|
Getting your Trinity Audio player ready...
|
(Photo by Sylvester)
A new study shows the potential power of imaging paired with radiation to shape treatment for glioblastoma patients in real time.
The study, led by researchers at Sylvester Comprehensive Cancer Center, part of the University of Miami Miller School of Medicine, is the first to quantify tumor changes in glioblastoma patients receiving MRI-guided radiation therapy. This novel technique, also known as MRI-linear accelerator or MRI-linac, pairs daily imaging with radiation. Sylvester was the first to use this technology for patients with glioblastoma and remains one of the few cancer centers to offer it for the disease.
The Sylvester researchers found that this daily imaging can serve as an important monitoring system to signal tumor growth during treatment earlier than standard imaging, providing evidence that the method could one day be used to guide rapid treatment adaptation during radiation therapy.
The study was published Sept. 30 in the International Journal of Radiation Oncology – Biology – Physics and simultaneously presented at the American Society for Radiation Oncology (ASTRO) meeting by the study’s first author, Kaylie Cullison, PhD, an MD/PhD student in the Miller School’s Medical Scientist Training Program.
“Our study shows that these daily scans can serve as an early warning sign for potential tumor growth,” Cullison said.
In the study, which was led by Eric A. Mellon, MD, PhD, a radiation oncologist and co-leader of Sylvester’s Neurologic Cancer Site Disease Group, the researchers followed 36 glioblastoma patients over a six-week course of daily radiation and MRI scans using MRI-linac. They then compared the data from these daily scans to standard-of-care imaging to measure tumor size, namely, a single MRI image with contrast performed one week before radiation treatment and another a month after the radiation course is completed. Although MRI-linac could be paired with a contrast agent, some patients are concerned about frequent use of these heavy metals, so the study was conducted without contrast for the daily scans.
Typically, brain radiation is guided by X-ray or CT scan to position the patient correctly under the radiation beam. But these kinds of imaging only reveal the position of the skull.
“Any machine that does not include MRI, which is 99 percent of radiation-delivery equipment out there, cannot see what’s going on inside of the brain,” Mellon said. “MRI-linac allows you to see what’s going on in the brain, for the first time.”
The researchers found that for 74 percent of the trial participants, their MRI-linac imaging matched the information found in the typical, contrast MRI performed before and after treatment. That is, both modalities agreed on whether the patients’ tumors grew, shrank, or remained the same size during the course of radiation therapy. For the other 26 percent of patients, the MRI-linac imaging predicted tumor growth while the pre- and post-treatment imaging showed that the tumor shrank.
Although the daily MRI did not agree with the contrast imaging 100 percent of the time, the fact that it did not miss any cases of true tumor growth suggests that it could be used to signal possible tumor growth during radiation therapy, the researchers said. That signal could then be confirmed with contrast imaging and, ultimately, could be used to adapt the patient’s treatment to more quickly address the tumor growth.
The daily imaging also could be useful in other cases besides tumor growth. If a tumor is shrinking, the radiation field could be narrowed to ensure only cancerous tissue is targeted.
Additionally, most glioblastoma patients undergo surgery before radiation therapy, and the site where the tumor was removed, the surgical resection cavity, often shrinks as the brain heals. Following that shrinkage over time and changing the radiation therapy accordingly could be critical to spare healthy tissue from irradiation. In their current study, the Sylvester researchers traced changes in both the tumor size and surgical cavity size.
Mellon and his team plan to conduct future studies to test MRI-linac’s ability to guide treatment decisions for glioblastoma patients during the course of radiation therapy as well as to test the method in other types of brain cancer. Because so few clinics use the technology to treat brain cancers, it was not realized prior to Mellon’s studies that glioblastomas change significantly during radiation. The research team hopes to use that knowledge to improve outcomes for patients with this all-too-often deadly form of cancer.
ABOUT US:
For more Miami community news, look no further than Miami Community Newspapers. This Miami online group of newspapers covers a variety of topics about the local community and beyond. Miami’s Community Newspapers offers daily news, online resources, podcasts and other multimedia content to keep readers informed. With topics ranging from local news to community events, Miami’s Community Newspapers is the ideal source for staying up to date with the latest news and happenings in the area.
This family-owned media company publishes more than a dozen neighborhood publications, magazines, special sections on their websites, newsletters, as well as distributing them in print throughout Miami Dade County from Aventura, Sunny Isles Beach, Miami Beach, Coral Gables, Brickell, Coconut Grove, Pinecrest, South Miami, Kendall, Palmetto Bay, Cutler Bay and Homestead. Each online publication and print editions provide comprehensive coverage of local news, events, business updates, lifestyle features, and local initiatives within its respective community.
Additionally, the newspaper has exclusive Miami community podcasts, providing listeners with an in-depth look into Miami’s culture. Whether you’re looking for local Miami news, or podcasts, Miami’s Community Newspapers has you covered. For more information, be sure to check out: https://communitynewspapers.com.
If you have any questions, feel free to email Michael@communitynewspapers.com or Grant@communitynewspapers.com.
