The technology

AlignRT (Vision RT) is a system for monitoring the precise location and movement of a patient during setup for and treatment with radiotherapy. This briefing focuses on its uses in breast radiotherapy. NICE has published a medtech innovation briefing on the use of Align RT in intracranial stereotactic radiosurgery.

AlignRT uses 3 stereo video camera pods to monitor a patient's position. It is accurate to within 1 mm of translation and 1 degree of rotation. The pods are mounted on the wall or ceiling, and each includes a red-light projector and 2 camera sensors. Before surgery, each camera pod projects a visible red light with a pseudo-random speckle pattern onto the patient's body. The AlignRT software generates a real-time 3D surface image of the patient. This real-time image is aligned with a previous reference image taken from an earlier CT scan (done to image the target location for treatment planning, or previous surface capture). By aligning the real-time and reference surfaces, the patient's position can be monitored accurately.

If needed, the patient's position can be adjusted through the AlignRT interface with the automatic treatment couch control system, to align them with the reference surface.

If AlignRT detects any patient movement during treatment, it can instruct the linear accelerator to stop the radiation beam, or prompt the user to manually pause treatment. This is intended to prevent radiation being delivered to neighbouring tissue and organs, which can lead to unwanted side effects and ineffective treatment.

AlignRT can integrate with the linear accelerator and record and verify systems settings. It is also marketed as part of the Varian EDGE radiosurgery system (Varian Medical Systems), in which it is called OSMS (optical surface monitoring system).


Monitoring and maintaining a patient's position is especially important when treating the breast (particularly the left breast), because movements from breathing can result in unintended irradiation. AlignRT can position and monitor the patient with the couch and gantry at different angles. AlignRT also tracks the entire patient surface, whereas most similar devices only monitor a few points.

Current NHS pathway

Location monitoring during radiotherapy varies and the best approach is decided by a multidisciplinary team. Patients are positioned using standard CT and X‑ray systems so that any movement is minimised. A range of breath-holding techniques and devices may also be used to ensure that the correct lung volume is maintained when the patient holds their breath. The Royal College of Radiologists UK consensus statements on post-operative radiotherapy for breast cancer (2016) notes that in patients with left-sided breast cancer, the heart should routinely be spared from the radiotherapy field. In addition, the statement notes that breath-hold techniques should be available in all UK radiotherapy departments.

NICE is aware of the following CE-marked devices that appear to fulfil a similar function to AlignRT:

  • Catalyst (C‑Rad)

  • Identify (HumediQ)

  • Active Breathing Coordinator (Elekta)

  • Real-Time Position Management System (Varian).

Population, setting and intended user

AlignRT would be used for patients with breast cancer in whom radiotherapy is suitable. Radiotherapy would be done in specialist tertiary centres and AlignRT would be used by an appropriately trained therapy radiographer.


Technology costs

The list price of AlignRT is £150,000 to £225,000 (excluding VAT). There is also a yearly service charge of £20,000.

Assuming a 10‑year lifespan, the total cost would be about £40,000 per year. If AlignRT were used for 250 patients each year, the cost per patient treatment course would be £160.00, or £10.67 per fraction for a 15-fraction treatment plan.

AlignRT can be used during radiotherapy for other cancers, which may reduce the cost per treatment.

The company provides training and this is included in the cost of AlignRT. Training consists of 2.5 days of in-person training for a therapeutic radiographer and physicist at the company's offices, with the intention that these staff then pass on their learning to the department. A representative from the company later visits the site for several days to help implement clinical use.

Costs of standard care

The most commonly used technique to move the heart further away from the treatment area is breath holding, which has no direct cost.

Resource consequences

AlignRT represents an additional cost to current methods such as breath-holding techniques. Except for the cameras being installed, adopting AlignRT is not expected to necessitate any changes in facilities or infrastructure.

AlignRT is currently used in some NHS centres during radiotherapy for breast cancer.