Replacing Invasive Bone Marrow Sampling With FDG-PET in Pediatric Rhabdomyosarcoma Staging

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Data Quality: STRONG
Summary of  Journal of Clinical Oncology https://doi.org/10.1200/JCO-25-03080 
Dr. Federico Mercolini  et al.

Points

University Medicine Halle researchers evaluated FDG-PET imaging as a non-invasive alternative to invasive bone marrow sampling in pediatric rhabdomyosarcoma staging.
Soft-tissue sarcomas in children are predominantly comprised of rhabdomyosarcoma, which accounts for approximately sixty percent of all pediatric cases.
Clinical evaluation of over three hundred patients demonstrated that seventy-five percent had no observable tumor involvement within their bone marrow.
FDG-PET imaging detected thirty percent of positive marrow involvement cases that were completely missed by standard localized bone marrow puncture biopsies.
Implementing FDG-PET as the primary screening tool allows nearly three-quarters of pediatric patients to avoid painful and unnecessary invasive biopsies.

Summary

This study evaluated the diagnostic accuracy of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) imaging as a primary, non-invasive alternative to invasive bone marrow aspiration or biopsy for staging bone marrow infiltration in pediatric rhabdomyosarcoma. Rhabdomyosarcomas account for approximately 60% of all pediatric soft-tissue sarcomas. Led by Simone Hettmer at University Medicine Halle and published in the Journal of Clinical Oncology, the trial assessed whether FDG-PET imaging could replace invasive sampling, which carries risks of missing patchy marrow involvement due to localized puncture limitations.

The cohort comprised more than 300 pediatric patients with rhabdomyosarcoma, with 50% falling between 1 and 10 years of age. All participants underwent baseline bone marrow sampling and FDG-PET imaging prior to receiving surgical resection or systemic chemotherapy. Quantitative diagnostic analyses revealed no bone marrow involvement in 75% of patients. Among the remaining 25% with positive marrow involvement, concordant detection via both sampling and FDG-PET occurred in 70% of cases, while 30% of positive diagnoses were identified exclusively by FDG-PET. Only one patient (0.33%) demonstrated positive infiltration on invasive biopsy that went undetected by PET imaging.

Routine diagnostic staging protocols should adopt FDG-PET imaging as the initial diagnostic modality, reserving confirmation biopsies solely for FDG-avid foci to verify tumor involvement against inflammatory or traumatic false positives. The authors conclude that negative FDG-PET scans reliably rule out marrow involvement, allowing approximately 75% of pediatric rhabdomyosarcoma patients to avoid painful invasive sampling procedures without compromising staging accuracy or treatment planning.

Link to the article: https://link.springer.com/article/10.1186/s40337-026-01696-6

References

Mercolini, F., Just, M., Shulkin, B. L., Collins, N. B., Crane, J., Harrison, D., Affinita, M. C., Allen-Rhoades, W., Alessi, A., Asaftei, S. D., Arnold, M. A., Chen, S., Chiaravalli, S., FitzGerald, F., Freitag, M. T., Iftner, J. L., Khalatbari, H., De Keizer, B., Von Luettichau, I., … Zucchetta, P. (2026). Omitting bone marrow sampling in fdg-avid rhabdomyosarcoma with 2-[¹⁸ f]fdg pet-negative marrow: Results from an international retrospective study. Journal of Clinical Oncology, JCO-25-03080. https://doi.org/10.1200/JCO-25-03080