Doses in family members after 131I treatment.
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Child↗
Biomedical subjects
C Beckers
Publications and source records attributed to C Beckers.
The predictive value of serum thyroglobulin in the follow-up of differentiated thyroid cancer.
A strict and careful strategy has to be adopted to cure thyroid cancer. Diagnostic iodine-131 whole-body scan (WBS) and serum thyroglobulin (Tg) are important tools to detect thyroid remnants after thyroidectomy and radioiodine therapy. The aim of this retrospective study was to compare the relative sensitivity of WBS and Tg in the detection of thyroid remnants or metastases and to evaluate the predictive value of Tg in the clinical and scintigraphic course of the disease. Ninety-three patients were followed up after total thyroidectomy and the administration 4-6 weeks later of an ablative dose of 100 or 150 mCi 131I. Eighty-five percent of the patients were free of regional or distant metastases. The follow-up scheme included clinical examination of the patient followed by WBS, Tg, thyroid-stimulating hormone and free thyroxine measurements performed 4 weeks after thyroxine withdrawal and the observance of a low-iodine diet for at least 1 week. WBS (+) patients received a 100- or 150-mCi therapeutic dose of 131I. All patients were further followed up in the same way every 6 months until both WBS and Tg became negative, and thereafter at 1-, 2- and 4-year intervals. Six months after the postoperative radioiodine treatment (first visit), the sensitivity of WBS and Tg was 87% and 26% respectively. Among patients who were WBS(+) at the first visit, 95% of those who were Tg(-) and 47% of those who were Tg(+) had become disease-free at a median of 4 years after surgery (chi2=13.6; P<0.05). Patients whose tests were both positive required more radioiodine to be cured (335+/-90 vs 250+/-95 mCi; P<0.05). Our data indicate that in early diagnosed thyroid cancer, serum Tg measured 6 months after the postoperative 131I ablative dose is less sensitive than WBS for the demonstration of persistence of residual thyroid tissue but provides predictive information on the disease course. WBS(+) and Tg(-) patients are cured earlier and with less radioiodine than those who remain Tg(+).
Adenocarcinoma, Follicular↗
Regulations and policies on radioiodine 131I therapy in Europe.
The European Union recently adopted the main International Commission on Radiological Protection (ICRP) recommendations on radiation protection. The annual limit for the members of the public on continuous exposure is 1 mSv/year, with a constraint dose of 0.3 mSv. Such regulation may raise a number of practical problems for 131I-treated patients, particularly those receiving radioiodine as outpatients. The radiation exposure evaluated on the basis of dose rate assessments and dose occupancy usually leads to results significantly higher than those obtained by direct measurements with thermoluminescent dosimeters carried for 2-3 weeks by the family members of the patient. From these direct measurements, it appears that reasonable instructions given to 131I-treated patients allow us to respond positively to the ICRP recommendations without disturbing too excessively the patient's daily life. Educational action remains essential in radiation protection.
Europe↗
99mTc-labelled immunoglobulin scintigraphy in arthritis: an analysis of synovial fluid activity.
The distribution of 99mTc-labelled human polyclonal non-specific immunoglobulin G (HIG) in the synovial fluid was studied in 14 patients with rheumatoid and non-rheumatoid arthritides. Analysis included the determination of the total activity per ml synovial fluid 6 h post-injection (p.i.) of the tracer as well as of the protein- and cell-bound fractions. At 6 h p.i., > 60% of the injected dose remained in plasma as protein-bound radioactivity. Values in the synovial fluid ranged between 0.001 and 0.009% of the injected dose per ml. Importantly, the synovial fluid to plasma ratio was consistently < 1 (range: 0.09-0.43), which is in the range of ratios observed for endogenous proteins in vivo. Similar values were obtained in samples of synovial tissue obtained at surgery in two patients. These data are consistent with the hypothesis that labelled HIG accumulates in the extracellular fluid (both within the synovial tissue and fluid) by non-specific mechanisms (such as increased blood pool and capillary permeability) and does not equilibrate with circulating plasma proteins in accordance with basic knowledge of synovial physiology. In addition, it was found that most of the activity remained bound to the proteins in the fluid and that cell-binding occurred to a very low degree that cannot be considered an important mechanism of uptake of this radiolabelled agent in vivo. These results provide the first evidence in an in vivo human setting that radiolabelled HIG accumulates mainly by non-specific mechanisms in inflamed joints.
Arthritis, Rheumatoid↗
Increased uptake of indium-111 pentetreotide up to 10 years after external thoracic irradiation: report of two cases.
Indium-111 pentetreotide scintigraphy was performed in two patients for the localization of recurrent medullary thyroid carcinoma treated by surgery and external radiotherapy 1 and 10 years earlier. A marked uptake of the radiopharmaceutical was demonstrated in the lung areas that had been irradiated. These cases strongly suggest that this uptake is related to pulmonary fibrosis, a well-known complication of radiotherapy, even long after the irradiation. Therefore, attention must be paid to the avoidance of false-positive interpretation of somatostatin receptor scintigraphy in patients previously treated by radiotherapy.
Aged↗
Technetium-99m L,L-ethylenedicysteine clearance and correlation with iodine-125 orthoiodohippurate for the determination of effective renal plasma flow.
Technetium-99m L,L-ethylenedicysteine (99mTc-L,L-EC) is a new renal tubular tracer that allows the determination of the effective renal plasma flow (ERPF). The aim of this study was to derive simplified methods for the estimation of 99mTc-L,L-EC clearance using one or two plasma samples after bolus injection. Fifty-nine multiple plasma dual-tracer samples (nine samples from 5 to 120 min after injection) were obtained after injection of kit-formulated 99mTc-L,L-EC and iodine-125 orthoiodohippurate (OIH). The studies were performed in 25 stable and 24 unstable transplant recipients, in five patients with renal insufficiency (four on chronic haemodialysis) and in five normal volunteers. This allowed a wide range of renal function values to be covered, with ERPF (estimated by OIH clearance) ranging from 25.4 to 604.0 ml/min. The reference 99mTc-L,L-EC clearance, as calculated from the multisample model, could be estimated from two samples at 15 and 90 min with an error of 11.3 ml/min and from one sample at 90 min with an error of 17.8 ml/min. Using appropriate linear regression analysis, ERPF could be estimated by the two- and one-sample 99mTc-L,L-EC clearance with an error of 24.2 and 22.8 ml/min, respectively. In conclusion, 99mTc-L,L-EC clearance can be accurately estimated by simplified one- or two-sample methods. Moreover, these methods can be used to estimate ERPF with an error that remains acceptable for clinical purposes.
Cysteine↗
[Acute tubulo-interstitial nephropathy with uveitis: apropos of case].
We report another case of acute interstitial nephritis with uveitis (TINU syndrome) in a 35-year-old woman. About thirty cases were described since the first ones 20 years ago. We discuss the assessment needed to reach the diagnosis. The evolution is unusually favourable with steroid therapy.
Adult↗
Exercise gated planar myocardial perfusion imaging using technetium-99m sestamibi for the diagnosis of coronary artery disease: an alternative to exercise tomographic imaging.
Single-photon emission tomography (SPET) using technetium-99m labelled myocardial tracers (e.g. 99mTc-sestamibi) has become one of the most popular myocardial imaging methods for the diagnosis of coronary artery disease (CAD). This prospective study was designed to evaluate the diagnostic performance of 99mTc-sestamibi exercise gated planar myocardial imaging by comparison with both visual and quantitative analyses of SPET. The study was conducted in 115 consecutive patients with known or suspected CAD, including 54 patients with a previous myocardial infarction (MI), referred for exercise testing prior to coronary angiography. Multi-gated planar imaging and SPET were performed after bicycle exercise. The end-diastolic (ED) and SPET images were visually scored (SVi). Myocardial uptake was quantitated on SPET slices using maximum count circumferential profiles (SQu) and defect extent was measured by comparison with gender-matched data sets obtained from 27 controls (< 5% likelihood of CAD). CAD was defined as coronary artery stenosis > 50% and/or regional wall motion abnormality. The cut-off criteria for positivity of the three procedures were determined from receiver operating characteristic (ROC) curves derived from the data of patients without previous MI. The area under the ROC curves was similar for ED, SVi and SQu. This was confirmed by the analysis of sensitivity performed using the ROC curve-derived cut-off criteria, in patients with or without previous MI. SVi was more sensitive than ED in identifying the diseased vessel(s) (ED: 41% vs SVi: 80%; P < 0.0005) but ED was more specific in this respect (ED: 79% vs SVi: 61%; P < 0.0005).(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Evaluation of disease activity in rheumatoid arthritis and other arthritides using 99mtechnetium labeled nonspecific human immunoglobulin.
OBJECTIVE: To determine the usefulness of 99mtechnetium (99mTc) immunoglobulin scintigraphy (99mTc IgG) in rheumatoid arthritis (RA) and in other arthritides. METHODS: Scintigraphic scores were compared with the Ritchie index and biochemical variables of disease activity. RESULTS: In RA, scintigraphic scores were reproducible and seemed to perform better than clinical scores. Moreover, the scores of synovial uptake correlated significantly with systemic variables of inflammation. Other inflammatory arthritides also disclosed uptake of 99mTc IgG but noninflammatory joints did not. CONCLUSION: Although nonspecific for RA, 99mTc IgG scintigraphy is a reliable tool to evaluate the degree and extent of joint inflammation.
Adult↗
Hyaluronidases of the gastrointestinal invasive nematodes Ancylostoma caninum and Anisakis simplex: possible functions in the pathogenesis of human zoonoses.
The gastrointestinal invasive stages of two parasitic nematodes, Ancylostoma caninum and Anisakis simplex, were each found to release in vitro a hydrolytic enzyme that degrades the glycosaminoglycan hyaluronic acid. The parasite hyaluronidases were partially purified by ion-exchange chromatography and biochemically characterized. The hyaluronidase from A. caninum adult worms had a molecular weight of 65,000 and a pH optimum of 6 with activity at neutral pH, while the hyaluronidase from A. simplex larvae had a molecular weight of 40,000 and a pH optimum of 4 with no activity at neutral pH. Both parasite hyaluronidases also degraded the glycosaminoglycan chondroitin sulfate A. Cupric sulfate and high concentrations of sodium chloride were inhibitory. The nematode hyaluronidases are postulated to have a role in tissue histolysis and mucosal invasion; their distinct biochemical properties have relevance to the pathogenesis of the zoonoses anisakiasis and eosinophilic enteritis.
Ancylostoma↗
[Semi-quantitative analysis of 3-phase bone scintigraphy data in algodystrophy of the limbs].
Three-phase bone scanning of the extremities (foot or hand) was performed in 40 normal subjects and in 56 patients with an unequivocal clinical diagnosis of reflex sympathetic dystrophy. Ten patients were in the "cold" or atrophic stage of the disease process, whereas 46 were in the "hot" or acute phase. The scintigraphic parameters studied were the ratios of tracer activity in the affected side over the healthy side established for blood flow (BF), blood pool (BP), early vasculo-tissular fixation (EF), and late bone fixation (LF). In the controls, blood flow, blood pool, and early fixation showed considerable interindividual variation and only the variation of late fixation remained within narrow limits. Among the patients, those at the hot stage of the disease had significantly higher values for all four parameters than those at the cold stage. The group at the cold stage did not differ from the controls except for a significantly higher late fixation value. Furthermore, among hot stage patients, 15% to 25% had normal or diminished blood flow, blood pool and early fixation values. At the cold stage of the disease, radionuclide parameters were similar in affected feet and hands, whereas at the hot stage values at the feet were double those at the hands. Finally, statistical analysis revealed that late fixation was most closely correlated with early fixation, which in turn was most close correlated with blood pool. The clinical and pathophysiological significance of these data is discussed.
Adult↗
Evaluation of technetium-99m-L,L-EC in renal transplant recipients: a comparative study with technetium-99m-MAG3 and iodine-125-OIH.
UNLABELLED: The clinical usefulness of kit-formulated 99mTc-L,L-EC, a new renal tubular tracer agent based on a diaminodithiol ligand was evaluated in a large population of renal transplant recipients. METHODS: Fifty patients with transplants were studied. Five patients with renal insufficiency and five normal volunteers were also included to extend the range of renal function values. The labeling efficiency of 99mTc-L,L-EC in routine conditions, i.e., without HPLC purification, and the safety of the tracer were evaluated. RESULTS: The mean radiochemical purity of 99mTc-L,L-EC determined by thin-layer chromatography was 97.4%. No side effects or significant biochemical changes were observed. The clearance of 99mTc-L,L-EC and 125I-OIH ranged from 10.7 to 417.5 and from 27.6 to 602.7 ml/min/1.73 m2, respectively. The clearance of 99mTc-L,L-EC and 99mTc-MAG3 averaged respectively 71% and 52% of that of 125I-OIH. CONCLUSION: The labeling procedure of kit-formulated 99mTc-L,L-EC is easy and efficient. This tracer is safe and suitable for both imaging and quantitative measurement of the renal tubular function. Technetium-99m-L,L-EC represents an excellent alternative to 99mTc-MAG3.
Adult↗
[Expression of DRC1 antigen by leukemic cells].
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Autoantigens↗
Influence of ureteral status on kidney washout during technetium-99m-DTPA diuresis renography in children.
To assess the influence of the ureter on renal washout during 99mTc-DTPA diuresis renography, ureteral images were reviewed in 42 children (median age: 5 mo) referred for hydronephrosis. Sixty-minute acquisitions were obtained in hydrated patients under bladder drainage. Furosemide was injected at 30 min. An abnormal ureter was defined as an intense and continuous image of greater than 10 min. A washout index was determined on renal (KT1/2) and ureteral (UT1/2) curves. Curve patterns corresponding to normal (type I), obstructive (II) and nonobstructive (III) cases were described. Compared with the x-ray data, diuresis renography was highly sensitive (91%) and specific (98%) for detecting any abnormality. Despite an obstructive KT1/2 (greater than 20 min), no patient with an abnormal ureter underwent therapy at the ureteropelvic junction. After surgery at the lower level, hydronephrosis regressed. Our data indicate that abnormal ureter findings at diuresis renography have to be recognized before planning therapy for children with hydronephrosis.
Adolescent↗
Noninvasive measurement of liver regeneration with positron emission tomography and [2-11C]thymidine.
The feasibility of liver regeneration determination with [2-11C]thymidine and positron emission tomography was investigated in partially hepatectomized rats. Serial tomographic scans were performed over a 120-minute period after injection of [2-11C]thymidine together with tritium-labeled thymidine. Within 10 minutes after injection, positron emission tomography scans showed a twofold higher hepatic uptake in regenerating than in nonregenerating livers. Time-activity curves over the liver area indicated that the maximal uptake was followed by a faster decrease of 11C radioactivity in controls than in regenerating animals, so that total 11C activity remaining in the liver at 120 minutes accounted for 68% of maximum in regenerating and only 38% in controls. Tissue distribution studies performed at 120 minutes showed that total 11C radioactivity, expressed in percent injected dose per gram, was six times higher in regenerating livers than in controls (0.62% +/- 0.07% in regenerating livers and 0.10% +/- 0.03% in nonregenerating livers; P less than 0.001) and correlated with 3H radioactivity measured in the nuclear fraction (r = 0.92; P less than 0.001). When the hepatic uptake was expressed in percent of dose per organ, the difference between both groups increased (2.31% +/- 0.23% in regenerating livers and 0.29% +/- 0.02% in nonregenerating livers; P less than 0.001) because of higher weight of regenerating livers than of nonregenerating livers (3.83 +/- 0.11 g in regenerating livers and 2.96 +/- 0.16 g in nonregenerating livers; P less than 0.001). In other organs examined, no difference in 11C radioactivity was found between the two groups of rats. These results indicated the potential usefulness of [2-11C]thymidine and positron emission tomography for noninvasive measurement of liver regeneration.
Animals↗
Additional prognostic value of exercise testing and thallium-201 scintigraphy in catheterized patients without previous myocardial infarction.
To determine whether exercise testing and thallium scintigraphy provide additional prognostic information in symptomatic patients undergoing catheterization, we studied 432 consecutive male patients without a previous myocardial infarction by means of an exercise test, thallium scintigraphy and catheterization. The follow-up period was 46 +/- 24 months (from 12 to 96). Events were defined as death (27 patients), nonfatal myocardial infarction (occurring in 27 patients) or late (greater than 60 days after test) surgery or dilatation (needed in 45 patients). The 5 year survival rate was 89% and the event-free rate was 72%. History, noninvasive and invasive variables were submitted to a stepwise Cox regression analysis. By multivariate analysis, the significant variables related to death were the number of diseased vessels and exercise workload; the selected variables for all cardiac events were the number of diseased vessels; the score at thallium exercise testing and exercise workload. Among the subgroups of 337 coronary patients, the predictive variables for death were exercise workload and the number of diseased vessels. For all cardiac events, the selected variables were the number of diseased vessels, the score of defects during thallium exercise and exercise workload. Thus, in patients without a previous myocardial infarction, noninvasive variables do provide prognostic information which is not available either from the history or from catheterization.
Cardiac Catheterization↗
Interest of gallium hepatic scintigraphy in hepatic abscess: a case study.
The interest of 67Ga-citrate scintigraphy in the diagnosis of hepatic abscess is illustrated by a study of a 56-year-old man, who was admitted to the hospital for upper abdominal pain. Ultrasound (US) and X-ray CT scan examinations suggested the presence of a liquid mass, the origin of which was unclear. Liver scintigraphy with 67Ga-citrate disclosed a lacunar zone surrounded by a rim of increased uptake, an image strongly suggestive of abscess or necrotic tumor. A US-guided needle aspiration of the hepatic mass yielded a purulent liquid, from which Streptococcus milleri were grown. This observation suggests that, despite the development of other diagnostic procedures, hepatic gallium scintigraphy still remains sometimes useful for the investigation of poorly characterized hepatic masses.
Citrates↗
Area-at-risk determination by technetium-99m-hexakis-2-methoxyisobutyl isonitrile in experimental reperfused myocardial infarction.
In a canine model of reperfused myocardial infarction, we tested the hypothesis that after reperfusion, technetium-99m-hexakis-2-methoxyisobutyl isonitrile (Tc-MIBI) tomographic imaging still reflects occlusion blood flow when the tracer is injected before reperfusion. Nine anesthetized dogs underwent 2 hours of coronary occlusion followed by 3 hours of reperfusion ending by being killed. Reference coronary blood flow was determined by radioactive microspheres injected during occlusion and after reperfusion. Biopsies in normal and ischemic myocardium and single photon emission computed tomography were obtained during occlusion and after reperfusion. Circumferential profiles were applied to axial slices divided into 5-degree sectors. The sectors were divided into 3 groups selected on the occlusion acquisition (normal, mildly reduced, and severely reduced) and compared with the postreperfusion acquisition. Tissular Tc-MIBI kinetics was assessed both by Tc-MIBI time-activity curves of normal and ischemic tissue obtained by biopsy and by the relative gradient between normal, ischemic, and necrotic postmortem tissue samples. In biopsy samples, Tc-MIBI content remained unchanged during occlusion and after reperfusion in normal as well as in ischemic tissue (4,662 +/- 2,237 counts/min/mg vs. 4,599 +/- 1,577 counts/min/mg in normal tissue, NS; 941 +/- 903 counts/min/mg vs. 1,087 +/- 721 counts/min/mg in ischemic tissue, NS). In postmortem tissue samples, there was a good correlation between occlusion microsphere blood flow and Tc-MIBI activity (r = 0.91). In the necrotic samples, mean normalized Tc-MIBI activity (10 +/- 17%) was slightly higher than the normalized microsphere blood flow (3 +/- 3%, p less than 0.001) but markedly lower than the normalized microsphere reperfusion blood flow (63 +/- 31%, p less than 0.001). Comparing the single photon emission computed tomographic acquisitions before and after reperfusion, Tc-MIBI activity remained unchanged in normal as well as in mildly reduced or severely reduced segments. Thus, our data are consistent with the hypothesis that Tc-MIBI traces blood flow, does not redistribute significantly despite reperfusion, and can be used for imaging the area at risk.
Animals↗