In ‘Radiotherapy-Compatible Robotic System for Multi-Landmark Positioning in Head and Neck Cancer Treatments,’ authors Mark Ostyn, Siqiu Wang, Yun-Soung Kim, Siyong Kim, and Woon-Hong Yeo discuss the challenges of dealing with spine flexibility in radiation therapy and explore the accompaniment of robotics to help improve positioning.
To prevent neck flexibility resulting in problems during therapy, medical professionals often employ passive immobilization masks to prevent motion and encourage successful positioning. The authors also point out, however, that studies over time have shown that such masks still have a margin of error of 3–5 mm between distant landmarks along the spine of the neck.
“Recent reports show that an accurate positioning in head and neck therapy can be achieved by independent positioning of the head from the rest of the body,” state the researchers. “However, these mechanical systems have not yet been introduced into regular clinical practice.”
No other systems have been radiotherapy-compatible so far, leaving the authors to take matters into their own hands and develop a robotic system which is suitable for radiotherapy.
“In this new system, all radiotherapy-incompatible components are arranged far outside of the radiation field, placed 40 cm inferior to radiation isocenter with a novel, plastic gearbox that reduces linear accelerator gantry clearance issues,” stated the researchers. “As a result of transitioning from direct to indirect power transmission from stepper motors to end effectors, a mostly-plastic secondary position feedback is introduced to aid in navigation.”
The system is validated with attenuation measurement, as well as radiographic imaging. In designing the robotic system, the researchers were determined to make structures as small as possible, but still able to offer the necessary range of motion. The researchers put the metal motors in between the patient and in this case for the study, the couch top.
They 3D printed almost all the components, to include:
- Gear box
- End effector assembly
- Mounting frame
Two 3D printers are capable of making such parts in a superior manner, according to the researchers: the Formlabs Form 2 printer and the Objet Eden 260VS. Materials used included ABS, as well as PLA when using other 3D printers.
“In addition, the top plate of the head/neck controller that needs an extra high strength is fabricated by machining a carbon-fiber-reinforced plastic, which holds a patient’s head,” stated the researchers.
The researchers included 15 trails, with a variety of displacements, from 1.1 to 5.2mm.
“This presented system is capable of positioning a patient’s head with submillimeter accuracy in clinically acceptable spatial constraints. Calculated attenuation of materials in the system have lower HU values than a reference material (bone tissue), which is validated by a set of radiographic images with no visible artifacts,” concluded the researchers.
“The result of positioning accuracy with a skeletal phantom determines the device’s accuracy as 0.7 ± 0.3 mm. In addition, CBCT imaging and post correction study validates the system’s functionality for aligning individual regions when the head and body are individually positioned. Future work will focus on the radiotherapy application for patients with head and neck cancer.”
3D printing and robotics go hand in hand quite literally in many instances, from ultra-programmable systems to sensor technology, and even manufacturing for industries such as furniture design. What do you think of this news? Let us know your thoughts; join the discussion of this and other 3D printing topics at 3DPrintBoard.com.[Source / Images: ‘Radiotherapy-Compatible Robotic System for Multi-Landmark Positioning in Head and Neck Cancer Treatments’]
You May Also Like
Delft University of Technology & Maaike Roozenburg 3D Print Chinese Porcelain
China is famous for its blue and white porcelain, delicately and artfully produced and painted. Crafted mainly in the southern Chinese city of Jingdezhen and purchased by travelers visiting the...
3D Printing News Briefs: July 11, 2019
We’ve got plenty of new products to talk about in today’s 3D Printing News Briefs, starting with materials from two chemical companies. WACKER announced new grades of of liquid and...
How do 3D Printed Dentures Stack up when Compared to Milled and Injection Molded Dentures?
In a new study, Korean medical researchers have been looking into the differences in quality and accuracy of several different modern ways to make dentures, with a focus on whether...
Additive Manufacturing Strategies Boston 2019 Speaker Roundup
January 29 to 31st Boston will host the Additive Manufacturing Strategies event which will be a chance for you to learn with and from your peers in medical and dental...
View our broad assortment of in house and third party products.