SGRT — Surface-Guided Radiation Therapy with AlignRT
Surface-Guided Radiation Therapy (SGRT) represents a paradigm shift in patient positioning and monitoring during radiation therapy. Unlike conventional methods — which rely on skin tattoos, lasers and frequent radiographic imaging — SGRT uses high-resolution 3D cameras to continuously map the patient’s body surface, comparing it in real time against the ideal position defined in the treatment plan.
This technology detects positional deviations at the sub-millimetre level, without physical contact and without additional ionising radiation. When the patient moves outside the defined tolerance, the system automatically signals the linear accelerator (LINAC) to pause the radiation beam, resuming treatment only when the correct position is re-established.
For medical physicists and radiation therapists, SGRT delivers greater setup accuracy, continuous intrafraction monitoring and reduced imaging dose. For hospital managers, it means improved operational efficiency — with average reductions of 22% in treatment time per fraction — and a significantly better patient experience, eliminating permanent markings and invasive immobilisation devices.
AlignRT — The World-Leading SGRT System
AlignRT, developed by VisionRT (the pioneer and inventor of SGRT), is the most widely used surface-guided radiation therapy system in the world, with over 3,000 systems in active clinical use at leading cancer centres. VisionRT systems are installed in 24 of the top 25 US cancer hospitals (US News & World Report).
Technical Capabilities
- 3D stereoscopic cameras — three ceiling-mounted camera pods simultaneously monitor thousands of points on the skin surface
- Real-time 6DoF monitoring — continuous tracking in six degrees of freedom (translations and rotations) with accuracy ≤0.5 mm / ≤0.2°
- Automatic beam gating — automatic radiation beam pause if the patient moves out of tolerance, without manual intervention
- Tattoo and mark-free — surface-based positioning replaces traditional permanent skin marks
- LINAC integration — compatible with major linear accelerators (Varian TrueBeam, Halcyon, Ethos; Elekta)
- Postural Video™ — real-time multi-angle patient visualisation for faster, more accurate setup
- Beam Guide™ — real-time visual projection of planned radiation fields onto the patient during setup
- Stereotactic Module (SRS) — enables frameless, open-mask SRS and SBRT/SABR using SGRT
- Respiratory Module — full support for phase, amplitude and backup gating with simultaneous 6DoF monitoring
- Real Time Coach™ — visual display providing breathing feedback to patients during DIBH
Clinical Applications
- Breast (DIBH) — Deep Inspiration Breath Hold with continuous monitoring for cardiac protection in left-sided breast
- Stereotactic Radiosurgery (SRS) — frameless treatments with open mask for brain metastases and other indications
- SBRT/SABR — stereotactic body radiation therapy for lung, liver, spine and other sites
- Paediatrics — contactless monitoring particularly advantageous in paediatric patients, potentially reducing the need for anaesthesia
- Head and neck — precise setup and monitoring with thermoplastic mask
- Non-coplanar treatments — with MapRT® for safe beam angle verification
- Every patient, every fraction — SGRT can be used for any pathology and at every treatment session
Proven Clinical Benefits
AlignRT is supported by over 300 peer-reviewed clinical studies. Key documented benefits include:
- Sub-millimetric accuracy — tracking accuracy ≤0.5 mm / ≤0.2° at all couch and gantry angles, ensuring radiation is delivered only when the patient is correctly positioned
- Cardiac protection in left-sided breast — in a prospective study at the University of North Carolina, 0% of patients treated with AlignRT for DIBH exhibited radiation-induced cardiac perfusion abnormalities at 6 months post-treatment
- 22% reduction in treatment time — proven average per fraction, with additional savings of 25 to 155 seconds per fraction with the Postural Video™ module
- Elimination of tattoos and markings — demonstrated to be as accurate as traditional marks for patient positioning; 70% of patients report negative feelings about skin marks (The Breast Journal)
- SRS comparable to frame-based techniques — clinical outcomes equivalent to traditional frame-based and closed-mask methods, with significant improvement in patient comfort
SGRT in Portugal and Spain — Adoption Trend
SGRT adoption in the Iberian Peninsula is growing rapidly. In Spain, the Spanish Society of Medical Physics (SEFM) established a dedicated SGRT working group, publishing official recommendations for acceptance, commissioning and quality control of these systems. Leading Spanish hospitals — including Hospital Universitario Puerta de Hierro (Madrid), Institut Català d’Oncologia (Barcelona), Clínica Universidad de Navarra (Pamplona), Hospital Juan Ramón Jiménez (Huelva), Hospital Torrecárdenas (Almería) and HM Sanchinarro (Madrid) — have implemented SGRT in their radiotherapy departments.
In Portugal, SGRT research is active, with published studies demonstrating the viability of the technique for replacing skin marks and reducing inter- and intrafraction positioning errors. The Iberian SGRT community benefits from joint scientific meetings and a growing base of local clinical evidence.
The trend is clear: SGRT is becoming the new standard of care in radiation therapy, as it has in the USA and Northern Europe. Iberian centres adopting this technology are positioning themselves at the forefront of oncological treatment.
VisionRT and Interphysix — Your Partner in the Iberian Peninsula
Interphysix is the authorised distributor of VisionRT in Portugal and the Iberian Peninsula, ensuring complete availability of the SGRT solutions portfolio — from SimRT™ for simulation to AlignRT for treatment and DoseRT™ for real-time dose visualisation.
Our offering includes:
- Pre-sales consultancy — assessment of departmental needs and appropriate solution sizing
- Installation and commissioning — by certified engineers, in coordination with VisionRT’s clinical applications team
- Clinical and technical training — training programmes for medical physicists, radiation therapists and biomedical engineers
- Local technical support — assistance in the Iberian Peninsula, with uptime guarantee ≥98.5%
- Post-sales support — ongoing support for protocol optimisation and implementation of new features
Bring SGRT to Your Radiotherapy Department
Want to know how AlignRT can transform patient positioning and monitoring at your centre? Contact Interphysix for a personalised demonstration or to discuss your needs with our technical team.
📋 Case Study
AlignRT at IPO Lisbon — Surface-Guided Radiation Therapy for Precision Positioning
Última actualização: 26/04/2026