Assessment of metabolic response to radioimmunotherapy with 90Y-ibritumomab tiuxetan in patients with relapsed or refractory B-cell non-Hodgkin lymphoma

Radiology. 2010 Jan;254(1):245-52. doi: 10.1148/radiol.09090603.


Purpose: To prospectively compare the assessment of metabolic response to yttrium 90 ((90)Y)-ibritumomab tiuxetan radioimmunotherapy (RIT) by using fluorine 18 ((18)F) fluorodeoxyglucose (FDG) combined positron emission tomographic-computed tomographic (PET/CT) imaging at 2 and 6 months to determine the most appropriate time to detect therapeutic response in refractory non-Hodgkin lymphoma (NHL) patients treated with RIT.

Materials and methods: The ethical committee of the university approved the protocol and all patients signed informed consent. Twenty-three consecutive patients (10 women, 13 men; mean age, 51.8 years +/-7.3 [standard deviation]) treated by using RIT for relapsed or refractory follicular NHL were enrolled. For all patients, (18)F FDG PET/CT scanning was performed at baseline and at 2 and 6 months after RIT. Response was assessed by using the International Workshop Criteria (IWC) and revised criteria (IWC + PET) as well as the criteria of the European Organization for Research and Treatment of Cancer. One-way analysis of variance for repeated measures, receiver operator curve analysis, and Kaplan-Meier curves were used for statistical analysis.

Results: PET/CT performed at 2 months revealed complete (n = 12) or partial (n = 4) metabolic response in 16 of 23 patients with complete or partial clinical response. These findings were all confirmed at 6-month scanning. PET/CT indicated refractory or persistent disease at 2 and 6 months in the remaining seven patients. Better overall survival was observed for patients with a reduction in the maximum standard uptake value of 49% or higher (both at 2 and 6 months after RIT) when compared with those with a decrease of less than 49% (P < .05).

Conclusion: Early assessment of response to RIT by using PET/CT might be useful in the identification of patients needing additional therapeutic strategies.

MeSH terms

  • Aged
  • Analysis of Variance
  • Antibodies, Monoclonal / therapeutic use*
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • Female
  • Fluorodeoxyglucose F18
  • Humans
  • Lymphoma, B-Cell / diagnostic imaging
  • Lymphoma, B-Cell / radiotherapy*
  • Male
  • Positron-Emission Tomography / methods
  • Prospective Studies
  • ROC Curve
  • Radiographic Image Interpretation, Computer-Assisted
  • Radioimmunotherapy / methods*
  • Radiopharmaceuticals
  • Survival Rate
  • Tomography, X-Ray Computed / methods
  • Treatment Outcome
  • Yttrium Radioisotopes


  • Antibodies, Monoclonal
  • Radiopharmaceuticals
  • Yttrium Radioisotopes
  • Fluorodeoxyglucose F18
  • ibritumomab tiuxetan