Thyroid stunning in clinical practice: is it a real problem?

Stunning is a phenomenon of reducing (131)I uptaking activity by residual or metastatic tissue during the follow-up of patients after total thyroidectomy for differentiated thyroid carcinoma. It was observed at whole body scintigraphy performed after therapeutic dose, administered for remnant ablation, in patients who were previously given a (131)I dose for diagnostic purpose. This phenomenon could influence the efficacy of radioisotopic therapy, making it unsuccessful. Stunning was observed also in case of hyperthyroidism treated by fractionated doses of (131)I. After a careful revision of literature, Authors report their last 10 years-experience about very few cases of supposed stunning, observed in oncological and hyperthyroidal patients who underwent diagnostic scan and radioiodine therapy. In case of differentiated thyroid carcinoma, we recommended a careful selection of patients who will be given ablative therapy using very low diagnostic doses and administering further therapeutic dose in a short time. In case of hyperthyroidism treatment, it is confirmed the opportunity of a single therapeutic dose with TSH value within the normal range. Because it was found out a very small number of cases in our wide population, we conclude that stunning is not influent in clinical practice, above all if ''well-practice'' diagnostic-therapeutical procedures are strictly observed.

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.

Our experience on pain palliation of bone metastasis with Sr-89 or Sm-153 in cancer patients resistant to a conventional analgesic therapy. A retrospective study.

OBJECTIVES: These retrospective study is aimed to evaluate the efficacy of therapy with Stronthium-chloride 89 (89SrCl) and Samarium 153 conjugated with ethylenediaminetetramethylene phosphonic acid (153Sm-EDTMP) in the palliation of bone pain due to metastatic malignancy. MATERIALS AND METHODS: The study refers to a presentation sample of 27 patients with bone metastases caused by different cancers (16 prostate, 5 breast, 6 lung) who were enrolled and followed-up for 11.5 +/- 6.3 months. 89SrCl (150MBq) was administered in 17 pts, 153Sm-EDTMP (37 MBq/Kg) in 10 pts. All patients showed multiple metastatic sites of 99Tc-HDP uptake documented by a standard bone scintigraphy. Effectiveness of treatment was evaluated by questionnaires about pain and quality of life, Karnofsky index, specific cancer markers, a post-treatment bone scintigraphy. Presence of flare reaction and haematological toxicity were evaluated too. RESULTS: Questionnaire scores decreased both in patients treated with 89SrCl and in those given 153Sm-EDTM, without significant difference. Karnofsky index significantly increased only in patients with prostate cancer. After therapy, there were no significant changes of tumor marker levels, neither in bone scintigraphic pattern. Flare reaction occurred in 44% of the cases within 2 weeks from the therapy. Remarkable variations of platelets and leukocytes occurred in 33.3% and 18.5% of patients, respectively, independently of the radiopharmaceutical used, but reversed within 6 weeks after therapy. CONCLUSIONS: Radionuclide therapy with bone-seeker agents 89Sr and 153Sm in the palliation of painful bone metastases allows a partial/total relief of pain with an improvement of quality of life. No tumoricid effect was found. Haematological toxicity was limited and reversible. Patients with prostate cancer seem to have a higher response rate.

Effectiveness of morphine in non-cardiogenic pulmonary edema due to chlorine gas inhalation.

We report the case of an 11-yr-old boy who developed a non-cardiogenic pulmonary edema following inhalation of chlorine gas at a swimming pool. Rapid clinical improvement was noted after i.v. administration of morphine.