PET and MRI predict effectiveness of chemotherapy in advanced breast cancer
For patients with advanced breast cancer, positron emission tomography (PET) and magnetic resonance imaging (MRI) can improve quality of life and survival by providing physicians with information on the effectiveness of chemotherapy prior to surgery, according to new research. The findings were presented at the 2013 Annual Meeting of the Society of Nuclear Medicine and Molecular Imaging in Vancouver, British Columbia.
Researchers combined the separate imaging systems of PET, MRI, and CT to map the course of chemotherapy before surgery, which is neoadjuvant chemotherapy. These different imaging systems provide complementary information, both physiologic and structural, about how chemotherapy will distribute through the body to kill breast cancer and metastatic tumors. This study employed the specialized molecular imaging agent F-18 fluorodeoxyglucose (FDG). This agent acts as a biomarker for cellular metabolism with PET in order to pick up on areas of cancer proliferation.
“Previous studies have shown that, separately, FDG PET and dynamic enhanced MRI can provide a prediction of how patients will respond to neoadjuvant treatment, but we have improved upon this concept by combining the two techniques side by side,” said lead author Sang Moo Lim, MD, of the Korea Institute of Radiological and Medical Sciences in Seoul, Korea. “Using both FDG PET and MRI to predict cancer progression-free survival allows us to apply more aggressive therapies that could potentially halt patients' cancers and extend their lives.”
This study, which evaluated survival after chemotherapy, included 44 women with advanced breast cancer. All underwent three cycles of neoadjuvant chemotherapy and sequential whole-body FDG PET/CT, breast MR, and delayed breast PET/CT a total of four times—once prior to the first course of chemotherapy, again after the first course, following the second course, and one more time prior to surgery to predict and confirm disease-free survival. Results of the study indicated that patient survival with no recurrence of cancer after neoadjuvant chemotherapy ranged from a little less than 3 months to approximately 3 years for a median of 661 days.
“Additionally, this study demonstrates the collective potential of these imaging systems, which provides evidence that fused PET/MR utilizing both metabolic and vascular perfusion imaging can benefit patients,” said Lim. “Together these techniques can help clinicians classify patients and provide risk stratification to not only predict cancer recurrence after treatment but also avoid chemotherapy for those who probably would benefit more from an alternative treatment.”
This research using combined, sequential PET and MRI provides additional proof of the potential benefit of simultaneous PET/MRI, an emerging molecular imaging technology.“This extends beyond just breast cancer,” Lim added. “We could potentially apply these technologies to other malignancies and develop some brilliant methods to improve clinical outcomes. Considering the results of our research, we now need to further develop the technology—not just imaging systems, but tracers and biomarkers—to advance our field.”