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The 'virtual tumor' is an object which looks in CT or MRI images as tissue, but is made of plastic material and so with long durability. The virtual tumor allows to image, plan and irradiate dose distributions repeatedly for QA purposes and verify with point dose measurements.
The idea came unexpectedly while testing a new 3D-printer. This devices are made for creating precise objects with good surface quality. Invisible structures inside give strength to the objects and make them durable.
The combination of 3D-CAD and 3D printing however opened the possibility for reverting this: dense stuctures inside the object are combined with uneven surfaces, and with some software modifications it is possible to create objects which are uneven, inhomogeneous, in all sizes and shapes and insde cavities for a variety of detectors. This all by design and easy to produce in quantities.
This objects are packed inside the smartCUBE housing, easy to use and versatile.
The smartCUBE inside the smartCTQA inside the smartIMRT gived hundreds of different configutations for positioning and orientation for the virtual tumor, so ideal for the cylinder phantom as 'Virtual Patient'.
There are many options, as the above green onion-structured object, which is helpful for autocontouring checks of targets from CT or MRI scans. And of course for checking merging/fusion algorithms based on scans.
And the orange object shows 3 different objects, as prostate with colon, and cavities for 2 small volume ion chambers. Density and texture can freely be defined and printed, a good and useful tool for checking the dose dstribution intarget and risk organ at the same time.
Density values can start from 0.5 up to 4, different material opens a variety of options, with special plastic blend even the printing of bony structures.
As the nozzle diameter is just 0,4mm or less the different internal structures at about same density appear on images as different tissue textures.
dose.point 'Vitual Tumors': just the beginning of fascinating new approach for RT end-to-end QA.