Indium-111-pentetreotide in Graves' disease.
Thyroidal and orbital lymphocytic infiltration in Graves' disease, as well as identification of somatostatin receptors on lymphocytes, has provided a rationale for receptor imaging with the radiolabeled somatostatin analog pentetreotide. Recently, we demonstrated that in contrast to controls, Graves' patients showed markedly increased orbital accumulation of pentetreotide. Longitudinal and follow-up data are presented here.


METHODS
In 20 (16 hyperthyroid) Graves' patients with active eye disease, planar (thyroid) and SPECT (orbit) images were performed 4 and 24 hr after injection of 111In-pentetreotide (222 MBq) before and 3 mo after starting antithyroid and combined steroid and orbital radiotherapy.


RESULTS
Thyroidal uptake decreased during methimazole treatment (4 hr postinjection, median: hyperthyroid 989 counts/pixel/MBq injected activity, euthyroid 253 counts, p = 0.001; 24 hr, 437 versus 95 counts/pixel/MBq, p = 0.005). Fourteen patients (70%) responded to steroid and radiotherapy. The pentetreotide orbit-to-brain ratio decreased markedly after completion of therapy (4 hr: 25 before versus 6.2 after therapy, p = 0.0003; 24 hr: 9.6 versus 2.7, p = 0.003). A high pretreatment ratio correlated with a response to therapy (p = 0.001: in 14 of 16 patients with a ratio > 10, 4 hr postinjection, ophthalmopathy improved; positive predictive value: 90%; median activity score before 6 versus 2 after therapy, p = 0.0001) in contrast to none of the four cases with a ratio less than 10 (score 5 versus 4, p = 0.08).


CONCLUSIONS
Pentetreotide scans may be regarded as a semiobjective tool in the evaluation of Graves' disease, both at initial stages as well as during treatment.
Kahaly
G
G
Department of Endocrinology/Metabolism, Gutenberg-University Hospital, Mainz, Germany.
Görges
R
R
Diaz
M
M
Hommel
G
G
Bockisch
A
A
D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D013956:Antithyroid Agents / Q000627:therapeutic use; D003037:Cobalt Radioisotopes / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006111:Graves Disease / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000453:epidemiology / Q000532:radiotherapy; D006801:Humans; D007205:Indium Radioisotopes; D008137:Longitudinal Studies; D008297:Male; D008713:Methimazole / Q000627:therapeutic use; D008875:Middle Aged; D011237:Predictive Value of Tests; D011239:Prednisolone / Q000627:therapeutic use; D011446:Prospective Studies; D011867:Radioisotope Teletherapy; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin / Q000032:analysis*; D012680:Sensitivity and Specificity; D013004:Somatostatin / Q000031:analogs & derivatives*; D015899:Tomography, Emission-Computed, Single-Photon
D000893:Anti-Inflammatory Agents; D013956:Antithyroid Agents; D003037:Cobalt Radioisotopes; D007205:Indium Radioisotopes; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin; D013004:Somatostatin; D008713:Methimazole; D011239:Prednisolone; C081788:pentetreotide