Indium-111-Octreotide scintigraphy in differentiated thyroid carcinoma metastases that do not respond to treatment with high-dose I-131.
OBJECTIVE
Differentiated thyroid cancer is characterized by a very good prognosis in the majority of the patients. The therapy of choice is surgery followed by ablation with Iodine-131 (I-131). However, some patients have metastases that have lost the capability of concentrating I-131, even when it is given in therapeutic doses. In the present study, we describe the value of Indium-111 Octreotide (Octreoscan) in differentiated thyroid cancer patients with increased Tg levels who failed to demonstrate a response to treatment with high-dose I-131.


METHODS
Fifteen consecutive patients with progressive differentiated thyroid cancer (ten female, five male) (mean age: 59 years, range 13-81 years; eight papillary, six follicular, and one Hürthle cell carcinoma) were studied. Progression was based on increasing Tg levels and was confirmed by radiological evaluation. Whole body scintigraphy (WBS) was performed after the administration of 200 MBq of Indium-111-Octreotide. The images were assessed by two experienced observers and compared with post-treatment I-131 WBS.


RESULTS
In seven out of 15 patients distant metastases were already present at initial stage, whereas in ten patients the primary tumor stage was T3 or T4 indicating that the majority of the patients had advanced disease. In two out of five patients with a positive I-131 WBS, Indium-111-Octreotide was false negative. In nine out of ten patients with a negative I-131 WBS, Indium-111-Octreotide demonstrated multiple metastases. In those patients with a positive SSR-scintigraphy, metastases were found in the lungs ( n=14), bone ( n=7), mediastinum ( n=3), liver ( n=2), brains ( n=1), and cutis ( n=1). Overall, three out of 15 patients had a negative Indium-111-Octreotide result revealing a sensitivity of 80%.


CONCLUSIONS
Our findings demonstrate the diagnostic value of Indium-111-Octreotide in differentiated thyroid cancer that fails to respond to I-131 treatment. It opens the possibility for additional treatment with high doses of Indium-111-Octreotide or its analogs in a majority of the patients.
Stokkel
Marcel P M
MP
Department of Nuclear Medicine, Leiden University Medical Center, P.O. Box 9600, 2300, RC Leiden, The Netherlands. m.p.m.stokkel@lumc.nl
Reigman
Henna I E
HI
Verkooijen
Robbert B T
RB
Smit
Jan W
JW
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal; D002291:Carcinoma, Papillary / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000532:radiotherapy; D018450:Disease Progression; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007205:Indium Radioisotopes; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D015282:Octreotide; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin / Q000032:analysis*; D013004:Somatostatin / Q000031:analogs & derivatives / Q000627:therapeutic use; D017256:Technetium Tc 99m Sestamibi; D013794:Thallium Radioisotopes; D013964:Thyroid Neoplasms / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000532:radiotherapy; D014055:Tomography, Emission-Computed / Q000379:methods; D017211:Treatment Failure
D018931:Antineoplastic Agents, Hormonal; D007205:Indium Radioisotopes; D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin; D013794:Thallium Radioisotopes; D019788:Fluorodeoxyglucose F18; D013004:Somatostatin; D017256:Technetium Tc 99m Sestamibi; D015282:Octreotide