RT Journal Article SR Electronic T1 90Y-Ibritumomab Therapy in Refractory Non-Hodgkin's Lymphoma: Observations from 111In-Ibritumomab Pretreatment Imaging JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1809 OP 1812 DO 10.2967/jnumed.108.052928 VO 49 IS 11 A1 Iagaru, Andrei A1 Gambhir, Sanjiv Sam A1 Goris, Michael L. YR 2008 UL http://jnm.snmjournals.org/content/49/11/1809.abstract AB Radioimmunotherapy is an effective treatment for non-Hodgkin's lymphoma (NHL). 90Y-ibritumomab is an antibody targeting CD20 receptors on the surface of lymphocytes. We present observations from our clinical experience with 90Y-ibritumomab in the management of NHL. Methods: This was a retrospective study of 28 NHL patients treated with 90Y-ibritumomab. There were 21 men and 7 women, 36–85 y old. A diagnostic dose of 111In-ibritumomab was administered on day 0, and imaging followed immediately and at 24, 48, and 72 h. The doses of 90Y-ibritumomab ranged from 629 to 1,258 MBq (17–34 mCi). Outcomes were compared with the findings of the 111In-ibritumomab scans. Results: 90Y-ibritumomab induced objective responses in 22 of 28 patients. A complete response was noted in 9 patients, a partial response in 9 patients, and a mixed response in 4 patients. Three patients had stable disease, and 3 patients had disease progression. 111In-ibritumomab findings were positive in 19 patients and negative in 9 patients. A complete response was noted in 2 of 19 patients with positive findings and 7 of 9 with negative findings. A partial response was seen in 7 of 19 patients with positive findings and 1 of 9 with negative findings. Disease progression was observed in 3 of 19 patients with positive findings and 0 of 9 with negative findings. The remaining patients had a mixed response or no changes. Conclusion: A higher rate of complete response after 90Y-ibritumomab treatment was seen in patients with negative 111In-ibritumomab findings, whereas a higher rate of disease progression despite therapy was noted in patients with positive 111In-ibritumomab findings. This observation suggests that patients with bulky disease may require more aggressive management.