TY - JOUR T1 - Dosimetry of <sup>90</sup>Y-Ibritumomab Tiuxetan as Consolidation of First Remission in Advanced-Stage Follicular Lymphoma: Results from the International Phase 3 First-Line Indolent Trial JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1837 LP - 1843 DO - 10.2967/jnumed.109.067587 VL - 50 IS - 11 AU - Angelika Bischof Delaloye AU - Cristian Antonescu AU - Thomas Louton AU - Jens Kuhlmann AU - Anton Hagenbeek Y1 - 2009/11/01 UR - http://jnm.snmjournals.org/content/50/11/1837.abstract N2 - The objective of this analysis was to assess the radiation exposure associated with 90Y-ibritumomab tiuxetan when used as consolidation therapy in adults with low or minimal tumor burden after first-line therapy of advanced follicular lymphoma (FL). Methods: The patients who were enrolled in the phase 3 first-line indolent trial were 18 y or older, with CD20+ grade 1 or 2 stage III or IV FL, and a partial response, complete response, or unconfirmed complete response to first-line chemotherapy. The patients were allocated randomly to receive a single infusion of unlabeled rituximab 250 mg/m2 on day −7 and consolidation on day 0 with a single dose of 90Y-ibritumomab tiuxetan, 14.8 MBq/kg, immediately after unlabeled rituximab, 250 mg/m2, or no further treatment. On day −7, a subset of patients received an injection of 185 MBq of 111In-ibritumomab tiuxetan immediately after unlabeled rituximab, 250 mg/m2, for central dosimetry analysis. Correlations were assessed between organ radiation absorbed dose and toxicity, body weight, body mass index, and progression-free survival. Results: Central dosimetry evaluations were available from 57 of 70 patients. Median radiation absorbed doses were 100 cGy (range, 28–327 cGy) for the red marrow and 72 cGy (range, 46–106 cGy) for the whole body. Radiation absorbed doses did not differ significantly between patients who had a partial response or complete response to initial therapy. Progression-free survival correlated significantly with the whole-body (r = 0.4401; P = 0.0006) and bone marrow (r = 0.2976; P = 0.0246) radiation dose. Body weight was significantly negatively correlated with whole-body radiation dose (r = −0.4971; P &lt; 0.0001). Neither the whole-body radiation dose nor the bone marrow radiation dose correlated with hematologic toxicity. Conclusion: In patients with low or minimal residual tumor burden after first-line chemotherapy of advanced FL, whole-body and bone marrow exposure after 90Y-ibritumomab tiuxetan consolidation showed a significant positive correlation with progression-free survival, whereas dosimetric data could not predict hematologic toxicity. ER -