Tech Briefs

3D Scanning for Post-Mastectomy Custom Breast Prosthesis

Creating a custom breast prosthesis that feels and looks more natural can be accomplished.

Breast cancer is a terrible affliction that affects approximately one in eight women in the US. In 2012, nearly a quarter- million cases of invasive breast cancer will be diagnosed among women. Due to the progress of medicine and associated treatment, the death rate associated with breast cancer has been declining since the 1990s to approximately 1 in 36 cases. At this time, there are more than 2.6 million breast cancer survivors in the United States alone. Different procedures can be attempted in order to treat and cure a cancer but the more advanced cases will sometimes need to undergo a complete mastectomy (a procedure in which a breast is removed entirely). A mastectomy is a rather radical procedure and some women may experience a post-surgical trauma due to the lifestyle disruption following the surgery.

After a mastectomy, it is possible to proceed to breast reconstruction to replace the removed tissue with synthetic implants or tissue flaps from another part of the body. However, reconstruction means that the patient has to undergo yet another surgery and comes along with its share of problems (skin grafts that will scar the skin, can hide a cancer recurrence, can end in mixed results, etc.). Some women will rather turn to breast prostheses instead. Unfortunately, no two bodies are alike and a standard size prosthesis will rarely fit perfectly. Patients quickly become uncomfortable with their prosthesis, which is likely to shift out of place as the patient moves around, making it a constant preoccupation. The prosthesis also must be used with custom-made bras, making this situation very restrictive in terms of available underwear.

How It Works

Faced with this situation a team of researchers from Quebec decided to develop a complete new approach to the way prostheses are made. They figured that it was practically impossible to develop a standard size prosthesis that would fit all patients and went for a custom made solution. Using their innovative process, they first digitize the scar tissue and surrounding area left after the surgical procedure using a handheld 3D scanner. Since the prosthesis is designed to be used while wearing a bra, they need to scan the remaining breast while it is being supported in a standard bra. With the use of 3D data edition software, the 3D scan of the remaining breast is mirrored along the middle axis of the thorax; the resulting surface is therefore perfectly symmetric. The mirrored surface is afterwards combined with the first scan of the scar tissue to create the upper and lower surfaces of the prosthetic. The combination of these two surfaces very accurately defines the shape of the tissue that was removed during the surgical procedure.

The 3D file is then used to create a mold that is machined on a CNC machine, and used to manufacture a unique prosthesis by injecting with several different types of silicone; a more rigid outer layer that behaves like human skin and then a softer core that feels more like human breast tissue. The outer layer is also custom painted by hand to match the patient’s skin tone and give it an even more natural look.

Choosing an adhesive to use is also an important part of this project as a shifting prosthesis can be a major preoccupation to patients. Not only does it have to fit but it must also stay in place while being gentle enough to prevent skin irritation if worn on a periodic basis. The team invested considerable efforts into this and developed a special natural adhesive allowing the patient to wear the prosthesis comfortably for a full day. The result is a very convincing artificial breast.

The process to manufacture a custom-made breast prosthesis is now complete and the next step will be to enter a clinical test phase that should start in early 2013. This test phase is expected to last two years and should to treat approximately 40 patients per year.

This article was written by François Leclerc, Product Manager, Creaform, Lévis, Québec, Canada. For more information, visit http://info.hotims.com/40440-168.