Specialized MRIs allow physicians to view progress in brain cancer treatment before it can be detected by standard MRI, allowing for early therapy changes.
Dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted MRI (DW-MRI) can demonstrate if treatment for brain cancer is shrinking the tumors before evidence appears on standard MRI, according to a study presented at the 55th Annual Meeting of the American Association of Physicists in Medicine (AAPM).
“The size of tumors that have responded to treatment look similar on a CT or MRI for quite a while until the body starts to absorb the tissue,” co-author Yue Cao, PhD, said in a release. “In the meantime, the patient has continued to undergo treatment that may not be working, therefore missing out on the opportunity to move on to a different or more powerful therapy.” Cao is a professor of radiation oncology, radiology, and biomedical engineering at the University of Michigan in Ann Arbor.
Researchers assessed the progress of 24 patients with a total of 67 brain tumors. The patients underwent DCE-MRI and DW-MRI two weeks after starting radiation therapy and standard MRI at one month after treatment to determine if the tumors had shrunk. Researchers found that the DCE-MRI and DW-MRI showed 24 tumors had decreased in density and/or abnormal blood volume two weeks after the patients began therapy. This was confirmed by the one-month MRI.
The DCE-MRI was also used to quantify additional information about the tumor, which could be used in the future to quickly assess whether treatment is working, the researchers said.
“If these findings bear out, MRI with perfusion and diffusion could be used to measure the effect of treatment earlier, in other words, during therapy instead of waiting until treatment has been completed,” Cao said. “If even a portion of the tumor is not responding, that would signal doctors to try more intensive therapy.”