title: [18F]-FDG PET/CT in the staging and management of indolent lymphoma: A prospective multicenter PET registry study.
abstract: BACKGROUND
  To measure the clinical impact of pretreatment fludeoxyglucose positron emission tomography/computed tomography (PET/CT) on the staging and management of apparent limited stage indolent lymphoma being considered for curative radiation therapy.
  
  
  METHODS
  We conducted a prospective multicenter registry study that included 197 patients accrued between May 1, 2012, and December 31, 2015. Pre-PET/CT stage, determined by clinical and CT data, was documented. If pre-PET/CT stage was indeterminate, a stage was assigned to the patient by the referring oncologist according to best clinical judgment and treatment intent. After PET/CT, revised stage and planned management were recorded and compared with data on actual treatment received available through provincial databases (n = 155).
  
  
  RESULTS
  PET/CT resulted in the upstaging of 47 (23.9%) patients with presumed limited stage disease (stage I-II) to advanced stage disease (stage III-IV) (P < .0001). Ten (5.1%) patients were downstaged by PET/CT, 4 of whom migrated from advanced to limited stage disease. Twenty-eight (14.2%) patients with a specific pre-PET/CT stage had equivocal PET/CT findings that required further evaluation to confirm disease extent. After PET/CT, 95 (61.3%) patients were planned to receive active treatment. Of the 59 patients planned for radiotherapy alone post-PET/CT, 34 (57.6%) received this treatment (P = .002), and nearly 80% of them (n = 27) had confirmed limited stage disease.
  
  
  CONCLUSIONS
  PET/CT has a significant impact on staging and management in patients with apparent limited stage indolent lymphoma who are being considered for curative radiotherapy. PET/CT should be routinely incorporated into the workup of these patients. Cancer 2017;123:2860-66. © 2017 American Cancer Society.
authors.affiliation: Joint Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Ur
authors.initials: U
authors.lastname: Metser
authors.affiliation: Department of Oncology, Cancer Centre of Southeastern Ontario, Queen's University, Kingston, Ontario, Canada.
authors.forename: Jill
authors.initials: J
authors.lastname: Dudebout
authors.affiliation: Department of Oncology, Cancer Centre of Southeastern Ontario, Queen's University, Kingston, Ontario, Canada.
authors.forename: Tara
authors.initials: T
authors.lastname: Baetz
authors.affiliation: Department of Radiation Oncology, University of Toronto, and Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario, Canada.
authors.forename: David C
authors.initials: DC
authors.lastname: Hodgson
authors.affiliation: Cancer Imaging, Clinical Programs and Quality Initiatives, Cancer Care Ontario, Toronto, Ontario, Canada.
authors.forename: Deanna L
authors.initials: DL
authors.lastname: Langer
authors.affiliation: Cancer Imaging, Clinical Programs and Quality Initiatives, Cancer Care Ontario, Toronto, Ontario, Canada.
authors.forename: Pamela
authors.initials: P
authors.lastname: MacCrostie
authors.affiliation: Cancer Analytics, Cancer Care Ontario, Toronto, Ontario, Canada.
authors.forename: Victor
authors.initials: V
authors.lastname: Mak
authors.affiliation: Joint Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Noam
authors.identifier: http://orcid.org/0000-0003-0849-1708
authors.initials: N
authors.lastname: Tau
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019468:Disease Management; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009864:Ontario; D000072078:Positron Emission Tomography Computed Tomography; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D012042:Registries; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: B-cell; chemoradiotherapy; follicular lymphoma; low-grade lymphoma; lymphoma; positron emission tomography computed tomography; radiotherapy; registries