Use of yttrium 90 in persistent synovitis of the knee. II. Direct comparison of yttrium colloid resin and yttrium citrate.

The choice of radiocolloid for intra-articular therapy depends largely on factors of efficacy and safety. The fl-emission from yttrium 90 (90 Y) has a satisfactory range for use in the knee and a short half-life as well as freedom from gamma-radiation and from contamination. Since the demonstration by Stevenson, Bedford, Hill, and Hill (1971) and Stevenson and 12 others (1973) that chromosomal changes occur in circulating lymphocytes after intra-articular injection of 198 Au and 90 Y, and that the degree of these changes relates most closely to the uptake of isotope by lymph nodes, there are now definite theoretical reasons for using isotope preparations that show least spread to regional lymph nodes. At the time of this study, three preparations of 90Y were commercially available, although one, the resin, has subsequently been withdrawn because of problems of manufacture. Prichard, Bridgman, and Bleehen (1970) had compared the resin and the silicate in the knee and had found better retention of resin with considerably less lymph node uptake. Subsequent workers have confirmed the good retention of the resin (Oka, Rekonen, Ruotsi, and Seppaila, 1971; Gumpel, Williams, and Glass, 1973) especially when the knees are at rest after injection. Ingrand (1972) has shown that there is little lymphatic spread using the citrate. This study is a comparison of the resin and the citrate preparations.