Novel treatment device safe, effective for early pancreatic cancer
Researchers at Virginia Commonwealth Massey Cancer Center became the first to implant the bio-absorbable internal radiation device known as CivaSheet for the treatment of early-stage pancreatic cancer.
The CivaSheet (CivaTech Oncology) is a flat, flexible membrane that provides unidirectional radiation to the tumor site while shielding healthy tissue. The device is placed in the patient during surgery and naturally decays within 50 to 70 days.
“The beauty of the CivaSheet is that we can place it face down on the section of removed tissue to give dose to the region at highest risk for a close or positive margin and protect the overlying intestines,” Emma Charlotte Fields, MD, assistant professor and residency program director in the department of radiation oncology at Virginia Commonwealth University, said in a press release. “Because of the radiation shields on the opposite side of the device, the intestines are essentially blocked and protected from the radiation. With external beam radiation, it is more difficult to pinpoint the tumor’s location and is harder to protect the intestines to this degree.”
HemOnc Today spoke with Fields about how the device works, the need for an option like this, and which patient populations may be the most appropriate candidates.
Question: Can you describe the need for a device like this?
Answer: In general, outcomes for pancreatic cancer have not improved during the past two decades and remain generally poor. At the time of diagnosis, it is rare to have disease that is amendable to surgical resection, which is the only way to cure pancreas cancer. There are about 15% to 20% of patients for whom curative surgery is a potential. However, another 15% to 20% of patients present with borderline or locally advanced disease. These patients first require treatment with chemotherapy or radiation, and then they are considered for surgery. Even then, surgery can be tricky because the tumor can be close to large blood vessels that cannot be resected. We have already started bringing stronger treatments forward from the metastatic setting for these patients with borderline resectable or locally advanced disease. Our goal is to do everything we can to get them to surgery. Pancreaticoduodenectomy is a very big surgery. If the entire tumor is removed with negative surgical margins, the patient potentially can be cured. However, if the surgery is done and positive margins are left behind, these patients have bad outcomes that are almost equivalent to outcomes of people who did not have surgery.
Q: How does the CivaSheet device work?
A: The device is made up of small dots that are laid out in a grid. Each dot is an individual source of Palladium-103, a radioisotope of the element palladium that naturally decays with a half-life of 17 days. At the time of surgery, we are able to place the localized radiation device exactly in the area we are concerned about. Because it is a unidirectional radiation source, we can place it against the region where we are worried there are tumor cells left behind. Everything behind it — such as the intestines, liver and kidney — is shielded. As the device decays, it gives radiation in one direction because the dots have a gold plate on one side of them, which shields one-tenth of the radiation off the back. The dose is given in about a 5-mm depth away from the seeds and the direction we are intending to reach. It is local radiation. The dots are imbedded in bio-absorbable mesh, so after the seeds have decayed, the mesh will bio-absorb as well. The sheet can be cut in the operating room by the surgeon or radiation oncologist to tailor the size and shape and individualize it to a person’s anatomy.
Q: Which patients are ideal candidates for this device?
A: The CivaSheet is for patients for whom we are worried about their margins. The patients we are targeting are those who are in that borderline resectable category or locally advanced disease stage. This typically means that, at diagnosis, the tumor abuts the important arteries, and people have encasement of some of the veins. These patients receive strong chemotherapy, followed by chemotherapy and radiation, with the goal of achieving a maximal response. However, if they are still at risk for having this closer margin, then they will be prime candidates.
Q: What are the next steps?
A: The device is approved by the FDA. However, it is not approved for any specific indication. It has general approval and so far, people have used it for patients who have already received radiation and have had a pelvic recurrence. We will be enrolling patients in an NIH-funded prospective study at Virginia Commonwealth University, Fox Chase Cancer Center, Rush Medical Center and East Carolina University.
Q: Is there anything else that you would like to mention?
A: This gives us another tool that hopefully will start to improve outcomes. It gives hope to patients who may be on the cusp of being in that ‘most perfect’ category in pancreatic cancer. Getting a really good surgery is the end all be all, and all of these additional treatments have to be able to make that better. The CivaSheet is novel, it is easy to use, and the risk for side effects is very low. It could potentially have a good deal of benefit. – by Jennifer Southall
For more information:
Emma Charlotte Fields, MD, can be reached at Virginia Commonwealth University, 401 College St., PO Box 980058, Richmond, VA 23298; email: firstname.lastname@example.org.
Disclosure: Fields reports no relevant financial disclosures.