Quality control of 188W/188re generators

Quality control of 188W/188Re generators from two different manufacturers and two levels of activity each, was carried out.Elution yields, chemical as well as radionuclidic and radiochemical purities, elution profiles along six months, were evaluated.Broad elution profile, high efficiency, with tandem alumina column added, ionic exchange column needed for increase of radionuclidic concentration were characteristics of type I generators.Easy handling with slightly lower yields and high concentrations of activity were observed in type II generators. Similar radionuclidic impurities namely 192Ir, 191Os, 188W, 110mAg, 54Mn, 134Cs and 60Co as well as similar radiochemical yields obtained in the labelling of 188 Re-HEDP were observed with eluates of both generator types.Absorbed doses to radiopharmacy staff were less important in type II generators.

Predictive value of (99m)Tc sestamibi scintigraphy in the evaluation of doxorubicin based chemotherapy response in patients with advanced breast cancer.

Resistance to doxorubicin based chemotherapy is a major therapeutic problem limiting advanced breast cancer treatment. 99mTc hexakis-2-methoxyisobutylisonitrile ((99m)Tc-MIBI) has been reported to be extruded from tumour cells by the P-glycoprotein and multidrug resistance protein encoded by MDR1 and MRP1 genes, respectively. These proteins are involved in the cellular efflux of several chemotherapeutic agents including doxorubicin. The aim of this study was to investigate the clinical value of a standard (99m)Tc-MIBI scintimammography technique in the prediction of response to chemotherapy in advanced breast cancer patients. Fifty-six lesions from 33 female patients with locally advanced (n=27) or recurrent breast cancer (n=6) were included in the study. MIBI scintigraphy was performed 2-8 days prior to chemotherapy (FAC regimen). Images were acquired 10 min and 1 h post-injection of 740-1110 MBq of (99m)Tc-MIBI. Tumour-to-normal background tissue uptake ratios were calculated on each lesion in the early (T/B(e)) and delayed phase of the study (T/B(d)). Both T/B(e) and T/B(d) ratios were significantly higher (P<0.0001) in responders (n=43) than nonresponders (n=13). Diagnostic values of (99m)Tc-MIBI in the prediction of chemotherapy response were evaluated using the arbitrary cut-off values of 1.5 for T/B(e) and 1.4 forT/B(d). Sensitivity, specificity, positive and negative predictive values were 88.4%, 92.3%, 97.4%, 70.6%; and 90.7%, 100.0%, 100.0%, 76.6%, for T/B(e) and T/B(d), respectively. We conclude that (99m)Tc-MIBI scintigraphy may be a clinically valuable tool for guiding chemotherapy in advanced breast cancer patients.

Reactor-produced radioisotopes from ORNL for bone pain palliation.

The treatment of painful skeletal metastases is a common clinical problem, and the use of therapeutic radionuclides which localize at metastatic sites has been found to be an effective method for treatment of pain, especially for multiple sites for which the use of external beam irradiation is impractical. There are currently several metastatic-targeted agents radiolabeled with various therapeutic radionuclides which are in various stages of clinical investigation. Since neutron-rich radionuclides are produced in research reactors and often decay by emission of beta- particles, most radionuclides used for bone pain palliation are reactor-produced. Key examples of radionuclides produced by single neutron capture of enriched targets include rhenium-186 and samarium-153. In addition, generator systems are also of interest which provide therapeutic daughter radionuclides from the decay of reactor-produced parent radionuclides. One important example is rhenium-188, available from generators via decay of reactor-produced tungsten-188. Tin-117m is an example of a reactor-produced radionuclide which decays with the emission of low-energy conversion electrons rather than by beta- decay. Each of these agents and/or radionuclides has specific advantages and disadvantages, however, the ideal agent for bone pain palliation has not yet been identified. The goal of this paper is to briefly review the production and use of several reactor-produced radionuclides for bone pain palliation, and to discuss the role of the ORNL High Flux Isotope Reactor (HFIR) for the production of many of these radionuclides.

Depression as an explanation for decreased subjective time in the elderly.

This study focuses on the occurrence of depression in the elderly as an explanation for conflicting findings regarding subjective time in this age group. Subjects were volunteers from a congregate meal program in central Pennsylvania. The sample (N = 68) was restricted to women over 65 years of age. Depression was measured by the Beck Depression Inventory. Subjective time was determined by having the subject give a production estimate of an interval of 40 seconds. Analysis of data, which showed a correlation coefficient of 0.35 (p less than .002) between depression and subjective time, supports the hypothesis that depression is related to decreased subjective time. The finding provides a tentative explanation for deviations from the demonstrated trend toward increased subjective time with aging.

[Clinical trial of tiapride in patients with dyskinesia (author's transl)]. / Traitement des dyskinésies par le tiapride.

Twenty-five patients with various forms of dyskinesia were given tiapride for three months. Maximal dosage was 900 mg per day. A double-blind trial of tiapride versus placebo showed significantly better results in the group given tiapride. The forms of dyskinesia which responded best to tiapride were the following: iatrogenic dyskinesia, tics (Gilles de la Tourette syndrome), and chronic chorea (Huntington disease). Patients with complex dyskinesia resulting from neonatal encephalopathy or vascular disease were not improved. The protocol used in l-dopa-induced dyskinesia is described. Changes in dyskinesia and "on-off" effect following variations in tiapride and l-dopa dosage are detailed. An unequivocal, although minor, tiapride-induced parkinson syndrome was recorded in a few patients. No instances of tiapride-induced dyskinesia or akathisia were seen. The other side-effects were either psychic (depression, drowsiness, agitation) or endocrinologic (menstrual disorders, overeating, galactorrhea).

Prognosis of epilepsy. Remission of seizures and relapse in 808 adult patients.

In a retrospective study of 808 adult epileptic patients undertaken at the Neurological Institute of Montevideo, Uruguay, the rate of remission of seizures (three seizure-free years) was 32%, and that of relapse 39%. Remission occurred mostly during the first years after onset, and relapse during the first years after remission. Patients with generalized or partial seizures alone had a better prognosis than when both types coexisted. Patients with Petit Mal absences persisting after 14 years of age, had the lowest rate of remission. Mental status, abnormal neurological examination and age of onset showed no significant prognosis value. Remission and relapse was similar in cryptogenetic and symptomatic epilepsy. Genetic predisposition did not change the prognosis. Withdrawal of drugs after a minimal seizure-free period of three years produced a higher rate of relapse than when medication was continued. In the first EEG, only the existence of a slow background rhythm had an unfavorable prognosis. These results are compared with those of other series. It is concluded that the differing results can be attributed to a different selection of population and different methods of study. Anyway, several factors showed a similar influence on prognosis in the different series. As to indication for method of drug withdrawal after remission, and its influence on relapse, no definite conclusion can be drawn and a large, multicentric, methodical study on this topic is suggested.

Procedimientos diagnosticos en cirugia hepato-biliar. (164 refs). / Diagnostic procedures in hepato-biliary surgery

Esta Mesa Redonda analizo algunos de los procedimientos diagnosticos en Cirugia Hepato-biliar referidos fundamentalmente a 2 situaciones: el paciente icterico y el higado nodular. La indicacion de cada uno de estos procedimientos se adecuara en primer lugar al problema clinico en cuestion y a las posibilidades terapeuticas del paciente y en segundo lugar y con un criterio racional y economico a: 1) grado de sensibilidad y especificidad; 2) riesgos (procedimientos invasivos y no invasivos); 3) disponibilidad; 4) limitaciones fisicas del examen: 5) contraindicaciones; 6) experiencia; 7) costos. En el paciente icterico la clinica y el laboratorio son de gran orientacion. Luego de ellos, si la ecografia muestra dilatacion de la V.B.P.se considerara al paciente quirurgico; en casos de duda o si se desean otras pautas diagnosticas, como altura y naturaleza del obstaculo se continuara con otros examenes tales, como la colangiografia endoscopica retrograda En el higado nudular,luego de la clinica y el laboratorio, el gamagrama orientara hacia el boratorio, el gamagrama orientara hacia el nodulo unico o multiple. En el primer caso la ecografia diferenciara entre lo quistico y lo solido siendo de indicacion en este ultimo caso la arteriografia selectiva. Frente a nodulos multiples el esquema es semejante, destacando el valor de la laparoscopia y biopsia en los nodulos solidos detectados por la ecografia

Colecentellografia: comunicacion preliminar sobre 50 observaciones. / Cholescintigraphy: preliminary communication of 50 observations

Se presenta un nuevo procedimiento incruento para la exploracion morfologica y funcional de la via biliar. El metodo esta basado en la administracion de compuestos marcados con 99m Tc (99mTc P G y 99mTc-HIDA) que son depurados de la sangre por el hepatocito y excretados conjuntamente con la bilis. El transito del radiofarmaco permite obtener imagenes secuenciales del relleno de la via biliar principal y accesoria, poniendo en evidencia la existencia o no, de pasaje de bilis al intestino.En la serie de pacientes estudiados fue posible observar alteraciones funcionales expresadas por el retraso de la excrecion biliar.El valor fundamental del metodo se mostro en la separacion del grupo de ictericias por obstruccion extrahepaticas, de las ictericias intrahepaticas con factor colostaticas predominante. En el grupo de las extrahepaticas se pudo evidenciar la altura de la obstruccion en relacion con la via biliar accesoria.Tambien se utilizo el procedimiento para el control de las anastomosis bilio digestivas y en el diagnostico de los cuadros agudos de origen vesicular