Frequently asked questions and answers

The phantom was designed as simple and versatile device for all kind of measurements and checks in the daily RT routine.
So it can be cylindrical or flat as a box by just removing 2 cylinder segments. Other segments can be inserted for tasks in stereotaxy, particle therapy or motion devices for mimicking respiratory motion. 
The phantom body can be fixed in a defined angular position or rotate with the Linac Gantry. 
But the major feature is the big box in the center which allows to use almost all QA equipment on the market, including 2D-Arrays, for rotational QA and of course for all types of IMRT verification.
RT-smartIMRT is invented and designed by dose.point, in patent pending process since 2012.
The application describes RT-smartIMRT as versatile, modular, cylindrical phantom for applications and was marketed before other cylindrical phantoms. So RT-smartIMRT is the original, and all the other dose.point products as well.

All products went through a development process in accordance with the requirements specified by Medical Device Directive 93/42/EEC by at Euromechanics medical, which is the manufacturer as well. All products bear the CE mark.
Euromechanics is well experienced as long term developer and manufacturer for Wellhofer / IBA.
The white plastic material is water equivalent RW3 as normally used for measurements of therapy and imaging beams.
All parts which require mechanical strength are made of  PMMA / Acrylic or carbon fiber.
The precision plasic bearings contain glass balls, so the entire phantom is metal free and can be used in MRI scanner
Very basic: as the centre of mass is very close to the rotational axis for all phantom configurations, the torque needed for phantom rotation is small. We use standard carbon fibre tubes for the link from the smartIMRT to the gantry. The connecting point is just a piece of Velcro tape, very simple and working perfectly.
Carbon fibre tubes are available in different diameters and can be combined to make the connection more stiff. The tubes in use now have outer diameter of 12 and 14 mm and can be purchased in many countries. The tubes are mass production parts and inexpensive.
No, no calibration required. The phantom body has cross hair marks for alignment with the collimator light field. Rotate the phantom with the connecting tube until the marks match, and then press the joint to the Velcro tape sticking on the Linac housing.
The correct attachment of the connecting tube to the Linac gantry takes only few seconds, fits perfectly and does not change over time.
The magnetic clutch is designed for different purposes:
  1. Stiff connection without play beween the 2 carbon tubes.
  2. Adjustment in 90 deg steps.
  3. Safety opening capability with release forces depending on phantom mass.

The magnets are positioned in a way that different number of magnets pair. For the cylinder phantom with some 40 kg of weight we have 8 magnets paired, maximum force,  without the cylinders 4 pairs and in kV-mode 5.
Yes, even it was not the intention as ARC therapie came later.

Using 2D-Arrays of any manufacturer the plan verification is based on composite plans with rotating gantry.
The verification is using the standard 2D-Array software and the comparison of 2 planar dose distributions. This is working well with all treatment modalities, is efficent and comes to good results, even with VMAT/RapidARC and fff beams.
 
The latest TPS releases use optimized beam segmentations and come to very reasonal results, so the QA can be fast and simple, and based on true measurements only. 3D views and DVH are available already with TPS and MU check software, not more needed from dosimetric verification.

As long a QA device fits with good ISO center position in the smartIMRT box it can be used at any gantry angle. Typical tasks are geometrical checks, flatness and symmetry, congruency checks, Winsten-Lutz, contrast and resolution, IGRT, absolute dosimetry.... the list is long and the smartIMRT 'open' for all.
We have a number of different segments on our digital drawing board and can manufacture all what fits beween the acrylic discs. The fixation with the 2 big red screws is always the same, ensuring a tight fit without mechanical play.
We have flat segments with RW3 slabs for user configurable thickness in 1mm increments, segments with smaller diameter for stereotaxy, segments with a sphere in the center.
As the data connection to Euromechanics goes with light speed we can design and produce prototypes within few weeks at reasonable prices.
We started with the biggest: IBA MatriXX, and designed the box with inside dimensions 320 x 300 x 70 mm. So all other 2D-or Star devices fit in as well.

This is all PTW 2D-Arrays and StarCheck devices in 30 cm width, all IBA MatriXX and StarTRACK devices, SNC MapCHECK 1 & 2 and Profiler 2.
Important: with simple and precise adapters the arrays are positioned with the reference point exactly in the geometrical center of the smartIMRT.
For adapters we try to use standard RW 3 plates, as used for slab phantoms. The mechanical setup is always basic, so the costs low and production quick.  
If you have a device you want to use just send us a drawing with information of positioning in respect to the ISO center. The design of an adapter is done in less than 1 hour, you get a 3D-drawing for approval and shortly after a quote with price and delivery time.
All adapters are designed after adapters which are already approved.
smartIMRT is the central part as most of the other devices fit inside and can be used for static and rotational application.


Yes, the intention during the design was to have simple, self interlocking parts for easy dismanteling and repair. The entire phantom can be stripped down in less than 5 minutes and reassembled in about the same time.
All mechanical parts are machined on modern CNC machine tools. The overall mechanical precision is in the order of 0,2 mm.
Yes, we are constantly increasing the functionality and cooperate with research institutes. One target area is particle therapy and RT-smartIMRT as carrier of new technology.
Yes, this was one of the major intentions when designing the phantom. We are open for integrating all kinds of interesting and innovative devices.
As the design is made by dose.point in 3D, it is fast and efficient to exchange drawings in digital 3D formats and talk about.
This allows fast decisions, and as Euromechanics is able to manufacture prototypes within few weeks, we can keep versatility high and waiting time low. And prices at reasonable level.

The 2 tubes which connect the Acrylic consoles are made of special carbon fibre material. There are no glass fibres inside which normally fix the carbon fibres, and the amount of 2K resin is reduced. So the material is maximum transparent to X-rays.
Wall thickness is 1 mm, the tubes are strong enough to use them for carrying the smartIMRT.
Yes, the RT-smartIMRT body is free of metal. The bearings work with glass balls. No artefacts on all type of imagers.
The carbon clutch is replaced in 10 seconds, it containes 16 magnets which of course are not compatible to MRI scanners.
Yes, the smartIMRT has a 4-point leveling at the base, comes with a water level and is adjusted to the patient couch in 2 minutes.
The angular positioning of the phantom body can be done with 1 deg resolution using the scale on top of the front acrylic console.
Yes, there is a degree scale at the front and marks on the front disk. The phantom is rotated by hand, in normal cases the center of mass is very close to the rotational axis. So it does not move. If yes, block the rotation with a piece of paper between the disk and bearing-wheel.
In principle yes, although there was no intention as smartIMRT was launched to market earlier than O4D.

In case standard verification based on composite plans is ok for you, which for standard IMRT most likely will be, yes it is.

Even if it is not....you need the OCTAVIUS 4D motor control unit and the inclinometer, which you attach to the smartIMRT clutch and not to the gantry.
So you can use the smartIMRT in this setup for IMRT verification with 3D pictures with all inclinometers and controlers and cables, in the simple and classical way for verification with composite planar distributions, and for all other fast and efficient QA jobs.

In the smartIMRT you can use the OCTAVIUS 2D-Array in different SDD. as the box has inside height of 7 cm. And you can shift the 2D-Array to the side and back for high resolution merged distributions. We can provide you with spacers and tools.
Any PTW 2D-Array fits inside the RT-smartIMRT, works very well!
In principle yes, but there was no intention as the smartIMRT rotational concept is far better than OII.

Just another lower cylinder segment with different diameter is required in order to compensate the lower array response when irradiated from below. The lower segment diameter can be designed to the beam energy, major improvement !

So you have the cylindrical phantom for the CT and the one with different lower cylinder segment for the irradiation.

Benefit: as the smartIMRT box is 70 mm high you can add inhomogeneities up and below the 2D-array and simulate a patient (which normally has no corners)
And you can measure dose distributions also at other SDDs, high res merged and of course at any gantry angle. So simple!
And as standard phantom rotating with the gantry and simple composite plan IMRT verifcation, incl. ARC and fff.
As RT-smartIMRT is metal free, you can scan it in the MRI and CT.

This are the outcomes of the innovative smartIMRT design.
This is easy as the phantom rotation can be blocked for this. There is simple mechanism at the rear using a long carbon tube.
When the phantom is attached to the gantry no separate blocking is required.
Yes, smartIMRT is ideal as it combines versatility with simplicity.

There are some modifications in the product portfolio. The smartCUBE avaiable with different functions can be inserted in the smartCTQA. This phantom contains inhomogeneity inserts. As it can be inserted in the smartIMRT in different orientations, and all can be rotated to defined positions, there are thousands of variations for defining a virtual tumor environment. 
The smartIMRT is now prepared for RT process QA starting with Imager, treatment planning and irradiation. We have adapters for ion chamber for verifying calculated point doses during the irradiation. 
So the entire chain from Imaging to treatment can be checked in a very simple and precise way.