Dual-isotope lymphoscintigraphy using albumin nanocolloid differentially labeled with 111In and 99mTc.
The aim of this study was to develop and evaluate 111In- and 99mTc-labeled derivatives of albumin nanocolloid (NC) for dual-label lymphoscintigraphy to allow simultaneous comparison of lymphatic flow from different tissue planes draining a tumour bed for accurate identification of sentinel lymph nodes (SLN). Using the chelator, p-isothiocyanatobenzyl-1,4,7, 10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), 111In-DOTA-NC and 99mTc-DOTA-NC were compared in vitro with respect to stability of labeling, colloidal status and particle size, then in vivo by measuring their clearance rates from a subcutaneous injection depot. 111In-DOTA-NC and 99mTc-DOTA-NC were indistinguishable on the basis of in vitro criteria. Their in vivo clearance rates, however, were disparate (0.0015 to 0.075 min(-1) for 111In and 0.0072 to 0.067 min(-1) for 99mTc), 111In being faster in three studies and markedly slower in three. This demonstrates that even when dual-labeled radiotracers behave identically in vitro, they will not necessarily do so in vivo. Further work is needed to develop dual-labeled NC.
Fowler
J Charlotte
JC
Department of Nuclear Medicine, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ, United Kingdom.
Solanki
Chandra K
CK
Barber
Robert W
RW
Ballinger
James R
JR
Peters
A Michael
AM
D003102:Colloids; D006573:Heterocyclic Compounds, 1-Ring; D006801:Humans; D066298:In Vitro Techniques; D007205:Indium Radioisotopes; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D010316:Particle Size; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012709:Serum Albumin; D013668:Technetium Tc 99m Aggregated Albumin
D003102:Colloids; D006573:Heterocyclic Compounds, 1-Ring; D007205:Indium Radioisotopes; D019275:Radiopharmaceuticals; D012709:Serum Albumin; D013668:Technetium Tc 99m Aggregated Albumin; C083602:technetium Tc 99m nanocolloid; C071349:1,4,7,10-tetraazacyclododecane- 1,4,7,10-tetraacetic acid