Localized internal radiotherapy with 90Y particles embedded in a new thermosetting alginate gel: a feasibility study in pigs.
BACKGROUND
Internal radiotherapy requires the localization of the radionuclide to the site of action. A new injectable alginate gel formulation intended to undergo immediate gelation in tissues and capable of encapsulating radioactive particles containing 90Y was investigated.


METHODS
The formulation was injected intramuscularly, into the bone marrow compartment of the femur and intravenously, respectively, in pigs. The distribution of radioactivity in various tissues was determined.


RESULTS
Following intramuscular injection, more than 90% of the radioactivity was found at the site of injection. Following injection into bone marrow, 30-40% of the radioactivity was retained at the site of injection, but a considerable amount of radioactivity was also detected in the lungs (35-45%) and the liver (5-18%). Following intravenous injection, 80-90% of the radioactivity was found in the lungs.


CONCLUSIONS
The present formulation appears suitable for localized radiotherapy in organs and tissues having low perfusion.
Holte
Oyvind
O
School of Pharmacy, University of Oslo, Norway. oholte@farmasi.uio.no
Skretting
Arne
A
Bach-Gansmo
Tore
T
Hol
Per Kristian
PK
Johnsrud
Kjersti
K
Tønnesen
Hanne Hjorth
HH
Karlsen
Jan
J
D000464:Alginates / Q000737:chemistry*; D000818:Animals; D004337:Drug Carriers / Q000737:chemistry*; D005240:Feasibility Studies; D005782:Gels / Q000737:chemistry; D007273:Injections, Intramuscular; D008081:Liposomes / Q000737:chemistry; D009928:Organ Specificity; D010316:Particle Size; D013552:Swine; D013696:Temperature; D014018:Tissue Distribution; D015021:Yttrium Radioisotopes / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics* / Q000627:therapeutic use*
D000464:Alginates; D004337:Drug Carriers; D005782:Gels; D008081:Liposomes; D015021:Yttrium Radioisotopes