Indium-111-Octreotide scintigraphy in differentiated thyroid carcinoma metastases that do not respond to treatment with high-dose I-131

Peptide receptor radionuclide therapy of differentiated thyroid cancer: efficacy and toxicity

In rare cases of differentiated thyroid carcinoma (DTC), radioiodine treatment is no longer effective due to cell dedifferentiation. Targeting somatostatin receptors in DTC cells by radiolabelled somatostatin analogues could provide an alternative therapy option. The aim of this study was to evaluate safety and efficacy of peptide receptor radionuclide therapy (PRRT) in patients with advanced, non-iodine avid DTC. Eleven patients aged 47–81 years (median: 65 years) with a history of several courses of radioiodine therapy, increasing thyroglobulin (Tg) and negative whole body scan, were qualified to the study. After confirming receptor expression by somatostatin receptor scintigraphy, PRRT with yttrium-90 labelled analogue was initiated. Fractionated treatment protocol was used with four doses of ⁹⁰Y-DOTA-TOC in 12-week intervals. Activity of each dose was 3.7 GBq (100 mCi). Of 11 patients, 5 died before receiving the fourth course of PRRT. In the remaining six patients, morphological response, evaluated 3 months after the last course using RECIST criteria showed partial remission (PR) in one patient, stable disease (SD) in two patients and progressive disease (PD) in three patients. Biochemical response based on Tg measurements before and after PRRT showed PR in one patient, SD in four patients and PD in one patient. Median survival was 21 months from the first course of PRRT. Only minor and transient hematological toxicity was observed in some patients. We conclude that PRRT is generally well-tolerated and may be a valuable option for some patients with radioiodine-refractory DTC.

Hürthle cell thyroid carcinoma metastatic to the sigmoid colon

Prognosis of differentiated thyroid cancer is favorable in the majority of cases. However, distant metastases occur in 10-15% of cases, predominantly in lungs and bones, especially in older patients exhibiting poorly differentiated forms or advanced stages. We report a case history of Hürthle cell thyroid carcinoma metastasized to the sigmoid colon. To the best of our knowledge, this location has never been described before. This case history illustrates the difficulties of diagnosis and treatment in patients whose metastases do not concentrate radioiodine. The interest of different imaging modalities, including fluoro-deoxy-glucose positron emission tomography scan and somatostatin receptor scintigraphy, is discussed.

Is there a role for sandostatin treatment in patients with progressive thyroid cancer and iodine-negative but somatostatin-receptor-positive metastases?

INTRODUCTION

The aim of our study was to determine whether treatment with a long-acting somatostatin-receptor analogue is effective in patients with (131)I-negative but somatostatin-receptor-positive metastases from dedifferentiated and anaplastic thyroid cancer.

MATERIALS AND METHODS

Twelve patients were screened for the study. All of them showed progressive disease confirmed by radiologic evaluation, increasing serum thyroglobulin (Tg), and negative diagnostic or posttherapeutic (131)I whole-body scans (WBS). Eight of 12 patients (4 males and 4 females; age range, 57-89 years; 1 papillary thyroid cancer; 4 poorly differentiated follicular thyroid cancer; 1 follicular and anaplastic thyroid cancer; 2 anaplastic thyroid cancer) showed positive somatosatin-receptor expression in Tc-99m depreotide WBS/SPECT (Tc-99m Dep.WBS). Initially, in all patients fluorine-18 2-fluoro-2- D-glucose-positron emission tomography-computed tomography ((18)F-FDG-PET-CT), Tc-99m Dep.WBS, and Tg measurements were performed. In the case of positive receptor scintigraphy, patients were treated with 20mg Sandostatin LAR (Novartis Pharmaceuticals, Basel, Switzerland) once per month intramuscularly over a period of 6 months followed by repeated (18)F-FDG-PET-CT, Tc-99m Dep.WBS, and Tg measurement to determine metabolic activity and tumor size. In case of tumor progression, the dose was increased to 30mg of Sandostatin LAR once per month.

RESULTS

Only 3 patients were able to undergo long-term treatment. Two patients were treated with octreotide long-acting release (LAR) for 1 year and 1 patient for 1(1/2) years. All patients showed progressive disease during the treatment: an increase of serum Tg on one hand and an increase in the number of lesions and extent in tumor size visible on FDG-PET-CT and Tc-99m Dep.WBS on the other. During the treatment there was no change in receptor expression, nevertheless, clear tumor progression under therapy with a somatostatin analogue was visible in FDG-PET-CT and in Tc-99m Dep.WBS.

CONCLUSION

Our data demonstrate that all of our patients treated with a somatostatin analogue showed clinical progression and that our attempt to achieve a stabilization of the disease failed.

111In-Pentetreotide uptake in a follicular adenoma of the thyroid gland: a pitfall for 111In-Pentetreotide scintigraphy

A patient with suspicion of a neuroendocrine tumor of the pancreas underwent a somatostatin receptor scintigraphy using 111In-Pentetreotide. 111In-pentetreotide scintigraphy showed discrete uptake of the radiotracer in the head of the pancreas and focal uptake in the right upper thyroid lobe. Tracer uptake in the 24h planar image was higher compared to the 4h image, and decreased after 48 hours. Normal thyroid tissue and thyroid disorders, such as cancers, Hashimoto's thyroiditis, and adenomas often show increased uptake of 111In-pentetreotide resulting in a possible false positive interpretation in patients with neuroendocrine tumor. Adding a 48h planar image might contribute to the differential diagnosis between benign or malignant lesions, as in the present case where the uptake decreased in an adenoma after 48 hours.

Tc-99m depreotide imaging of I-131-negative recurrent metastatic papillary thyroid carcinoma

The detection of radioiodine (I-131)-negative metastases of differentiated thyroid carcinoma (DTC) has been hitherto successfully tried by the well-known synthetic somatostatin analogue indium-111-labeled DTPA-octreotide (In-111 pentetreotide). The objective of this study was to evaluate the usefulness of scintiscan with the newer synthetic somatostatin analogue Tc-99m depreotide, in the restaging of papillary thyroid carcinoma (PTC) with detectable serum thyroglobulin (Tg) levels and negative I-131 whole-body scan (WBS). Whole-body planar and cervico-thoracic tomographic scintigraphy (single-photon emission tomography-SPET) with Tc-99m depreotide was performed in a 68-year-old male patient suffering from PTC stage III, with a mild increase in serum Tg levels coupled with a recent negative I-131 WBS. The findings were compared with those of neck ultrasonography (US) and computerized tomography (CT). Nodal neck dissection and histopathology provided the definitive diagnosis. Tc-99m depreotide scanning revealed foci of cervical lymph node metastases, which did not accumulate I-131. The findings were in accordance with neck US and CT. Histopathology established the diagnosis of metastatic cervical lymph node PTC. Lymph node immunoreactivity was positive for the somatostatin receptor subtypes 2, 5 and 3. Scintigraphy with Tc-99m depreotide could prove a useful adjunct to the armamentarium for the follow-up of PTC, especially in the setting of detectable serum Tg and negative I-131 WBS.

The management of advanced thyroid cancer

Although the prognosis of the majority of patients with thyroid cancer is excellent there are some patients with advanced thyroid cancer in whom the prognosis is poor. Such patients include: patients with locally invasive or recurrent differentiated thyroid cancer and medullary thyroid cancer, and all patients with anaplastic cancer. The management of patients with advanced thyroid cancer is reviewed with emphasis on the role of external beam radiotherapy.

Six month follow-up after 111In-DTPA-octreotide therapy in patients with progressive radioiodine non-responsive thyroid cancer: a pilot study

BACKGROUND AND AIM

111In-DTPA-octreotide is internalized by thyroid and neuroendocrine cancer cells via somatostatin receptor subtypes and can cause DNA damage by the emission of conversion and Auger electrons. The aim of the study was to determine the effect of 111In-DTPA-octreotide therapy in patients with progressive radioiodine non-responsive thyroid cancer in relation to 111In-DTPA-octreotide uptake by tumour localizations assessed on pre-treatment diagnostic octreotide scans.

METHODS

Eleven consecutive patients, selected on positive pretreatment diagnostic scans, were treated with fixed doses of approx. 7400 MBq of 111In-DTPA-octreotide with an interval of 2-3 weeks between the doses. In one patient, the dose was adjusted because of sickle-cell disease. To assess the effects during treatment with 111In-DTPA-octreotide thyroglobulin levels were gathered from 2 years before treatment, during treatment and up to 1 year after treatment. A computed tomography scan was performed 3 months after the last treatment.

RESULTS

Two patients died during and shortly after the treatment course. Death was due to a sepsis and an insulin overdose, respectively. In 44% of the patients, stable disease was achieved up to 6 months after the first treatment according to both criteria. All four had relative low pretreatment thyroglobulin values (mean value 275 microg.l), representing limited metastasized disease. In two patients biochemical stable disease was observed, whereas computed tomography showed tumour progression.

CONCLUSION

Treatment with high doses of 111In-DTPA-octreotide in differentiated thyroid cancer results in a stable disease in a subgroup of patients. Our results suggest that a low pre-treatment thyroglobulin value, representing a small tumour load, may be a selection criterion for treatment.