RESUMO
OBJECTIVE: The aim of this study was to evaluate angular, spatial, and energy resolution, sensitivity, and shielding of a gamma-probe. MATERIALS AND METHODS: The EUROPROBE II gamma-probe (EuroRad) with sources of technetium-99m was assessed according to NEMA NU-3-2004. Resolution tests were evaluated considering the full width at half maximum (FWHM). The following parameters were evaluated: angular resolution in air, spatial resolution with a scattering medium and in air, energy resolution, and sensitivity and shielding. The collimator was used to evaluate angular and spatial resolution, sensitivity, and shielding. Background radiation was considered and did not affect the counts. RESULTS: FWHM of angular resolution (at 3/30 cm) was 39.17°/33.13° with the collimator and 74.08°/71.51° without the collimator; FWHM of spatial resolution in air at 10 mm was 13.32 mm with the collimator and 21.23 mm without the collimator. Energy resolution (%FWHM) was 20.51%. Sensitivity at 10 mm was 4.642±5 cps/MBq without the collimator and 1.063±2 cps/MBq with the collimator; shielding effectiveness of the probe tip was 99.52%. Background was not relevant to the counts. CONCLUSION: We showed that the collimator improved angular and spatial resolution to the detriment of sensitivity. Feasible results of energy resolution, sensitivity, and shielding were achieved.
Assuntos
Raios gama , Proteção Radiológica , Biópsia de Linfonodo Sentinela/instrumentação , Raios gama/efeitos adversos , Biópsia de Linfonodo Sentinela/efeitos adversos , Tecnécio/efeitos adversosRESUMO
INTRODUCTION: There is a considerable body of evidence describing that the pharmacokinetics and pharmacodynamics of radiopharmaceuticals may be changed by a variety of drugs, disease states and in some cases, surgical procedures. OBJECTIVE: : To systematically search the medical literature and review the published evidence on adverse reactions to radiopharmaceuticals. METHOD: MEDLINE, EMBASE, International Pharmaceutical Abstracts and Science Citation Index were searched for studies reporting adverse reactions to radiopharmaceuticals. Controlled trials, cohort studies, case-control studies and case series published in major Western languages were considered for the review. Each study included in the present review was described in a narrative way, and major components of each study were reported (ie, research design, patient characteristics, types of drugs and radiopharmaceuticals, dosing information and adverse reactions). RESULTS: The majority of adverse reactions to radiopharmaceuticals described in the literature required little or no treatment, and their negative effects were generally mild and self-limited. Large longitudinal greater than 5-year studies reported prevalence rates of adverse reactions due to radiopharmaceuticals ranging from 0 to 25 cases per 100,000 administrations. Case studies on the use of technetium reported mild adverse reactions; however, some led to potentially harmful complications. Similarly, studies involving fluorodeoxyglucose reported more severe adverse reactions. CONCLUSION: The literature on radiopharmaceuticals adverse effects is scarce, and just a few studies were conducted to investigate the association between radiopharmaceuticals and adverse reactions. Despite relatively mild and self-limited symptoms, the current widespread use of radiopharmaceuticals requires constant monitoring for adverse reactions.
Assuntos
Fluordesoxiglucose F18/efeitos adversos , Compostos Radiofarmacêuticos/efeitos adversos , Neoplasias da Mama/diagnóstico por imagem , Estudos de Casos e Controles , Ensaios Clínicos como Assunto , Estudos de Coortes , Reações Falso-Positivas , Feminino , Humanos , Estudos Longitudinais , Pessoa de Meia-Idade , Estudos Prospectivos , Cintilografia , Estudos Retrospectivos , Inquéritos e Questionários , Tecnécio/efeitos adversosRESUMO
Radiopharmaceuticals are used in nuclear medicine for diagnostic and therapeutic purposes. Many adverse reactions and false positive reactions related to radiopharmaceuticals take place every day in hospitals, but most of them are not reported. It is therefore important to understand the definition of each undesirable reaction. Adverse reactions are defined as any noxious or unintended reactions to a drug, which is administered in standard doses through the proper route for the purpose of prophylaxis, diagnosis, or treatment. False positive reactions can be defined as any imaging appearance caused by undue physiological or pathological accumulation of radiopharmaceuticals. Information concerning these undesirable reactions is limited for radiopharmaceuticals. The present study intends to be a source of information that could be accessed by all nuclear medicine staff. A review of the literature from 1957 to January 2009 was carried out using the criteria of a systematic review, established by the Cochrane Collaboration, an international non-profit organization, that provides up-to-date information about the health care. The present study has revealed that radiopharmaceuticals cause adverse reactions. Six cases of adverse reactions with radiopharmaceuticals were found: 2 cases with (18)F-fluorodeoxyglucose (FDG) and 4 cases with technetium 99m ((99m)Tc). Among the 4 cases of adverse reactions with (99m)Tc, one subject who received (99m)Tc-labeled sestamibi developed anaphylactic reactions. Moreover, a total of 8 cases with false positive reactions were found with FDG. In conclusion, a worldwide effort should be made to report as many cases as possible of adverse events and false positive reactions with radiopharmaceuticals.
Assuntos
Medicina Nuclear/métodos , Compostos Radiofarmacêuticos/efeitos adversos , Reações Falso-Positivas , Fluordesoxiglucose F18/efeitos adversos , Humanos , Tecnécio/efeitos adversosRESUMO
Stannous chloride (SnCl2) is employed as a reducing agent to obtain Technetium-99m-labelled radiophamaceuticals in nuclear medicine kits, being injected endovenously in humans. Toxic effects of these kits were not studied, thus making it important to evaluate their impact in humans. In this study, the toxic effects were evaluated from peripheral blood nuclear cells (PBNC) from patients who received radiopharmaceuticals obtained using such kits. The analyses included results performed by comet assay. DNA damage was visualized in PBNC samples collected within a time up to 2 hr, and 24 hr after radiopharmaceutical injection in the patients. Initially we observed an increase of comet signals, which subsequently were reduced to zero after 24 hr. The diminishing of comet amounts probably is associated with DNA repair of damaged cells or with the elimination by apoptosis of cells whose DNA are not repaired.
Assuntos
Dano ao DNA , Leucócitos/efeitos da radiação , Compostos Radiofarmacêuticos/efeitos adversos , Apoptose/efeitos da radiação , Ensaio Cometa , Reparo do DNA , Humanos , Leucócitos/metabolismo , Leucócitos/patologia , Tecnécio/efeitos adversos , Compostos de Estanho/efeitos adversosRESUMO
Ior egf/r3, a neutralizing monoclonal antibody (mAb) against Epidermal Growth Factor Receptor (EGFR) was generated at the Cuban Institute of Oncology. Immunoscintigraphic studies in 148 patients with this 99-m Technetium (99Tc) labeled mAb, showed a high sensitivity and specificity for in vivo detection of epithelial tumors. To study safety, pharmacokinetic and immunogenicity of ior egf/r3 at high doses, a phase I clinical trial was conducted. Nineteen patients with advanced epithelial tumors received 4 mAb intravenous infusions at 6 dose levels: from 50 to 500 mg. Previously, immunoscintigraphic images using the same mAb labeled with 99Tc were acquired. Blood samples were collected for pharmacokinetic analysis and HAMA response. After mAb therapy, objective response was classified according to WHO criteria. Ior egf/r3 was well tolerated in spite of the high-administered doses. Only a severe adverse reaction consisting of hypotension and lethargy was observed. In 13 patients, selective accumulation of 99Tc-labeled mAb was observed at the site of the primary tumor or the metastasis. Pharmacokinetic analysis revealed that elimination half-life and the area under the time-concentration curve increased linearly with dose. HAMA response was detected in 17 patients. After 6 months of mAb therapy, 4 patients had stable disease. One patient had a tumor partial remission after 3 cycles of ior egf/r3.
Assuntos
Anticorpos Monoclonais , Anticorpos Antineoplásicos , Carcinoma/diagnóstico por imagem , Receptores ErbB/imunologia , Proteínas de Neoplasias/imunologia , Neoplasias/diagnóstico por imagem , Radioimunodetecção , Compostos Radiofarmacêuticos , Tecnécio , Adulto , Idoso , Animais , Anticorpos Anti-Idiotípicos/biossíntese , Anticorpos Heterófilos/biossíntese , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacocinética , Anticorpos Monoclonais/uso terapêutico , Anticorpos Antineoplásicos/efeitos adversos , Anticorpos Antineoplásicos/imunologia , Anticorpos Antineoplásicos/uso terapêutico , Especificidade de Anticorpos , Carcinoma/radioterapia , Carcinoma/terapia , Estudos de Coortes , Terapia Combinada , Ensaio de Imunoadsorção Enzimática , Feminino , Febre/induzido quimicamente , Seguimentos , Meia-Vida , Humanos , Hipotensão/induzido quimicamente , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/terapia , Masculino , Camundongos , Pessoa de Meia-Idade , Neoplasias/radioterapia , Neoplasias/terapia , Testes de Neutralização , Radioimunoterapia , Compostos Radiofarmacêuticos/efeitos adversos , Compostos Radiofarmacêuticos/farmacocinética , Compostos Radiofarmacêuticos/uso terapêutico , Segurança , Especificidade da Espécie , Tecnécio/efeitos adversos , Tecnécio/farmacocinética , Tecnécio/uso terapêutico , Distribuição TecidualRESUMO
En este trabajo se analizó la frecuencia de aberraciones cromosómicas y de intercambios de cromátides hermanas (ICH) en los linfocitos de 10 niños expuestos a una dosis diagnóstica de Tc 99mm-DTPA para una gammagrafía cerebral. La frecuencia de aberraciones cromosómicas fue de 0.015 antes del estudio y de 0.010 después de la radiación. La frecuencia de ICH fue de 7.3 antes y 7.1 después de la gammagrafía. Estos resultados sugieren que este procedimiento diagnóstico que implica una sola dosis de radiaciones gamma no induce daño cromosómico