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PubMed1984

[Access control system for a radioisotope laboratory with a personal computer].

This paper describes an access control system for a radioisotope laboratory. The system is composed of a personal computer, three card readers, an electric auto door, a hand foot cloth monitor, a monitor TV, a video tape recorder (VTR), and a thermo sensor. The personal computer controls other equipment with a registered user's number. When a user inserts an identification card into the card reader, the computer stores the gate number, the user's number and the time; it processes those data and prints out a document. The VTR records the person passing through the gate to identify if he uses his card. It works only when the sensor catches users being within its sensitive area. This system proved to effectively prevent intrusion into the area of an unregistered person or release of contaminated materials from that area.

Computers↗

PubMed1986

An examination of 3H and 14C hand contamination at the radioisotope laboratory of a medical school.

In a field of bio-medical science, low energy beta-emitting nuclides, such as 3H and 14C, are used frequently. However, contamination with those nuclides on laboratory workers is not detectable by the ordinary hand-foot-cloth monitor, if it occurs. Therefore, a new contamination check method, hand washing combined with lyophilization, was studied and feasibility of the method has been confirmed. The lyophilization step of the method takes about ten hours so it is not practical to use the method as a daily contamination check. However, it can be done at regular intervals and it will give valuable information for the maintenance of the radioisotope laboratory.

Carbon Radioisotopes↗

PubMed1999

[Radioisotopic localization of the sentinel lymph node in breast cancer. Preliminary results].

The aim of this preliminary work is to show the results of the radioisotopic localization of the sentinel node in breast cancer and the surgical resection using a gamma probe. We studied 10 patients with breast cancer without primary chemotherapy and 3 patients with primary chemotherapy before surgery. A lymphoscintigraphy was made after injection of 111 MBq of Tc99m-nanocolloid in a volume of 3 ml. The scans were performed after 30 minutes, 2 hours, 4 hours and 24 hours after injection. We detected the node and then a skin mark was made. The next day, surgical resection of this node was performed, guided by a gamma probe. We detected all sentinel nodes but one: 12 sentinel nodes and 7 second echelon nodes. The mean time for a surgical detection was about 16 minutes. In our experience this technique allows an accurate localization of the sentinel node in patients with breast cancer. We are able to localize the node in the surgical room guided with gamma probe. The peroperatory evaluation by anatomopathological techniques shown the status of this node. All this, does not delay the surgical time.

Adult↗

PubMed1976

[A radioisotope test of muscular function (skeletal)].

A new radioisotopic method measuring the alterations in local blood volume of a muscle before, during and after exercise would seem to make possible the detection of frankly pathological muscular irrigation. The latter is characterised by a marked reduction in blood volume during effort, with or without slight secondary hyperhaemia. Given the correlation between flow and volume, the state of the blood flow may be deduced, and probably to follow the spontaneous progression of progress with treatment of the vascular problem and to assess its prognosis.

Humans↗

PubMed1976

Radioisotope techniques in delineation of the environmental behavior of cadmium.

Radioisotope techniques are being developed and utilized at Oak Ridge National Laboratory (ORNL) for evaluating the environmental behavior of toxic elements such as cadmium in aquatic and terrestrial ecosystems. Tracer techniques using 109Cd in microcosm, field plot, and stream systems are providing information on biogeochemical cycling and distribution of cadmium in the environment. Parameters being measured include adsorption capacity for cadmium in mineral soils and sediments; uptake rates of cadmium in various plant species from both soils and nutrient solutions as affected by pH, competing cations, and chemical form of cadmium; and distribution of cadmium in various components of both aquatic and terrestrial ecosystems following application of 109Cd to soil vegetation, or directly to streams. Food chain parameters being estimated with 109Cd include uptake, assimilation, and turnover by both aquatic and terrestrial organisms. Information obtained in these radiotracer studies is providing insight into the behavior of cadmium in aquatic and terrestrial ecosystems, especially transport rates of cadmium and potential biomagnification or dilution in food chains. The factors which influence the incorporation of cadmium into vegetative material as well as those affecting residence time in ecosystems have been identified. Use of 109Cd also has permitted evaluation of a cadmium specific electrode as a tool for rapid assay of free cadmium ions in soil solutions.

Adsorption↗

PubMed2000

The impact of stent design and delivery upon the long-term efficacy of radioisotope stents.

Both gamma and beta irradiation delivered via a radioactive catheter-based line source have been shown to have efficacy in reducing restenosis. However, these catheter-based treatments have some limitations, including the safety of handling sources ranging from 30 mCi to 500 mCi. Alternatively, one could use a stent as the platform for local radiation delivery as a means to prevent restenosis. Experimental studies have demonstrated that stents ion implanted with the b-particle emitter 32P can reduce neointima formation. Clinical evaluation of the radioisotope stent began in the fall of 1996. Dose escalation studies have now been completed in approximately 250 patients with 32P, b-particle emitting stents ranging from 0.5 microCi to 24 microCi. Overall, these feasibility trials have demonstrated a clear, dose-dependent reduction of neointimal hyperplasia within the stent structure, but with an unanticipated finding of a relatively high incidence of restenosis at the stent margins. The purpose of this paper is to review the current status of radioactive stents, with an emphasis on the key elements of stent design and stent delivery that could impact the long-term efficacy of this device.

Brachytherapy↗

PubMed1976

[A radioisotope method of measuring pulmonary vascularization].

The study of regional perfusion of the lungs by a radioisotopic method using a multiple detectors system and 133 Xenon as radioactive tracer, seems to us, an interesting tool in the investigation of valvular or congenital cardiopathy. This method can be repeated as much as necessary and is not traumatic. The reproductibility is good. The radiation exposure is minimal as well for the patient as for the physician.

Animals↗

PubMed2001

Microscopic distribution of iodine radioisotopes in the thyroid of the iodine deficient new-born rat: insight concerning the Chernobyl accident.

UNLABELLED: Thyroid cancer markedly increased in children exposed to iodine radioisotopes following the Chernobyl accident. This increase exceeded predictions based on dose estimates to the whole organ. We sought to investigate whether iodine deficiency may have influenced the pattern of microscopic distribution of radioiodines, which may be important to interpretation of the observed effects. Iodine-deficient new-born rats were injected with iodine-129 (129I) and the microscopic distribution in the thyroid tissue was studied at 24 hr and at one week after administration, using secondary ion mass spectrometry (SIMS). Twenty-four hr after administration, SIMS images showed large differences in 129I uptake among thyroid follicles, with more than a factor ten variation in the local concentration. In addition, the distribution of 129I inside follicles varied with time. At 24 hr, the highest concentration was found at the periphery of the colloid, close to the thyroid cells. There also was enhanced concentration of 129I at one pole of follicles. Distribution inside follicles was homogeneous at 7 days. CONCLUSIONS: 1/Dosimetric models, which assume uniform iodine uptake by thyroid follicles, give an oversimplified picture of radiation dosimetry in cases involving iodine deficiency, which induces patchy tissue irradiation. 2/The dynamic pattern of iodine distribution within thyroid follicles suggests that decay events from short-lived iodines will occur closer to thyroid cells than events resulting from iodine-131.

Animals↗

PubMed1975

In vivo study of a new radioisotope-powered cardiac pacer.

A new radioisotopic pulse generator has been developed. It is 6 cm. long, 4.7 cm. high, 1.92 cm. wide, and weighs 61 Gm. (2 oz.). It is the smallest pulse generator made and has a life expectancy of over 20 years. The circuit is a conventional ventricular-inhibited (V.V.I.) type. In vitro testing has passed all Atomic Energy Commission requirements. The present study is concerned with in vivo testing of the complete pacemaker system, by means of both myocardial and endocranial electrodes, in 20 dogs with and without induced heart block. Extensive testing for electromagnetic compatability was carried out on 1 animal with induced heart block and a special, fast-rate pulse generator. Based on studies to date, the Atomic Energy Commission has issued a license for limited clinical trial which has already begun at the collaborating institutions.

Animals↗

PubMed1975

[Treatment of circulatory insufficiency in patients with ischemic heart disease with digoxin and determination of its concentration in the blood serum by radioisotope method].

The radioisotope method with Rb86 was used for determining in vitro the serum concentration of Digoxin. The study was conducted in 57 patients with cardiac insufficiency in the acute period of myocardial infarction and with post infarction cardiosclerosis. The mean values of Digoxin concentration depending on the daily maintenance dose were obtained. The direct correlation between the amount of the drug taken and the content of the drug in the blood serum was proved. Digoxin intoxication was found to develop in cases of its content exceeding the mean level for the given dosage (4 patients), however, in 2 patients signs of intoxication developed with a low concentration of Digoxin. The causes favouring the development of intoxication are discussed.

Adult↗

PubMedDate not supplied

[Radiation hazard in the use of radioisotopic neutralizers of static electricity].

Spectrometry was used by means of an alpha-radiometer on a [symbol: see text]porpecc-[symbol: see text] hard-and-software complex to study the radioactive contamination of the surfaces of neutralizers with plutonium 239-based ionizing radiation sources, which are employed to remove electrical charges from electrifiable materials. While using the neutralizers, the operating personnel is shown to be exposed to radiation. The level of removed radioactive contamination during half-a-year exploitation of the neutralizers was greater than the maximum allowable values on the average by several times. Radiation hazard in the use of radioisotopic neutralizers of static electricity is outlined.

Environmental Monitoring↗

PubMed1975

[Radioisotope cisternographic study on cerebrospinal fluid circulation after subarachnoid hemorrhage].

Although recent advance in neurological surgery has diminished mortality rate of aneurysmal surgery, there still exist several complex problems for the management of aneurysms. Persistent neurological deficits or clinical deterioration after subarachnoid hemorrhage can result from subsequent communicating hydrocephalus which can be treated by shunting operation. We have studied alterations in the cerebrospinal fluid (CSF) circulation after SAH in 43 patients. Sources of hemorrhages were aneurysm in 30 cases, arteriovenous malformation in 6 and unknown in 7. Radioisotope cisternography was performed using 0.5 to 1.0 mCi of 169Yb-DTPA which was given intrathecally by lumbar injection. Results of cisternogram were classified into 4 groups and 7 subgroups; group 0: non filling (4%), group I: persistent ventricular filling (45%), A) absence of convexity flow (11%), B) partial convexity flow (34%), group II: transient ventricular filling (23%), A) delayed convexity flow (11%), B) normal convexity flow (12%), group III: no ventricular filling (28%), A) delayed convexity flow (17%), B) normal convexity flow (11%). The radioactivity in serial blood samples was measured by a well-type scintillation counter. Three types of curves for transfer of 169Yb-DTPA from CSF to blood were classified; delayed type, medium type, and normal type. In delayed type, the count ratio of blood activity at 24 hr to that at 3 hr is over 30%. In normal type, it is below 10%. There was a close correlation between cisternogram and transfer curve. In most cases with persistent ventricular filing, the transfer curve showed a delayed type. The relationship of cisternogram to classification of patient's condition by Hunt was studied. The grade of patient's condition was found to be closely related to the degree of abnormality in CSF circulation. The existence of rebleeding in the patients history was also found to influence the degree of abnormality in CSF circulation. However, single bleeding may also cause abnormality, such as persistent ventricular filling on cisternogram. In regard to the site of aneurysms, those of anterior communicating artery appeared to cause communicating hydrocephalus more frequently. Laterality of convexity flow was analyzed in 17 cases. All cases with internal carotid aneurysms showed decreased activity on the side of bleeding. Shunt operation was performed on 10 cases according to the results of cisternography, transfer curve, pneumoencephalography, and angiography. Seven cases showed improvement and 2 died of other complications soon after the shunt, and the effect of the procedure cannot be evaluated. Patients with clinical signs of NPH and abnormal cisternogram (group I) with evidence of ventricular dilatation are indicated for shunting operation.

Adult↗

PubMedDate not supplied

Intrathecal radioisotopes and phlebography in investigation of ventriculo-atrial shunts in children.

The Authors describe their experience in investigating the functioning and patency of ventriculo-venous shunts in hydrocephalic patients. They examined 41 hydrocephalic children with Pudenz valves, with radioisotope techniques. The radioactive tracers were administered by the lumbar route, by the ventricular route, or directly into the shunt. For lumbar or ventricular administration 131I-HSA, 99mTc-HSA and 169Yb-DPTA were used, whilst 99mTCO4 was the only isotope used for direct introduction into the shunt, effected by piercing the pump of the Pudenz system. The results of these investigations show that introduction of the isotope into the shunt allows obtaining morphological information, depending on the patency of the shunt and on the site of any obstruction. It also provides information about the functioning of the shunt, depending on the presence of hyper- or hypo-shunting. In cases where revision of the distal catheter might be necessary, moreover, phlebographic investigations of the superior vena cava were made. These proved to be particularly useful for indicating the patency of the affluent veins of the heart, thus enabling a precise surgical schedule to be planned prior to operation.

Cerebrospinal Fluid Shunts↗

PubMed2003

Breast sentinel lymph node biopsy using radioisotope injection: is one-day better than two-day protocol?

Sentinel lymph node (SLN) biopsy is an evolving treatment approach for patients with operable breast cancer. There have been a number of variations in the biopsy technique. One is the timing of radioisotope injection, which might have a significant influence on the radiation exposure of the personnel in the operating room. The present study aims to compare the one-day with the two-day protocol to see which one is associated with a lower radiation hazard while giving similar results. There were 60 patients recruited; half of them had the SLN biopsy 4 hours after the injection and the other half 24 hours later. Patient characteristics were comparable in both groups. The mean numbers of SLNs found per patient were 1.46 and 1.96 respectively. There was a statistically significant difference in the dosage of radioactivity present in the resected specimen between both groups of patients. However, there were still a number of confounding factors, so the proposed hypothesis of getting less radiation exposure to the medical personnel by using a two-day approach should be further investigated.

Breast Neoplasms↗

PubMed2004

Susceptibility of the human pathogenic fungi Cryptococcus neoformans and Histoplasma capsulatum to gamma-radiation versus radioimmunotherapy with alpha- and beta-emitting radioisotopes.

UNLABELLED: Fungal diseases are difficult to treat in immunosuppressed patients and, consequently, new approaches to therapy are urgently needed. One novel strategy is to use radioimmunotherapy (RIT) with fungal-binding monoclonal antibodies (mAbs) labeled with radionuclides. However, many fungi manifest extreme resistance to gamma-radiation, such that the doses of several thousand gray are required for 90% cell killing, whereas for mammalian cells the lethal dose is only a few gray. We compared the susceptibility of human pathogenic fungi Cryptococcus neoformans (CN) and Histoplasma capsulatum (HC) to external gamma-radiation and to the organism-specific mAbs 18B7 and 9C7, respectively, conjugated to (213)Bi and (188)Re radionuclides. METHODS: CN and HC cells were irradiated with up to 8,000 Gy ((137)Cs source, 30 Gy/min). RIT of CN with (213)Bi- and (188)Re-labeled specific mAb and of HC with (188)Re-labeled specific mAb used 0-1.2 MBq per 10(5) microbial cells. After irradiation or RIT, the cells were plated for colony-forming units (CFUs). Cellular dosimetry calculations were performed, and the pathway of cell death after irradiation was evaluated by flow cytometry. RESULTS: Both CN and HC proved to be extremely resistant to gamma-radiation such that significant killing was observed only for doses of >4,000 Gy. In contrast, these cells were much more susceptible to killing by radiation delivered with a specific mAb, such that a 2-logarithm reduction in colony numbers was achieved by incubating them with (213)Bi- and (188)Re-labeled mAb 18B7 or with (188)Re-9C7 mAb. Dosimetry calculations showed that RIT was approximately 1,000-fold more efficient in killing CN and approximately 100-fold more efficient in killing HC than gamma-radiation. Both gamma-radiation and RIT caused cell death via an apoptotic-like pathway with a higher percentage of apoptosis observed in RIT-treated cells. CONCLUSION: Conjugating a radioactive isotope to a fungal-specific antibody converted an immunoglobulin with no antifungal activity into a microbicidal molecule. RIT of fungal cells using specific antibodies labeled with alpha- and beta-emitting radioisotopes was significantly more efficient in killing CN and HC than gamma-radiation when based on the mean absorbed dose to the cell. These results strongly support the concept of using RIT as an antimicrobial modality.

Antibodies, Monoclonal↗

PubMed1975

A radioisotopic assay for proline oxidase activity.

We developed a radioisotopic assay for proline oxidase in which product deltal-pyrroline-5-carboxylate-14-C is reacted with o-aminobenzaldehyde and the radioactivity trapped as the dihydroquinazolinium compound is recovered by ion-exchange chromatography. The sensitivity of this method allows the measurement of proline oxidase activity in small specimens (10 to 20 mg.) of liver.

Amines↗

PubMed1992

[Radioisotope therapy of malignant pheochromocytoma with iodine-131 metaiodobenzylguanidine--absorbed dose assessments using SPECT].

The correlation of absorbed doses D (rad) of tumors in 4 patients with malignant pheochromocytoma, who were treated by 131I-MIBG (3.7 GBq), with their clinical courses were analyzed and the clinical significance of determination of absorbed dose was discussed. Absorbed doses of 131I-MIBG in the tumors were measured by using SPECT at the time of therapy. Absorbed dose was calculated based on the MIRD (medical internal radiation dose committee) equation. Tumor volumes were ranged from 17 g-100 g (mean 40 g), effective half lives were ranged from 1.3 days-5.9 days (mean 3.6 days), and tumor absorbed doses were varied between 5.4 Gy-68 Gy (mean 40 Gy). When the absorbed doses of the tumor exceeded over 40 Gy, good clinical responses were obtained. The initial treatment seemed to be important for 131I-MIBG therapy, since the absorbed doses in the following therapy became reduced. These results indicate that the quantitative SPECT for radioisotope therapy is clinically valid and that the calculated absorbed doses correlate well with clinical responses.

3-Iodobenzylguanidine↗

PubMedDate not supplied

[Radioisotopes for the evaluation of pulmonary capillary permeability in ARDS].

The dysfunction of pulmonary capillary represents the marker of Acute Respiratory Distress Syndrome (ARDS). Each current mean of investigation in ARDS (radiography, CT, ultrasonography, double dilution technique, electric impedance, bronchoscopy) has its downfalls and has not succeeded in becoming a gold standard in evaluation of this pathology. The development of any treatment is hampered by the lack of a rapid and objective method of evaluation of the progress of the disease. The radioisotopic evaluation of pulmonary capillary permeability realizes a picture of a physiologic process blood-interstitial exchange at pulmonary level. The most recent studies appear to suggest that this method of investigation can objectively evaluate and be a predictive parameter for ARDS evolution. We will present the principle of the radio-isotopic method and some of its current clinical applications.

Capillary Permeability↗