Roland Unterhinninghofen PhD, Presenter: Nothing to Disclose

Jacob Kuypers, Abstract Co-Author: Nothing to Disclose

Moritz Wade, Abstract Co-Author: Nothing to Disclose

Alan Preuss, Abstract Co-Author: Nothing to Disclose

Florian Sterzing MD, Abstract Co-Author: Nothing to Disclose

Frederik Lars Giesel MD, MBA, Abstract Co-Author: Nothing to Disclose

Juergen Debus MD, PhD, Abstract Co-Author: Nothing to Disclose

Ruediger Dillmann PhD, Abstract Co-Author: Nothing to Disclose

By integrating modern radiological imaging and rapid manufacturing techniques with a dedicated algorithmic data processing we propose a completely new approach that is straightforward and significantly improves patient comfort. In the near future it may replace the last manual segment in the radiotherapy workflow by an almost fully automated production line.

In radiation therapy patients need to be accurately immobilized in order to hit the tumor target exactly and to prevent damage to healthy tissue. For repeated sessions patient position must be reproducible. Usually immobilization devices are made manually using cast (ScotchCast) or thermoplastic material, which is costly and time-consuming. Especially with the head to be immobilized this causes significant discomfort to the patient. We developed a new approach to produce individual immobilization devices for the head based on tomographic image data and 3D printing technologies: using in-house developed software, MRI or CT images are processed to generate a surface mesh model of the fixation mask. Subsequently apertures for eyes, nose, mouth, and ears are cut into the mask model. Also, an interface for fixation to the intervention table is added. Finally the mask model is materialized using a Dimension SST1200es 3D printer (Stratasys, Eden Prairie, MN, USA).

The concept has been implemented in a prototypical fashion and has proven to be feasible. In a qualitative study with healthy volunteers (N=10) the masks fitted well on the volunteers’ faces leaving marginal space for moving. However, with some masks, specific areas of the faces such as eyebrows, nose, or chin experienced uncomfortable stress. A quantitative evaluation of the fixation accuracy is ongoing.

The main advantage of our solution is that the mask is produced in a completely contact-free way using radiological image data already acquired for planning. It hence improves patient comfort and reduces psychological stress considerably. Also, our approach has the potential to outsource the production of the masks from the clinics, thereby reducing costs and releasing human resources that were needed for conventional mask production.

Unterhinninghofen, R, Kuypers, J, Wade, M, Preuss, A, Sterzing, F, Giesel, F, Debus, J, Dillmann, R, 3D Printing of Individual Immobilization Devices based on Radiological Imaging to Improve Daily Clinical Procedures in Radiation Therapy.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045742.html