title: The role of positron emission tomography (PET) in the management of lymphoma patients.
abstract: BACKGROUND
  Treatment of both Hodgkin's disease (HD) and aggressive non-Hodgkin's lymphoma (NHL) with abdominal presentation at the time of diagnosis is often followed by detection of residual masses by computed tomography (CT). However, CT is usually unable to discriminate between residual tumor and fibrosis/necrosis. We investigated the ability of fluorine-18 fluorodeoxyglucose positron emission tomography (PET) to differentiate between residual active tumor tissue and fibrosis.
  
  
  METHODS
  Forty-four patients with HD or aggressive NHL presenting abdominal involvement (41% with bulky mass) were studied with CT and PET at the end of chemotherapy +/- radiation therapy.
  
  
  RESULTS
  After treatment, seven patients had negative PET and CT, and none of them relapsed. The remaining 37 patients all had positive CT (abnormalities < or = 10%). All of the 13 who also had positive PET relapsed (100%). By contrast, there was only 1 (4%) relapse among the 24 patients who were positive at CT but negative at PET. The two-year actuarial relapse-free survival rate was 95% for those with negative PET compared with 0% for positive PET patients (P < 0.000000).
  
  
  CONCLUSIONS
  In lymphoma patients with abdominal masses who present CT positivity at restaging, PET should be considered the noninvasive imaging modality of choice for differentiating early recurrences or residual disease from fibrosis.
authors.affiliation: Institute of Hematology and Medical Oncology Seràgnoli, University of Bologna, Italy. seragnol@kaiser.alma.unibo.it
authors.forename: P L
authors.initials: PL
authors.lastname: Zinzani
authors.forename: M
authors.initials: M
authors.lastname: Magagnoli
authors.forename: F
authors.initials: F
authors.lastname: Chierichetti
authors.forename: M
authors.initials: M
authors.lastname: Zompatori
authors.forename: G
authors.initials: G
authors.lastname: Garraffa
authors.forename: M
authors.initials: M
authors.lastname: Bendandi
authors.forename: F
authors.initials: F
authors.lastname: Gherlinzoni
authors.forename: C
authors.initials: C
authors.lastname: Cellini
authors.forename: V
authors.initials: V
authors.lastname: Stefoni
authors.forename: G
authors.initials: G
authors.lastname: Ferlin
authors.forename: S
authors.initials: S
authors.lastname: Tura
mesh_terms: D000005:Abdomen / Q000000981:diagnostic imaging; D000293:Adolescent; D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D005355:Fibrosis / Q000000981:diagnostic imaging; D006689:Hodgkin Disease / Q000000981:diagnostic imaging* / Q000628:therapy; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011860:Radiography, Abdominal; D012008:Recurrence; D012189:Retrospective Studies; D016019:Survival Analysis; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed