# Stereotactic radiosurgery and SBRT: planning and delivery safeguards

Source: https://onco.cc/protocols/stereotactic-radiosurgery-and-sbrt-delivery-safeguards/  
OnCo record `stereotactic-radiosurgery-and-sbrt-delivery-safeguards` (Protocol). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Stereotactic treatment gives a very high dose in one to a few sessions to a small target, so a small error matters more than in ordinary radiotherapy. The team uses a firm head frame or a close-fitting mask or body cushion, checks the plan with an independent calculation, takes images to confirm the target's position before every treatment, and has a physicist present for the first session.

## Summary

AAPM-RSS MPPG 9.b (2025) sets minimum practice for linac SRS and SBRT in the United States. The service needs standard operating procedures for every step, a safety checklist, participation in an incident learning system, at least two radiation therapists at every session (one trained in the technique), 4D CT for thoracic and abdominal SBRT, and MRI and PET fusion. At simulation the therapists prepare immobilisation and document set-up after the radiation oncologist approves position, images and target localisation. In planning, prior radiotherapy plans are obtained for re-irradiation and cumulative dose reported; brain metastases are named with the MRI date so new and old targets cannot be confused; a calculation grid of 2 mm or finer is used (1 mm for targets of 1 cc or less); the radiation oncologist signs the plan; an independent dose calculation and a physicist's plan and chart review are done before treatment. At delivery a pre-treatment QA check including a dry-run collision check is done, target localisation is verified by imaging before every treatment, imaging-to-treatment isocentre coincidence must be within 1 mm for SRS and 1.5 mm for SBRT (tested daily on treatment days), and a qualified medical physicist personally supervises the first session and directly supervises the rest (new in 9.b). For frameless intracranial SRS, open-face masks let surface guidance use the face. In one randomised trial of SRS for brain metastases, a 1 mm margin around the visible tumour gave similar local control to 3 mm with less radionecrosis (5 of 6 biopsy-proven cases in the 3 mm arm, P=.10), and the authors judged 1 mm more appropriate.

## Fields

- Kind: Protocol
- Last checked: 2026-11-11
- Also known as: SRS safety; SBRT safety; SABR safeguards; stereotactic ablative radiotherapy; radiosurgery checklist; MPPG 9.b; TG-101; frameless radiosurgery; Gamma Knife frame; CyberKnife

## Connected records

- protocols: [Breathing motion in lung and upper abdominal radiotherapy: 4D CT, gating, breath-hold and compression](https://onco.cc/protocols/respiratory-motion-management-4d-ct-and-gating/), [Immobilisation mask for head and neck and brain radiotherapy, including mask anxiety](https://onco.cc/protocols/head-and-neck-radiotherapy-immobilisation-mask/), [Patient identification and pre-treatment time-out in radiotherapy](https://onco.cc/protocols/radiotherapy-patient-identification-and-time-out/)
- cancers: [Non-small-cell lung cancer](https://onco.cc/cancers/nsclc/)
- technologies: [CyberKnife robotic radiosurgery](https://onco.cc/technologies/cyberknife/), [Gamma Knife](https://onco.cc/technologies/gamma-knife/), [In-room imaging for radiotherapy (cone-beam CT, ExacTrac, CT-on-rails, HyperSight)](https://onco.cc/technologies/in-room-imaging-systems/), [Radiotherapy treatment planning and QA software](https://onco.cc/technologies/treatment-planning-systems/), [Respiratory motion management (4D-CT, gating, breath-hold, tracking)](https://onco.cc/technologies/respiratory-motion-management/), [SBRT / SABR (stereotactic radiotherapy)](https://onco.cc/technologies/sbrt/), [Stereotactic ablative radiotherapy for oligometastatic disease](https://onco.cc/technologies/sabr-oligometastases/), [Stereotactic radiosurgery (Gamma Knife, CyberKnife, linac SRS)](https://onco.cc/technologies/radiosurgery-srs/), [Surface-guided radiotherapy (SGRT)](https://onco.cc/technologies/surface-guided-radiotherapy/)
- terms: [Brain metastases (intracranial disease)](https://onco.cc/terms/brain-metastases/), [GTV, CTV and PTV (target volumes)](https://onco.cc/terms/planning-target-volume/), [Stereotactic body radiotherapy (SBRT / SABR)](https://onco.cc/terms/sbrt-term/), [Stereotactic radiosurgery (SRS)](https://onco.cc/terms/stereotactic-radiosurgery/)
- key papers: [Defining the optimal planning target volume in image-guided stereotactic radiosurgery of brain metastases: results of a randomized trial](https://onco.cc/key-papers/paper-kirkpatrick-srs-margin-trial-ijrobp-2015/)

---
JSON: https://onco.cc/api/v1/entities/stereotactic-radiosurgery-and-sbrt-delivery-safeguards.json