Addition of 131 I-MIBG to PRRT ( 90 Y-DOTATOC) for Personalized Treatment of Selected Patients with Neuroendocrine Tumors

• Published in: Journal of Nuclear Medicine Vol. 62; no. 9; pp. 1274 - 1277
• Main Authors: Bushnell, David L., Bodeker, Kellie L., O’Dorisio, Thomas M., Madsen, Mark T., Menda, Yusuf, Graves, Stephen, Zamba, Gideon K.D., O’Dorisio, M. Sue
• Format: Journal Article
• Language: English
• Published: United States 01.09.2021
• Subjects: 3-Iodobenzylguanidine - therapeutic use; Adult; Aged; Female; Humans; Iodine Radioisotopes; Male; Middle Aged; Neuroendocrine Tumors - radiotherapy; Octreotide - analogs & derivatives; Octreotide - therapeutic use; Organometallic Compounds - therapeutic use; Precision Medicine; Radiometry; Radiopharmaceuticals - therapeutic use; Receptors, Peptide - metabolism; Treatment Outcome; PRRT; DOTATOC; MIBG; personalized dosimetry
• ISSN: 0161-5505; 2159-662X; 1535-5667
• DOI: 10.2967/jnumed.120.254987

Peptide receptor radionuclide therapy (PRRT) is an effective treatment for metastatic neuroendocrine tumors. Delivering a sufficient tumor radiation dose remains challenging because of critical-organ dose limitations. Adding I-metaiodobenzylguanidine ( I-MIBG) to PRRT may be advantageous in this regard. A phase 1 clinical trial was initiated for patients with nonoperable progressive neuroendocrine tumors using a combination of Y-DOTATOC plus I-MIBG. Treatment cohorts were defined by radiation dose limits to the kidneys and the bone marrow. Subject-specific dosimetry was used to determine the administered activity levels. The first cohort treated subjects to a dose limit of 1,900 cGy to the kidneys and 150 cGy to the marrow. No dose-limiting toxicities were observed. Tumor dosimetry estimates demonstrated an expected dose increase of 34%-83% using combination therapy as opposed to Y-DOTATOC PRRT alone. These findings demonstrate the feasibility of using organ dose for a phase 1 escalation design and suggest the safety of using Y-DOTATOC and I-MIBG.