Major developments in molecular imaging’s ability to detect and facilitate treatment of Alzheimer's disease and prostate cancer were among the key scientific papers highlighted last week at the 57th annual SNM conference in Salt Lake City by Past President Peter Conti, MD. The papers were among many more presented, which included 88 platform sessions with 600 oral presentations and 825 scientific poster presentations.
Research out of Australia shows PET’s progress in detecting very early signs of Alzheimer’s disease, which afflicts some 25 percent of people over 85 years old. There are 18 million people living with Alzheimer’s worldwide, which is expected to double by 2025, according to the World Health Organization. Current pharmaceutical therapies can push off symptoms for several years but more successful treatments will depend on early diagnosis via molecular imaging and thus new drugs to enable a cure.
The Australian Imaging, Biomarkers and Lifestyle (AIBL) study, conducted in Perth and Melbourne, included elderly 200 patients, 34 with confirmed Alzheimer’s and 57 with mild cognitive impairment. All patients were imaged using PET with carbon-11-labeled Pittsburgh Compound B (C-11 PiB) that binds to beta-amyloid in brain tissue. The agent detects changes in and build ups of beta amyloid plaque, with excessive build ups often preceding cognitive impairment associated with Alzheimer’s—and bringing with 13 times the level of risk of progressing to Alzheimer’s in 20 months. They observed that the disease could develop as early as 10 years prior to signs of dementia.
Conti, professor of radiology, clinical pharmacy and biomedical engineering at the University of Southern California's Keck School of Medicine in Los Angeles, noted that continued progressive in PET imaging could lead to an antiamyloid drug that may prevent beta-amyloid plaques to develop in the brain. “The right therapeutics are not yet available [for Alzheimer’s], but [molecular imaging] brings clinical and clinical trial advantages for the future.”
Patients with a strong family history of Alzheimer’s or who show mild signs of memory loss could be screened for the disease to help them plan for the future—or imaging could be used to evaluate the effectiveness of new treatments as they become available.
Detection of recurrent prostate cancer is getting a boost from a fluorine-based imaging agent coupled with PET/CT imaging, Conti noted.
Another research study presented at the SNM conference involves a new molecular imaging agent that could improve the diagnosis of recurrent prostate cancer and determine the best possible course of treatment for patients.
The agent, developed by Mark Goodman, MD, at Emory University in Atlanta, consists of a fluorine-based radioisotope paired with a synthetic amino-acid analog similar to the naturally occurring amino acid L-leucine.
Researchers scanned 83 patients suspected of recurrent prostate carcinoma with PET/CT anti-F18 FACBC, which positively identified recurrent cancer in the prostate region with 74 percent accuracy. Metastatic cancers were detected with 96 percent accuracy, catching even small tumors with lymph nodes that other imaging agents could not detect were discovered using anti-F18 FACBC.
Conti noted that not only was the agent shown to be highly accurate in differentiating recurrent tumors in the prostate from metastatic cancer, but researchers believe the agent could help change patient treatment and improve the prognosis for prostate cancer patients. “This could lead to custom-tailored treatments for prostate cancer patients that cater to their specific tumor type and progression of disease,” said study lead author David Schuster, MD, director of the division nuclear medicine and molecular imaging and assistant professor at Emory.