Federico Mercolini, Marissa Just, Barry L Shulkin, Natalie B Collins, Jacquelyn Crane, Douglas Harrison, Maria C Affinita, Wendy Allen-Rhoades, Alessandra Alessi, Sebastian D Asaftei, Michael A Arnold, Sonja Chen, Stefano Chiaravalli, Forrest FitzGerald, Martin T Freitag, Jessica L Iftner, Hedieh Khalatbari, Bart de Keizer, Irene von Luettichau, Christine Mauz-Körholz, Claudia Rossig, Guido Rovera, Stefan Rutkowski, Justin B Sims, Stephan D Voss, Ayami Yoshimi, Suzi Birz, Gianni Bisogno, Martin Ebinger, Johannes H M Merks, Monika Sparber-Sauer, Bernhard Haller, Aaron R Weiss, Corinne M Linardic, Reineke A Schoot, Simone Hettmer, INSTRuCT Imaging/Pathology/Biology Network
Bone marrow sampling may be omitted in patients without evidence of FDG-avid bone marrow disease by PET. If there are FDG-avid bone marrow lesions, further investigation by MRI and/or biopsy should be considered.
PURPOSE: Detection of bone marrow disease has been a major component of rhabdomyosarcoma (RMS) staging with bilateral bone marrow aspirates/biopsies (BMAB) from the iliac crests considered the diagnostic gold standard. This study's goal was to determine if 2-18F-labeled fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG PET/CT) or PET/magnetic resonance imaging (MRI) may replace BMAB in RMS staging.
METHODS: Patients were recruited in Europe and North America. Medical records, FDG PET/CT or FDG PET/MRI (PET), and BMAB reports were collected retrospectively. Images were re-reviewed by nuclear medicine physicians at the patients' home institutions if PET reports indicated increased FDG uptake at bone/bone marrow sites or if tumor cells were detected in bone marrow samples.
RESULTS: PET imaging and BMAB were performed before chemotherapy and tumor resection in 301 patients with FDG-avid RMS. Bone marrow metastases were detected by PET and BMAB in 54, by PET only in 24, and by BMAB only in one of 301 patients with FDG-avid primary tumors. Absence of bone marrow metastases was confirmed by PET and BMAB in 222 of 301 patients. These observations translated into 98% sensitivity and 90% specificity for PET in detecting bone marrow metastases when BMAB was considered as gold standard. FDG-avid marrow disease was patchy (1-5 foci) in one third of cases. Patients with marrow disease indicated by PET and BMAB had more FDG-avid bone marrow foci, more metastatic sites, and lower survival than those with marrow disease indicated by PET only, suggesting more advanced disease stages.
CONCLUSION: Bone marrow sampling may be omitted in patients without evidence of FDG-avid bone marrow disease by PET. If there are FDG-avid bone marrow lesions, further investigation by MRI and/or biopsy should be considered.