PET/CT Successfully Monitors Crohn's Disease Activity

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PET/CT Successfully Monitors Crohn's Disease Activity

WASHINGTON, DC -- June 6, 2007 -- The molecular imaging power of

PET/CT is invaluable in noninvasively monitoring Crohn's disease,

according to a study released by Belgian scientists at the 54th

Annual Meeting of the Society of Nuclear Medicine. " Our study is the

first one demonstrating the value of PET/CT in Crohn's disease, " said

Roland Hustinx, head of the nuclear medicine division at the

University Hospital of Liège and professor of nuclear medicine at the

University of Liège. " PET/CT (positron emission tomography/computed

tomography) imaging--with the radiotracer fluorodeoxyglucose or FDG--

could be used as a first-step test in patients with clinical or

biological signs suggesting active disease, " he noted. " PET/CT can

answer the major question: What is the activity of the disease. "

Crohn's disease, an inflammatory bowel disease (IBD) that can affect

the digestive system, has no medical cure, and its causes are

unknown, explained Hustinx. Once the disease begins, it can fluctuate

between periods of remission and relapse. During relapses, symptoms--

varying in nature, frequency and intensity--include abdominal pain,

diarrhea and worsening general physical condition. Estimates indicate

that up to 2 million people in this country could be affected by

Crohn's and related diseases. IBD most commonly begins during

adolescence and early adulthood. " The clinical course of the disease

is characterized by a succession of periods of clinical relapses and

remissions, " said Hustinx. " Its diagnosis relies on clinical and

biological signs (markers of inflammation in the blood) as well as

direct examination of the bowel using ileocolonoscopy, an endoscopic

examination of the large bowel, where the last part of the small

bowel (ileum) is also examined, " added Hustinx, who indicated that

prevalence of the disease is increasing. " Endoscopic evaluation--a

diagnostic medical procedure in which a small, flexible tube with a

light and lens is inserted into the body to assess the interior

surfaces of an organ--is the gold standard to answer, 'What is the

activity of this disease'. " said Hustinx. The answer to this question

will decide whether the clinician prescribes a treatment that is

likely to be effective but also very costly and associated with side

effects. " Ileocolonoscopy is invasive, unpleasant for the patient,

sometimes incomplete due to unreachable segments and can only assess

mucosal lesions, while the disease may sometimes affect deeper parts

of the bowel wall, " he indicated. " The big advantage of PET/CT is

that it is noninvasive, simple, fast and without any side effects.

There was no preparation for the patients, except that they fasted

for six hours. Each study took less than 20 minutes, " said

Hustinx. " If the PET/CT is positive, the doctor should confirm the

results using endoscopy. If the PET/CT is negative, there would be no

need for the endoscopy--given the high negative predictive value of

the technique, " he added. " In our study, all bowel areas that showed

severe endoscopic lesions were correctly identified by PET/CT. There

was not a single case in which the ileocolonoscopy showed severe

lesions and PET/CT showed a normal metabolic activity, " said

Hustinx. " Conversely, this means that when the PET/CT is negative--no

matter how important the clinical symptoms are--the disease is not

active, " he added. " PET/CT has, therefore, the potential to deeply

modify the exploration algorithm of patients with Crohn's, reducing

the number of endoscopic examinations and allowing a better,

noninvasive monitoring of the disease's activity, " he indicated.

PET/CT molecular imaging--with radioactive drugs such as FDG--enables

the collection of both biological and anatomical information during a

single exam, with PET picking up metabolic signals of body cells and

tissues and CT offering a detailed map of internal anatomy. " Our

results must be confirmed by other investigators on a larger scale, "

said Hustinx, indicating that his team is currently conducting a

study evaluating the capacity of PET/CT to assess early on the

response of the disease to " biological treatments. " Treatment has

been significantly improved over the past few years with the

development of biological treatments, which have shown potential for

obtaining mucosal healing in Crohn's disease, noted Hustinx. " This

mucosal healing has been associated with higher sustained quality of

life, lower rate of hospitalization and lower need for surgery. A

sustained clinical remission--and a control of intestinal lesion--has

become the target of new treatment strategies, " he said.

SOURCE: Society of Nuclear Medicine