TY - JOUR T1 - Does Delayed Excretion of Therapeutic <sup>131</sup>I-MIBG Interfere with a <sup>123</sup>I-MIBG Diagnostic Scan 6 Weeks After the Therapy? JF - Journal of Nuclear Medicine Technology JO - J. Nucl. Med. Technol. SP - 81 LP - 84 DO - 10.2967/jnmt.119.229583 VL - 48 IS - 1 AU - Miguel de la Guardia AU - Jaime A. Barnes AU - Susan Corey AU - Jennifer Sims AU - Meaghan Granger Y1 - 2020/03/01 UR - http://tech.snmjournals.org/content/48/1/81.abstract N2 - 131I-metaiodobenzylguanidine (131I-MIBG) is a theranostic agent useful for treatment of neuroendocrine malignancies. In this case, a child with a Curie score of 21 was administered 17.871 GBq (483 mCi) of 131I-MIBG. The elimination half-life progressively increased from 23 h to 77 h during the 11 d that the patient was hospitalized for radiation isolation. Six weeks after the posttherapy scan, a survey with an ion-chamber device yielded readings of 0.3 μSv/h (0.03 mR/h) on contact with spinal regions that had shown increased uptake on the scan. A planar image obtained using the 131I setting and a high-energy collimator did not demonstrate any focal uptake. 123I-MIBG was administered, and the 24-h scan was of diagnostic quality, without degradation from the remaining 131I-MIBG. Additional study is needed on whether the Curie score affects elimination of 131I-MIBG and on whether the period of hospitalized radiation isolation needs to be extended. ER -