Q&A: IDEAS Study Opens Diagnostic Options for Complicated Dementia Cases

informationBright IDEAS spoke with Constantine Lyketsos, M.D., M.H.S., Elizabeth Plank Althouse Professor for Alzheimer’s Research, director of the Memory and Alzheimer’s Treatment Center and associate director of the Alzheimer’s Disease Research Center, all at Johns Hopkins.

The Imaging Dementia-Evidence for Amyloid Scanning (IDEAS) Study is an open-label, longitudinal cohort study to assess the impact of brain amyloid PET on patient outcomes under Coverage with Evidence (CED) in patients meeting appropriate use criteria (AUC) for amyloid PET (Johnson, et al. 2013).

The hypothesis is that amyloid PET imaging will decrease uncertainty and increase confidence in the underlying cause of cognitive impairment, that this will translate into earlier counseling and other interventions, and that these interventions will lead to improved patient outcomes.

  • Aim 1: To assess the impact of amyloid PET on the management of patients meeting Appropriate Use Criteria (AUC)
  • Aim 2: To assess the impact of amyloid PET on hospital admissions and emergency room visits in patients enrolled in the study cohort (amyloid PET-known) compared to matched patients not in the cohort (amyloid PET-naïve) over 12 months.


The study launched in February 2016 and has now gathered more than 8,000 of the planned 18,488 scans through a national network of PET facilities and referring physicians. For more information, please visit the IDEAS Study website.

The IDEAS Study is led by the Alzheimer’s Association and the American College of Radiology Imaging Network (ACRIN®) and managed by the American College of Radiology (ACR®). We gratefully acknowledge the contributions of our industry partners — as well as our collaborators from the Society for Nuclear Medicine and Molecular Imaging and the Medical Imaging and Technology Alliance.Constantine Lyketsos, M.D., M.H.S, is the Elizabeth Plank Althouse Professor for Alzheimer’s Research at Johns Hopkins. Dr. Lyketsos is director of the Memory and Alzheimer’s Treatment Center and associate director of the Alzheimer’s disease Research Center at Johns Hopkins. His research interests include the epidemiology of dementia, as well as the epidemiology and treatment of neuropsychiatric disorders in dementia.

(Bright IDEAS): How are you involved in the IDEAS Study, Dr. Lyketsos?
(Dr. Lyketsos): Johns Hopkins is a study site. Esther Oh, M.D., Ph.D. is the principal investigator for Hopkins, but I’m involved. I’ve referred four patients to the study.
(Bright IDEAS): What has your experience been with the IDEAS Study so far?
(Dr. Lyketsos): It’s been very positive. Since the study pays for individuals who meet entry criteria to have a brain amyloid PET scan, there’s been a steady stream of patients for whom it would be helpful diagnostically to have the result of such a scan.

Previously, we didn’t have an effective way of offering this option to patients due to the high cost of these imaging studies. Now, through the IDEAS Study, my patients have an important diagnostic alternative. Fortunately, the appropriate use criteria for use of the scans fit well with the way I have wanted to apply this test.

(Bright IDEAS): Have you had any challenges in either understanding or applying the appropriate use criteria?
(Dr. Lyketsos): There’s some gray in the criteria, but, no, I haven’t had any major issues.
(Bright IDEAS): What about issues around payment or reimbursement?
(Dr. Lyketsos): We’ve had some patients who have a copay, which at our place is about $1,200, but it’s much better than paying $6,000 to $7,000 out of pocket
NOTE: The IDEAS Study strongly recommends discussing Medicare reimbursement with potential study patients. Be prepared to provide an estimate of out-of-pocket costs. Traditional Medicare plans (Part B) provide 80 percent of payment; the other 20 percent may be provided by supplemental insurance plans or self-pay. Medicare Advantage plans (Part C) may have a copay or require pre-authorization. Encourage patients to contact their specific plan to learn more.
(Bright IDEAS): How extensively were your patients screened or evaluated before you chose to refer them into the IDEAS Study for the brain amyloid scan?
(Dr. Lyketsos): There was no more or less screening than my standard practice. This study fits very nicely with what I do every day. It simply provides an additional tool.
(Bright IDEAS): Before the IDEAS Study, how often did you encounter patients where making the diagnosis of the cause of dementia was challenging? How often did you recommend them for a brain PET scan even though it wasn’t covered?
(Dr. Lyketsos): Well, there are a couple of alternative ways to approach diagnostic clarification for Alzheimer’s, other than an amyloid PET. For some questions, an FDG PET scan is a “poor man’s cousin” of an amyloid PET. And so in the past I would sometimes recommend FDG PET. That said, I think amyloid PET is more precise and more helpful.


We could repeat cognitive testing without the scan over the next six months to a year, and that might give us greater clarity about the diagnosis and how we should treat the patient. Finally, a lumbar puncture to measure amyloid and tau proteins has been an option for a while, but this is not very popular with patients and there have been problems with standardization across labs.

(Bright IDEAS): Has there been anything about participating in the IDEAS Study that surprised you, positively or negatively?
(Dr. Lyketsos): Being a tertiary center, we get a number of complicated patients where the clinical presentation is atypical enough that it’s important to know whether or not they have significant amounts of amyloid in their brain. Those are the people that I’ve sent on to the study. It’s been positive in that regard.

In every single case so far it was very useful to them — and to my ability to care for them — to know the result.

(Bright IDEAS): Can you talk about one of the cases? What was your impression of the person before getting the amyloid PET scan results, and what was it after?
(Dr. Lyketsos): I had a patient with very atypical MCI — more or less a posterior cortical atrophy-type clinical presentation with preserved memory — who I thought probably had Alzheimer’s disease, but I wasn’t prepared to refer them to an Alzheimer’s clinical trial, an amyloid clinical trial or put them on one of the approved Alzheimer’s drugs.


The scan was very helpful; it was pretty clear cut. Not only did he have amyloid but he had it more posteriorly. So it fit the clinical picture. I was able to refer him with confidence to a clinical trial testing an anti-amyloid agent. I don’t know if he actually ended up in the trial, but he was screened.

(Bright IDEAS): Talk about the experience of sharing those results, either specifically with that patient or in general. Are they receptive? What has the response been?
(Dr. Lyketsos): I take care to set things up well ahead of time. I talk about why I think the scan should be done, what will happen if the result is positive and also if the result is negative. If by some chance the scan is indeterminate, which has not happened yet, we would sit down to discuss it and go from there.

This kind of pre-scan preparation is very important, but that’s true of any diagnostic test. This kind of counseling is no different than when the person is getting a brain MRI or a genetic test that’s specific to Alzheimer’s

(Bright IDEAS): After sharing the results of the scan, do you find that the patients and family members strive to learn more about the disease? And do they appreciate having the additional information?
((Dr. Lyketsos): If you have MCI and your amyloid scan is negative, that’s good news. For people that have positive scans? Frankly, by the time we’re having a conversation about doing a brain amyloid scan, they’re pretty educated. They’ve already done their reading. So, I can’t say that the scan results change that very much.
(Bright IDEAS): Do you have any advice for your colleagues about the best way to discuss amyloid PET results?
(Dr. Lyketsos): Think through why you want to do the test, and use that as a basis for the discussion. Why do you think this patient is eligible? What will you do with the information, regardless of whether it is positive, negative or indeterminate. It is not different than any other diagnostic test.
(Bright IDEAS): How would you describe to your peers what the brain amyloid PET scan results give you, in terms of your decision-making process?
(Dr. Lyketsos): If I pick the patients carefully, and I think through what I’ll do with any result, the scan gives me much more precision in being able to prognosticate and make treatment decisions. It helps me provide options for research participation to patients who might not ordinarily have such options because their presentation is atypical.
(Bright IDEAS): What would you say to your peers who’ve heard of the IDEAS Study, but are reluctant to get engaged
(Dr. Lyketsos): I would strongly encourage them to get engaged for two reasons. One reason is that they will have some number of patients who will benefit from having the scan. This is not something that the majority of their patients will need, but there will be some. We’ve been at this for about six months, and I’ve referred four people. But I probably see fewer patients than the average geriatric psychiatrist in practice. So they will definitely have patients where the scan will be beneficial.


The other important reason is that this is really a landmark study, and it’s going to help us understand whether or not Medicare and other insurance ought to pay for these very expensive scans.

(Bright IDEAS): What are next steps for you in the IDEAS Study?
(Dr. Lyketsos): While continuing to refer eligible patients, my emphasis now is to encourage my colleagues to take part in IDEAS. It’s going to help some of their patients, and make a big difference to the field to get the study done right.

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