title: Does tumoral (111)In-ibritumomab accumulation correlate with therapeutic effect and outcome in relapsed or refractory low-grade B-cell lymphoma patients undergoing (90)Y-ibritumomab radioimmunotherapy?
abstract: OBJECTIVE
  The aim of this study was to determine whether tumoral (111)In-ibritumomab accumulation on pre-treatment imaging correlates with therapeutic responses and progression-free survival (PFS) in patients with non-Hodgkin's lymphoma (NHL) undergoing (90)Y-ibritumomab radioimmunotherapy (RIT).
  
  
  METHODS
  This was a retrospective study of 39 patients with low-grade B-cell NHL treated with RIT. We classified the patients into positive and negative groups according to the presence or absence of tumoral (111)In-ibritumomab accumulation on pre-treatment (111)In-ibritumomab examinations. We then determined the correlation between the (111)In-ibritumomab imaging findings and the patients' therapeutic responses and PFS.
  
  
  RESULTS
  Tumoral (111)In-ibritumomab accumulation was positive in 64.1% and negative in 35.9% of the patients. The (111)In-positive patients had a significantly higher overall response rate (ORR) compared to the (111)In-negative patients (100.0% vs. 78.6%, p = 0.02). The (111)In-negative patients with advanced disease (stages III/IV) had a significantly lower ORR (40%) and a significantly higher rate of progressive disease (40.0%) compared to those of the (111)In-negative patients with limited disease (stages I/II) (100% and 0%, p = 0.009 each). However, these two groups had similar 2-year PFS rates (65.0% vs. 50.0%, p = 0.80).
  
  
  CONCLUSIONS
  (111)In-ibritumomab imaging findings seem to correlate with ORR and the progressive disease rate after RIT, but not with PFS.
  
  
  CONCLUSIONS
  All 39 NHL patients had tumoral accumulation on pretreatment FDG-PET/CT. 64.1% of NHL patients had tumoral accumulation on a pretreatment (111) In-ibritumomab examination. (90) Y-ibritumomab RIT resulted in high overall response and complete remission rates. (111) In-ibritumomab avidity of lymphoma lesions could predict a strong therapeutic effect. (111) In-ibritumomab imaging findings did not correlate with progression-free survival.
authors.affiliation: Department of Radiology, National Kyushu Cancer Center, National Hospital Organization, 3-3-1 Notame, Minami-ku, Fukuoka, 811-1395, Japan, kkaneko-kyu@umin.ac.jp.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Kaneko
authors.forename: Ilseung
authors.initials: I
authors.lastname: Choi
authors.forename: Makoto
authors.initials: M
authors.lastname: Nakagawa
authors.forename: Kenji
authors.initials: K
authors.lastname: Shinozaki
authors.forename: Naokuni
authors.initials: N
authors.lastname: Uike
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007205:Indium Radioisotopes / Q000493:pharmacokinetics*; D016393:Lymphoma, B-Cell / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D016499:Radioimmunotherapy / Q000379:methods*; D012074:Remission Induction; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D000911:Antibodies, Monoclonal; D007205:Indium Radioisotopes; C422802:ibritumomab tiuxetan