title: 18F-FDG PET/CT is useful in initial staging, restaging for pediatric rhabdomyosarcoma.
abstract: BACKGROUND
  This study aimed to evaluate 18F-fluordeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) as an adjunct to CT and/or magnetic resonance imaging (MRI) in the staging and follow-up of pediatric rhabdomyosarcoma (RMS).
  
  
  METHODS
  A total of 28 consecutive pediatric RMS (20 males, 8 females; mean age: 4.8 years, 10 embryonal, 18 alveolar), in whom FDG PET/CT was performed at staging (13 patients), to evaluate the therapeutic effects and to follow-up (15 patients), were retrospectively included. FDG PET/CT was compared with MRI or CT performed with a less than a 10-day interval for initial staging in 13 patients. Histological data and follow-up (mean, 18 months) were considered as the standard of reference for result interpretation.
  
  
  RESULTS
  At staging, FDG PET/CT and CT/MRI were equally effective in the detection of the primary RMS (accuracy, 100%). FDG PET/CT revealed metastases in lymph nodes, prostate, intestinal wall, chest wall and the peritoneum in 5 patients missed by CT or MRI, and found 41positive lymph node territories in 6 patients, 8 lung metastases in 3 patients and 40 lesions located in other anatomical regions (muscle, brain, etc.) in 4 patients versus 16, 6, and 29 for CT or MRI. In 4 patients (31%), modifications were made and comprised 1 local therapy change and 3 changes of systemic treatment as well. Follow-up time ranged from 3 to 48 months, with a median follow-up time of 18 months in 15 patients for evaluation of therapeutic effects. Alveolar RMS (ARMS) had significantly high SUVmax, and more metastases was found in ARMS.
  
  
  CONCLUSIONS
  18F-FDG PET/CT may be useful in staging and restaging pediatric RMS, especially for assessing secondary lesions with potential therapeutic strategy alteration. The significant high SUVmax of ARMS and more metastases may indicate worse prognosis which needs further study. This study confirms that 18F-FDG PET/CT is also valuable in therapeutic assessment and follow-up.
authors.affiliation: Nuclear Medicine, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.|Radiation Oncology, NO.9 People Hospital Affiliated to Shanghai Tiao Tong, University School of Medicine, Shanghai, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Department of Surgery, Linyi People's Hospital, Linyi, Shandong, China.
authors.forename: Xuemei
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Nuclear Medicine, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Shaoyan
authors.initials: S
authors.lastname: Wang
authors.affiliation: Nuclear Medicine, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Suyun
authors.initials: S
authors.lastname: Chen
authors.affiliation: Nuclear Medicine, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China - mc_7419@hotmail.com.
authors.forename: Chao
authors.initials: C
authors.lastname: Ma
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000737:chemistry*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D064847:Multimodal Imaging / Q000379:methods; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D011467:Prostate / Q000000981:diagnostic imaging; D019275:Radiopharmaceuticals / Q000737:chemistry*; D012189:Retrospective Studies; D018232:Rhabdomyosarcoma, Alveolar / Q000000981:diagnostic imaging / Q000473:pathology*; D018233:Rhabdomyosarcoma, Embryonal / Q000000981:diagnostic imaging / Q000473:pathology*; D012680:Sensitivity and Specificity
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18