Abstract: OBJECTIVES: To assess the impact of the intra-articular distribution of (90)yttrium-citrate ((90)Y) on the clinical effect of radiosynoviorthesis (RSO) of the knee and on (90)Y leakage from this joint. METHODS: Patients with arthritis of the knee received 185 MBq (90)Y combined with a glucocorticoid, followed by clinical bed rest. Intra-articular (90)Y distribution, measured with a dual-head gamma camera immediately or after 24 hours, was scored as mainly diffuse or mainly focal. Leakage to regional lymph nodes, the liver and spleen was assessed with a dual-head gamma camera after 24 hours. Clinical effect was scored after 6 months by a composite change index (CCI), range 0-12; responders were defined as having a CCI > or =6. RESULTS: Seventy-eight knees of 69 patients, mostly suffering from undifferentiated arthritis (42%) or RA (28%), were treated. (90)Y distribution was mainly diffuse in 54% and mainly focal in 46% with clinical response rates of 40% versus 56%, respectively, p = 0.3. CCI was not correlated with distribution. (90)Y leakage was found only to the liver and the spleen (mean leakage 0.4% and 1.1%, respectively). Leakage was significantly less in case of diffuse intra-articular (90)Y distribution, whereas leakage to the liver was correlated with distribution (r = 0.68, p<0.001). (90)Y leakage was not correlated with CCI. CONCLUSIONS: Intra-articular (90)Y distribution does not influence the clinical effect of RSO of the knee. Although (90)Y leakage from the joint is less if (90)Y distributes diffusely in the joint cavity, leakage does not seem to hamper the clinical effect.
Abstract: In 1942, Dr. Seidlin of the Memorial Hospital in New York was faced with a 51-year- old patient who had undergone a thyroidectomy in 1923 [1]. At the time, the histologic diagnosis was a 'malignant adenoma' of the thyroid. In 1938 the patient returned with overt signs of thyroid hyperfunction (hyperthyroidism) and lower back pain. A metastasis was found in the lower spine, and surgically removed. Over the next years the patient remained hyperthyroid and developed more bone metastases. At the time of presentation to Dr. Seidlin, the patient was in an extremely poor condition: he was in severe pain, severely hyperthyroid, and severely underweight. At this time radioiodine therapy had just reached the clinical arena. In 1937 Hertz, Roberts and Evans investigated the rabbit's thyroid function using I-128 [2]. Later they pursued therapeutic goals for e.g. Graves' disease using I-130. They used dosages that we now know would have been merely diagnostic if it were not for a probable 10% I-131 contaminant [3]. Livingood and Seaborg identified I-131 as a separate isotope. In 1942 two groups independently reported on the successful treatment of hyperthyroidism with I-131 sodium iodide [4,5]. Radioiodine was so rare that it was recovered from the urine, purified and re-administered to the patient. The patient responded favourably to the radioiodine treatment, and he received several more courses of I-131. Geiger-counter examination of the patient revealed two previously unknown metastases, thereby indicating the diagnostic capabilities of radioiodine. The patient did very well on these courses: the hyperthyroidism subsided, the body-weight kg increased from 38 to 53 kilograms, and the pains diminished. This report of a potential cure for terminally ill patients fuelled the public imagination to a degree that it hit the political agenda. Effective on August 1, 1946, the Atomic Energy Act (AEA) made radioisotopes available for medical use in the USA. This date marks the beginning of 'atomic medicine', later named nuclear medicine.
Abstract: AIM: The aim of this study was to assess the efficacy of treatment of patients with papillary thyroid carcinoma (PTC) and lymph node metastases at the time of diagnosis and its influence on the course of the disease. METHODS: It is a retrospective review of all 51 patients with PTC and histologically proven lymph node metastases treated with I-131 ablation in our center between January 1990 and January 2003. Patients were considered disease-free if during follow-up thyroglobulin levels were undetectable and scintigraphy with 370 MBq (131)I was negative during thyroid-stimulating hormone stimulation. Staging of patients was in accordance with the 5th edition of the TNM system. RESULTS: After a median follow-up of 84 months, 33 (65%) patients were never free of detectable disease; and 3 of these patients had died of the PTC. In total, 22 patients still showed persistent activity in the neck outside the thyroid bed, which was suspect to be cervical lymph node metastasis on postablation scintigraphy; it was not related to the initial clinical presentation (lymph node metastasis or a thyroid nodule without suspicion of metastatic disease) or to the extent of surgery. Altogether, 34 patients required additional treatment. Patients presenting with clinically overt lymph node metastasis showed a significantly (p = 0.022) lower rate of becoming disease-free than those in whom microscopic lymph node involvement was unexpectedly found upon pathologic examination. There was no significant association of the eventual outcome with the extent of surgical treatment, TNM staging, or age. CONCLUSIONS: Patients with lymph node metastasis are considerably less likely to become disease-free. If the initial treatment does not result in a disease-free status, chances are low that additional treatment will succeed in achieving it.
Abstract: No experimental data exist on the thyroid toxicity of nitrate among humans. We aimed to show that no significant antithyroid effect could be observed after exposure to a three times the acceptable daily intake of nitrate in humans. In a randomized controlled non-inferiority trial, 10 volunteers received 15mg/kg sodium nitrate during 28 days whereas 10 control participants received distilled water. We performed 5- and 24-h measurements of thyroidal (131)I uptake (RAIU) before and at the end of the exposure period. Thyroid hormone plasma concentrations of T3, rT3, T4, TSH were also measured prior to and after exposure. Differences in RAIU between the intervention and the control groups at 4 weeks were 3.4% (95% confidence interval -0.5 to 7.3, and 4.8% (95% confidence interval -1.4 to 11.0, respectively, for the 5- and 24-h RAIU measurement. Plasma concentrations of thyroid hormones stayed normal. In conclusion, no significant effects on thyroidal (131)I uptake and thyroid hormones plasma concentrations were observed after sub-chronic exposition to 15mg/kg sodium nitrate among humans.
Abstract: A case of suspected thyroid stunning is presented in a previously hyperthyroid patient with a diffuse goiter, who had undergone a 185 MBq (131)I-NaI thyroid scan shortly before a (99m)Tc-pertechnetate scan. A less likely alternative hypothesis is the development of early hypothyroidism, 3.5 weeks after a modest (131)I dose.
Abstract: There are three options for the treatment of benign thyroid disorders: medication, surgery, and radioiodine therapy. Medical treatment with anti-thyroid drugs (ATD) and/or levothyroxine is unsatisfactory for patients with nodular disorders, and life-long medical treatment is unsafe. ATD treatment can restore euthyroidism in 40%-50% of patients with Graves' disease. However, if normal thyroid function has not been regained after 1-1.5 years of ATD use, a definitive cure may not be expected from reinstalling this medication. The pros and cons of total or subtotal thyroidectomy are well known; they were again stipulated in this Journal. Since the 1970's radioiodine treatment has largely replaced surgery, which is nowadays reserved for children and for patients with exceedingly large goiters. No more than four years after its discovery in 1938, iodine-131 ((131)I) was introduced for the treatment of hyperthyroidism and thyroid cancer. The molecular processes explaining the principles of radioiodine treatment remained unresolved until the genetics and the functionality of the human sodium-iodide symporter (hNIS) were recently identified. The thyroid's unique capacity to store iodide (thus also radioiodine, (131)I-NaI) makes it a natural target for radioiodine therapy. For more than 60 years radioiodine has been administered to patients with thyroid diseases. Millions have been cured, and yet to date there is no complete agreement with regard to the optimal therapeutic regimen in individual patients. Radioiodine is a safe treatment form for all patients with primary hyperthyroidism. The prevailing dosage strategies for patients with nodular thyroid diseases are rather successful. For patients with Graves' disease, however, the therapy outcome is not easily predicted unless ablative doses of radioiodine are being applied. Ablation, however, cures one disease (hyperthyroidism) at the cost of another (hypothyroidism). With non-ablative strategies, both recurrent hyperthyroidism and hypothyroidism are frequently observed treatment outcomes. This empirical fact has led to different opinions with regard to the preferred radioiodine dosage strategy for patients with Graves' disease. Nonetheless, the efficacy of prevailing dosage protocols is hardly questioned. This may be illustrated by a beautifully ironic quote from Galenus: 'All those who drink from this remedy recover in a short time, except those whom it does not help and who all die. Therefore, it is obvious that it fails only in incurable cases.' A review of the literature indicates that substantial improvement of the present results might be feasible if more consideration is given to the biological state of our patients at the time of radioiodine treatment. Pathogenesis. Nodular thyroid disorders. After the first clinical observations by Plummer in 1913 and Goetsch in 1918, recent advances in molecular biology have aided our understanding of the histopathological phenomena underlying toxic adenoma and toxic multinodular goiter. Although these disorders are often viewed as distinct and separate entities, they in fact represent a spectrum of disorders that are characterized by nodular growth and autonomous hyperfunction. Studies of RAS proto-oncogene expression have shown that micronodules develop from bursts of follicular cell growth. Mutations in the TSH receptor gene, which activate the TSH receptor in the absence of its ligand, are responsible for hyperfunctioning thyroid adenomas. Somatic gain-of-function mutations in the TSH receptor itself (or in the Gsa protein linked to it) result in the accumulation of cyclic adenosine monophosphate (cAMP) which stimulates the growth and differentiated thyroid function of the thyroid gland. Activating TSH receptor mutations are identified in 20%-80% of thyrotoxic nodules and multinodular goiters. Adenomas are usually solitary nodules that may occur at any age from the teens to the elderly. Only about 25% of these are associated with hyperthyroidism; a toxic adenoma usually sets in about 15 years after the first presentation of the nodule. Most nodules degenerate after a hyperfunctioning state during this process-nontoxic autonomously functioning thyroid nodules are in fact much more common than toxic lesions. In toxic multinodular goiter, multiple hyperfunctioning and hypofunctioning nodules are present in the thyroid. The iodine uptake capacity of these follicular nodules is as heterogenic as that of individual thyroid cells. Both in toxic adenoma and in toxic multinodular goiter, T3 toxicosis (thyrotoxicosis with elevated serum T3 concentrations and less markedly elevated serum T4 concentrations) is relatively frequent. The development of sporadic nontoxic nodular goiter (SNNG) from sporadic diffuse nodular goiter is essentially the same as for toxic nodular thyroid disorders. SNNG is usually discussed separately in textbooks because the indication for radioiodine treatment in this condition has been recognized only recently. Most patients are clinically and biochemically euthyroid at the time of presentation. Over the years this may develop into subclinical or clinical hyperthyroidism. Obstructive symptoms (esophageal and/or tracheal compression) and cosmetic problems are usually predominant in the clinical picture, and volume reduction is frequently necessary. Thyroid hormones have been used to shrink goiters and to arrest further growth, and are still favoured by many doctors. However, in a double-blind controlled study, it has been shown that levothyroxine (LT4) suppressive therapy is not effective. This was confirmed by several later studies, as summarized in two excellent reviews. Surgical treatment - subtotal thyroidectomy or hemithyroidectomy - is effective, but transient voice disabilities and hypothyroidism are relatively frequent complications (about 20% and 10%, respectively, depending on the extent of surgery). A recurrence of the goiter is seen in almost 20% of the patients. For these patients, as well as for those with a high surgical risk, non-operative reduction of the thyroid volume would be a desirable alternative; the use of radioiodine in this area is discussed hereafter. Endemic goiter occurs when the prevalence of thyroid enlargement in the population of an area exceeds 10%. Its main cause is iodine deficiency, superimposed on other goitrogenic factors normally present and responsible for sporadic goiter. Endemic goiter can be totally eliminated by prophylaxis using iodine administered in salt, oil or some other vehicle. The efficacy or indeed the rationale of radioiodine therapy for endemic goiter is not endorsed by clinical data. Graves' disease is an autoimmune disorder characterized by hyperthyroidism, diffuse goiter, ophthalmopathy and (rarely) dermopathy. In this editorial we shall concentrate on the thyroidal manifestations. Graves' disease may occur at any age, with a peak incidence in the age group of 35-55 years. The annual incidence is 1-10 per 100,000. It affects women about 5 times more often than men. Inheritance is probably autosomal dominant, or maybe autosomal recessive with relative sex limitation to females. A number of genes are involved in the development of autoimmune thyrotoxicosis. At present three loci, namely 6p21.3 (human leukocyte antigen, HLA), 2q33 (cytotoxic T-lymphocyte-associated esterase-4, CTLA4) and 14q31 (thyroid-stimulating hormone receptor, TSHR), are known genetic determinants for Graves' disease. Several other loci are under investigation. Antibodies against the TSH-receptor (TSHR-Ab), responsible for hyperthyroidism and goiter, are primarily produced within the thyroid gland itself. The interaction of TSHR-Ab with the receptor causes overproduction of T4 (and to a lesser extent T3) in the absence of high TSH levels. Increased intracellular iodide concentration is mediated by IgG, which activates the upstream enhancer of the sodium/iodide symporter (NIS). Antibodies against thyroglobulin and thyroid peroxidase may be present, but are not diagnostic. In concordance with the everyday experience of many clinicians, stressful life events and lack of social support have been identified as risk factors for the occurrence of Graves' disease. Radioiodine treatment: indications and best practice. Toxic adenoma. Radioiodine therapy for toxic adenoma has been systematically applied since around 1975. Different dosage strategies have coexisted for many years. Notwithstanding the large differences in effective half-life of thyroidal radioiodine in patients with toxic adenoma (varying from less than 2 days to over 100 days), the results with individualized dosages are not superior to those with fixed dose regimens. Successful ablation of the adenoma can be achieved with relatively high dosages, without hampering the functioning of the thyroid gland. However, this only applies if there is (almost) complete suppression of the normal thyroid tissue surrounding the adenoma. It has been stipulated that the radiation dose to the normal thyroid tissue is usually underestimated. According to the literature, a fixed dosage of 740 MBq is optimal. Less than 5% recurrent hyperthyroidism and less than 10% hypothyroidism is observed with this strategy. If there is incomplete suppression of normal thyroid tissue, a reduced dose (370 MBq) may be warranted in order to avoid unduly increased hypothyroidism rates. In the 1990's a different therapeutic approach was introduced, viz. intra-lesional injection with ethano. This treatment form is relatively inexpensive, but 4-8 successive treatments are usually required to achieve success. Potential complications include (transient) dysphonia, exacerbation of thyrotoxicosis, fever, pain at the injection site, and hematoma. Patients with adenomas larger than 30 ml are not eligible for this treatment form because of a high failure rate. Toxic multinodular goiter. (ABSTRACT TRUNCATED)
Abstract: Individualised dosage models are frequently applied for radioiodine therapy in patients with Graves' hyperthyroidism, especially in Europe. In these dosage schemes the thyroid volume is an important parameter. Thyroid volume determinations are usually made with ultrasonography or with thyroid scintigraphy, although the accuracy of planar scintigraphy for this purpose is not well established. The aim of this study was to compare the accuracy of three modalities for the determination of the thyroid volume in patients with Graves' disease: planar scintigraphy (PS), single-photon emission tomography (SPET) and ultrasonography (US). These three modalities were compared with magnetic resonance imaging (MRI) as the gold standard. Thyroid volume estimations were performed in 25 patients with Graves' disease. The PS images were subjected to filtering and thresholding, and a standard surface formula was used to calculate the thyroid volume. With SPET the iteratively reconstructed thyroid images were filtered, and after applying a threshold method an automatic segmentation algorithm was used for the volume determinations. Thyroid volumes were estimated from the US images using the ellipsoid volume model for multiple two-dimensional measurements. For MRI, thyroid segmentation was performed manually in gadolinium-enhanced T1-weighted images and a summation-of-areas technique was used for the volume measurements. The thyroid volumes calculated with MRI were 25.0+/-13.8 ml (mean+/-SD, range 7.0-56.3 ml). PS correlated poorly with MRI ( R(2)=0.61) and suffered from a considerable bias (-4.0+/-17.6 ml). The differences between PS and MRI volume estimations had a very large spread (33+/-58%). For SPET both the correlation with MRI ( R(2)=0.84) and the bias (1.8+/-11.9 ml) were better than for PS. US had by far the best correlation with MRI ( R(2)=0.97) and the best precision, but the bias (6.8+/-7.5 ml) was not negligible. In conclusion, SPET is preferred over PS for accurate measurements of thyroid volume. US is the most accurate of the three modalities, if a correction is made for bias.
Abstract: In 124 primary breast cancer patients the maximum values of the lateralisation of the internal mammary chain (IMC) and their corresponding depths could be determined by scintigraphy and ultrasonography in 77% and 85% of the cases, respectively. With respect to the lateralisation it appeared that these values were uncorrelated between the two methods. With respect to depth correlation was found (correlation coefficient 0.34; P=0.001). We conclude that substantial differences are noted. Irradiation of the IMC based on computed tomography treatment planning might be a better alternative.
Abstract: From a Dutch questionnaire, it was apparent that nearly all institutions used percentage of radioiodine uptake for calculation of the radioiodine dose in Graves' disease. Although there is a general belief that fluctuations in radioiodine uptake may occur, with few exceptions relatively long intervals were accepted between the uptake measurement and the actual therapy dose. With the aim of optimizing the pretherapeutic work-up, we evaluated the stability of iodine uptake over time in patients with Graves' disease who were referred for 131I therapy. 131I uptake was measured in 300 consecutive patients for the calculation of the required 131I therapy dose; data were complete for 291 patients (97%). After discontinuing thyroid medication for 3 days, standardized thyroid probe measurements were performed 5 and 24 h after ingestion of a capsule containing 0.37 MBq 131I-NaI. Measurements were performed at the time of scintigraphic diagnosis (test 1), as well as immediately before 131I therapy (test 2). The time interval between test 1 and test 2 ranged from 2 to 421 (median 40) days. A relative increase or decrease greater than 10% between tests 1 and 2 occurred in 180 of 291 cases (62%) at 5 h and in 158 of 291 patients (54%) at 24 h. These changes were not related to the interval between the tests or to initial uptake values, thyroid mass, gender or age. Rapid turnover of radioiodine (5 h/24 h uptake ratio > 1) was noted in 17% of the patients during test 1 and in 15% during test 2. Rapid turnover was persistent (present in both tests 1 and 2) in only 9%. We conclude that patients with Graves' disease show considerable changes in 131I uptake over relatively short periods of time, and the turnover rate of 131I in this condition is not constant.
Abstract: Two-dimensional SPECT display and three methods for integrated visualization of SPECT and MRI patient data are evaluated in a multiobserver study to determine whether localization of functional data can be improved by adding anatomical information to the display. METHODS: SPECT and MRI data of 30 patients were gathered and presented using four types of display: one of SPECT in isolation, two integrated two-dimensional displays and one integrated three-dimensional display. Cold and hot spots in the peripheral cortex were preselected and indicated on black-and-white hard copies of the image data. Nuclear medicine physicians were asked to assign the corresponding spots in the image data on the computer screen to a lobe and a gyrus and give a confidence rating for both localizations. Interobserver agreement using kappa statistics and average confidence ratings were assessed to interpret the reported observations. RESULTS: Both the interobserver agreement and the confidence of the observers were greater for the integrated two-dimensional displays than for the two-dimensional SPECT display. An additional increase in agreement and confidence was seen with the integrated three-dimensional display. CONCLUSION: Integrated display of SPECT and MR brain images provides better localization of cerebral blood perfusion abnormalities in the peripheral cortex in relation to the anatomy of the brain than single-modality display and increases the confidence of the observer.
Abstract: Both Tc-99m pertechnetate and radioactive iodine (I-123 NaI or I-131 NaI) are useful in thyroid scintigraphy. These radiopharmaceuticals yield similar functional information in most patients. Occasionally, however, discordant results have been reported in the literature (warm or hot on the pertechnetate image and cold on the radioiodide image). Most of these reports have concerned the solitary thyroid nodule. A case is presented here with diffusely decreased Tc-99m pertechnetate uptake and normal I-131 NaI uptake in a patient with a diffuse goiter and subclinical hyperthyroidism, so-called reverse discordant behavior.
Abstract: A patient with seizures and a contrast-enhancing temporal lesion after radiation therapy for a chondrosarcoma of the nasal septum is described. To differentiate between radiation necrosis and recurrent tumor, thallium-201 (201Tl) SPECT was used. 201Tl SPECT revealed high local accumulation suggesting tumor growth; however, pathologic examination demonstrated focal necrosis with reactive changes but without tumor. The 201Tl SPECT findings in this patient demonstrate a possible diagnostic pitfall in differentiating recurrent tumor from radiation necrosis.
Abstract: OBJECTIVE: To determine the contribution of 18FDG PET, 11C-flumazenil PET, and 123I-iomazenil SPECT to the presurgical evaluation of patients with medically intractable complex partial seizures. METHODS: Presurgical evaluation was performed in 23 patients, who were considered candidates for temporal lobe resective surgery (14 females and nine males with a median age of 34 (range 13 to 50) years). The presurgical diagnosis was based on seizure semiology as demonstrated with ictal video recording, ictal and interictal scalp EEG recordings, and MRI. RESULTS: Eighteen patients had convergent findings in clinical semiology, interictal and ictal EEG with scalp and sphenoidal electrodes, and MRI that warranted surgery without depth EEG (DEEG). In five patients with insufficient precision of localisation, DEEG with intracerebral and subdural electrodes was performed. MRI showed abnormalities in 22 out of 23 patients. Of these 22, 18 had mesial temporal sclerosis. This was limited to the mesial temporal lobe in four and more widespread in the temporal lobe in 14 patients. In one patient only enlargement of the temporal horn was found and in three others only white matter lesions were detected. 18FDG PET showed a large area of glucose hypometabolism in the epileptogenic temporal lobe, with an extension outside the temporal lobe in 10 of 23 patients. Only in one of these patients DEEG showed extratemporal abnormalities that were concordant with a significant extratemporal extension of hypometabolism in 18FDG PET. 18FDG PET was compared with the results of scalp EEG: in none of the patients was an anterior temporal ictal onset in scalp EEG related to a maximum hypometabolism in the mesial temporal area. By contrast, the region of abnormality indicated by 11C-flumazenil PET was much more restricted, also when compared with DEEG findings. Extension of abnormality outside the lobe of surgery was seen in only two patients with 11C-flumazenil and was less pronounced compared with the intratemporal abnormality. Both 18FDG PET and 11C-flumazenil PET reliably indicated the epileptogenic temporal lobe. Thus these techniques provide valuable support for the presurgical diagnosis, especially in patients with non-lesional MRI or non-lateralising or localising scalp EEG recordings. In those patients in whom phase 1 presurgical evaluation on the basis of classic methods does not allow a localisation of the epileptogenic area, PET studies may provide valuable information for the strategy of the implantation of intracranial electrodes for DEEG. Previous studies have suggested that 11C-flumazenil binding has a closer spatial relationship with the zone of ictal onset than the area of glucose hypometabolism, but this study suggests rather that the decrease in the 11C-flumazenil binding simply reflects a loss of neurons expressing the benzodiazepine-GABA receptor. 11C-flumazenil PET did not prove to be superior to 18FDG PET. CONCLUSION: In 21 patients sufficient material was obtained at surgery for a pathological examination. In 17 mesial temporal sclerosis, in one an oligodendroglioma grade B, in another a vascular malformation and in two patients no abnormalities were found. Although all 21 patients with pathological abnormality showed hypometabolic zones with 18FDG PET and a decreased uptake in 11C-flumazenil binding, there was no strong correlation between pathological diagnosis and functional abnormal areas in PET. Grading of medial temporal sclerosis according to the Wyler criteria showed no correlation with the degree of hypometabolism in either 18FDG or 11C-flumazenil PET. The interictal 123I-iomazenil SPECT technique was highly inaccurate in localising the lobe of surgery.
Abstract: The effect of radioiodine in the treatment of nontoxic goiter is seldom evaluated quantitatively. The aim of this study was threefold: (a) to assess the effect of 131I on goiter volume, (b) to establish a relationship between CT volume reduction and the amount of radioactivity taken up by the thyroid and (b) to assess the precision of scintigraphic thyroid volume measurements. METHODS: In 27 patients with sporadic nontoxic goiter, the thyroid volume was estimated from a [99mTc]pertechnetate scintigram. Two different models (cylinder model and surface model) were applied. The 131I dosage varied between 507 and 3700 MBq. In all patients, noncontrast CT scanning of the neck was performed before therapy and 1 yr after therapy. RESULTS: The mean CT thyroid volume before therapy was 194 +/- 138 ml. A reduction was obtained in all patients and averaged 34% +/- 17%. The volume reduction measured by CT correlated well with the amount of 131I in the thyroid (r = 0.70). In thyroids larger than 200 ml, both scintigraphic volume estimation methods were imprecise. For smaller volumes, the surface model was superior. Hypothyroidism developed in 14% of the patients. No other side effects occurred. CONCLUSION: Iodine-131 therapy for volume reduction in nontoxic goiter is a safe and effective treatment. For scintigraphic estimation of thyroid gland volumes smaller than 200 ml, the surface model is preferred.
Abstract: The objectives were to investigate the efficacy and safety of yttrium-90 colloid (Y-90) synovectomy in joints with persistent synovitis and to examine the effect of a second synovectomy using a double dose after an initial inadequate response. Of the 45 patients at the University Hospital Utrecht who underwent Y-90 synovectomy between July 1987 and October 1995, the effectiveness and side-effects of all yttrium procedures (n = 83) were assessed retrospectively. Glucocorticoids were administered together with the yttrium, except in 1987. Radiation synovectomy had an overall success rate of 75% (complete or almost complete remission of synovitis) initially, i.e. within 1 month of the procedure, partly due to co-administration of glucocorticoids. However, in October 1995, only 17 joints (22%) were still in remission with a mean (S.D.) duration of remission of 20.8 months (22.0), range 1-95 months (median 16 months). In 60 joints (78%), synovitis was present at that time because of an unsatisfactory initial response to the Y-90 injection (19 joints) or recurrent synovitis during follow-up (41 joints); the mean (S.D.) duration of remission of these 60 joints was 3.3 months (5.9), range 0-22 months. A second injection of a double dose of Y-90 after an initial inadequate response (n = 8) did not contribute significantly to a better result. Short-term side-effects occurred in two cases after two Y-90 injections (2%) without glucocorticoid co-administration: a post-injection flare-up of synovitis and a local skin burn lesion. Persistent synovitis can be treated by Y-90 synovectomy with an overall success rate of 75% within 1 month. However, prolonged remission of synovitis is only achieved in 29% of joints with a good initial response. It does not appear worthwhile to perform a second synovectomy with a double dose if the initial response was inadequate. Y-90 synovectomy leads to only minor short-term side-effects (2%).
Abstract: The aim of this study was to determine the incidence of pulmonary embolization occurring after mechanical or pharmacomechanical percutaneous intravascular thrombolysis in 23 patients with occluded hemodialysis grafts. In all patients, pulmonary perfusion scintigraphy was performed before and immediately after thrombolysis. In eight (35%) of the patients, there was evidence of pulmonary embolism resulting from the interventional procedure; however, in only one was there clinical symptoms. It is concluded that there is substantial risk of pulmonary embolism in patients undergoing percutaneous intravascular thrombolysis for an occluded hemodialysis graft.
Abstract: The cause of sodium retention in nephrotic syndrome is unclear. Hypovolaemia has traditionally been labelled as the cause but there is evidence in adults of a renal disturbance as the main cause. We aimed to find out whether children with early nephrosis can be classified as hypovolaemic by objective measures. We measured blood volume, kidney function, and hormone concentrations in children with early relapse of minimal-change nephrosis. Three presentations could be defined. The first was patients with incipient proteinuria and normal plasma protein, characterised by sodium retention, increased renal plasma flow, and slightly increased aldosterone, but normal noradrenaline. The second was patients with severe proteinuria, hypoproteinaemia, and hypovolaemic symptoms, who had oedema, sodium retention, and high concentrations of plasma renin, aldosterone, and noradrenaline, low atrial natriuretic peptide, and low glomerular filtration rate. The third was patients with equally severe proteinuria and hypoproteinaemia, but without hypovolaemic symptoms; they had oedema, but no active sodium retention, and normal plasma hormones and glomerular filtration. Neither blood pressure nor blood volume discriminated patients with or without hypovolaemic symptoms. These findings show that children with early full-blown nephrosis can present both with and without hypovolaemic symptoms and laboratory signs, despite equally severe hypoproteinaemia, and also that sodium retention precedes the reduction in serum protein.
Abstract: OBJECTIVE. To assess the incidence of hypothyroidism, euthyroidism, and recurrent hyperthyroidism following a standard dose of Na131I (3.7 MBq or 100 microCi) per g thyroid tissue, adjusted for radioiodine tracer uptake. DESIGN. A single-centre prospective follow-up study from January 1990 to December 1992. SETTING. Academic Hospital in Utrecht, the Netherlands. SUBJECTS. Newly diagnosed patients with Graves' disease (n = 148). INTERVENTIONS. Radioiodine treatment at a standard dose of 3.7 MBq or 100 microCi per g thyroid tissue. MAIN OUTCOME MEASURES. Confidence interval testing of resulting thyroid status, defined by biochemical criteria. RESULTS. The overall cure rate was 70% (103 of 148 subjects), confidence interval (CI) 62-77%. A 90% incidence of hypothyroidism was found in patients with a small thyroid (less than 20 g). Recurrent hyperthyroidism was found significantly more often in subjects with a thyroid weight exceeding 60 g compared to those who had a thyroid of 9-59 g. More recurrences were found in subjects in the highest tertile of a 24-h radioiodine uptake test (> 80% uptake) compared to those in the lowest tertile (< 60% uptake). CONCLUSIONS. No uniform treatment results expressed per thyroid weight category were obtained, in spite of standardizing the treatment Na131I dose (3.7 MBq per g thyroid). Graves' patients with a thyroid smaller than 20 g and those with less than 60% 24-h radioiodine uptake have a 50-90% chance of hypothyroidism at the 12-month follow-up.
Abstract: Scintigraphy remains the most reliable method to measure gastric emptying. Standardized dual-isotope radionuclide gastric emptying techniques and appropriate meals, which stimulate small bowel receptors and utilize correction factors for technical errors, are widely available for research purposes. It is now necessary to apply the same standardized techniques in clinical settings to make the test diagnostically worthwhile. It is possible to quantify gastric motor function scintigraphically and to apply this methodology to study the pathophysiology of gastric emptying in various motor disorders. Ambulatory gastric emptying methods with intraluminal gamma counting probes are currently under development.
Abstract: Different structural as well as functional imaging techniques are becoming increasingly important in the investigation of patients suffering from an ischemic stroke. Available imaging procedures usually provide complementary data, but the images can not easily be compared due to differences in patient positioning, angulation, and slice thickness. We studied the value of spatial integration of images from different modalities in a patient with an ischemic stroke and used skin markers to integrate the obtained information. Computed tomography (CT), magnetic resonance imaging (MRI), 99mTcHMPAO-single photon emission computed tomography (SPECT) and magnetic resonance spectroscopic imaging (MRSI) were performed in a patient, presenting with a right sided hemiparesis caused by an ischemic stroke. Combination of MRI with CT demonstrated that the infarction visible on CT and MRI corresponded in size and volume. Furthermore, structural and functional images could readily be integrated, thus allowing us to obtain accurate information in this stroke patient. Different imaging modalities provide complementary information in the acute phase of cerebral infarction and multimodality matching can be of great value for improvement of our understanding of the pathophysiology and course of ischemic stroke.
Abstract: 123I-Iomazenil SPECT was performed in 17 patients who were considered candidates for surgery of epilepsy because of medically intractable complex partial seizures. In addition to this examination their presurgical evaluation consisted of long term ictal EEG-CCTV monitoring, CT, MRI and 18FDG PET. In eight patients intracranial ictal EEG recordings were performed. SPECT was assessed visually while PET data were analyzed quantitatively. Both SPECT and PET were compared to ictal EEG data and showed asymmetries in over 80% of patients in agreement with EEG findings. These three methods were in agreement in 65% of patients. SPECT showed abnormality contralateral to the EEG focus in one patient (6%) while PET always demonstrated ipsilateral dysfunction. It is concluded that 123I-Iomazenil SPECT may be considered a more economical and more widely available alternative to 18FDG PET in the presurgical evaluation of patients with medically intractable complex partial seizures. In this respect 123I-Iomazenil specifically reflects functional changes in the membranes of neurons while 18FDG is related to glucose metabolism not only of neurons but also of glial cells.
Abstract: Diffusely increased uptake in the calvarium on bone scintigraphy (a hot skull) is often present in patients with bone metastases and metabolic diseases. Excluding these known facts the prevalence of the hot skull and its relation with malignancy and, more specifically, with breast carcinoma have been studied in 673 patients. In women, the hot skull is clearly related to malignancy and to a lesser extent to breast carcinoma. However, another remarkable feature of the hot skull is its predominance in women in general (compared to men) and, therefore, the data suggest that the hot skull can also represent a normal variant of the female skull. We conclude that the hot skull has no clinical value in screening protocols.
