title: Prognostic significance of pretreatment ¹⁸F-FDG PET/CT in patients with relapsed/refractory B-cell non-Hodgkin's lymphoma treated by radioimmunotherapy using ¹³¹I-rituximab.
abstract: OBJECTIVE
  It was the aim of this paper to identify prognostic factors in patients with relapsed or refractory B-cell non-Hodgkin's lymphomas, treated by radioimmunotherapy (RIT) with radioiodinated human/murine chimeric anti-CD20 monoclonal antibody rituximab (¹³¹I-rituximab).
  
  
  METHODS
  Twenty-four patients were enrolled prospectively and were treated with unlabeled rituximab 70 mg and a therapeutic activity (median 7.3 GBq) of ¹³¹I-rituximab. Contrast-enhanced ¹⁸F-FDG PET/CT scans were performed before and after 1 month of RIT. Tumor sizes and maximum standardized uptake values (SUVmax) of scans were measured.
  
  
  RESULTS
  Four of the 24 patients survived. High SUVmax in a pretreatment scan was found to be related to poorer overall survival (OS) and progression-free survival (p = 0.04 and 0.02, respectively). Furthermore, a large tumor size in a pretreatment scan was associated with poorer OS but not with progression-free survival (p < 0.01 and p = 0.07, respectively). By multivariate analyses, a high SUVmax, a large tumor size in a pretreatment scan and diffuse large B-cell lymphoma histology were significantly associated with poorer OS [p = 0.04/hazard ratio (HR) = 3.54, p < 0.01/HR = 5.52, and p = 0.02/HR = 3.38, respectively).
  
  
  CONCLUSIONS
  SUVmax and tumor size determined by a pretreatment ¹⁸F-FDG PET/CT result as significant predictors of OS in patients with relapsed or refractory B-cell non-Hodgkin's lymphoma treated by RIT.
authors.affiliation: Department of Nuclear Medicine, Korea Cancer Center Hospital, Seoul, Republic of Korea.
authors.forename: Ilhan
authors.initials: I
authors.lastname: Lim
authors.forename: Joon Yeun
authors.initials: JY
authors.lastname: Park
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Kang
authors.forename: Jae Pil
authors.initials: JP
authors.lastname: Hwang
authors.forename: Seung Sook
authors.initials: SS
authors.lastname: Lee
authors.forename: Kyeong Min
authors.initials: KM
authors.lastname: Kim
authors.forename: Tae Hyun
authors.initials: TH
authors.lastname: Choi
authors.forename: Sung Hyun
authors.initials: SH
authors.lastname: Yang
authors.forename: Byung Il
authors.initials: BI
authors.lastname: Kim
authors.forename: Chang Woon
authors.initials: CW
authors.lastname: Choi
authors.forename: Sang Moo
authors.initials: SM
authors.lastname: Lim
mesh_terms: D000328:Adult; D000368:Aged; D058846:Antibodies, Monoclonal, Murine-Derived / Q000627:therapeutic use*; D018572:Disease-Free Survival; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000627:therapeutic use*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008228:Lymphoma, Non-Hodgkin / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D016017:Odds Ratio; D049268:Positron-Emission Tomography; D011379:Prognosis; D016499:Radioimmunotherapy; D019275:Radiopharmaceuticals / Q000627:therapeutic use*; D012008:Recurrence; D000069283:Rituximab; D014057:Tomography, X-Ray Computed
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D000069283:Rituximab; C507388:131I-rituximab