Retrobulbar 99mTc-diethylenetriamine-pentaacetic-acid uptake may predict the effectiveness of immunosuppressive therapy in Graves' ophthalmopathy.

BACKGROUND: In Graves' ophthalmopathy (GO), only patients with immunologically active disease respond to immunosuppressive therapy. Previous studies and theoretical considerations suggest that elevated orbital (99m)Tc-diethylenetriamine-pentaacetic-acid (DTPA) single photon emission computed tomography (SPECT) reflects inflammatory disease activity. We studied whether corticosteroid treatment causes a substantial decrease in DTPA uptake in GO, a result consistent with successful immunosuppressive treatment of GO and referred to as a favorable treatment outcome. METHODS: One hundred fourteen orbits in 57 patients with active GO (CAS >or= 4) were entered into the study. All patients received corticosteroid treatment. Orbital DTPA uptakes were numerically quantified for the entire orbit as well as the anterior and posterior segments separately. DTPA SPECT was performed before, and 2 to 9 months after the initiation of immunosuppressive treatment. The normal range for DTPA uptake was established in 34 orbits of 17 patients who were being worked up for Raynaud's phenomenon and had no thyroid disease. RESULTS: The mean DTPA uptake of the 114 orbits of GO patients was higher prior to corticosteroid therapy than after this treatment (11.03 +/- 4.26 MBq/cm(3) and 9.84 +/- 3.51 MBq/cm(3), respectively, p < 0.001) but a substantial decline in DTPA uptake was seen in only 39.5% of GO patients. The positive predictive value of an initial DTPA >12.28 MBq/cm(3) for a substantial decline in DTPA uptake (favorable treatment outcome) was 76%, while a negative predictive value of a pretreatment DTPA

Imaging of disease activity in Graves' orbitopathy with different methods: comparison of (99m)Tc-DTPA and (99m)Tc-depreotide single photon emission tomography, magnetic resonance imaging and clinical activity scores.

BACKGROUND: The immunosuppressive treatment of Graves' orbitopathy (GO) influences the course of the disease in the early, active, retrobulbar inflammatory phase (active GO), which cannot be detected by direct clinical examination. AIM: To evaluate the clinical effectiveness of a newly developed method for the detection of intraorbital inflammatory activity in patients suffering from Graves' orbitopathy, utilizing a four-headed single photon emission tomograph (SPET) camera and (99m)Tc-diethylenetriamine pentaacetic acid (Tc-DTPA). METHODS: The magnetic resonance imaging (MRI) T2 relaxation time score, as a measure of ongoing orbital inflammation (reference method), was compared with the uptake activities (UA) of (99m)Tc-DTPA orbital SPET and the more specific (99m)Tc-Neospect ((99m)Tc-depreotide) SPET, as well as the clinical activity scores (CAS), in 21 patients (42 orbits). RESULTS: By visual inspection, the 'eye SPET' frames of patients suffering from active GO could be easily distinguished from those with inactive GO. Although the distributions of the two radiopharmaceuticals were mildly different, the information obtained was essentially the same. The MRI activity scores correlated well with both (99m)Tc-DTPA and Tc-depreotide UA. The mean (99m)Tc-DTPA UA value of 25 inactive GO orbits was (6.55 +/- 1.4) x 10(-6) ID x cm3 (where ID is the injected dose); the values of the active GO orbits (12 orbits with an MRI score of 1 and five orbits with an MRI score of 2) were significantly higher: (8.87 +/- 1.63) x 10(-6) and (10.36 +/- 1.60) x 10(-6) ID x cm3, respectively. Similar differences were observed for the (99m)Tc-depreotide UA values: the averages in the inactive and active groups with MRI scores of 1 and 2 were (5.23 +/- 1.23) x 10(-6), (7.69+/-2.24) x 10 and (10.92 +/- 3.85) x 10(-6) ID x cm3, respectively. The (99m)Tc-DTPA accumulation pattern in the orbital region of active GO patients was similar to that of the more specific (99m)Tc-depreotide. There was a good correlation (r = 0.71, P<0.001) between the UA values of the two radiopharmaceuticals, but CAS did not correlate with either of the UA values. CONCLUSIONS: (99m)Tc-DTPA eye SPET is a potentially useful method, allowing rapid imaging at an acceptable cost. It provides essential supplementary information to traditional CAS in assessing disease activity in Graves' orbitopathy.

Volume changes in intra- and extraorbital compartments in patients with Graves' ophthalmopathy: effect of smoking.

The objective of this study was to demonstrate the effect of smoking history on soft tissue expansion in specific orbital compartments in patients with Graves' ophthalmopathy. The volumes of the rectus muscles, intra and extraorbital connective, and soft tissues were measured in 110 orbits of 35 patients and 20 control subjects. Data sets from current smokers, ex-smokers, and non-smokers were compared. The total number of cigarettes smoked was calculated, and it was used as an estimate for the severity of smoking (cumulative smoking). The volume measurements were performed on T1-weighted contiguous transversal magnetic resonance images of the orbits. Connective tissue volumes were influenced by smoking history, while muscle volumes were not affected. Ex-smokers had larger amount of extraorbital connective tissue than current smokers (p = 0.012), and this volume showed a good correlation with the number of cigarettes smoked (r = 0.539, p < 0.05). In current smokers, the amount of intraorbital connective tissue correlated well with the cumulative smoking (r = 0.635, p < 0.001). We conclude that connective tissue volumes in certain orbital compartments correlate well with cumulative smoking. Extraocular muscle volumes are not influenced by smoking in patients with Graves' ophthalmopathy.

[Assessment of autoimmune disease activity in endocrine orbitopathy: comparison of SPECT using 99m-Tc-DTPA or 99m-Tc-depreotide and MRI scores]. / Az autoimmun folyamat aktivitásának megítélése izotópdiagnosztikai módszerekkel endokrin orbitopathiában: a 99mTc-DTPA, a 99m-Tc-depreotid SPECT és az MR összehasonlítása.

INTRODUCTION: Currently there is no ideal imaging technique which could estimate the degree of inflammation in thyroid eye disease. AIM: A new, rapid and cost-effective method, using 99mTc-labelled DTPA and 4-headed SPECT, was developed which is able to diagnose inflammatory activity in patients with endocrine orbitopathy (EOP). METHODS: The MRI T2 relaxation time was used as reference. Comparative orbital SPECT with the more specific 99mTc-Neospect (depreotide) was also performed in the same patients. RESULTS: Visual evaluation of orbital SPECT frames of patients suffering from active EOP could be easily distinguished from inactive EOP patients'. Despite the supposedly different characteristics of the two tested radiopharmaceuticals, there was essentially no difference between their accumulation in the orbit and the information obtained. The MRI activity scores correlated well with 99mTc-DTPA activity uptake (AU). The mean AU value in patients with inactive EOP was 6.26 +/- 1.6 10(-6) ID/cm3, while in active EOP 10.78 +/- 0.61 10(-6) ID/cm3, significantly higher. The 99mTc-DTPA accumulation in the orbital region in active disease was similar to that of depreotide. There was a good correlation (r = 0.91, P < 0.0001) between the two methods. CONCLUSION: The authors concluded that 99mTc-DTPA orbital SPECT is a potentially useful method, which--after initial clinical and MRI staging--gives useful quantitative estimation of disease activity in endocrine orbitopathy. It may provide important visual and quantitative information during the follow up of patients.

Using morphologic parameters of extraocular muscles for diagnosis and follow-up of Graves' ophthalmopathy: diameters, areas, or volumes?

OBJECTIVE: The objective of this study was to find the most appropriate, accurate, and convenient muscle parameter that can be used as a substitute for volume in monitoring the effectiveness of therapy of patients with Graves' ophthalmopathy. SUBJECTS AND METHODS: The four rectus muscles in 110 orbits (35 patients and 20 control subjects) were evaluated with MR imaging. The diameter at the largest extent of the muscle belly, as well as the long and the short diameters and the cross-sectional areas in a preselected coronal scan, were measured for each muscle and were compared with the corresponding muscle volume measured on contiguous T1-weighted transverse slices. RESULTS: The measured coronal area correlated well with the volume of the superior (r = 0.694, p < 0.0001) and inferior (r = 0.783, p < 0.0001) recti, and the largest transverse diameter showed strong correlation with the volume of the lateral (r = 0.868, p < 0.0001) and medial (r = 0.869, p < 0.0001) recti. For the latter muscle, the coronal area also exhibited a good correlation with the volume (r = 0.838, p < 0.0001). Coronal cross-sectional areas can be well estimated by measuring both the short and long coronal muscle diameters (r values were between 0.914 and 0.966; p < 0.0001). CONCLUSION: In Graves' ophthalmopathy, the volume of three of the rectus muscles can be well estimated by simple measurements on a single coronal slice, and the largest transverse diameter of the lateral rectus is suitable for the same purpose.