Before and after major regulatory decisions

A pair of the top molecular imaging stories from the past month offered something resembling symmetry, with one touting the effectiveness of a radiopharmaceutical soon after it received regulatory approval, and the other confirming the benefits of PET scanning in Alzheimer’s patients just ahead of another important regulatory decision.

The first study assessed 99mTc-tilmanocept, or Lymphoseek (Navidea Biopharmaceuticals), as a SPECT/CT agent used for localization of sentinel lymph nodes before surgical treatment of oral cavity squamous cell carcinoma. Researchers from The Ohio State University in Columbus found Lymphoseek had a 0 percent false-negative rate and a negative predictive value of 100 percent in a small cohort of patients. The findings suggest Lymphoseek could replace current imaging agents like sulfur colloid and make an effective alternative to elective neck dissection.

The FDA approved Lymphoseek as a drug for lymph node mapping this past spring, making it the first new drug of its type approved in more than 30 years.

The other big story comes this week from the Medical Biotech Forum in China, where interim results of the Metabolic Cerebral Imaging in Incipient Dementia study confirmed that early diagnosis of Alzheimer’s disease with FDG-PET imaging leads to earlier treatment and improved outcomes. This is the first controlled, robust study to assess the benefits of early PET scanning for Alzheimer’s disease, according to the researchers.

Sixty-three patients were included in the initial findings, and of the patients whose doctors saw evidence of Alzheimer’s on an early PET scan, 40 percent were prescribed drugs to treat dementia within six months. For the patients whose doctors didn’t have access to PET data, none were given medication within six months and only 12 percent were given prescriptions at one year.

“During the subsequent two years after their PET scans, [patients receiving early PET scans and treatment] had superior executive function, better memory abilities and greater preservation of overall cognitive function," Daniel Silverman, MD, PhD, of the University of California, Los Angeles, said in a press release.

Medicare doesn’t currently reimburse PET scans of patients who show signs of cognitive decline but do not yet have a diagnosis of dementia, but that might change next week following a major PET coverage decision from the Centers for Medicare & Medicaid Services.

Be sure to check back next week for the results of that decision, and any future coverage or regulatory decisions.


-Evan Godt
Editor – Health Imaging