188Re-SSS lipiodol: radiolabelling and biodistribution following injection into the hepatic artery of rats bearing hepatoma.
BACKGROUND
Although intra-arterial radiation therapy with 131I-lipiodol is a useful therapeutic approach to the treatment of hepatocellular carcinoma, various disadvantages limit its use.


OBJECTIVE
To describe the development of a method for the labelling of lipiodol with 188Re-SSS (188Re (S2CPh)(S3CPh)2 complex) and to investigate its biodistribution after injection into the hepatic artery of rats with hepatoma.


METHODS
188Re-SSS lipiodol was obtained after dissolving a chelating agent, previously labelled with 188Re, in cold lipiodol. The radiochemical purity (RCP) of labelling was checked immediately. The 188Re-SSS lipiodol was injected into the hepatic artery of nine rats with a Novikoff hepatoma. They were sacrificed 1, 24 and 48 h after injection, and used for ex vivo counting.


RESULTS
Labelling of 188Re-SSS lipiodol was achieved with a yield of 97.3+/-2.1%. The immediate RCP was 94.1+/-1.7%. Ex vivo counting confirmed a predominantly hepatic uptake, with a good tumoral retention of 188Re-SSS lipiodol, a weak pulmonary uptake and a very faint digestive uptake. The 'tumour/non-tumoral liver' ratio was high at 1, 24 and 48 h after injection (2.9+/-1.5, 4.1+/-/4.1 and 4.1+/-0.7, respectively).


CONCLUSIONS
Using the method described here, 188Re-SSS lipiodol can be obtained with a very high yield and a satisfactory RCP. The biodistribution in rats with hepatoma indicates a good tumoral retention of 188Re-SSS lipiodol associated with a predominant hepatic uptake, a weak pulmonary uptake and a very faint digestive uptake. This product should be considered for intra-arterial radiation therapy in human hepatoma.
Garin
Etienne
E
UPRES EA 1794/Service de Médecine Nucléaire Centre Eugène Marquis, Rennes, France. etienne.garin@univ-rennes1.fr
Denizot
Benoit
B
Noiret
Nicolas
N
Lepareur
Nicolas
N
Roux
Jerome
J
Moreau
Myriam
M
Herry
Jean-Yves
JY
Bourguet
Patrick
P
Benoit
Jean-Pierre
JP
Lejeune
Jean-Jacques
JJ
D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D004338:Drug Combinations; D004353:Drug Evaluation, Preclinical; D005260:Female; D007269:Injections, Intra-Arterial; D007459:Iodized Oil / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D007553:Isotope Labeling / Q000379:methods*; D008113:Liver Neoplasms / Q000378:metabolism*; D008657:Metabolic Clearance Rate; D009928:Organ Specificity; D009942:Organometallic Compounds / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D019275:Radiopharmaceuticals / Q000008:administration & dosage / Q000138:chemical synthesis / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D014018:Tissue Distribution; D014915:Whole-Body Counting
D004338:Drug Combinations; D009942:Organometallic Compounds; D019275:Radiopharmaceuticals; C494618:rhenium-SSS-lipiodol; D007459:Iodized Oil