The Children's Hospital of Philadelphia
www.chop.edu
Unraveling the Mysteries of Hyperinsulinism - PET: A Breakthrough in Testing

Laura Ann Warner, NP: If patients don't respond to medical therapy then we have other diagnostic techniques that we use.

N. Scott Adzick, MD: Clinically if you have a baby with diffuse disease next to a baby with focal disease they look exactly alike, clinically. So it was our task to try to differentiate the two, because obviously treatment of the two groups is completely different.

Lisa Mass, Parent: Our daughter, Caroline, was born on June 13, at Central Baptist Hospital in Lexington, Kentucky. She was pronounced healthy and we were discharged from the hospital and getting ready to go home when a very astute nurse noticed and thought that Caroline seemed cold and a little bit lethargic.

Michael Mass, Parent: We were worried about the usual things that you worry about. You know you want them to be healthy and you want them to have ten fingers and ten toes, but we had never heard about hyperinsulinism.

Charles A. Stanley, MD: What's really been exciting in the last five years is the realization that there are a large number of babies with focal disease that can be cured by surgery and so we have a much more directed approach to surgery.

N. Scott Adzick, MD: The breakthrough diagnostically has been the development of a PET scan technique, which can precisely tell us whether the baby has diffuse disease or focal disease. And then with a great deal of accuracy for those babies with focal lesions tell us where in the pancreas the focal lesion is.

Michael Mass, Parent: We knew that we had hyperinsulinism, but we didn't know what type of hyperinsulinism we had and the PET scan was something that they are working with here to try and help identify whether you're dealing with a focal issue, or if it was diffuse.

Abass Alavi, MD: The way the PET scan works is based on radiopharmaceuticals. That means drugs that are labeled with radioactive material. We send these drugs into the body and ask them, "tell us what's happening in the brain. Tell us what's happening in the heart. Tell us what's happening in the pancreas."

Charles A. Stanley, MD: You inject radioactively labeled dopa and collect images of the pancreas and in the focal lesion it's accumulated within the cell and as it releases radioactivity that's then detected to make an image of the pancreas that shows where the focal lesion is.

Laura Ann Warner, NP: A focal lesion on the PET scan lights up like a light bulb.

N. Scott Adzick, MD: It's a very intuitive thing. You see a beacon, quite bright, that localizes a focal lesion.

Charles A. Stanley, MD: So it tells the surgeon exactly where to go to look for the focal lesion and it also allows us to very accurately discriminate between babies that have diffuse disease and those that have focal disease.

N. Scott Adzick, MD: The substance 18-fluorodopais used for this PET scan is actually prepared in the PET cyclotron.

Abass Alavi, MD: This is not a drug that you can put on a shelf and use it whenever you want. This is the case with penicillin, aspirin. But in our case these are radioactive drugs and have a finite half-life. Then in a short period of time they will disappear.

Charles A. Stanley, MD: We currently have to do the PET scans under a Food and Drug Administration IMD protocol. So it's available here at Children's Hospital of Philadelphia, but it's not widely available across the U.S.

Laura Ann Warner, NP: Planning and scheduling your PET scan requires a multi-disciplinary team approach between the cyclotron, who must make the 18-fluorodopa on the day of the study, and the PET center.

Abass Alavi, MD: We have to determine the dose that we have to give to the child based on the child's body weight and by then we have positioned the child in the machine area. The anesthesiologist has induced anesthesia and the dose is ready to be injected.

Unknown speaker in background: So what he wants to know is where does this fall in the CT?

Abass Alavi, MD: Combining PET with CAT scan allows us to show the disease superimposed on the structure for the surgeon to find exactly where he should go. So having, of course, function, which is what we do with PET, and the structure, which is what the CAT scan shows, gives him a road map as to where things are.