TY - JOUR T1 - Whole-Body Dosimetry for Individualized Treatment Planning of <sup>131</sup>I-MIBG Radionuclide Therapy for Neuroblastoma JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1518 LP - 1524 DO - 10.2967/jnumed.109.064469 VL - 50 IS - 9 AU - Susan E. Buckley AU - Sarah J. Chittenden AU - Frank H. Saran AU - Simon T. Meller AU - Glenn D. Flux Y1 - 2009/09/01 UR - http://jnm.snmjournals.org/content/50/9/1518.abstract N2 - The aims of this study were to examine the relationship between whole-body absorbed dose and hematologic toxicity and to assess the most accurate method of delivering a prescribed whole-body absorbed dose in 131I-metaiodobenzylguanidine (131I-MIBG) therapy for neuroblastoma. Methods: A total of 20 children (1–12 y), 5 adolescents (13–17 y), and 1 adult (20 y) with stage 3 or 4 neuroblastoma were treated to a prescribed whole-body absorbed dose, which in most cases was 2 Gy. Forty-eight administrations of 131I-MIBG were given to the 26 patients, ranging in activity from 1,759 to 32,871 MBq. For 30 administrations, sufficient data were available to assess the effect of whole-body absorbed dose on hematologic toxicity. Comparisons were made between the accuracy with which a whole-body absorbed dose could be predicted using a pretherapy tracer study and the patient's most recent previous therapy. The whole-body absorbed dose that would have been delivered if the administered activity was fixed (7,400 MBq) or determined using a weight-based formula (444 MBq·kg−1) was also estimated. Results: The mean whole-body absorbed dose for patients with grade 4 Common Terminology Criteria for Adverse Events (CTCAE) neutropenia after therapy was significantly higher than for those with grade 1 CTCAE neutropenia (1.63 vs. 0.90 Gy; P = 0.05). There was no correlation between administered activity and hematologic toxicity. Absorbed whole-body doses predicted from previous therapies were within ±10% for 70% of the cases. Fixed-activity administrations gave the largest range in whole-body absorbed dose (0.30–3.11 Gy). Conclusion: The results indicate that even in a highly heterogeneous and heavily pretreated patient population, a whole-body absorbed dose can be prescribed accurately and is a more accurate predictor of hematologic toxicity than is administered activity. Therefore, a whole-body absorbed dose can be used to deliver accurate and reproducible 131I-MIBG therapy on a patient-specific basis. ER -