RESEARCH - Retrobulbar 99mTc-DTPA uptake may predict the effectiveness of immunosuppressive therapy in Graves' ophthalmopathy

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Thyroid. 2009 Apr;19(4):375-80.

Retrobulbar 99mTc-diethylenetriamine-pentaacetic-acid uptake may

predict the effectiveness of immunosuppressive therapy in Graves'

ophthalmopathy.

Ujhelyi B, Erdei A, Galuska L, Varga J, Szabados L, Balazs E, Bodor M,

Cseke B, Karanyi Z, Leovey A, Mezosi E, Burman KD, Berta A, Nagy EV.

Department of Ophthalmology, University of Debrecen Medical and Health

Science Center, Debrecen, Hungary.

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 <or=12.28 MBq/cm(3) was 78%.

CONCLUSIONS: Corticosteriod treatment is associated with a decline in

DTPA uptake in a fraction of GO patients. GO patients with a DTPA

uptake above 12.28 MBq/cm(3) are more likely to have a favorable

response to corticosteroid therapy while patients with lower values

are less likely to have this potentially favorable response. An

elevated DTPA uptake may identify patients who are most likely to

benefit from immunosuppressive treatment.

PMID: 19355827

http://www.ncbi.nlm.nih.gov/pubmed/19355827

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