Boron-lipiodol: a potential new drug for the treatment of liver tumors.
BACKGROUND
Boron neutron capture therapy (BNCT) is a form of radiation therapy and has been proposed for the treatment of some malignancies with encouraging results. However, none of them has ever been applied to liver malignancy. The purpose of this study was to evaluate the potential of boron-lipiodol (B-lipiodol) for the treatment of VX2 liver tumor via BNCT.


METHODS
Twelve New Zealand rabbits were randomly separated into two groups: lipiodol and boron-lipiodol groups. The rabbits were anesthetized, a midline incision was made and the left lobe of the liver was injected with 0.1 ml of VX2 tumor cells. After the tumor reached 2-3 cm in diameter, the rabbits were anesthetized and 0.5 ml of boron-lipiodol was injected into the hepatic artery via an angiocatheter. Liver function tests and renal function tests were performed before, at 12 hours, 24 hours, 48 hours and 7 days after injection of drugs in both groups. The concentration of boron in various tissues was determined on the 7th day after injection.


RESULTS
Liver function was abnormal at 12 hours after injection, and then gradually returned to normal at 7 days, indicative of acute temporary hepatic damage. As for the renal function, no significant change was noted in either group. The boron level was 49.7 ppm in tumor and 6.31 ppm in the healthy liver 7 days after injection of B-lipiodol. The ratio of boron concentrations between the tumor and the normal liver tissue was 7.87. As for blood and other organs including spleen, heart and kidney, the concentration of boron was low. In the lipiodol group, the boron concentrations in tumor and various organs were low.


CONCLUSIONS
The high concentration of boron after intra-arterial injection of B-lipiodol can be used for neutron capture therapy. B-lipiodol has potential for the treatment of liver malignancy.
Lin
Wan-Yu
WY
Department of Nuclear Medicine, Taichung Veterans General Hospital, Taichung 40705, Taiwan.
Chi
Chin-Wen
CW
Ho
Yung-Jen
YJ
Wu
I-Chieh
IC
Chung
Yang-Tsung
YT
Chen
San-Duo
SD
Chou
Fong-In
FI
Kai
Ji-Jong
JJ
Lui
Wing-Yiu
WY
Chen
Te-Jung
TJ
Lin
Yungchang
Y
D000818:Animals; D001895:Boron / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000494:pharmacology; D016754:Boron Neutron Capture Therapy / Q000379:methods*; D007459:Iodized Oil / Q000493:pharmacokinetics* / Q000494:pharmacology; D007668:Kidney / Q000187:drug effects; D008099:Liver / Q000187:drug effects; D008114:Liver Neoplasms, Experimental / Q000378:metabolism* / Q000532:radiotherapy; D008297:Male; D011817:Rabbits; D014018:Tissue Distribution
D007459:Iodized Oil; D001895:Boron