Monitoring the genotoxic effects of radiosynovectomy with Re-186 in paediatric age group undergoing therapy for haemophilic synovitis.

PURPOSE: The aim of this study was to investigate the genotoxic effect on the peripheral blood lymphocytes potentially induced by Re-186 in paediatric age group undergoing radiosynovectomy for haemophilic synovitis, by using chromosomal aberration analysis (CA) and the micronuclei (MN) assay for detecting chromosomal aberrations, as well as the sister chromatid exchanges (SCE) technique for assessing DNA damage. METHODS: Cytogenetic analyses were evaluated in 20 boys (mean age: 13.8 +/- 2.7 years) before, and 2 and 90 days after radiosynovectomy from the peripheral lymphocytes of the patients. Joint retention and extra-articular spread of the radionuclides were evaluated by using quantitative gamma camera imaging. RESULTS: Imaging after radiosynovectomy revealed local lymph node visualization in 8 (40%) patients and hepatosplenic visualization in 3 (15%) patients due to extra-articular leakage of radioactive material. The mean frequency of chromosome aberrations (0.2 +/- 0.4/1000 cells) determined prior to the onset of therapy was not significantly increased in comparison with control values obtained 2 days (0.4 +/- 0.5/1000 cells) and 90 days (0.2 +/- 0.4/1000 cells) after therapy (P = 0.754 and P = 1.0). In the analysis of MN and SCE, when we compare the baseline levels, the mean MN and SCE frequencies were slightly higher in the control analyses performed 2 and 90 days after radiosynovectomy but there were no significant differences between baseline and control levels (chi(2) = 2.621, P = 0.270 and F = 0.573, P = 0.569, respectively). CONCLUSION: The major finding of this study with relatively small sample is that, radiosynovectomy with Re-186 does not seem to induce early genotoxic effects on the peripheral blood lymphocytes in paediatric age group.

Comparison of Tc-99m methylene diphosphonate, Tc-99m human immune globulin, and Tc-99m-labeled white blood cell scintigraphy in the diabetic foot.

PURPOSE: The aims of this prospective study were to evaluate the contribution of Tc-99m methylene diphosphonate (MDP), Tc-99m human immune globulin (HIG), and Tc-99m white blood cell (WBC) to the diagnosis of osteomyelitis in the diabetic foot and to evaluate the surgical or medical therapy with Tc-99m HIG and Tc-99m WBC scans. METHODS: Twenty patients (15 men, 5 women) with suspected pedal osteomyelitis were included in the study. All patients had type II diabetics. Three- and four-phase bone scintigraphy (3P-MDP, 4P-MDP), early (e) and late (l) HIG, and WBC scans were completed within 1 week in all patients. The lesion-to-background ratios were calculated for early and late images of the feet for all scans and named as the indices. Eight weeks after the end of medical or surgical therapy, Tc-99m HIG and Tc-99m WBC scans were repeated in 10 patients. The difference in indices between 3P-MDP and 4P-MDP for osteomyelitis and indices for osteomyelitis, cellulitis, and inflammation in Tc-99m HIG and Tc-99m WBC in early and late scans were tested for significance. RESULTS: In 20 patients, 53 lesions were investigated. Among these 53 lesions were 25 sites of proved osteomyelitis, 6 sites of cellulitis, and 22 sites of inflammation confirmed by radiography, microbiologic culture, and clinical evaluation. 4P-MDP was more specific than 3P-MDP for detecting osteomyelitis (50% and 67%, respectively). There was also a significant difference between the mean indices of 3P-MDP and 4P-MDP (P < 0.000). The index values were increased in 4P-MDP scans. There was no significant difference between the indices of early and late Tc-99m HIG scans for inflammation, cellulitis, and osteomyelitis. Early and late Tc-99m WBC scans did not show a significant difference in differentiating osteomyelitis. However, Tc-99m WBC scans could differentiate aseptic inflammation from infection (P < 0.031) in early and late scans. There was a significant difference of index values between pre- and post-treatment Tc-99m HIG and Tc-99m WBC scans. The best combination of scans for detecting osteomyelitis was 4P-MDP with WBC scans, with an accuracy rate of 92%. CONCLUSIONS: These results show that four-phase bone scintigraphy with early Tc-99m WBC scanning is preferred for detecting osteomyelitis of the diabetic foot. To evaluate the response to therapy, Tc-99m WBC scans are the preferred method, but if this is not available, Tc-99m HIG scanning can be used.

99Tc(m)-polyclonal IgG scintigraphy in the detection of infected hip and knee prostheses.

We investigated the usefulness of 99Tc(m)-polyclonal human IgG (99Tc[m]-HIG) scintigraphy in the diagnosis of infected hip and knee prostheses. Twenty-nine scintigraphic studies were performed in 27 patients (17 females, 10 males) with a suspected prosthetic infection. As some patients had bilateral prostheses, a total of 35 prostheses were evaluated. There were 25 hip replacements and 10 knee prostheses. The images were analysed both visually and quantitatively. The scintigraphic results were compared with the culture results of surgical specimens and also with clinical follow-up after 3 months. Increased uptake was observed in 22 prostheses, of which 12 were true-positive and 10 were false-positive results. Staphylococci were the agents most commonly isolated. In all false-positive patients, aseptic inflammation was diagnosed. Based on quantitative analysis, no statistically significant difference was found between the true-positive and false-positive cases. For the prostheses as a whole, the sensitivity, specificity, positive predictive value and negative predictive value were 100%, 41%, 54% and 100% respectively. For the hip prostheses alone, these values were 100%, 53%, 57% and 100% respectively. Taking its high sensitivity and predictive value into consideration, 99Tc(m)-HIG scintigraphy can be used as a screening test to help eliminate prosthetic infection.

The role of quantitative 99Tcm-glucoheptonate scintigraphy in the evaluation of acute uveitis in patients with Behçet's disease.

The purpose of this study was to evaluate the role of quantitative 99Tcm-glucoheptonate (99Tcm-GH) scintigraphy in the assessment of patients with Behçet's disease who suffered from ocular inflammation (uveitis). The study consisted of 13 patients with uveitis and five control subjects. There were a total of 25 eyes with chronic uveitis. Of these 25 eyes, 10 were in a state of remission, and the other 15 were in an acute phase of the illness. The study was performed by administering 370 MBq (10 mCi) 99Tcm-GH intravenously. Planar images were acquired 6 h later. Eye/scalp indices were quantified by drawing regions of interest (ROIs) around each eye and normalizing the mean counts per pixel by the mean counts in the scalp. The mean eye/scalp indices were 1.87 +/- 0.19 in controls and 1.98 +/- 0.19 in the affected eyes that were in remission (P = 0.23, nonsignificant). However, during the acute phase of the illness, the mean eye/scalp index was 2.18 +/- 0.28. The difference between controls and the eyes that were in the acute phase of the illness was significant (one way analysis of variance, P = 0.007). The mean value of the index for affected eyes in remission was not significantly different to that for eyes in the acute phase (P = 0.068, nonsignificant). These preliminary findings suggest that, despite previously published reports in animals with experimentally induced uveitis, 99Tcm-GH scintigraphy may not be a very sensitive method for evaluating human ocular inflammations.