title: The value of fourth and subsequent post-treatment 18F-FDG PET/CT scans in the management of patients with non-Hodgkin's lymphoma.
abstract: OBJECTIVE
  To evaluate the impact of fourth and subsequent follow-up PET/computed tomography (PET/CT) scans in patients with non-Hodgkins lymphoma (NHL).
  
  
  METHODS
  This retrospective study evaluated all biopsy-proven NHL patients who had more than three follow-up scans after completion of primary treatment from 2000 to 2013 at our academic center. Among 586 patients with NHL who had at least one fluorine-18 fluorodeoxyglucose (F-FDG) PET/CT scan at our institution, a total of 77 patients with 208 fourth and subsequent follow-up F-FDG PET/CT scans, were included in the study. The impact of these follow-up scans on the clinical assessment and the management of the patients was evaluated.
  
  
  RESULTS
  Among 208 fourth and subsequent follow-up scans, 33 were performed with a previous clinical suspicion of recurrence and 175 were performed without a previous clinical suspicion of recurrence. Fourth and subsequent follow-up PET/CT results were useful in excluding tumor in 27.3% of scan times when there was a clinical suspicion of recurrence and in identifying recurrence in 5.1% of scan times when there was no previous clinical suspicion of recurrence. Clinicians changed management after 36.4% (12/33) scans that were performed with previous clinical suspicion of recurrence and 9.2% (16/175) scans that were performed without previous clinical suspicion (P=0.001).
  
  
  CONCLUSIONS
  Fourth and subsequent follow-up PET/CT scans affect the treatment and management of patients with NHL and add value to clinical assessment and management, especially in patients with a previous clinical suspicion of recurrence.
authors.affiliation: aRussell H Morgan Department of Radiology and Radiological Sciences bDepartment of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins School of Medicine cDepartment of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Taghipour
authors.forename: Charles
authors.initials: C
authors.lastname: Marcus
authors.forename: Shani
authors.initials: S
authors.lastname: Jones
authors.forename: Rutuparna
authors.initials: R
authors.lastname: Sarangi
authors.forename: Tyler J
authors.initials: TJ
authors.lastname: Trahan
authors.forename: Rathan M
authors.initials: RM
authors.lastname: Subramaniam
mesh_terms: D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging* / Q000517:prevention & control*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18