Semi-quantification and grading of amyloid PET: A project of the European Alzheimer's Disease Consortium (EADC).

BACKGROUND: amyloid-PET reading has been classically implemented as a binary assessment, although the clinical experience has shown that the number of borderline cases is non negligible not only in epidemiological studies of asymptomatic subjects but also in naturalistic groups of symptomatic patients attending memory clinics. In this work we develop a model to compare and integrate visual reading with two independent semi-quantification methods in order to obtain a tracer-independent multi-parametric evaluation. METHODS: We retrospectively enrolled three cohorts of cognitively impaired patients submitted to 18F-florbetaben (53 subjects), 18F-flutemetamol (62 subjects), 18F-florbetapir (60 subjects) PET/CT respectively, in 6 European centres belonging to the EADC. The 175 scans were visually classified as positive/negative following approved criteria and further classified with a 5-step grading as negative, mild negative, borderline, mild positive, positive by 5 independent readers, blind to clinical data. Scan quality was also visually assessed and recorded. Semi-quantification was based on two quantifiers: the standardized uptake value (SUVr) and the ELBA method. We used a sigmoid model to relate the grading with the quantifiers. We measured the readers accord and inconsistencies in the visual assessment as well as the relationship between discrepancies on the grading and semi-quantifications. CONCLUSION: It is possible to construct a map between different tracers and different quantification methods without resorting to ad-hoc acquired cases. We used a 5-level visual scale which, together with a mathematical model, delivered cut-offs and transition regions on tracers that are (largely) independent from the population. All fluorinated tracers appeared to have the same contrast and discrimination ability with respect to the negative-to-positive grading. We validated the integration of both visual reading and different quantifiers in a more robust framework thus bridging the gap between a binary and a user-independent continuous scale.

Real-life management and outcome of thyroid carcinoma-related bone metastases: results from a nationwide multicenter experience.

PURPOSE AND PATIENTS: The M.O.S.CA.TI. (Metastases of the Skeleton from CArcinoma of the ThyroId) is a multicenter, retrospective study investigating the real-life outcome and management of bone metastases (BM) in 143 patients (63 M, 80 F; median age 64 years, range 11-87) with differentiated thyroid carcinoma (DTC). RESULTS: Radio-active iodine (RAI) treatment was performed in 131 patients (91.6%), surgical approach and/or external radiotherapy in 68 patients (47.6%), and anti-resorptive bone-active drugs in 32 patients (22.4%; in 31 zoledronate and in one denosumab). At the start of treatment, 24 patients (75.0%) receiving anti-resorptive bone-active drugs had at least one clinical skeletal-related event (SRE) (p < 0.001). One or more clinical SREs (pathological fractures and/or malignant hypercalcemia and/or spinal cord compression) developed in 53 patients (37.1%). Development of SREs was significantly associated with metachronous BM (hazard ratio (HR) 2.04; p = 0.04), localization of BM to cervical spine (HR 3.89; p = 0.01), and lack of avid RAI uptake (HR 2.66; p = 0.02). Thirty-nine patients (27.3%) died in correlation with development of SREs (HR 6.97; p = 0.006) and localization of BM to the hip (HR 3.86; p = 0.02). Moreover, overall mortality was significantly decreased by RAI therapy (HR 0.10; p = 0.02), whereas no significant effects were induced by bone-active drugs (p = 0.36), external radiotherapy (p = 0.54), and surgery (p = 0.43) of BM. CONCLUSIONS: SREs are very frequent in BM from DTC and they impact patient survival. In the real life, the use of bone-active drugs is currently limited to zoledronate in patients with pre-existing SREs. In this clinical setting, RAI therapy, but not zoledronate, decreased mortality.

Right putamen and age are the most discriminant features to diagnose Parkinson's disease by using 123I-FP-CIT brain SPET data by using an artificial neural network classifier, a classification tree (ClT).

OBJECTIVE: The differential diagnosis of Parkinson's disease (PD) and other conditions, such as essential tremor and drug-induced parkinsonian syndrome or normal aging brain, represents a diagnostic challenge. 123I-FP-CIT brain SPET is able to contribute to the differential diagnosis. Semiquantitative analysis of radiopharmaceutical uptake in basal ganglia (caudate nuclei and putamina) is very useful to support the diagnostic process. An artificial neural network classifier using 123I-FP-CIT brain SPET data, a classification tree (CIT), was applied. CIT is an automatic classifier composed of a set of logical rules, organized as a decision tree to produce an optimised threshold based classification of data to provide discriminative cut-off values. We applied a CIT to 123I-FP-CIT brain SPET semiquantitave data, to obtain cut-off values of radiopharmaceutical uptake ratios in caudate nuclei and putamina with the aim to diagnose PD versus other conditions. SUBJECTS AND METHOD: We retrospectively investigated 187 patients undergoing 123I-FP-CIT brain SPET (Millenium VG, G.E.M.S.) with semiquantitative analysis performed with Basal Ganglia (BasGan) V2 software according to EANM guidelines; among them 113 resulted affected by PD (PD group) and 74 (N group) by other non parkinsonian conditions, such as Essential Tremor and drug-induced PD. PD group included 113 subjects (60M and 53F of age: 60-81yrs) having Hoehn and Yahr score (HY): 0.5-1.5; Unified Parkinson Disease Rating Scale (UPDRS) score: 6-38; N group included 74 subjects (36M and 38 F range of age 60-80 yrs). All subjects were clinically followed for at least 6-18 months to confirm the diagnosis. To examinate data obtained by using CIT, for each of the 1,000 experiments carried out, 10% of patients were randomly selected as the CIT training set, while the remaining 90% validated the trained CIT, and the percentage of the validation data correctly classified in the two groups of patients was computed. The expected performance of an "average performance CIT" was evaluated. RESULTS: For CIT, the probability of correct classification in patients with PD was 84.19±11.67% (mean±SD) and in N patients 93.48±6.95%. For CIT, the first decision rule provided a value for the right putamen of 2.32±0.16. This means that patients with right putamen values <2.32 were classified as having PD. Patients with putamen values ≥2.32 underwent further analysis. They were classified as N if the right putamen uptake value was ≥3.02 or if the value for the right putamen was <3.02 and the age was ≥67.5 years. Otherwise the patients were classified as having PD. Other similar rules on the values of both caudate nuclei and left putamen could be used to refine the classification, but in our data analysis of these data did not significantly contribute to the differential diagnosis. This could be due to an increased number of more severe patients with initial prevalence of left clinical symptoms having a worsening in right putamen uptake distribution. CONCLUSION: These results show that CIT was able to accurately classify PD and non-PD patients by means of 123I-FP-CIT brain SPET data and provided also cut-off values able to differentially diagnose these groups of patients. Right putamen uptake values resulted as the most discriminant to correctly classify our patients, probably due to a certain number of subjects with initial prevalence of left clinical symptoms. Finally, the selective evaluation of the group of subjects having putamen values ≥2.32 disclosed that age was a further important feature to classify patients for certain right putamen values.

The widened use of exogenous stimulation with recombinant human TSH to treat metastatic thyroid carcinoma in Italy.

Recently, in Italy, the reimbursement for the use of rhTSH in preparing patients for radiometabolic treatment of iodine-avid metastases from differentiated thyroid cancer has been made possible. Intramuscular administration of rhTSH increases the radioiodine uptake and thyroglobulin production by thyroid cells. In addition to the previous indications on the use of rhTSH (mainly: serum thyreoglobulin assay with or without 131I scintigraphy and ablation with 131I of remnants in low risk patients), the reimbursement is now allowed for the treatment with radioiodine of iodine-avid loco-regional and distant metastases, in subjects with inability to reach adequate TSH levels and/or severe clinical conditions which could be potentially worsened by other concurrent diseases (history of stroke or transient ischemic attack, severe cardiac disease, renal failure or major psychiatric disorders). The Italian Medicines Agency (AIFA) approved this use (and added this hormone in the special list of drugs regulated by the D.Lgs 648/96) on the basis of a series of scientific evidences, proposed by a "team of experts". In the present paper we illustrate the scientific background of the use of rhTSH (clinical usefulness, economic considerations, aspects related to a better quality of life) that allowed the modification of the reimbursement and how it was made possible in the Italian legislative context.

[Radiometabolic therapy for metastatic thyroid carcinoma: overview of the literature and rational bases for the use of recombinant human TSH]. / La terapia radiometabolica del carcinoma della tiroide metastatico: overview della letteratura e basi razionali all'utilizzo del TSH umano ricombinante.

The established treatment for differentiated thyroid carcinoma (DTC) is founded on total thyroidectomy and subsequent administration of radioiodine (131I) to ablate the thyroid remnant and to treat the metastatic disease. In the case of metastatic or recurrent disease, further cycles of 131I therapy are often necessary. The condition for maximizing the effectiveness of the treatment is to have an adequate stimulation from TSH, which must be >25-30 mIU/L. This elevation is achieved either discontinuing the hormone suppression therapy for an appropriate period, or administering recombinant human TSH (rhTSH). The latter has shown good clinical efficacy in patients with residual thyroid gland and is nowadays commonly employed since it is easy to use and allows to avoid the side effects of hypothyroidism. It thus represents a good alternative to thyroid hormone withdrawal for the remnant ablation, while is still open the question if its efficacy on the management of metastatic disease is superimposable to thyroid hormone withdrawal. To this purpose, a Panel of expert reviewed the literature, assessing the advantages and disadvantages for the patient, as well as the impact in terms of cost and benefit to the National Health Service. The work of the Panel concluded with a proposal for the use of rhTSH in selected patients with metastatic DTC, in which is considered the efficacy and safety of the product and is examined its use in terms of costs; this proposal was accepted by the Italian Drug Agency resulting in an update of the indications for rhTSH.

Iron lung versus mask ventilation in acute exacerbation of COPD: a randomised crossover study.

OBJECTIVE: To compare iron lung (ILV) versus mask ventilation (NPPV) in the treatment of COPD patients with acute on chronic respiratory failure (ACRF). DESIGN: Randomised multicentre study. SETTING: Respiratory intermediate intensive care units very skilled in ILV. PATIENTS AND METHODS: A total of 141 patients met the inclusion criteria and were assigned: 70 to ILV and 71 to NPPV. To establish the failure of the technique employed as first line major and minor criteria for endotracheal intubation (EI) were used. With major criteria EI was promptly established. With at least two minor criteria patients were shifted from one technique to the other. RESULTS: On admission, PaO(2)/FiO(2), 198 (70) and 187 (64), PaCO(2), 90.5 (14.1) and 88.7 (13.5) mmHg, and pH 7.25 (0.04) and 7.25 (0.05), were similar for ILV and NPPV groups. When used as first line, the success of ILV (87%) was significantly greater (P = 0.01) than NPPV (68%), due to the number of patients that met minor criteria for EI; after the shift of the techniques; however, the need of EI and hospital mortality was similar in both groups. The total rate of success using both techniques increased from 77.3 to 87.9% (P = 0.028). CONCLUSIONS: The sequential use of NPPV and ILV avoided EI in a large percentage of COPD patients with ACRF; ILV was more effective than NPPV on the basis of minor criteria for EI but after the crossover the need of EI on the basis of major criteria and mortality was similar in both groups of patients.

Skin prick-test reactivity to aeroallergens and allergic symptoms in an urban population of central Italy: a longitudinal study.

BACKGROUND: Cross-sectional studies report an increasing prevalence of allergic diseases, such as rhinitis and asthma. Not thoroughly known, instead, is the natural history of allergic sensitization and the progress of the allergic disease-related symptoms. AIM: The purpose of this study was to evaluate longitudinally the skin reactivity for the most common aeroallergens and the allergic symptoms in an urban population living in Perugia, a town of central Italy with a low-level of air pollution exposure. METHODS: In the 1998-1999 period 788 subjects were tested for skin reactivity to a panel of aeroallergens and underwent the administration of a questionnaire. These same subjects were part of a cohort of 1200 subjects who participated in a previous epidemiological study performed in 1984-1985 using the same tools. Subjects were aged between 14 and 64 years at the time of the first survey. RESULTS: In the present survey 196 subjects (24.9%) had skin reactivity to at least one aeroallergen, while in the previous survey 143 subjects (18.1%) had skin prick-test reactivity. The increase of the skin reactivity between the two observations was highly significant (P<0.001) and was mainly observed in subjects <40-years old. The greatest increment in skin reactivity was seen to Dermatophagoides pteronyssinus (house dust mite) allergen. Data obtained from questionnaires showed that subjects who declared allergic symptoms increased from 341 (43.3%) to 380 (48.2%). However, the increase was significant (P<0.01) only in subjects who had a positive association between allergic symptoms and prick-test reactivity and was greater for rhino-conjunctivitis than for asthma-related symptoms. CONCLUSIONS: In a cohort of urban population of the centre of Italy, exposed to a low and stable level of air pollution, the sensitization to common aeroallergens increased with time, mostly in people <40-years of age. The greatest increment was found for indoor allergens such as Dermatophagoides pteronysimus. A significant increase in allergic symptoms, mainly related to rhino-conjunctivitis, was observed only in the presence of positive prick test.

Nuclear medicine in diagnosis, staging and follow-up of thyroid cancer.

Diagnostic strategy in thyroid cancer is conditioned by epidemiological, pathophysiological, cost-effective issues changing with age and countries. Nuclear medicine has a role mainly in differentiated carcinomas, i.e. in the large majority of thyroid cancers. In diagnosis of thyroid nodule (99m)Tc-perthecnetate is indicated in patients with low TSH levels, multinodular goiter, solid nodules at US negative at FNA. Radiolabeled somatostatin analogs or Metaiodobenzylguanidine (MIBG) can be used in suspicion of medullary carcinoma. There is no role in staging. WBS with 131I has a role after surgical resection of the thyroid gland and it is no more suggested before ablative therapy, because of the possible stunning effect. In the follow-up thyroglobulin (Tg) test is mandatory both after therapy withdrawal or after rhTSH administration. Some authors already suggest to use this test alone, as 1st step, in patients with differentiated carcinoma at low risk of recurrence, but this approach is not yet generally accepted and it has not yet been validated in tumors at intermediate/high risk. WBS with 131I is ever indicated when autoantibodies can affect reliability of Tg values and in presence of high Tg levels to better define a radiometabolic therapy. In case of negative WBS, PET-FDG can be proposed. In WBS, 123I can be an alternative to 131I, but it is not yet generally accepted mainly because of its higher costs. The clinical use of rhTSH to increase accuracy both of Tg and WBS can be already accepted in patients at high risk following hypothyroidism, with a worst prognosis or a low pituitary response.

Surgery of thyroid cancer: twelve years' personal experience.

Diagnosis and treatment of thyroid carcinoma require a multidisciplinary approach. The close and long-standing collaboration between the Otorhinolaryngology, Pathological Anatomy and Nuclear Medicine Departments of Legnano Hospital has led to a precise diagnostic and therapeutic protocol in thyroid patients. In the 1990-2002 period, 131 patients underwent total thyroidectomy after diagnosis of thyroid cancer at the Otorhinolaryngology--Head and Neck Surgery Department. Patients submitted to lobectomy for differentiated thyroid cancer were excluded from the present study. The patient population is composed of 96 females (73%) and 36 males (27%) aged between 22 and 85 years. Of the 131 patients, 115 (87%) presented papillary carcinoma, 13 (10%) follicular carcinoma, 2 (2%) medullary carcinoma and one (1%) undifferentiated carcinoma. Two patients (2%) suffered from a preoperative monolateral recurrent nerve palsy. Total thyroidectomy was performed in all 131 patients. Selective neck dissection was performed only in patients with positive lymph nodes for papillary (37/115, 32%) and follicular carcinoma histotype (2/13, 15%) and, in both patients with medullary carcinoma (100%). Of the 131 patients, 15 (11%) did not undergo routine follow-up and were, therefore, excluded from the study, the remainder completed a mean follow-up of 47 months. During follow-up, the incidence of the two most frequent complications of thyroid surgery were evaluated: recurrent nerve paralysis and permanent hypoparathyroidism (exceeding the postoperative 6 months). Results of treatment have been evaluated considering the incidence of local and/or distant recurrences and patient survival rate. As far as concerns papillary and follicular histotype, we have considered as healed (absence of signs suggesting loco regional and distant recurrence) only those patients presenting both negligible levels of plasma thyroglobulin and a negative total-body 131I scintigraphy. Briefly, in 3 cases (3%), all papillary carcinomas, local recurrence occurred; 9 (8%), all with papillary carcinoma, developed lateral neck recurrence; 6 (5%), 5 with papillary carcinoma and one with follicular carcinoma, developed distant metastases, of which 3 pulmonary, 2 bone and 1 hepatic. Serum thyroglobulin values were considered during the last control visit in 95/113 patients (84%). Of these, 86 (91%) with negligible thyroglobulin levels and negative 131I scintigraphy, were considered healed. All 113 patients with differentiated thyroid carcinoma were alive at the last control visit. Both patients with medullary carcinoma are alive with no sign of illness at the last follow-up control. The patient presenting undifferentiated carcinoma died 2 months after surgery. In conclusion, at the last follow-up control, 1 (1%) patient has died, 5 patients (4%) are alive with disease (2 of whom suffered from multiple recurrences) and the remaining 110 (95%) patients are alive without evidence of disease. As far as concerns complications of surgery, iatrogenic recurrent palsy and permanent hypoparathyroidism are present in 2 (2%) and 10 patients (8%), respectively.

Sleep-disordered breathing in nonobese diabetic subjects with autonomic neuropathy.

To assess the occurrence and nature of sleep-disordered breathing (SDB) in 26 adult, nonobese diabetics (18 with autonomic neuropathy (DAN+) (age 45 (41-50) yrs; body mass index (BMI) 24.1 (22-26) kg x m(-2)) and eight without autonomic neuropathy (DAN-) (age 45 (35-55) yrs; BMI 24.8 (23-26) kg x m(-2))) overnight full sleep studies and measurements of central and peripheral carbon dioxide (CO2) chemosensitivity were performed. DAN+ were divided in two subgroups, according to the presence (DAN+PH+; n=10) or absence (DAN+PH-; n=8) of postural hypotension. Ten normal subjects were studied as controls (age 42 (36-48) yrs; BMI 24.4 (23-25) kg x m(-2)). In contrast to DAN- and controls, who did not show SDB, five DAN+ (four DAN+PH- and one DAN+PH+) had an apnoea/hypopnoea index > or = 10 and four DAN+ (two DAN+PH- and two DAN+PH+) had an apnoea index > or = 5. All the events were obstructive, occurring mainly during rapid eye movement (REM) sleep. Ten DAN+ exhibited a mean lowest oxygen saturation < 90% during REM sleep. No periodic breathing or central sleep apnoeas were found in DAN+PH+, although they had an enhanced central chemoresponsiveness to CO2. Both DAN+ subgroups showed a marked reduction in peripheral CO2 chemosensitivity. In conclusion, adult nonobese diabetics with autonomic neuropathy, independent of the severity of their dysautonomy, have obstructive sleep apnoea/hypopnoea with a frequency > 30%. A decrease in peripheral carbon dioxide chemosensitivity prevents adult nonobese diabetics with autonomic neuropathy and postural hypotension from experiencing posthyperventilatory central sleep apnoea, despite an increased hypercapnic central drive.

Second primary malignancies in thyroid cancer patients.

The late health effects associated with radioiodine ((131)I) given as treatment for thyroid cancer are difficult to assess since the number of thyroid cancer patients treated at each centre is limited. The risk of second primary malignancies (SPMs) was evaluated in a European cohort of thyroid cancer patients. A common database was obtained by pooling the 2-year survivors of the three major Swedish, Italian, and French cohorts of papillary and follicular thyroid cancer patients. A time-dependent analysis using external comparison was performed. The study concerned 6841 thyroid cancer patients, diagnosed during the period 1934-1995, at a mean age of 44 years. In all, 17% were treated with external radiotherapy and 62% received (131)I. In total, 576 patients were diagnosed with a SPM. Compared to the general population of each of the three countries, an overall significantly increased risk of SPM of 27% (95% CI: 15-40) was seen in the European cohort. An increased risk of both solid tumours and leukaemias was found with increasing cumulative activity of (131)I administered, with an excess absolute risk of 14.4 solid cancers and of 0.8 leukaemias per GBq of (131)I and 10(5) person-years of follow-up. A relationship was found between (131)I administration and occurrence of bone and soft tissue, colorectal, and salivary gland cancers. These results strongly highlight the necessity to delineate the indications of (131)I treatment in thyroid cancer patients in order to restrict its use to patients in whom clinical benefits are expected.

Cerebrovascular reactivity and hypercapnic respiratory drive in diabetic autonomic neuropathy.

Because abnormalities in cerebrovascular reactivity (CVR) in subjects with long-term diabetes could partly be ascribed to autonomic neuropathy and related to central chemosensitivity, CVR and the respiratory drive output during progressive hypercapnia were studied in 15 diabetic patients without (DAN-) and 30 with autonomic neuropathy (DAN+), of whom 15 had postural hypotension (PH) (DAN+PH+) and 15 did not (DAN+PH-), and in 15 control (C) subjects. During CO(2) rebreathing, changes in occlusion pressure and minute ventilation were assessed, and seven subjects in each group had simultaneous measurements of the middle cerebral artery mean blood velocity (MCAV) by transcranial Doppler. The respiratory output to CO(2) was greater in DAN+PH+ than in DAN+PH- and DAN- (P < 0.01), whereas a reduced chemosensitivity was found in DAN+PH- (P < 0.05 vs. C). MCAV increased linearly with the end-tidal PCO(2) (PET(CO(2))) in DAN+PH- but less than in C and DAN- (P < 0.01). In contrast, DAN+PH+ showed an exponential increment in MCAV with PET(CO(2)) mainly >55 Torr. Thus CVR was lower in DAN+ than in C at PET(CO(2)) <55 Torr (P < 0.01), whereas it was greater in DAN+PH+ than in DAN+PH- (P < 0.01) and DAN- (P < 0.05) at PET(CO(2)) >55 Torr. CVR and occlusion pressure during hypercapnia were correlated only in DAN+ (r = 0.91, P < 0.001). We conclude that, in diabetic patients with autonomic neuropathy, CVR to CO(2) is reduced or increased according to the severity of dysautonomy and intensity of stimulus and appears to modulate the hypercapnic respiratory drive.

Myasthenic inspiratory vocal cord dysfunction: efficacy of nasal continuous positive airway pressure treatment.

Myasthenic vocal cord dysfunction (VCD), presenting with severe inspiratory stridor, was successfully treated with nasal continuous positive airway pressure (nCPAP), thus giving the medical staff time to make the diagnosis and avoiding intubation or tracheostomy. An important sign leading to diagnosis was the very high MEF(50)/MIF(50) ratio calculated from the flow-volume loop. nCPAP treatment induced prompt remission of stridor and a sharp reduction in the MEF(50)/MIF(50) ratio from 9.90 to 1.36. A review of the literature has shown that VCD with inspiratory stridor is an unusual onset symptom of myasthenia gravis and that nCPAP treatment may avoid emergency oral/tracheal intubation and tracheostomy. After diagnosis, the patient underwent thymectomy, and today, 3 years later, he is well without any further therapy.

Usefulness of fine-needle aspiration in the diagnosis of thyroid carcinoma: a retrospective study in 37,895 patients.

BACKGROUND: Nodular thyroid disease is a frequent occurrence in clinical practice. The numerous diagnostic procedures available make the diagnosis of thyroid carcinoma possible but, if not used rationally, may lead to an unjustified increase in cost with little practical gain. The aim of the current study was to evaluate the usefulness of fine-needle aspiration (FNA) of palpable thyroid nodules after functional evaluation by thyroid scintigraphy. METHODS: The authors retrospectively evaluated 37,895 FNAs performed between 1980-1997. FNAs were performed on palpable thyroid nodules, except unambiguously autonomous ("hot") nodules, at the time of thyroid scintigraphy. Cytologic and histologic diagnoses were compared in 4069 patients to estimate the accuracy of FNA. RESULTS: The sensitivity of FNA was 91.8% and the specificity was 75.5%. A pretest probability of thyroid carcinoma of 4% was reduced to 0.4% in the patients with a cytologic diagnosis of benign nodular goiter, whereas it was increased to 90.7% in those patients with a positive cytologic diagnosis. Only in the case of a cytologic diagnosis of "follicular neoplasm" was the probability of malignancy not changed significantly and histologic evaluation of the nodule was necessary. CONCLUSIONS: In the majority of cases, FNA of palpable thyroid nodules allows for the identification of thyroid carcinoma and the planning of subsequent appropriate therapy. This can be achieved by using simple and inexpensive procedures, if cooperation among clinicians, pathologists, and nuclear physicians is maximized.

Differentiated thyroid carcinoma in childhood.

Differentiated thyroid carcinoma is rare in childhood and shows different characteristics as compared to thyroid carcinoma in adults. The male/female ratio is different, it has a higher aggressiveness, locoregional and distant metastases are frequent, response to surgery and 131I radioiodine therapy is optimal. A better knowledge of these characteristics has resulted in the understanding of some relevant aspects of the pathogenesis and natural history of the disease, the suitability of the therapeutic approach and the incidence of adverse side-effects. The increased incidence of differentiated thyroid carcinoma in childhood following the Chernobyl nuclear accident of April 1986 renewed the interest of the scientific community and the public opinion and allowed an in-depth study of some important aspects correlated with the carcinogenic effect of ionizing radiation.

Severe thyrotoxicosis due to hyperfunctioning liver metastasis from follicular carcinoma: treatment with (131)I and interstitial laser ablation.

Liver metastases from differentiated thyroid tumors are unusual clinical findings, and are only rarely hyperfunctioning. We report a case of thyrotoxicosis caused by a huge and surgically unresectable liver metastasis from follicular thyroid cancer, unresponsive to treatment with large doses of thionamides. To avoid the hazardous side effects of (131)I treatment in a severely thyrotoxic patient, a preliminary debulking of the liver mass was performed by means of percutaneous interstitial laser photocoagulation. Three treatments (total energy delivery: 7200 J) were performed under ultrasound guidance, with no serious complications, during a 2-week period. One month later, serum thyroid hormones had decreased, general condition was improved, and magnetic resonance evaluation revealed large and well-defined areas of necrosis of metastatic tissue. During the following 10 months, the patient underwent 3 radioiodine treatments. Eighteen months after diagnosis, thyroid hormones were within normal levels, liver mass decreased, and the clinical condition markedly improved. The combination of percutaneous interstitial laser photocoagulation treatment and radioiodine therapy made possible the effective management of a hyperfunctioning and surgically untreatable liver metastasis from thyroid follicular carcinoma, avoiding the side effects of (131)I therapy in a thyrotoxic patient and increasing the effectiveness of radioiodine-induced neoplastic tissue ablation.

Severe thyrotoxicosis due to functioning pulmonary metastases of well-differentiated thyroid cancer.

We report two cases of thyrotoxicosis resulting from hyperfunctioning lung metastases from differentiated thyroid cancer. In both patients, a simultaneous diagnosis of thyrotoxicosis and metastatic thyroid cancer was made, based on thyroid function tests as well as 131I whole-body scans showing low thyroid uptake of radioiodine and multiple foci of intense 131I uptake in the lungs. After total thyroidectomy (performed in Patient 2 only) and 131I therapy (cumulative dose of 12.3 GBq in Patient 1 and 9.6 GBq in Patient 2), there was a rapid clinical improvement with significant reduction of the pulmonary metastatic disease in both patients: Patient 1 became euthyroid, while Patient 2 became hypothyroid. Analysis of the 54 cases reported in the literature, including the 2 cases described here, shows this to be a very rare cause of thyrotoxicosis and one that can pose serious problems for both the diagnostic evaluation and choice of therapeutic strategy when compared with the much more common nonhyperfunctioning metastases from thyroid cancer. Lesser degrees of thyroid hormone secretion by differentiated thyroid cancer may be detected and exploited diagnostically by the chromatographic analysis of serum for endogenously labeled thyroid hormones after 131I administration.

Influence of autonomic neuropathy of different severities on the hypercapnic drive to breathing in diabetic patients.

To investigate the effects of the autonomic nervous system on control of breathing, the neuromuscular (mouth occlusion pressure at 0.1 s after onset of inspiration [P0.1]) and ventilatory (minute ventilation [VE]) response to progressive hyperoxic hypercapnia was assessed in diabetic patients with autonomic dysfunction of different severity. Eighteen diabetics with autonomic neuropathy, nine with parasympathetic damage (DANp), and nine with parasympathetic and sympathetic damage (DANp+s), as indicated by marked postural hypotension, low increment of diastolic BP during sustained handgrip, and lowest resting catecholamine plasma levels, were studied together with a group of 10 diabetic patients without autonomic neuropathy (D) and a group of 10 normal subjects (C). All subjects had pulmonary function tests, including maximal voluntary ventilation and diffusion of carbon monoxide, measurements of respiratory muscle strength as maximal inspiratory mouth pressure (MIP) and maximal expiratory mouth pressure (MEP), and a CO2 rebreathing test (Read's method). Although in the normal range, lung volumes and FEV1 and forced expiratory flows were lower in the DANp and DANp+s groups than in the D and C groups, MIP and MEP were similar among C and diabetic groups, as well as resting P0.1, VE, tidal volume (VT), and respiratory rate (RR). The slope of the linear relationship between P0.1 and end-tidal PCO2 (PETCO2) was higher in DANp+s (0.63+/-0.07 cm H2O/mm Hg) than in C (0.45+/-0.06 cm H2O/mm Hg; p<0.05) and three times greater in DANp+s than in D (0.26+/-0.03 cm H2O/mm Hg; p<0.001) and DANp (0.24+/-0.03 cm H2O/mm Hg; p<0.001), who in turn showed a lower deltaP0.1/deltaPETCO2 than C. The VE increase with increasing PETCO2 was greater in DANp+s (3.70+/-0.85 L/min/mm Hg) than in DANp (2.13+/-0.20 L/min/mm Hg; p<0.05) and D (2.37+/-0.40 L/min/mm Hg; p=0.07), but not significantly higher from that of C (3.17+/-0.36 L/min/mm Hg). No differences were found for deltaVT/deltaPETCO2 among the groups, whereas the deltaRR/deltaPETCO2 relationship was steeper in DANp+s than in DANp (p<0.05) and D (p=0.055). These data reflect a depressed CO2 response both in D and DANp. The presumable decrease of the sympathetic nerve traffic in DANp+s appears to reverse this abnormality. DANp+s, however, exhibit an enhanced CO2 neuromuscular response even in respect to C, suggesting that the sympathetic nervous system might modulate the output of the respiratory centers to hypercapnic stimulus.

Differentiated thyroid carcinoma in children and adolescents: a 37-year experience in 85 patients.

UNLABELLED: This study reports on 85 differentiated thyroid carcinoma (DTC) (72 papillary, 13 follicular) patients, younger than 18 yr of age at the time of diagnosis, consecutively treated during the period 1958-1995. METHODS: Follow-up (median: 111 mo, range 1-324 mo) consisted of clinical examination, serum thyroglobulin (Tg), 131I whole-body scintigraphy (whole-body scan) and other imaging procedures. RESULTS: Forty-six patients had undergone total thyroidectomy, 38 partial thyroidectomy and 1 thyroid biopsy. In 47 patients, lymph-adenectomy was also performed. Five patients were treated after surgery by external radiotherapy, 59 by 131I therapy and 16 by both modalities. Iodine-131 therapy was successful in ablating thyroid remnants in 35/48 cases, lymph node metastases in 8/11 cases and lung metastases in 12/16 cases. Among the patients with scintigraphic-confirmed disappearance of lung metastases, serum Tg was still detectable in 10 cases, but continued to decrease spontaneously even without further therapeutic doses of 131I. All patients were still alive after a median period of 137 mo (range 5-444 mo). Six patients experienced a recurrence of the disease in the neck. Sixty-seven patients were free of disease, 3 had lymph node metastases, 4 lung metastases and 11 had detectable levels of Tg without demonstrable metastases. No impairment of female fertility or untoward genetic effects were noticed. One male patient, treated with 3.33 GBq of 131I, was infertile due to oligospermia. One case of gastric cancer and one of breast cancer occurred 8 and 19 yr, respectively, after 131I therapy. CONCLUSION: Iodine-131 therapy is highly effective in reducing lung metastases, but undetectable levels of Tg are seldom achieved. Total thyroidectomy and 131I therapy is an effective and safe treatment for the majority of patients with DTC diagnosed in childhood or adolescence.

Ineffectiveness of a four week treatment with the thromboxane synthetase inhibitor, imidazole salycilate, in reducing airway hyperresponsiveness to methacholine in asthmatics.

In a randomized, double-blind, placebo-controlled study, the acute and long-term effects of the reduction of thromboxane A2 (TxA2) synthesis on airway sensitivity and maximal airway narrowing in response to methacholine was evaluated in 12 subjects with mild-to-moderate stable asthma, using imidazole salycilate (IS), an anti-inflammatory drug which selectively inhibits the TxA2 synthetase. Dose-response curves with methacholine (MCh) were performed in basal conditions (baseline); 1-1.5 h after administration of 1,500 mg of IS or placebo (acute); at 15 and 30 days of treatment with 750 mg t.i.d. of IS or placebo; and after a 2 week period of run-off (45 days). The serum levels of thromboxane B2 (TxB2) were measured at the same time points, except after acute administration, in five patients from each group. Baseline forced expiratory volume in one second (FEV1) was 78 +/- 7 and 85 +/- 8% of predicted in the IS and control group, respectively (NS). Throughout the study FEV1 remained unchanged in both groups, indicating that IS did not caused substantial modification of resting bronchial calibre. The initial provocative dose of methacholine causing a 20% fall in FEV1 (PD20) amounted to 27.0 +/- 1.5 micrograms in the IS group and 41.7 +/- 1.5 micrograms in the control group (geometric mean +/- GSEM) (NS). Despite a reduction of TxB2 serum levels with IS vs placebo at 15 days (24.9 +/- 8.5 vs 45.5 +/- 3.4 pg.mL-1; p < 0.05) and 30 days (27.0 +/- 6.3 vs 45.0 + 3.2 pg.mL-1; p < 0.05), MCh-induced bronchoconstriction, evaluated either as PD20 or maximal airway narrowing, did not change significantly during active treatment compared to placebo. These results show that prolonged reduction of thromboxane A2 synthesis does not improve airway sensitivity and limit maximal bronchoconstriction in asthmatic subjects, suggesting that thromboxane A2 per se does not play a substantial role in the pathogenesis of the airway hyperresponsiveness in human asthma.