The team is using 3-D printing to create customized boluses, or tissue-equivalent molds, for cancer patients with tumors close to their skin’s surface. Boluses create an even surface for radiation to hit. They centralize the radiation beam and evenly distribute the dose into one area, like water sinking into soil.
Currently, to treat a superficial tumor, like near a patient’s eye or nose, the team uses wet towels or SuperFlab (a skin-equivalent gel) as a bolus. Unfortunately, these don’t perfectly conform to the patient’s tumor, meaning the treatment can be inaccurate. When a patient receives multiple treatments each day, this adds up.
Besides the bolus issues, treating superficial tumors with radiation is problematic. Radiation works well on deep tumors, but if it’s somewhere such as the skin or the breast, it’s less effective.
“When radiation hits you, it deposits its energy deep within your body,” explains Physicist, DJ Vile, PhD. “If you have a deeper tumor, that’s a good thing, but when there’s tumor involvement on the skin, it’s very difficult to treat because of this effect.”
This is where the 3-D printing comes in. The Simon Cancer Center team has teamed up with Paul Yearling, PhD, from the Mechanical Engineering Technology program to use the lab housed within the Purdue School of Engineering and Technology, IUPUI (conveniently located across the street) to print molds. They send over a dosimetrist’s (a specialist in radiation therapy treatment planning) mock-up to the lab. Then, 40 hours later—voila—you’ve got a mold that perfectly conforms to a patient’s anatomy.
3-D printing isn’t limited to boluses—it can also improve other medical devices. Overshiner’s department CT scans children as well as adults using a standard-size head rest. With a 3-D printer, they can make something that teach patient. The team is also investigating brachytherapy, where radioactive material is inserted into the body with a special device.
What is the best part about this technology? If other departments, like plastic surgery, want to use 3-D printing, they only have to send Overshiner’s team a copy of their patient’s CT scan. Overshiner’s team is applying for a $50,000 grant and looking for other funding opportunities to get a more advanced 3-D printer to decrease the time it takes to create molds. After it’s purchased, they hope to start using it to revolutionize cancer treatment.
