External Beam Radiation Therapy (EBRT) treatments require efficient immobilization systems,
which aims the minimization of intra and inter-fraction movements and the “set-up” deviations [1],
as well as daily reproducibility of positioning,
in order to achieve planned dose prescription.
In this context,
prototyping can be a very interesting tool for the production of objects,
both for the mobilization of patients and for other purposes,
which,
in the scope of the radiotherapy treatments can be developed according to the needs of the patient.
Rapid Prototyping (RP) [2] is a technique that allows the construction of models and functional prototypes to deliver three-dimensional representations developed in Computer Aided Design (CAD) programs (3).
The RP is being applied in medicine since the beginning of 2000,
when the technology was first used to make dental implants and custom prostheses.
It is currently being as an additive manufacturing (AM) technology to develop tissues and organs,
prostheses,
implants,
anatomical models and pharmaceutical research [3][4].
Combining the acquisition of 3D images,
by CT,
the parametric CAD software 3D modelling and 3D printing,
this project aims the development of a production devices protocol applicable to EBRT treatments namely Bolus products.
Bolus is an element used in EBRT to “overcome the skin sparing effect”.
However,
in practice,
the commercial bolus cannot adhere to the irregular surface of the patient´s skin,
resulting in air gaps [5].
These devices (bolus,
immobilization masks and devices for positioning) have as aim key the custom adaptation according to the morphology of the patient,
improving the positioning in EBRT [6].
The objective of this work was to develop a methodology for printing 3D objects,
from the planning CT,
to fit the anatomical surface of the patient.
Technical aspects from EBRT induced the nose as the selected anatomical area for the experimental work.
It is a stable structure,
representing an essential attachment point to a mask,
and,
from AM point of view,
represents a small anatomical area,
providing both shorter production time and lower cost and higher customization.