Neuroblastoma is a tumor of the sympathetic nervous system that occurs primarily in young children. Every year, 25 children in the Netherlands are diagnosed with this tumor. To determine the most appropriate treatment plan for each child, a scan is first used to determine the size of the tumor and whether there are metastases in the body. Multiple scans are also taken throughout treatment to see the effect of the treatment.
To make the tumors visible on the scans, a substance called mIBG is used to which a radioactive Iodine-123 tag is attached. The radioactive iodine emits gamma radiation which is then picked up by a special type of CT scanner, the SPECT-CT scanner, and converted into images.
Faster and friendlier
Atia Samim is a clinical researcher from the Tytgat group at the Princess Máxima Center involved in this study as part of her PhD. She conducted the study together with Dr. Bart de Keizer, principal investigator and nuclear medicine physician at Máxima and UMC Utrecht, and Dr. Lieve Tytgat, pediatric oncologist and research group leader at the Máxima Center. Samim explains why this study is important: 'Nine out of ten children diagnosed with neuroblastoma are younger than five years old. Because the current scan requires the children to lie still for 1.5 hours, they go under anesthesia for this. This is uncomfortable for many of these young children. In addition, the Iodine-123-labeled mIBG currently used is potentially harmful to the thyroid gland. Therefore, children must take medication to prevent damage.'
As the first in Europe, and partly thanks to KiKa's support, Samim was able to investigate whether the alternative mFBG scan is also applicable for children. This research is part of the Theranostics Research Group, a collaboration between the Máxima Center and UMC Utrecht, and has been published in scientific journal European Journal of Nuclear Medicine and Molecular Imaging.
Chemistry with radioactivity
To make the mFBG scan applicable to the children who participated in the study, Samim is working with Dr. Alex Poot. He is a radiochemist and works for both the Máxima Center and UMC Utrecht. 'By replacing the iodine atom, the I in mIBG, with a fluorine-18 atom, you get mFBG. We did this using various chemical processes. mFBG emits a different kind of radiation. We can make this so-called positron radiation visible with a PET scanner. This makes sharper images than the SPECT scanner we use with mIBG.'
All children who participated in the study received both scans. Thanks to the higher scan resolution of the mFBG PET scan, the tumors were seen sharper on image. With the mFBG PET scan, the researchers also found more frequent metastases that were not visible on the mIBG scan.
Where to go from here?
De Keizer: 'The goal of this first study was to determine whether the use of fluorine-18 mFBG is safe and practical for children. The results of this first study are promising, but a follow-up international study in a larger group of children is needed to put this into practice. For this we have once again received funding from KiKa. The preparations for the follow-up study from a European partnership have now started.'
Want to know more about this study? Then watch the video, made at the start of the study.