MFBG PET-CT / PS22PET

Recruiting

Who can enter

• Children and young adults with (suspected or proven) neuroblastoma who have been referred for an MIBG scan

• Age: 0-30 years

Goal

The goal of this study is to compare the MFBG scan with the current standard, the MIBG scan, in children and young adults with neuroblastoma. We want to see if this method is equally good at detecting the disease.

Background

Children with neuroblastoma often receive multiple MIBG scans at different times during treatment. These are used to visualize the extent of the disease and assess response to treatment. For these scans, children receive an injection with a mildly radioactive substance called meta-iodobenzylguanidine (MIBG). MIBG is then absorbed by the tumor cells. After 24 hours, the emitted radiation is imaged using a SPECT scanner.

A new scanning technique, the MFBG PET-CT scan, has recently become available and has important advantages over the MIBG scan. The substance meta-fluorobenzylguanidine (MFBG) is very similar to MIBG, only the radioactive iodine has been replaced by radioactive fluorine.

In a pilot study, 20 MFBG PET-CT scans were performed in children with neuroblastoma. Results were promising. MFBG PET-CT scanning was safe and less burdensome for the children. The children did not need to take medication to protect the thyroid gland. The injection and scan took place on the same day, instead of two days. The scan time was much shorter (10 minutes instead of 90 minutes), often eliminating the need for anesthesia. Because of the much sharper images, the MFBG PET-CT scan showed almost all (and often more) disease localizations that were visible on the MIBG scans.

More research is needed before this technique can be used in the clinic. In this study, the MFBG PET-CT scan will be compared with the MIBG scan in a larger group of children. We hope to prove that the MFBG PET-CT scan is indeed as good as the MIBG scan in detecting disease.

Currently, findings on the MIBG scan are used to make clinical decisions. If the MFBG PET-CT scan does indeed find more neuroblastoma locations, this may have implications for the patient, for example, for determining disease stage or treatment. Therefore, we also want to study possible changes in treatment and the prognostic value of the MFBG PET-CT scan.

Children participating in this study will undergo an MFBG PET-CT scan within two weeks of the MIBG scan. This means an additional appointment of about two hours, usually on the same day of the MIBG injection or MIBG scan. For the MFBG PET-CT scan, children receive an additional injection of MFBG via a vein. After about 60 minutes of waiting time, a 10-minute PET-CT scan is made. Patients who consent to a dynamic PET-CT scan will undergo a 70-minute scan (no waiting time) immediately after the injection. The radiation dose of an MFBG PET-CT scan is similar to that of an MIBG scan and is considered negligible. After the first MFBG PET-CT scan, children can undergo two more MFBG PET-CT scans.

In order to participate in a study please refer to your/your child’s doctor.

Last reviewed

March 23, 2026

The above information is intended as a brief summary only and may not reflect the most up-to-date information. For full details and the current status of a protocol, physicians can contact the Princess Máxima Center directly.

Summary

Better and faster visibility of neuroblastoma with mFBG PET-CT scans

Neuroblastoma tumors are becoming more accurately and quickly visible on scans thanks to a small modification in the radioactive agent used for this purpose. The mFBG PET scan being studied takes ten minutes instead of the hour and a half that the current mIBG scan takes. This is according to an initial clinical study. Fourteen children treated for neuroblastoma at the Princess Máxima Center participated. An international follow-up study is ongoing.

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 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.

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?

Principal investigator 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 follow-up study from a European partnership is now ongoing.'

This research is part of the Theranostics Research Group, a collaboration between the Máxima Center and UMC Utrecht.

Would you like to read the scientific publication? Please look here: Samim A, et al. [18F]mFBG PET-CT for detection and localisation of neuroblastoma: a prospective pilot study. Eur J Nucl Med Mol Imaging. 2023 Mar;50(4):1146-1157.