Effectiveness of retinoic acid treatment for redifferentiation of thyroid cancer in relation to recovery of radioiodine uptake.

BACKGROUND: Retinoic acid (RA) treatment has been used for redifferentiation of metastatic thyroid neoplasia that have lost radioiodine (131I) uptake with heterogeneous results. AIM: Retrospective analysis of the recovery rate of 131I uptake after RA treatment in patients from 11 Spanish hospitals. METHODS: Twenty-seven patients (14 men, 13 women) with papillary [21], follicular [4], and oncocytic [2] thyroid cancer initially treated with total thyroidectomy plus 131I, and with 131I negative metastatic disease, were given 13-cis RA (0.66-1.5 mg/kg for 5-12 weeks) followed by a therapeutic 131I dose (3700-7400 MBq); 3 months later thyroglobulin levels and computed tomography imaging were performed. RESULTS: In 9 out 27 cases (33%) (8 papillary, 1 follicular) optimal positive 131I scan was observed after RA treatment; in the remaining 18, 10 had a suboptimal uptake (7 papillary, 2 follicular, 1 oncocytic) and in the rest there was no 131I uptake recovery (6 papillary, 1 follicular, 1 oncocytic). In 17 positive responses to RA (either optimal or suboptimal) in which image follow-up was available, decrease or stabilization of metastatic growth was observed in 7, while tumor mass increased at short term in the remaining 10. No major side effects were detected. CONCLUSION: Quite a high rate of 131I uptake recovery after RA treatment may be obtained in advanced differentiated thyroid cancer, but the potential modification of the natural course of the disease is uncertain. A better biological characterization of these tumors allowing the identification of potential responders to RA may improve the outcome of RA coadjuvant therapy.

Cognitive dysfunction in systemic lupus erythematosus: prevalence and correlates.

Little is known about the mechanisms and relevance of cognitive dysfunction in systemic lupus erythematosus (SLE) patients who never displayed major neuropsychiatric manifestations (nSLE). Thirty-one nSLE female patients and 31 cognitively healthy control women were recruited. Sociodemographic, clinical, neuropsychological and SLE-related markers were collected including cerebral perfusion by single-photon emission computed tomography. Prevalences of cognitive complaints were 22.6% in nSLE versus 6.5% in the control group (p = 0.147); respective prevalences of cognitive dysfunction were 32.3 versus 6.5% (p = 0.01). Within the nSLE group, all cognitive domains appeared similarly affected, and correlations were found between cognitive dysfunction and less skilled occupation (r = -0.41, p = 0.02) and between cognitive complaints and depressive symptoms (r = 0.35, p = 0.05). Cognitive dysfunction is rather frequent in nSLE and seems to negatively impinge on social functioning.

[Meta-analysis of the diagnostic performance of 18F-FDG PET in renal cell carcinoma]. / Meta-análisis sobre el rendimiento diagnóstico de la tomografía por emisión de positrones con 18F-FDG en el carcinoma de células renales.

AIM: Renal cell carcinoma is the most frequent solid kidney tumor. At present, PET is not the imaging test of choice, the helical CT being the best method to assess these patients. The aim of the study was to perform a meta-analysis of the literature to evaluate the performance and accuracy of 18F-FDG PET in the detection of primary disease, recurrence and metastasis of renal cell carcinoma. MATERIALS AND METHODS: A systematic search was done of the available literature in primary and secondary databases published until October 2004 indexed in MEDLINE and CANCERLIT. Exclusion/inclusion criteria were applied. Their quality was evaluated using the Flynn criteria and joint estimators of sensitivity (S), specificity (Sp), likelihood ratios (LR), diagnostic odds ratio (DOR) and summary ROC (SROC) curve were obtained. The presence of the threshold effect was evaluated and the summary ROC (SROC) curve was calculated. RESULTS: Seven out of 46 studies fulfilled the inclusion criteria and were analyzed. Three studies evaluated the use of 18F-FDG PET in the differential diagnosis of renal masses. Two studies analyzed restaging and two analyzed the role of 18F-FDG PET in the detection of metastatic disease. All the selected studies were classified according to Flynn's criteria. We found the highest S in restaging with S 0.87 (95 % CI, 0.75-0.95) and in metastases detection with S 0.72 (95 % CI, 0.56-0.85) as well as the high Sp in differential diagnosis of renal masses. CONCLUSIONS: The results of this meta-analysis suggest that 18F-FDG PET can be useful in restaging and detection of metastatic disease, based on its acceptable S and Sp. However, the performance of 18F-FDG PET in the detection of primary disease is limited, but this may improve with the new PET/CT systems.

Technetium-99m-HMPAO in Tourette's syndrome on neuroleptic therapy and after withdrawal.

UNLABELLED: Both decreased and increased perfusion and metabolism have been described with PET and SPECT in different areas of the brain in patients with Gilles de la Tourette's syndrome. The aim of this study was to define the regional cerebral perfusion pattern in drug-free patients and the changes in perfusion with the usual neuroleptic treatment. METHODS: A group of 13 normal control subjects and 15 unmedicated Gilles de la Tourette's syndrome patients were studied with 99mTc-HMPAO brain SPECT. Thirteen of the initial group of patients were retested on neuroleptic treatment. A semiquantitative analysis of the images was performed. RESULTS: Decreased perfusion in orbital and anterior medial regions of both frontal lobes as well as in both temporal lobes was observed in the nontreated group compared with control subjects. With treatment, a perfusion increase in these frontal regions and in the left medial temporal cortex was observed. CONCLUSION: Neuroleptic treatment could decrease the hyperactivity of the dopaminergic system leading to improvement of the clinical symptoms and reperfusion of some previously hypoperfused regions.

Comparison of bone and gallium-67 imaging in heroin users' arthritis.

Nine cases of primary septic arthritis in heroin addicts are reported. Fibrous and cartilaginous joint localizations are prominent (four sternoarticular, three sacroiliac, one sacroccocygeal, and one knee). In all patients but one, conventional roentgenographic studies were negative. In six cases the causative agent was Staphylococcus aureus and in two cases, Candida albicans. In one case, it could not be determined. Our clinical observations, correlating the radioisotopic studies, suggest that in the first week of evolution the diagnostic procedure of choice is the [67Ga]citrate scintigram. Indeed, during this period the [99Tc]MDP bone scan is usually negative. The early demonstration and localization of the disease, together with the rapid bacteriologic diagnosis, allows for an early and more appropriate antibiotic treatment and better results.

Efficacy of preoperative diagnostic imaging localization of technetium 99m-sestamibi scintigraphy in hyperparathyroidism.

BACKGROUND: Until now, preoperative parathyroid imaging has been considered unnecessary because currently available techniques do not provide any better results than an expert surgeon. We conducted a multicenter prospective study evaluating the capability of technetium 99m sestamibi scintigraphy in the preoperative identification of pathologic glands. METHODS: Ninety-three patients with hyperparathyroidism, seven of them reoperative cases, were studied. In addition, 20 age-matched normocalcemic control subjects were also studied. RESULTS: Surgical confirmation of scintigraphic images was obtained in 91 of 93 cases (sensitivity, 97.8%). In all reoperative cases (n = 7), in all cases of ectopic glands (whether operated or not; n = 6), and in all patients with a single-gland disease (n = 70), topographic identification of the pathologic gland was correct in 100%. In multiple-gland disease (n = 23), involvement of more than one gland was visualized in only 61% of the patients; however, in 91% of patients, at least one gland was localized. Surgical success-defined as postoperative normocalcemia-with this approach was 100%. All scans of normocalcemic control subjects were negative. Of 31 patients in whom a multinodular goiter coexisted, seven presented a significant radionuclide background at 120 minutes' scan. False-positive images were found together with those corresponding to the pathologic glands in only three cases. CONCLUSIONS: 99mTc-sestamibi is a highly reliable, sensitive, and specific technique for imaging of pathologic glands in hyperparathyroidism, especially in single-gland disease. It may be considered as a first line single-procedure when a preoperative topographic diagnosis is required.

[Gammagraphy with HMPAO-99mTc leukocytes in intestinal inflammatory disease]. / Gammagrafía con leucocitos HMPAO-99mTc en la enfermedad inflamatoria intestinal.

The value of 99mTc-hexamethylpropyleneamine oxime (HMPAO) leukocyte images has been confirmed in patients with Inflammatory Bowel Disease. We performed 121 scintigraphic examination. The results were evaluated by radiologic and/or endoscopic examinations. The patients were divided into three subgroups: A) patients with active disease and less than 15 days of corticotherapy (n = 42). B) patients with active disease and more than 15 days of corticotherapy (n = 31). C) asymptomatic patients (n = 48). Over all sensitivity and specificity were 86% and 92.2% respectively. The sensitivity in subgroup A was 97.5% and 70% in the subgroup B. In the subgroup A the isotopic study showed the entire area of active inflammation in 95% (38/40) and colonoscopy in 32.5% (13/40). The leucocyte scanning showed clear pathologic activity in the ileum with a sensitivity of 86%. We conclude that 99mTc-leukocyte scintigraphy is the best method to assess the location of active inflammation in patients with less than 15 days of treatment. Scintigraphy was best in the assessment of active disease especially in Crohn's disease of the small bowel.

[Neuroimaging techniques in the Gilles de la Tourette syndrome]. / Técnicas de neuroimagen en el síndrome de Gilles de la Tourette.

Tourette's syndrome (GdT) is a chronic neuropsychiatric disorder of unclear etiology characterized clinically by the presence of motor and phonic tics as well as a variety of behavioral and cognitive abnormalities such as Obsessive-Compulsive Disorder (TOC) and Attention Deficit Hyperactivity Disorder (ADHD). Dopaminergic pathway and movement control related structures may have some implications for pathogenesis. Neuroimaging techniques may yield relevant data for a better understanding of the symptoms and physiopathology of this disease. Among them, functional isotopic techniques such as PET and SPECT and other like quantitative EEG are the most remarkable. In this article we intend to perform a thorough review of the most recent literature, contributing with our own experience and discuss the pathogenesis of GdT.

[Usefulness of spect with 99mTc-tetrofosmin and stimulus with dipyridamole in patients with left bundle branch block of His]. / Utilidad del SPECT con 99mTc-tetrofosmin y estímulo con dipiridamol en pacientes con bloqueo completo de rama izquierda del haz de His.

BACKGROUND: In patients with left bundle branch block, the 201Tl scintigraphic studies show high sensitivity, but with low specificity, in the diagnosis of coronary artery disease. OBJECTIVE: [corrected] To assess the value of 99mTc-tetrofosmin Single Photon Emission Computed Tomography (SPECT) and dipyridamole administration in patients with left bundle branch block. METHODS: 22 patients with angina and left bundle branch block were retrospectively studied by cardiac catheterization and Tc-Tf after dipyridamole administration (0,142 mg/kg/min. i.v.) and at rest. RESULTS: The mean number of territories with perfusion defects was 1.5+/-1.0, and the average number of diseased vessels in the coronariographic study was 1.6+/-1.3 (r = 0.77, p<0.001). Sensitivity, specificity, positive predictive value, negative predictive value, total predictive value and Kappa index in the diagnosis of multivessel disease were 92%, 90%, 92%, 90%, 91% and 0.82, respectively. In the diagnosis of anterior descending artery disease, these values were 83%, 70%, 77%, 78%, 77%, and 0.54, respectively. CONCLUSION: In patients with angina and left bundle branch block, SPECT with Tc-Tf-dipyridamole is of great value in the study of coronary artery disease extension. Sensitivity and specificity for the diagnosis of anterior descending artery disease were similar to that shown in series with thallium-dipyridamole.

[Bone scintigraphy findings in patients with recently diagnosed adenocarcinoma of the prostate: relationship with prostate specific antigen levels]. / Hallazgos de la gammagrafía ósea en pacientes con adenocarcinoma de próstata recién diagnosticado: relación con los niveles de antígeno específico prostático.

BACKGROUND AND OBJECTIVES: Although it has been suggested that bone scintigraphy (BS) may not be necessary in patients with prostate adenocarcinoma (PA) and normal prostate specific antigen (PSA) plasma levels, controversy still remains. The objective of the study was to evaluate the existing relationship between PSA plasma levels and BS findings in patients with a recently diagnosed PA in order to assess whether BS may be omitted on the basis of the PSA levels in these patients. METHODS: The 475 patients (70+/-7 years old) consecutively diagnosed of PA between 1994 and 1998 in our institution made up the study population. PSA plasmatic levels were determined and BS was performed (body planar study after 99mTc-methyl diphosphonate 900 MBq administration) in all the patients. RESULTS: In 362 patients (76.2%), BS was negative, in 108 (22.7%) positive and undetermined in the remaining 5 patients (1.1%). The mean PSA level in the whole study population was 74+/-267 ng/ml (range 0.4-4.200) and was higher in patients with positive GO (218+/-512 vs 31+/-89, p<0,0001). As PSA increased, the rate of patients with positive BS was significantly higher, this being 0%, 16.4%, 9.7%, 14.0%, 31.0% and 48.3% in patients with PSA 4, 4.1-10; 10.1-20; 20.1-30; 30.1-40, and >40 ng/ml, respectively (p<0.0001). In patients with positive BS, the PSA levels were 20 and 10 ng/ml in 30.6% and 18.6% of the patients, respectively. CONCLUSION: According to our experience, there is a significant association between PSA plasma levels and the BS results in patients with recently diagnosed PA. However, a significant proportion of patients with bone metastasis have normal PSA levels, and therefore BS should be performed in all patients with recently diagnosed PA regardless of the PSA levels.

[Integration of multimodal medical images]. / Integración de imágenes médicas multimodalidad.

Multimodality analysis is becoming a required tool in medical practice due to the development of different image techniques and new imaging processing tools. This paper is a review of the basis of medical image integration, image fusion techniques, and their clinical applications, especially addressing our experience with brain tomographic studies in nuclear medicine and radiology.

[Scintigraphy diagnosis of renovascular hypertension in renal transplanted patients]. / Diagnóstico gammagráfico de hipertensión renovascular en trasplantados renales.

UNLABELLED: Captopril renography (CR) has been shown to be a useful technique in the diagnosis of renovascular hypertension (RVH). This disease is a significant complication of the kidney transplanted patient so that early diagnosis would be extremely useful to preserve renal function and prevent graft loss. This work evaluates the role of CR, together with arteriography and doppler-ultrasound, in the diagnosis of RVH. MATERIALS: A total of 19 transplanted patients with clinical suspicion of RVH underwent an isotopic study, a doppler-ultrasound study and an arteriography. Scintigraphy was performed 1 hour after a 50 mg dose of captopril, with oral hydration and i.v. administration of approximately 111 MBq of 99mTc-MAG3 and 20 mg of furosemide. If abnormal, a subsequent renography in baseline conditions was performed for comparison. RESULTS: Overall, 11 patients had renovascular hypertension. Sensitivity and specificity of CR were 91% and 80% respectively, 100% and 60% for US and 91% and 100% for arteriography. The CR yielded one false positive result and 2 false negatives cases: one with 50% stenosis and one polar artery stenosis. Six patients were successfully dilated or operated. CONCLUSION: CR seems to be a reliable diagnostic tool for the diagnosis of renovascular hypertension in kidney transplanted patients.

[Meaning of clinical and electrical positivity in the myocardial perfusion scintigraphy during the administration of dipyridamole]. / Implicaciones de la positividad clínica y eléctrica en la gammagrafía de perfusión miocárdica durante la administración de dipiridamol.

BACKGROUND AND OBJECTIVES: Administration of dipyridamole produces angina and ST depression in 20%-30% and 6%-34% of patients, respectively. This study aimed to evaluate the clinical implications of the presentation of angina and/or ST depression during the administration of dipyridamole in the study of coronary heart disease by myocardial perfusion SPECT (MPS). METHODS: The study population is constituted by 593 consecutive patients without left branch block or ventricular pacemaker rhythm who were referred to our service to undergo MPS with dipyridamole. A SPECT was performed after the administration of 99mTc-tetrosfosmine and drug stimulation with dipyridamole (0.142 mg/kg/min for 4 minutes). A coronariography was performed in 338 patients (57%). The frequency of clinical and electrical positivity and their relationship with the MPS and the coronariography were studied. RESULTS: The rate of angina and ST depression was 32% (n = 190) and 10% (n = 58), respectively. Myocardial perfusion defects were observed in 465 patients (78%), and signs of scintigraphic ischemia in 311 (52%). The patients with ST depression presented a higher frequency of perfusion defects (93% vs 76%, p = 0.0012) and scintigraphic ischemia (89% vs 49%, p < 0.0001). In addition, perfusion defects in more than one territory were observed in these patients in a higher percentage (53% vs 34%, p = 0.0036). Among the patients who underwent cardiac catheterization, those who had a ST depression had a greater extension of coronary heart disease (1.8 +/- 1.2 vs 1.3 +/- 1.0 diseased vessels, respectively. p = 0.0100) and a higher frequency of multivessel disease (61% vs 43%, p = 0.0380). Those patients who had clinical positivity showed a scintigraphic ischemia more frequently (66% vs 47%, p < 0.0001), however no statistically significant differences were observed between the presence of patients with perfusion defects or in the extension of these defects as well as in the number of diseased vessels in the coronariographic study. CONCLUSIONS: During the administration of dipyridamole, the ST depression is associated with more frequent scintigraphic ischemia, larger extension of perfusion defects and more diseased vessels. The appearance of angina is associated with scintigraphic ischemia, but it is not necessarily associated with the extension of perfusion defects or greater number of diseased vessels.

[Utility of SPECT with 99m Tc-tetrofosmin and stimulus with dipyridamole in patients with permanent ventricular pacemakers]. / Utilidad del SPECT con 99mTc-tetrofosmin y estímulo con dipiridamol en pacientes portadores de marcapasos ventricular permanente.

BACKGROUND AND OBJECTIVE: Patients with permanent ventricular pacemakers (PP) are a difficult subgroup to assess in the study of coronary artery disease. The objective of this study was to evaluate the diagnostic value of the myocardial perfusion scintigraphy with 99mTC-Tetrofosmin (Tc-Tf) and stimulus with dipyridamole in patients with PP and suspected coronary artery disease. PATIENTS AND METHODS: Fourteen patients with suspected coronary artery disease and without structural cardiopathy, who underwent Tc-Tf and cardiac catheterization, were studied retrospectively. Sensitivity, specificity, predictive values and Kappa index were calculated for the diagnosis of coronary artery disease, multivessel disease, and for each one of the coronary arteries (left anterior descending, right coronary, and circumflex). In addition, the correlation between the number of territories with perfusion defects and the number of diseased vessels was studied. RESULTS: In regards to the diagnosis of coronary artery disease, sensitivity, specificity, positive predictive value, negative predictive value and the Kappa index were 100%, 50%, 83%, 100% and 0.55, respectively. For multi-vessel disease, these values were 83%, 64%, 64%, 83% and 0.43 respectively. The correlation coefficient between the number of territories with perfusion defects and the number of diseased vessels was 0.61 (p = 0.02). In the diagnosis of anterior descending disease, sensitivity and specificity were 83% and 88% respectively. For the right coronary artery, these values were 100% and 44% and for the circumflex artery 38% and 83%, respectively. CONCLUSION: In patients with PP and suspected coronary artery disease, myocardial perfusion scintigraphy with Tc-Tf and stimulus with dipyridamole is of great value in the diagnosis of coronary artery disease and in the assessment of its extension.

[Results of myocardial scintigraphy with 99mTc-tetrofosmin and dipyridamole administration in patients diagnosed of microvascular angina]. / Resultados de la gammagrafía de perfusión miocárdica con 99mTc-tetrofosmina y estímulo con dipiridamol en pacientes diagnosticados de angina microvascular.

The objective of the study was to evaluate the results of the myocardial scintigraphy with 99mTc-tetrofosmin (Tc-Tf) and pharmacological stimulation with dipyridamole in patients diagnosed of microvascular angina. The study population is made up of 50 patients discharged with the diagnosis of microvascular angina who had undergone Tc-Tf-dipyridamole. Clinical and electrical positivity appeared in 40% and 12% of the patients, respectively. Myocardial perfusion defects were found in 35 patients (70%), and were reversible in 21 (60%), fixed in 11 (21%), and combined in 3 (9%). Abnormalities were inferior, anteroseptal and lateral in 21, 18, and 2 patients, respectively. Patients with a positive exercise treadmill test, compared with those with a negative one, had more frequent perfusion abnormalities (91% vs 50%, p = 0.0327) and myocardial ischemia (64% vs 20%, p = 0.392). Women, in comparison with men, had angina (56% vs 22%, p = 0.013), and anteroseptal perfusion abnormalities (26% vs 4%, p = 0.028) more frequently. On the contrary, men had inferior perfusion abnormalities more frequently (57% vs 30%, p = 0.057). Thus, Tc-Tf-dipyridamole shows perfusion abnormalities in 70% of patients with microvascular angina (91% in patients with a positive exercise treadmill test). Scintigraphic pattern may be partially conditioned by gender in these patients.