Imaging agent to diagnose Parkinson’s approved
November 21, 2018
MISSISSAUGA, Ont. – The symptoms can start with something as minor as a trembling hand, stiffness in the morning, the loss of sense of smell, or trouble tying shoes and buttoning shirts. Individually, these changes might be nothing to worry about, but together they could be signs of Parkinson’s disease (PD).
Parkinson’s disease is a chronic, degenerative neurological disorder marked by a progressive loss of dopamine in the brain, which can cause symptoms to appear like tremors, muscle stiffness and difficulty with balance and walking. It’s estimated that PD affects at least one million people in the United States and more than 10 million worldwide.
“In Canada there are about 100,000 people with Parkinson’s. We want to ensure that each individual who needs help receives it in a timely way from those who can best provide it,” says Joyce Gordon (pictured), CEO of Parkinson Canada, an organization that advocates on issues that affect the Parkinson’s community in Canada.
Most Parkinson’s patients can be diagnosed by an experienced neurologist during a clinical exam. But PD symptoms can be similar to other neurological conditions, which can make it difficult even for experienced clinicians to accurately diagnose PD in selected patients.
Since the beginning of 2018, GE Healthcare’s DaTscan (Ioflupane I 123 Injection) imaging agent has been available in Canada to help physicians evaluate patients with a suspected parkinsonian syndrome (PS), such as Parkinson’s disease. Currently, it’s the only imaging agent on the market approved to aid in the diagnosis of PS.
DaTscan is a radiopharmaceutical indicated for visualization of functional striatal dopamine transporter using single photon emission computed tomography (SPECT) brain imaging.
In adult patients with suspected Parkinsonian Syndromes (PS), DaTscan SPECT imaging may be used as an adjunct to other established evaluations to help differentiate essential tremor from tremor due to PS related to idiopathic Parkinson’s Disease (PD), multiple system atrophy (MSA) and progressive supranuclear palsy (PSP). DaTscan is unable to discriminate between PD, MSA and PSP.
DaTscan is contraindicated in patients who are hypersensitive to this drug or to any ingredient in the formulation or component of the container.
Radiopharmaceuticals should be used only by those health professionals who are appropriately qualified in the use of radioactive prescribed substances in or on humans. As in the use of any other radioactive material, care should be taken to minimize radiation exposure to patients consistent with proper patient management, and to minimize radiation exposure to occupational workers.
“It’s a new opportunity to help aid in the diagnosis of people with Parkinson’s and that makes it exciting,” Gordon says. “I think doctors will be glad to know there is another tool they can use to help people get a timely diagnosis.”
Timely diagnosis may help patients get a jump start on treatment, including lifestyle choices, and gather information about new treatment options and building strong support networks.
DaTscan is a radioactive drug that is injected into the bloodstream to image a specific area of the brain (the striatum) using a SPECT camera.
“You inject a small amount of this radioactive iodine and it then lights up the brain,” says Dr. Anthony Lang, movement disorders specialist at Toronto Western Hospital. “In a normal individual you see very active dopamine transporter activity in the region of the striatum, which tells you that the dopamine cells are intact and they’re normally functioning and taking up the dopamine. In Parkinson’s disease, and other degenerative diseases where the dopamine cells are damaged and are dying, you see a loss of the dopamine transporter.”
Dr. Philippe Rizek, movement disorders specialist at Credit Valley Hospital, explains his most recent clinical experience with DaTscan. “I have a patient, 35 years old, who presented to my clinic with atypical Parkinson’s Disease symptoms. His onset of symptoms began four years ago, and it was difficult to determine if this was related to neurodegenerative parkinsonism or other factors, especially since his initial response to levodopa treatment was unclear,” says Dr. Rizek.
“The diagnosis was difficult to make due to atypical features, but the DaTscan test helped to assess he indeed has neurodegenerative Parkinson disease, and now my primary goal is to optimize his medications to better manage the symptoms.”
“We now have a diagnostic test, when used in the right subset of patients, which can help diagnose unexplained clinical presentations for confident patient management.”
Dr. Rizek adds, “The diagnosis of PD is largely clinical, but DaTscan may be useful in cases of doubt after being seen only by a movement disorder specialist.”
Probhash Mondal, CEO and managing director, Guelph Medical Imaging, says, “Access to this important diagnostic test offers Canadian patients and Movement Disorders Specialists in our community and across the country an opportunity for a more confident diagnosis. Guelph Medical Imaging is proud to offer the DaTscan test at our facility and have offered it recently to two eligible Canadian patients.”
Further, Dr. Lang says DaTscan can help patients, while also helping push research forward.
“There is a lot of research to study experimental therapies that could slow the progression of the disease,” says Dr. Lang. “It’s very important to have patients at the earliest stages of the disease, often when it’s more difficult to make an accurate diagnosis. You have to be pretty certain that they actually have the dopamine deficiency typical of Parkinson’s if you’re going to enroll them.”
Until these types of studies eventually lead to a cure, Dr. Lang, Dr. Rizek and Parkinson Canada will continue to work together to advocate for Parkinson’s patients and their families.
“We are building a movement of people that will engage the Parkinson’s community and develop meaningful change for people living with Parkinson’s to live well,” says Gordon. “For the more than 25 people in Canada diagnosed each day, a cure can’t wait.”
For more information please consult the product monograph at http://www3.gehealthcare.com/~/media/Documents/MarketoPDFsnogating/