiation"],"technologies":["sbrt"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"category":"Procedures"},"route":"/terms/stereotactic-radiosurgery/","neighbours":{"term":[{"id":"brain-metastases","kind":"term","name":"Brain metastases (intracranial disease)","route":"/terms/brain-metastases/"},{"id":"graded-prognostic-assessment","kind":"term","name":"Graded Prognostic Assessment (GPA) for brain metastases","route":"/terms/graded-prognostic-assessment/"},{"id":"tnbc-symptom-control-palliation","kind":"term","name":"Palliation in advanced triple-negative breast cancer: brain, bone, pleura, skin and end of life","route":"/terms/tnbc-symptom-control-palliation/"},{"id":"sbrt-term","kind":"term","name":"Stereotactic body radiotherapy (SBRT / SABR)","route":"/terms/sbrt-term/"},{"id":"wbrt","kind":"term","name":"Whole-brain radiotherapy (WBRT)","route":"/terms/wbrt/"}],"section":[{"id":"radiation","kind":"section","name":"Radiation Therapy","route":"/fronts/radiation/"}],"technology":[{"id":"cyberknife","kind":"technology","name":"CyberKnife robotic radiosurgery","route":"/technologies/cyberknife/"},{"id":"gamma-knife","kind":"technology","name":"Gamma Knife","route":"/technologies/gamma-knife/"},{"id":"sbrt","kind":"technology","name":"SBRT / SABR (stereotactic radiotherapy)","route":"/technologies/sbrt/"},{"id":"radiosurgery-srs","kind":"technology","name":"Stereotactic radiosurgery (Gamma Knife, CyberKnife, linac SRS)","route":"/technologies/radiosurgery-srs/"},{"id":"zap-x","kind":"technology","name":"ZAP-X gyroscopic radiosurgery","route":"/technologies/zap-x/"}],"cancer":[{"id":"secondary-brain-tumours","kind":"cancer","name":"Brain metastases (secondary brain tumours)","route":"/cancers/secondary-brain-tumours/"},{"id":"her2-positive-breast-brain-metastases","kind":"cancer","name":"HER2-positive breast cancer with brain metastases","route":"/cancers/her2-positive-breast-brain-metastases/"},{"id":"lung-cancer","kind":"cancer","name":"Lung cancer (all types)","route":"/cancers/lung-cancer/"},{"id":"meningioma","kind":"cancer","name":"Meningioma","route":"/cancers/meningioma/"},{"id":"metastatic-cancer","kind":"cancer","name":"Metastatic cancer (cancer that has spread)","route":"/cancers/metastatic-cancer/"},{"id":"tnbc","kind":"cancer","name":"Triple-negative breast cancer (TNBC)","route":"/cancers/tnbc/"},{"id":"vestibular-schwannoma","kind":"cancer","name":"Vestibular schwannoma (acoustic neuroma)","route":"/cancers/vestibular-schwannoma/"}],"paper":[{"id":"paper-auperin-prophylactic-cranial-irradiation-sclc-nejm-1999","kind":"paper","name":"Prophylactic cranial irradiation for patients with small-cell lung cancer in complete remission","route":"/key-papers/paper-auperin-prophylactic-cranial-irradiation-sclc-nejm-1999/"}],"idea":[{"id":"idea-lung-brain-metastasis-prevention-as-a-primary-endpoint","kind":"idea","name":"Measure brain metastasis prevention as a primary endpoint, not as a secondary one","route":"/ideas/idea-lung-brain-metastasis-prevention-as-a-primary-endpoint/"}],"trial":[{"id":"alliance-n0574","kind":"trial","name":"Alliance N0574 (NCCTG N0574)","route":"/trials/alliance-n0574/"}]}}