The aim of this protocol is to build tailor-made prototypes of breast implants to respect some fundamental features such as clinical and pathological datas from the tumor, type of resection that will be performed, anthropometric parameters of the patientand of the contralateral breast.
Actual techniques to replace the breast include flaps, prosthesis and stem cells. This study was carried out to add to those tools another one to give better pre-operative counseling to the patients.
Methods and Materials: we selected the case of a patient with a palpable mono-focal lump, who had never been irradiated and who did never undergo breast surgery. We acquired T2-weighted NMR images without contrast agents and saved them in DICOM format (Digital Imaging and Communications in Medicine).
We imported those images in MIMICS (Materialise Interactive Medical Image Control System), a software that elaborates packs of 2D images to create 3D models, to obtain the segmentation of the planes.
Taking advantage of the intrinsic contrast in the structures we repeated the procedure to segmentate the tumor (applying a green mask) and the breast of the patient (applying a pink mask).
We then prototyped the implant, by manually drawing the resection area over the NMR images. Using the tool “Morphology operations” we drew a resection margin far 1.5 cm by the tumor area, that allowed the creation of the 3D model. Using some Smoothing filters we plained the model.
Final improvements to the model were made using the MeshLab software.
Summary of results: At the end of the procedure we came up with five models to print: the tumor, the left and the right part of the breast, the left and the right part of the prosthesis.
We printed those models using a Ultimalker 3D-printer. The printing technology used is called “fused deposition modeling”.
The extruded material is PLA (polylactic acid): this 3-D ink allows the creation of high-resolution objectsthanks to its good surface quality, it’s easy to work with, it’s safe, it’s reliable and it comes in variety of colours. We printed in red the tumor, in orange the prosthesis and in blue the breast of the patient.
As supporting ink we used PVA (polyvinyl alcohol), used to print complex models that require supports for deep internal cavities and large overhangs.
Conclusion: once the models were printed we reached our objective. After the first senological visit, the patient performs a NMR study and the multi-disciplinary team (following the Plastic Surgeon’s directions) prototype and print the prosthesis that can be easily used to better inform the patient before surgery.
The process showed a very high accuracy, so high that in the future it could be possible to use it to directly print implantable custom-made prosthesis following the knowledge of the 3D-biopriting field. In fact, it is suitable both for printing custom-made silicon prosthesis and bioscaffolds.