Role of the clinical radiopharmacist in patient safety during myocardial perfusion imaging with vasodilator stress agents.

AIM: To assess the radiopharmacist's role in a multidisciplinary team focused on the contraindications of regadenoson in order to ensure the safe use of pharmacologic vasodilator stress agents in patients undergoing SPECT-MPI. METHODS: We ambispectively studied its safe use in 1905 patients (54.1% female, mean age: 66.6±11.7 years, range: 20-95 years). Sex, age, medical history, medications, drug allergies, and contraindications for stress testing were registered together with recommendations for the nuclear physician in charge. RESULTS: Detected contraindications and corresponding recommendations were as follows: risk factors for QTc interval prolongation 7.5% - measurement of QTc interval previously to test and monitor ECG; prior stroke or TIA 4.2% - consider carotid stenosis assessment; salicylates/sulfonamides allergy 3.1% - use 99mTc-sestamibi; epilepsy or risk factors for seizures 2.4% - use of adenosine or reconsider test indication; systemic corticosteroid therapy for severe COPD 1.3% - reassessment of patient's condition; acute exacerbation of COPD 0.8% - defer test until acute episode is over; severe asthma 0.4% - do not perform test; methylxanthine ingestion 0.3% - avoid consumption previously; other 6.1% - evaluation of other contraindications. No contraindications were detected in 73.6% of patients. The test was canceled due to absolute contraindications in 2.9% of the requests. CONCLUSIONS: Working in a systematic way, the radiopharmacist was able to detect a high number of issues related to regadenoson, with one out of four patients presenting some clinical contraindication. The recommendations given by the radiopharmacist were well accepted by the nuclear physicians who changed their approach contributing to increase the safety of patients referred for MPI.

Change of the melanocortin system caused by bilateral subthalamic nucleus stimulation in Parkinson's disease.

OBJECTIVES - Determine whether bilateral subthalamic nucleus stimulation (STN-DBS) in Parkinson's disease (PD) is associated with an increase in neuropeptide Y (NPY) and/or resistance to inhibition by leptin in relation to post-surgery weight gain. MATERIALS AND METHODS - This prospective study included 20 patients who underwent bilateral STN-DBS and 17 who refused surgery. Data were obtained at baseline, 3 and 6 months on neurological and nutritional status, including determination of body mass index (BMI) and serum NPY and leptin levels. RESULTS - NPY and leptin levels changed over time, with a distinct pattern. The BMI increase at 6 months was greater in the surgical group (5.5 ± 6.3% vs 0.5 ± 3.5%; P = 0.035). Medical group exhibited a reduction in leptin level (-2.0 ± 4.3 ng/ml) and a consequent increase in NPY level (72.4 ± 58.7 pmol/ml). However, STN-DBS patients showed an increase in leptin (3.1 ± 5.0 ng/ml; P = 0.001 vs medical group) and also in NPY (12.1 ± 53.6 pmol/ml; P = 0.022 vs medical group) levels, which suggests resistance to inhibition by leptin. Rise in NPY level correlated with higher stimulation voltages. CONCLUSIONS - Bilateral STN-DBS causes disruption of the melanocortin system, probably related to diffusion of the electric current to the hypothalamus. This mechanism may in part explain the weight gain of patients with PD after surgery.

[PET/CT: focal lung uptake of 18F-fluorodeoxyglucose on PET but no structural alterations on CT]. / PET-TAC: captación pulmonar focal de FDG sin alteracion estructural en TAC.

The combination of positron emission tomography (PET) and computed tomography (CT) in a single device (PET/CT) offers a powerful diagnostic tool that opens up new horizons for imaging diagnosis. In order to correctly interpret PET/CT studies, knowledge of the biodistribution of 18F-fluorodeoxyglucose (FDG), the physiological variants as well as the pitfalls, including artefacts, which may be found, is necessary. We report four cases performed during the follow-up diagnostic context of an oncology study performed with 18F-FDG-PET/CT. In every case, this study showed focal uptake in the lung parenchyma in the PET study with no structural lesions being found on the CT scan. Radiotracer extravasation in three of these patients and a recent change in the injection protocol used suggest that an artefact was responsible for these discrepancies.

BNCT research activities at the Granada group and the project NeMeSis: Neutrons for medicine and sciences, towards an accelerator-based facility for new BNCT therapies, medical isotope production and other scientific neutron applications.

The Granada group in BNCT research is currently performing studies on: nuclear and radiobiological data for BNCT, new boron compounds and a new design for a neutron source for BNCT and other applications, including the production of medical radioisotopes. All these activities are described in this report.

Development of a positron emission tomography risks map. / Desarrollo de un mapa de riesgos para la tomografía por emisión de positrones.

Patient safety is an essential component of quality of care, especially when the complexity of care has reached extreme levels. Currently achieving this safety is considered a basic strategy of the National Health System. Nuclear Medicine departments have certain peculiarities that make them special in terms of patient safety, with situations that go beyond the common healthcare practice of other departments. Namely, that both encapsulated and non-encapsulated ionizing radiation is used in daily practice, and numerous groups of professionals must be coordinated to undertake positron emission tomography (PET) specifically, from the clinical management unit itself, and from other departments of the hospital (as well as companies outside the hospital itself and the Public Health System). The objective of this paper was to identify the risks to which a patient who is to be explored through PET can be exposed in a Nuclear Medicine department and draw up a risk map for the PET process. The methodology used is part of the proposal of the Ministry of Health (2007), and its practical implementation (given the limited literature available on Nuclear Medicine), follows as far as possible that of related care areas (radiodiagnosis and radiotherapy). For this purpose, a multidisciplinary team of professionals directly related to the PET process was created, using the modal analysis of faults and effects methodology to identify possible failures, their causes and the potential adverse events causing each. As a final step, a risk map was created, locating the previously identified faults at each stage of the process. This paper exposes the PET process, and describes the risks that patients might run when a PET scan is required, as well as the adverse events deriving from it. All this is shown in a risk map of the PET process.

Utility of fluorine-18-fluorodeoxyglucose positron emission tomography in differentiated thyroid carcinoma with negative radioiodine scans and elevated serum thyroglobulin levels.

BACKGROUND: This study aimed to determine the role of fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) in the follow-up of patients who underwent total thyroidectomy and iodine-131 ((131)I) ablation therapy for differentiated thyroid cancer and presented increased thyroglobulin levels with negative (131)I and thallium-201 ((201)Tl) scans. METHODS: Two patients with follicular carcinoma and eight with papillary tumors underwent total thyroidectomy and (131)I therapy until the (131)I scan was negative. (131)I and (201)Tl scans were performed with negative results in all cases, while serum thyroglobulin measurements were all positive with negative thyroglobulin autoantibodies. One week after the (131)I scans, all the patients underwent FDG-PET whole-body scans. RESULTS: The FDG-PET scan detected in 4 patients, a single focal increase of FDG uptake in one lymph node metastasis (subsequently confirmed histologically); in 1 patient, multiple pathological focal uptakes in brain, neck, and chest; and in 1 patient, two mild focal uptakes in the mediastinum, close to the tracheal branch. In 2 other patients, pathological FDG uptakes in cervical spine and mediastinum were not confirmed by other imaging techniques, and in the 2 remaining patients the scan results were inconclusive. The sensitivity of FDG-PET whole-body scan for detecting metastatic thyroid cancer was 60%. CONCLUSIONS: This study indicates that the FDG-PET whole-body scan is a useful tool in the follow-up of patients with differentiated thyroid cancer, negative (131)I and (201)Tl scans and elevated serum thyroglobulin levels. The FDG-PET scan detects metastatic disease in 60% of patients with differentiated thyroid cancer, enabling surgical therapy to be performed on accessible lesions.

Hormonal response to surgical stress in schoolchildren.

PURPOSE: To determine hormone concentrations (ACTH, cortisol, beta-endorphin) in children before and after surgery, to assess the correlation between any hormonal changes and to study the influence exercised on them by the severity of surgical stress and the elective/emergency nature of the surgery. PATIENTS AND METHODS: Prospective cohort of 78 children (age= 10+/-2.6 years, range 6-13 years) undergoing elective or emergency surgery. Preoperative and postoperative (1 and 24 hours postoperation) plasma concentrations of ACTH, cortisol and beta-endorphin were determined in all children. The severity of surgical stress was evaluated as low (< 6) or high (> 6) according to the Oxford scale. Student's t-test was used to analyse hormonal changes and the influence of degree of surgical stress and elective/emergency character of the surgery, and Pearson's coefficient for correlations between hormonal values. p < 0.05 was regarded as significant. RESULTS: We observed a significant increase in hormonal concentrations one hour after surgery. ACTH and cortisol values normalised 24 hours after surgery, but beta-endorphin concentrations remained increased. There was a correlation between ACTH and beta-endorphin values both before surgery and one hour after. Operations with high surgical stress significantly increased cortisol concentrations one hour after surgery and beta-endorphin concentrations 24 hours after surgery. Patients selected for emergency surgery showed significantly higher concentrations of cortisol and ACTH both before and after surgery. CONCLUSIONS: Postoperative hormonal response among children of school age is characterised by increases in ACTH, cortisol and beta-endorphin one hour after surgery, and by high concentrations of beta-endorphin 24 hours after surgery. Cortisol is an index of surgical stress. Emergency surgery is associated with significant increases in ACTH and cortisol.

[Diagnosis of renovascular hypertension by pre- and post-captopril renal scintigraphy with 99mTc-DMSA]. / Diagnóstico de hipertensión vasculorrenal mediante gammagrafía renal con 99mTe-DMSA pre y postcaptopril.

AIM: Value the utility of studies with 99mTc-DMSA with captopril (scintigraphy imaging and unilateral renal function) in identifying renovascular disease or renal disease in hypertension patients with high probability of renovascular hypertension. METHODS: We studied 27 hypertension patients (12 males, 15 females) mean age 49 years, SD: 9.46, with high probability of renovascular disease. General analysis and radiology was made to all of them including renal arteriography as gold standard. Two renal scintigraphies with 99mTc-DMSA were made to all of them, baseline study and one hour after administration of 50 mg of captopril, a week between both studies. Renal scintigraphy (anterior and posterior images) was obtained 4 hours after the administration of 111 MBq (3 mCi) of 99mTc-DMSA and results were evaluated quantitatively and qualitatively calculating unilateral renal function. We considered positive for renovascular hypertension studies with decrease of more than five percentual points in unilateral renal function or a new defect absent in baseline study. Scintigraphic results were compared with arteriography to determine sensitivity, specificity and predictive values. RESULTS: Arteriography demonstrated significant renal artery stenosis in 18.5% of patients. Renal scintigraphy with captopril using 99mTc-DMSA demonstrated sensitivity of 60%, specificity of 91%, positive predictive value of 60% and negative predictive value of 91%. We identified 3 patients with segmental defects of uptake consistent with chronic pyelonephritis scarring. CONCLUSIONS: Studies with 99mTc-DMSA using captopril present high specificity and are useful in patients with high probability for renovascular hypertension, identifying high number of patients with significant renal artery stenosis. The utility of DMSA in identify renal abnormalities, as specially pyelonephritis scarring, add value to renal studies with captopril using others tracers. DMSA could identify renal etiologies of renovascular hypertension different to renal artery stenosis.

[Quality control dose calibrators]. / Control de calidad de activímetros.

We have reviewed the legislation about the quality control of dose calibrator. The importance of verifying the correct work of these instruments, is fundamental in daily practice of radiopharmacy and nuclear medicine. The Spanish legislation establishes to include these controls as part of the quality control of radiopharmaceuticals, and the program of quality assurance in nuclear medicine. We have reviewed guides and protocols from international eminent organizations, summarizing the recommended tests and periodicity of them.

[Surgical stress and hypophyseal-adrenal activation in childhood]. / Estrés quirúrgico y activación hipófiso-suprarrenal en edad pediátrica.

INTRODUCTION: The study on the physiological alterations due to surgical aggression (surgical stress), widely investigated in adults, is less known in paediatric age. THE OBJECTIVE: Of this work is to quantify surgical stress (evaluated by means of Oxford Scale as high or low depending on its value bigger or lower than 6), after determining changes of plasmatic concentrations of ACTH, beta-endorphin and cortisol in operated children. PATIENTS AND METHODS: Observational analytic design of a prospective cohort with internal comparison of the groups. SAMPLE SIZE: 33 (age 10 +/- 2.6 years; range 5 to 14 years). DEPENDENT VARIABLES: plasmatic concentrations of ACTH, beta-endorphin and cortisol determined before and after the intervention (1 and 24 hours after surgery), by radio-immune-analysis. RESULTS: Significative increase of the three considered hormones one hour after surgery, with decrease of them until preoperative levels 24 hours later. Significative correlation between beta-endorphin (24 hours after surgery), cortisol (1 hour after surgery) and surgical stress levels. CONCLUSIONS: Surgery in children provokes the activation of hipophysal-suprarrenal system. These levels early came back to normal ones, 24 hours after surgery. There is a specific change in beta-endorphin, that is why it is possible to assure that beta-endorphin is a "stress-hormone", since it is affected by surgical aggression. Cortisol seems to be a good index of level of surgical stress.