131I therapy and Graves' disease in a long term observation: euthyroidism is a suitable goal. Our experience.

OBJECTIVE: The aim of the study was to verify early and definitive outcome of radioiodine therapy in patients with Graves' disease, administering 131I calculated dose to pursue euthyroidism. PATIENTS AND METHODS: We retrospectively analyzed 639 patients affected by Graves' disease and treated by one or more 131I calculated doses. Results dose by dose are reported. As to the first administration, outcome is related to parameters used to calculate dose and to patients' available features. Failures and hypothyroidism onset are evaluated. RESULTS: A mean dose of 10 mCi shows great effectiveness: 75% of patients were cured after one administration, 88% after two. Of the failures, 84.1% occurred in a mean time of 0.34±0.23 years and were more frequent for larger glands, accelerated intra-gland radioiodine turnover, ophtalmopathy, administration of antithyroid drugs until 131I therapy. Of hypothyroid patients, 39.8% were diagnosed within the first year. After a sharp initial rise, hypothyroidism occurred at a slower rate, with estimated yearly increases of 3.8% until 10 years and of 1.8% later. In still followed up patients, euthyroidism was observed in about half the population after 10 years and in a third after 25 years. CONCLUSIONS: 131I can be the first line treatment for Graves' disease in small-medium thyroids. Calculated doses can achieve a high amount of long term euthyroid patients. Similar results could be expected by fixed doses of 10 mCi.

Lymph node metastases from differentiated thyroid carcinoma: does radioiodine still play a role?

OBJECTIVES: Ultrasonography and surgery have now become the elective diagnostic and therapeutic tools for neck lymph node (LN) metastases from differentiated thyroid carcinoma (DTC), reserving radioiodine therapy (RAI) for surgery failures. Aim of the present retrospective study was to evaluate results of RAI in cases of LN metastases displaying (131)I uptake over a long-term observation period and its possible role today. MATERIALS AND METHODS: From a series of 1276 patients who had undergone surgery for DTC, 130 cases were selected showing (131)I uptaking LN metastases, detected during follow-up scans and who were then submitted to surgery and/or RAI. Patients were divided into groups according both to extent of surgery, with/without lymphectomy, and to following treatment and outcome. RESULTS: The initial surgical approach does not seem to significantly influence the outcome. (131)I therapy alone, sometimes at low doses, can be very effective in the management of LN metastases detected at Whole Body Scan, but multiple doses are often needed. The age at diagnosis is confirmed as a negative prognostic factor. CONCLUSIONS: Considered radioprotection questions, RAI may solve (131)I uptaking LN metastases, above all if < 10 mm. For larger LN metastases and in the case of failure of RAI surgical excision is mandatory, while a subsequent therapeutic dose of (131)I could be useful to reveal incomplete excision.

A finding of myocardial uptake at a bone scintigraphy with Tc-99m HDP.

We present a patient admitted to our Department for a Tc-99m HDP three-phase bone scintigraphy to evaluate a hip prosthesis. Delayed images showed diffuse myocardial uptake at whole body scan. In such cases, several diseases should be considered in the differential diagnosis.

Sensitivity of [99mTc]methoxyisobutylisonitrile scan in patients with metastatic differentiated thyroid cancer.

AIM: The aim of the present study was to evaluate the diagnostic sensitivity of [(99m)Tc]methoxyisobutylisonitrile ([(99m)Tc]MIBI) in a large series of patients with metastatic differentiated thyroid carcinoma (DTC), as compared with (131)I-whole body scan (WBS) and other diagnostic imaging techniques. METHODS: Eighty-four patients with known metastases from DTC where recruited during the course of replacement thyroxine therapy and undergone [(99m)Tc]MIBI scan. All patients previously performed a (131)I-WBS with thyroglobulin (Tg) measurement and neck ultrasound or computerized tomography, or magnetic resonance imaging, or bone scan or positron emission tomography (PET) scan. RESULTS: Patients were divided in two groups: group A (n=50) with known metastases and positive at a previous (131)I-WBS and group B (n=34) with known metastases, but negative at (131)I-WBS. All patients had elevated serum Tg level in absence of replacement therapy. Technetium-99m-MIBI scan showed 76.2% sensitivity in detecting metastases, Tg during opotherapy 64.3%, and the other imaging techniques combined 86.9%. Sensitivity of [(99m)Tc]MIBI was greater in metastases without (131)I uptake than in metastases with (131)I uptake, although the difference was not statistically significant. CONCLUSION: Technetium-99m-MIBI scan improves sensitivity of Tg measurement in patients with suspected metastases from DTC during the course of opotherapy and is a useful alternative to fluorodeoxyglucose-PET or other imaging techniques in patients with elevated serum Tg and negative (131)I-WBS.