Detection of acute postoperative mediastinitis in mice using (99m)Tc-liposomes.
OBJECTIVE
To evaluate the usefulness of size-modified (99m)Tc-labeled liposomes for the detection of acute postoperative mediastinitis in a mouse model.


METHODS
Fourteen mice underwent low-neck collar incision and had sterile abscesses induced in mediastinum with turpentine. Ten of these animals were injected intravenously with anionic liposomes of 516 +/- 20 nm containing poly(ethylene)glycol labeled with (99m)Tc; the remaining four mice were injected with (67)Ga citrate and used as positive controls. In addition, eight mice either underwent the same surgical procedure but without turpentine (n = 4) or were not operated (n = 4). These were used as negative controls. Therefore, scintigraphy using (99m)Tc-liposomes was performed in eighteen and (67)Ga citrate in four mice. Target area of interest was outlined, and target to background count density ratio and percentage-injected dose were measured.


RESULTS
Significant accumulation of radiolabeled liposomes was observed at sites of inflammation within 1 hour in abscess-bearing animals. This correlated well with the findings of the lower quality (contrast) of (67)Ga images at 24 and 48 hours. The radiopharmaceutical did not significantly accumulate in the mediastinum of negative control animals.


CONCLUSIONS
(99m)Tc-liposomes (size modified) may prove useful nonspecific agent for the early diagnosis of postoperative mediastinitis.
University of Texas M.D. Anderson Cancer Center, Houston, Texas.; From the Baylor College of Medicine, the Methodist, Houston, Texas 77030-4009, USA.
Dimitrios
D
Andreopoulos
LeelapP
L
Kasi
E
E
Edmund Kim
Miguel
M
Diaz
David J
DJ
Yang
Panayiotis J
PJ
Asimacopoulos
D000818:Animals; D002951:Citrates; D005708:Gallium; D005710:Gallium Radioisotopes; D008081:Liposomes; D008297:Male; D008480:Mediastinitis / Q000000981:diagnostic imaging*; D051379:Mice; D011092:Polyethylene Glycols; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D013667:Technetium
D002951:Citrates; D005710:Gallium Radioisotopes; D008081:Liposomes; D019275:Radiopharmaceuticals; D011092:Polyethylene Glycols; D013667:Technetium; D005708:Gallium; C103850:gallium citrate