Imaging features of pediatric rhabdomyosarcoma on 18F-FDG PET/CT

Abstract

Objective To summarize the 18F-fluorodeoxyglucose (FDG) PET/CT findings of pediatric rhabdomyosarcoma (RMS), and to explore the value of PET/CT in the diagnosis of RMS. Methods PET/CT images and clinical data of 29 RMS patients (15 males, 14 females, age range: 1-14 years) histopathologically confirmed from July 2011 to September 2017 were evaluated retrospectively. The imaging features were analyzed, and the maximum standardized uptake value (SUVmax) ratios of tumors to the liver (TLR) in different pathological types of RMS were calculated and compared. Mann-Whitney u test was used to analyze the data. Results There were 19 patients with embryonic RMS, 7 with alveolar RMS, and 3 with unknown types. The median SUVmax of primary lesion was 6.8(4.3, 8.9). There were no statistically significant differences in SUVmax (6.2(4.3, 8.8) vs 5.3(4.0, 9.0)) and TLR (3.6(2.6, 8.1) vs 3.0(2.2, 6.3)) between embryonic RMS and alveolar RMS (u values: 60.00 and 48.50, both P>0.05). PET/CT detected lymph nodes lesions with increased metabolism in 15 patients, lung lesions in 6 patients, bone or bone marrow lesions in 4 patients and breast involvement in 2 patients. Conclusion 18F-FDG PET/CT can indicate the extent and metabolic activity of RMS, thus providing information for clinical practice. Key words: Rhabdomyosarcoma; Child; Positron-emission tomography; Tomography, X-ray computed; Deoxyglucose