Preliminary studies with 188rhenium-tin colloid for radiation synovectomy: preparation, size determination, in-vivo distribution, effect and dosimetry studies.
BACKGROUND
Generator-produced beta-emitting radionuclides such as (188)Re are gaining in importance for radiosynoviorthesis because of their availability on a regular basis.


METHODS
We prepared a (188)Re-tin colloid in a reaction carried out either at 100 degrees C or at room temperature (RT). The size of the colloid particles was measured with a laser lightscattering method, and their biodistribution, dosimetric aspects and therapeutic effects were studied in an antigen-induced arthritis (AIA) model in rabbits. (188)Re-tin colloid solution was injected intra-articularly into the knee joints of rabbits with AIA and imaging studies were performed. Blood samples were collected post injection for estimation of the blood residence time. We also injected 2 intact rabbits in the same manner with (188)Re perrhenate solution in order to observe its effects and distribution in the body. All the treated rabbit knees were subjected to histopathology.


RESULTS
The colloid particle size distribution was different after preparation at the different reaction temperatures, with a more suitable mean of 4.53 micro m in the RT preparation. The dose delivered to the synovial surface was between 3.51 and 4.21 Gy and that to the bone surface was between 0.70 and 0.84 Gy. Histopathologic examination revealed the development of fibrous connective tissue in the AIA knees 4 weeks after treatment, but not in the control group.


CONCLUSIONS
The (188)Re-tin colloid preparation used in this study was suitable for radiation synovectomy application. It requires modifications in the preparation protocol so as to increase the labeling efficiency in correlation with an appropriate particle size.
Department of Applied Radioisotopes, Fregeric Joliot-Curie National Institute of Radiobiology and Radiohygiene, Budapest, Hungary. mdomokos@hp.osski.hu
Domokos
D
Máthé
Pradip R
PR
Chaudhari
Lajos
L
Balogh
András
A
Polyák
Réka
R
Király
Gábor
G
Andócs
Edina
E
Perge
Róbert
R
Glávits
Gyõzõ A
GA
Jánoki