MFBG PET Improves Baseline Staging in Neuroblastoma
Key Takeaways
- Among children undergoing baseline staging for newly diagnosed neuroblastoma, [18F]MFBG PET detected marrow metastases more often than comprehensive anatomic imaging: 65% versus 32.5%.
- Additional imaging findings were associated with INRG upstaging in 20% of children and tumor-board treatment modification in 10%.
- Half of the children initially classified as stage L2 were upstaged after hNET-targeted PET.
- In children examined with both PET tracers, patient-level INRG stage was fully concordant, although marrow and nodal findings differed.
Investigators enrolled children with newly diagnosed neuroblastoma in a prospective baseline imaging study. All underwent [18F]MFBG PET and comprehensive anatomic imaging, described by the authors as neck-to-pelvis computed tomography (CT) and/or magnetic resonance imaging (MRI) plus whole-body ultrasonography; for the 36 children with abdominal or pelvic primaries, their results specify contrast-enhanced abdominopelvic CT/MRI and noncontrast cervicothoracic CT.. Lesion distribution and International Neuroblastoma Risk Group (INRG) stage were recorded. A subset also underwent paired fluorodeoxyglucose ([18F]FDG) PET.
[18F]MFBG PET identified marrow metastases significantly more often than comprehensive anatomic imaging. The difference persisted when the comparison was restricted to the overlapping field of view from the neck to the proximal femur, rather than relying on the broader coverage of PET. Additional findings were associated with INRG upstaging and treatment modification after tumor-board review.
In the paired PET subset, the two tracers produced fully concordant patient-level INRG stage assignments. Their lesion-level findings differed: [18F]MFBG PET showed greater marrow disease burden, whereas [18F]FDG PET identified additional nodal lesions in some children.
The comparison with [18F]FDG PET was limited to children who received both examinations, rather than the full enrolled cohort. The observed associations between additional marrow findings, stage reclassification, and tumor-board treatment modification do not establish that the scan itself caused a particular treatment decision.
The authors concluded that baseline hNET-targeted PET identified marrow involvement beyond comprehensive anatomic imaging in newly diagnosed neuroblastoma, accompanying stage and management changes in some children. In paired examinations, patient-level staging matched between PET tracers despite differences in marrow and nodal lesion findings.
Clinician Questions
Were [18F]MFBG PET and anatomic scans interpreted independently in newly diagnosed neuroblastoma?
Yes. Investigators independently interpreted baseline [18F]MFBG PET and comprehensive anatomic imaging in consecutively enrolled children with newly diagnosed neuroblastoma, then recorded lesion distribution and INRG stage.
How were detection and agreement between neuroblastoma imaging modalities compared?
In children with newly diagnosed neuroblastoma, investigators used the McNemar test for paired marrow detection-rate comparisons and Cohen κ statistics for intermodality concordance; Wilcoxon signed-rank tests compared Curie scores.