Stereotactic Radiosurgery
A surgeon-and-radiation-oncologist's reference on stereotactic radiosurgery and stereotactic body radiotherapy: the radiobiology and physics that make a single high dose safe, the platforms that deliver it, and the cranial and spinal indications where it competes with, or replaces, open surgery. Written for residents, fellows, and practitioners across both specialties; presented platform-neutral, with practice preferences flagged as such.
Companion Library
Radiation Oncology Board Review
Disease-site management, dose anchors, radiobiology and therapy physics, plus radiopharmaceuticals, adaptive radiotherapy, and targeted agents. Structured for focused review and practical use at the console.
Start Here
History, Philosophy & Terminology
From Leksell's idea to modern practice; SRS vs SRT vs SBRT/SABR vs hSRT nomenclature.
Quick Reference
Imaging sequences, typical marginal doses/fractionation, and key OAR constraints by indication, with links to each full page.
Dose Tables
RTOG 90-05, N107C, A071801, TG-101, HyTEC, and spine trial schedules, with a BED/EQD2 calculator.
Dose Calculator
BED and EQD2 at any α/β, re-irradiation sums against published CNS limits, and a pre-plan estimate of dose falloff and V12 by target size and platform.
Technical Foundations
Platforms & Delivery
Gamma Knife, LINAC (cranial and spine), robotic, and proton systems: a brand-neutral comparison.
Gamma Knife Workflow
Frame versus mask, stereotactic imaging, shot construction, plan review, verification, delivery, and failure modes.
Radiobiology of High Dose per Fraction
Why the linear-quadratic model strains at ablative doses; vascular and immunologic effects; BED.
Small-Field Physics & Dosimetry
Small-field dosimetry pitfalls, detectors, output factors, and the steep gradient.
Imaging, Registration & Immobilization
Current stereotactic imaging, indication-specific MRI sequences, fusion, and frame, mask, and body immobilization.
Dose Selection & Fractionation
Disease-specific starting ranges, prescription versus maximum dose, dose modifiers, and when to fractionate or change modality.
Planning, Constraints & QA
Target/OAR delineation, conformity and gradient indices, normal-tissue constraints, and end-to-end QA.
Cranial Radiosurgery
Brain Metastases
Intact, postoperative cavity, multiple lesions, and repeat SRS; SRS vs WBRT and the neurocognition data.
Vestibular Schwannoma
Koos grading, marginal dose, and hearing/facial/trigeminal outcomes; SRS vs observation vs microsurgery.
Meningioma
WHO grade, skull base and parasagittal disease, dose selection, and the cavernous sinus.
Pituitary Adenoma & Sellar Lesions
Functioning vs nonfunctioning tumors, hormonal remission, hypopituitarism, and optic constraints.
Arteriovenous Malformations
Obliteration vs the latency-period hemorrhage risk, grading scores, volume-staging, and the ARUBA debate.
Trigeminal Neuralgia & Functional Radiosurgery
SRS for trigeminal neuralgia, radiosurgical thalamotomy for tremor, and emerging functional targets.
Less-Common Cranial Targets
Glomus/paraganglioma, chordoma and chondrosarcoma, hemangioblastoma, and pediatric/rare indications.
Spine Radiosurgery
Spine SBRT: Foundations & Patient Selection
NOMS, SINS, and ESCC frameworks; simulation, immobilization, image guidance, and target delineation.
Spine SBRT: Clinical Practice
Intact metastases, postoperative/separation surgery, reirradiation; cord constraints and toxicity (VCF, pain flare).
Primary, Benign & Vascular Spine Targets
Chordoma and sarcoma, benign nerve-sheath and meningeal tumors, and spinal vascular malformations.
Evidence, Tools & Reference
Surveillance & Response Assessment
Disease-specific follow-up, RANO-BM and SPINO, pseudoprogression, treatment effect, and triggers for salvage.
Evidence & Controversies
Landmark randomized trials and the open debates: met-count ceiling, pre- vs postop cavity SRS, LQ validity, radionecrosis, and SRS with immunotherapy.
Practical Tools
Conformity and gradient indices, BED/EQD2, prognostic scores (GPA; NOMS/SINS/ESCC), and TG-101/QUANTEC/HyTEC constraint references.
Complications & Special Topics
Adverse Radiation Effects
Radionecrosis (necrosis vs progression on imaging), ARE after AVM, optic neuropathy, hypopituitarism, myelopathy, VCF, pain flare, and the steroid/bevacizumab/LITT/surgery ladder.
Cranial Vascular Beyond AVM
Cavernous malformations (hemorrhage-rate rationale), dural and carotid-cavernous fistulas (cortical venous reflux), and the hemangioblastoma vascular note.
Sellar & Parasellar Beyond Pituitary
Craniopharyngioma and cyst dynamics, the perioptic fractionation decision, and optic-pathway dose constraints.
Glioma & Radiation-Related Tumors
Recurrent high-grade glioma re-irradiation (RTOG 1205), the negative SRS boost (RTOG 9305), low-grade edge cases, and radiation-induced tumors (Cahan criteria).