title: Pediatric nonlymphoblastic non-Hodgkin lymphoma: baseline, interim, and posttreatment PET/CT versus contrast-enhanced CT for evaluation--a prospective study.
abstract: OBJECTIVE
  To prospectively examine the roles of positron emission tomography (PET)/computed tomography (CT) and conventional contrast material-enhanced CT at baseline, after two cycles of chemotherapy, and after completion of chemotherapy in pediatric patients with nonlymphoblastic non-Hodgkin lymphoma (NHL) who were treated with similar standard treatment protocols.
  
  
  METHODS
  The institutional ethics committee approved the study protocol, and all patients were enrolled after written informed consent was obtained. Patients with nonlymphoblastic NHL were prospectively enrolled between January 2008 and March 2010. Patients underwent contrast-enhanced CT and PET/CT for staging and for response assessment after two cycles of chemotherapy (interim) and treatment completion. Complete metabolic response versus no metabolic response at PET/CT and complete response versus no complete response at contrast-enhanced CT was analyzed by using Kaplan-Meier survival analysis.
  
  
  RESULTS
  The final study included 34 patients with nonlymphoblastic NHL (median age, 10.5 years). Baseline PET/CT and contrast-enhanced CT showed concordance in depiction of 112 disease sites; PET/CT depicted 18 more disease sites and two fewer disease sites than contrast-enhanced CT (P = .0003). Disease in five of 34 patients was upstaged, and disease in no patient was downstaged at PET/CT. There was 100% (four of four) concordance between bone marrow involvement at biopsy and stage at PET/CT. The median length of follow-up was 20.3 months. Response at interim PET/CT and contrast-enhanced CT could not predict progression-free survival (PFS) (P = .083 and .18, respectively) or overall survival (OS) (P = .159 and.08, respectively). Posttreatment PET/CT and contrast-enhanced CT findings could predict PFS (P = .036 and .002, respectively) and posttreatment contrast-enhanced CT findings could predict OS (P = .035); however, posttreatment PET/CT findings could not predict OS (P = .067).
  
  
  CONCLUSIONS
  PET/CT depicts additional sites compared with contrast-enhanced CT and results in upstaging of disease. Either PET/CT or contrast-enhanced CT may be used for response assessment and prognostication in stage III or IV nonlymphoblastic pediatric NHL.
authors.affiliation: Department of Medical Oncology, Dr BRA Institute Rotary Cancer Hospital, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India. sambakh@hotmail.com
authors.forename: Sameer
authors.initials: S
authors.lastname: Bakhshi
authors.forename: Venkatraman
authors.initials: V
authors.lastname: Radhakrishnan
authors.forename: Punit
authors.initials: P
authors.lastname: Sharma
authors.forename: Rakesh
authors.initials: R
authors.lastname: Kumar
authors.forename: Sanjay
authors.initials: S
authors.lastname: Thulkar
authors.forename: Sreenivas
authors.initials: S
authors.lastname: Vishnubhatla
authors.forename: Deepa
authors.initials: D
authors.lastname: Dhawan
authors.forename: Arun
authors.initials: A
authors.lastname: Malhotra
mesh_terms: D000293:Adolescent; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D003973:Diatrizoate; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007479:Iopamidol / Q000031:analogs & derivatives; D053208:Kaplan-Meier Estimate; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000473:pathology; D008297:Male; D064847:Multimodal Imaging / Q000379:methods*; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D011857:Radiographic Image Interpretation, Computer-Assisted; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D003973:Diatrizoate; C057937:iomeprol; D007479:Iopamidol