title: 18F-FDG PET-CT imaging versus bone marrow biopsy in pediatric Hodgkin's lymphoma: a quantitative assessment of marrow uptake and novel insights into clinical implications of marrow involvement.
abstract: OBJECTIVE
  To evaluate whether positron emission tomography/computed tomography using fluorine-18 fluoro-deoxyglucose (18F-FDG PET-CT) predicts bone marrow involvement (BMI) in pediatric Hodgkin's lymphoma (pHL) with sufficient accuracy to supplant routine staging bone marrow biopsy (BMB), and to assess the clinical importance of marrow disease by comparing the prognosis of stage IV HL with BMI versus that without BMI.
  
  
  METHODS
  Data were retrospectively analyzed for all cases of pHL between July 2010 and June 2015 referred for staging18F-FDG PET-CT scan and BMB. The reference standard was BMB. Stage IV patients were divided into three groups to compare their progression-free and overall survival: PET+ BMB-, PET+ BMB+, and PET- BMB-.
  
  
  RESULTS
  Of the 784 patients, 83.3% were male and 16.7% female, with age ranging from 2 to 18 years (mean 10.3 years). Among the total cases, 104 (13.3%) had BMI; of these, 100 were detected by PET imaging and 58 by BMB. BMB and18F-FDG PET/CT scans were concordant for BMI detection in 728 patients (93%): positive concordance in 54 and negative in 674. Of the 56 discordant cases, four had a false-negative PET scans and were upstaged by BMB, 46 with focal uptake were PET/CT-positive and BMB-negative (not obtained from active sites), and six with diffuse uptake were false-positive on PET due to paraneoplastic marrow activation. The sensitivity, specificity, PPV, and NPV of PET for identifying BMI was 93.6, 94, 53, and 99.4% respectively. On quantitative assessment, mean iBM-SUVmaxof bilateral iliac crests was significantly higher in those with BMI versus those without (p < 0.05).
  
  
  CONCLUSIONS
  18F-FDG PET-CT imaging is more sensitive than BMB for BMI detection in pHL staging. BMB should be limited to those with normal marrow uptake in the presence of poor risk factors or those with diffusely increased uptake to exclude marrow involvement in the background of reactive marrow.
authors.affiliation: Department of Nuclear Medicine, Shaukat Khanum Memorial Cancer Hospital and Research Centre, 7-A, Block R-3, Johar Town, Lahore, Pakistan, 54000. aamnah@skm.org.pk.
authors.forename: Aamna
authors.initials: A
authors.lastname: Hassan
authors.affiliation: Department of Nuclear Medicine, Shaukat Khanum Memorial Cancer Hospital and Research Centre, 7-A, Block R-3, Johar Town, Lahore, Pakistan, 54000.
authors.forename: Maimoona
authors.initials: M
authors.lastname: Siddique
authors.affiliation: Department of Nuclear Medicine, Shaukat Khanum Memorial Cancer Hospital and Research Centre, 7-A, Block R-3, Johar Town, Lahore, Pakistan, 54000.
authors.forename: Humayun
authors.initials: H
authors.lastname: Bashir
authors.affiliation: Department of Nuclear Medicine, Shaukat Khanum Memorial Cancer Hospital and Research Centre, 7-A, Block R-3, Johar Town, Lahore, Pakistan, 54000.
authors.forename: Saima
authors.initials: S
authors.lastname: Riaz
authors.affiliation: Paediatric Oncology, Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan.
authors.forename: Rabia
authors.initials: R
authors.lastname: Wali
authors.affiliation: Paediatric Oncology, Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan.
authors.forename: Asma
authors.initials: A
authors.lastname: Mahreen
authors.affiliation: Department of Nuclear Medicine, Shaukat Khanum Memorial Cancer Hospital and Research Centre, 7-A, Block R-3, Johar Town, Lahore, Pakistan, 54000.
authors.forename: M Khalid
authors.initials: MK
authors.lastname: Nawaz
mesh_terms: D000293:Adolescent; D001692:Biological Transport; D001706:Biopsy; D001853:Bone Marrow / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D006689:Hodgkin Disease / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D008297:Male; D009367:Neoplasm Staging; D000072078:Positron Emission Tomography Computed Tomography; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: Bone marrow biopsy; Para-neoplastic marrow activation; Pediatric Hodgkin’s lymphoma; Staging 18F-FDG PET-CT; Standardized uptake value