Utility of Tc-99m human polyclonal immunoglobulin G scintigraphy for assessing the efficacy of yttrium-90 silicate therapy in rheumatoid knee synovitis.
OBJECTIVE
The aim of this study was to determine the utility of Tc-99m human polyclonal immunoglobulin G (HIG) scintigraphy for evaluating the efficacy of yttrium-90 (Y-90) silicate therapy in rheumatoid knee synovitis.


METHODS
Fifteen patients (13 women, 2 men; mean age, 53.5 +/- 8.4 years) with rheumatoid arthritis had radionuclide synovectomy using 185 MBq (5 mCi) Y-90 silicate to evaluate 24 knee joints with chronic persistent synovitis. Radiologic and clinical evaluations and Tc-99m HIG scans were performed in each patient before radionuclide synovectomy. Each patient was reassessed 3, 6, 9, and 12 months after therapy using clinical examination and Tc-99m HIG scintigraphy.


RESULTS
In 14 of 24 knee joints (4 Larsen stage I, 10 Larsen stage II) that had excellent or good clinical responses to Y-90 silicate therapy, the Tc-99m HIG index values 3 months after treatment were significantly lower than the pretreatment index values (P < 0.001). In 13 of these 14 joints, these low index values and clinical results remained constant throughout the 1 year of follow-up. One patient (1 of the 14 knee joints) experienced severe pain and swelling as a result of recurrent arthritis at 9 months, and the Tc-99m HIG index value increased at 9 months and remained high 12 months after therapy. In 10 of 24 knee joints (4 Larsen stage II, 6 Larsen stage III) that had a fair or poor clinical response, Tc-99m HIG index values were statistically similar before and after radionuclide therapy.


CONCLUSIONS
Quantitative Tc-99m HIG scintigraphy is a valuable method for assessing the efficacy of Y-90 silicate therapy in rheumatoid knee synovitis.
Gencoglu
Esra Arzu
EA
Department of Nuclear Medicine, Ankara University Medical Faculty, Ankara, Turkey. arzugencoglu@hotmail.com
Aras
Gulseren
G
Kucuk
Ozlem
O
Atay
Gulay
G
Tutak
Ibrahim
I
Ataman
Sebnem
S
Soylu
Ayfer
A
Ibis
Erkan
E
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000000981:diagnostic imaging / Q000532:radiotherapy; D002908:Chronic Disease; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007136:Immunoglobulins / Q000378:metabolism; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D012008:Recurrence; D012720:Severity of Illness Index; D017640:Silicates / Q000627:therapeutic use; D013585:Synovitis / Q000150:complications / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D013667:Technetium / Q000493:pharmacokinetics; D016896:Treatment Outcome; D015021:Yttrium Radioisotopes / Q000008:administration & dosage / Q000627:therapeutic use*
D007136:Immunoglobulins; D017640:Silicates; D015021:Yttrium Radioisotopes; C065376:technetium Tc 99m immunoglobulin; D013667:Technetium