Scans Reveal Changes in the Brain After Cancer Treatment
For some cancer survivors, “chemo brain” can be a debilitating side effect of life-saving treatments.
--by Joann Jovinelly
Cancer survivors who complain of a variety of mental deficits following treatment finally have physiological evidence to support their claims.
For decades, cancer patients receiving chemotherapy spoke of a mental delay they called “chemo brain”—a catch-all term that includes everything from the inability to multitask to increased forgetfulness to the inability to easily solve problems. Once thought to be an anomaly, chemo brain is now considered a very real and common side effect of chemotherapy and radiation treatments.
In the past, evidence revealed small changes in the brains of chemo patients when examined using magnetic resonance imaging (MRI), but the latest study, presented this month at the annual meeting of the Radiological Society of North America (RSNA), is the first of its kind to examine those brain changes using PET/CT scans. Researchers were less concerned with changes in the brain’s appearance in the group in question, but rather focused on how chemotherapy and radiation temporarily altered brain function.
Overall, the brain changes the team observed were described as “obvious” when comparing scans taken before and after chemotherapy treatments. They appeared to pertain to specific areas of the brain—including those that control planning and prioritizing—and scans showed those regions using less energy following treatment.
The Expert Take
“The chemo brain phenomenon is described as ‘mental fog’ and ‘loss of coping skills’ by patients who receive chemotherapy,” said lead study author Rachel A. Lagos, D.O., a diagnostic radiology resident at the West Virginia University School of Medicine. “Chemo brain is more than a feeling. It is not depression; it is a change in brain function observable on PET/CT brain imaging."
In the study, Lagos explains, chemo patients often complained of their inability to prepare family meals. The process of deciding on a meal, noting which ingredients were required, and then following through with the plan by cooking that meal were all but impossible for many patients undergoing chemotherapy. Those same patients, when provided a written meal plan by researchers, were much better able to cope with the tasks at hand.
“When researchers provided patients with written and planned menus for each meal, the women were able to buy the groceries, prepare the meals and enjoy them with their families,” Lagos said.
Source and Method
For the study, Lagos and her colleagues used specialized software to analyze PET/CT brain scans from 128 patients who had undergone chemotherapy for breast cancer. The software helped them discern minute differences in brain metabolism before and after treatment. Scan results were correlated with each patient's history, neurological exams, and chemotherapy treatments, including dosing amounts and frequency rates.
Lagos believes that future chemo patients will likely undergo brain scans that could assist doctors in determining their level of brain dysfunction, and these scans could possibly be used for earlier intervention.
“The next step is to establish a prospective study that begins assessing new patients at the time of their cancer diagnosis,” she said. “The prospective study has the potential to establish an understanding of the change in brain neurotransmitters during chemotherapy, which may lead to improved treatment or prevention.”
Delayed or slowed cognition is a very real and debilitating side effect of cancer treatments for many people. Worse, sometimes those cognitive deficits are long lasting, affecting patients years after the chemo treatments stop.
While physicians now have detailed physiological evidence of the reallocation of resources that commonly occurs in the brains of cancer patients, the next steps must address those deficits and find ways to improve them.
If chemotherapy has eliminated your cancer but robbed you of your quick-thinking skills, doctors suggest doing a battery of regular brain stimulating activities, such as solving puzzles, reading, and pursuing the arts. Developing personalized coping skills may assist in activities that require planning and strategizing, such as taking notes during conversations or creating detailed shopping and ‘to-do’ lists.
Another 2012 study, this one published in the Journal of Clinical Oncology, examined the cerebral while matter of cancer patients before and after chemotherapy treatments by using MRI scans. Those results showed “slower resting brain activity” after chemotherapy courses began. Incredibly, those same patients showed cognitive deficits even five to ten years after treatment.
A year earlier, another study published in the Journal of Clinical Oncology observed similar outcomes. In that study, the most common problem patients described was their inability to quickly find the right words to express what they wanted to communicate. Study authors concluded that up to 41.5 percent of participants still had cognitive and dexterity problems at the five-year mark following treatment, compared with 19 percent in the control group.
Still, the total cognitive dysfunction experienced by those with cancer may not only be the result of chemotherapy. In this 2012 study conducted at the University of Michigan, researchers found that women with breast cancer who had undergone surgery but were not yet being treated with chemotherapy also performed worse on memory and attention tests, which researchers attributed to higher-than-normal stress levels.