SLC6A2 and neoplasm: To understand the estimated radiation dose from 131I-MIBG, prior studies were completed using 124I-MIBG as a quantitative tool for tumor imaging and dosimetry in vivo [29]. Several studies have estimated human-equivalent internal radiation doses using 124I-MIBG and PET/CT in murine NB1691-LUC/NET xenograft models [29, 34].