Preparation for radioiodine therapy: How to increase therapeutic efficacy and accelerate unbound radioiodine excretion

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Comparison of thyroglobulin concentrations measured by two immunoradiometric assay

© 2020, University of Kragujevac, Faculty of Science. All rights reserved. Circulating thyroglobulin measurements is a highly specific test in the management of patients affected by differentiated thyroid cancer after total thyroidectomy, followed by radioiodine ablation. The aim of our study was to com-pare two thyroglobulinimmunoradiometric assays (INEP, Serbia and Cisbio Bioassays, France). Study included 42 patients of both genders with DTC. The subjects were on suppres¬sive doses of levothyroxine and followed up. Results showed concordance between the two assay methods for determining serum thyroglobulin for 39 (92.85%) pa-tients. Statistical analysis showed that there was a direct correlation between two IRMA tests, with a positive correlation coefficient r=0.613 (p 0.05). We concluded that there is good agreement between the two thyroglobulin assays compared in this study

Redox Parameters in Blood of Thyroid Cancer Patients After the Radioiodine Ablation

The radioactive iodine (I-131) ablation is a well-accepted treatment modality for differentiated thyroid cancer patients. Unfortunately, the radiation induces the oxidative stress and damages cells and tissues, simultaneously activating the mechanisms of antioxidative defense. Since the mechanisms of those processes are not completely known, we wanted to examine the changes in the most important reactive oxygen species and antioxidative components, as well as their correlation and significance for lipid peroxidation. Our results showed that the level of thiobarbituric acid reactive substances was increased during the first 30 days after the radiotherapy. Among antioxidant components, superoxide dismutase was increased in the 3rd and 30th day; catalase in 7th and reduced glutathione in 3rd and 7th day after the radiotherapy. As regards the prooxidants, the reduction of hydrogen peroxide (H2O2) was recorded in 7th and 30th day, and superoxide anion radical (O-2(center dot-)) was unchanged after the exposure to I-131. These results indicate that differentiated thyroid cancer patients are under constant oxidative stress despite the observed increase in antioxidative and reduction in prooxidative parameters. The understanding of these early processes is important since their progress determines the latter effects of I-131 therapy

Diagnostic nuclear medicine in pediatric oncology-what we should know before scanning?

Cancer is second only to trauma as a cause of death in children, accounting for approximately 10% of all childhood deaths. The application of radioisotopes in the treatment of malignant diseases in children consists of detecting and estimating the degree of tumour spread by application of tumour-specific and non-specific radiopharmaceuticals, as well as the treatment of some malignant diseases. Paramount to any successful nuclear medicine examination is the establishment of acquisition protocols that allow high quality images to be obtained while ALARA principles are followed. Pediatric-specific issues should be anticipated and addressed in the planning of the studies to maximize the utility of the technique in this challenging group of patients, so the goal of this article is to summarize general prerequisites for the application of nuclear medicine diagnostic procedures in pediatric oncology patients. © 2012, Oncology Institute of Vojvodina, Sremska Kamenica

Online remote monitoring of patients with differentiated thyroid carcinomas and neuroendocrine tumors treated with high doses of radionuclides

Background: Telemedicine could be very useful for patients in remote areas experiencing adverse drug reactions or being in need of sophisticated diagnostic or therapeutic procedures. The aim of this article is to show the experience of our Department of Nuclear Medicine (DNM) in telemonitoring patients with differentiated thyroid carcinomas and neuroendocrine tumors. Subjects and Methods: The DNM at the Clinical Center Kragujevac, Serbia, uses continuous remote monitoring of patients' vital functions, including heart rate, electrocardiogram, respiration rate, blood pressure, and oxygen saturation, as well as video surveillance of the physical isolation area for patients with neuroendocrine tumors (NETs) and some patients with differentiated thyroid carcinomas (DTCs), during administration of radionuclide therapy and for the days following treatment. Results: The DNM used a telemonitoring system for 156 patients with either DTC or NET who received radionuclide therapy during the last 3 years. There were 32 interventions on patients in the physical isolation area based on changes of the patients' vital functions detected by the telemonitoring system. Twenty-five patients (78%) experienced symptoms, whereas the other seven patients (22%) were symptomless. A responsible physician intervened with treatment of tachycardia (18 cases), hypertension (10 cases), hypotension (2 cases), ventricular extrasystoles (1 case), and ST-segment depression (1 case). After administration of the treatment the health status of the patients was normalized. Conclusion: From our experience gained over the past 3 years, this model of organization and supervision with a telemonitoring system of patients receiving radionuclide therapy ensures a high level of safety for the patient, with significant reduction of staff costs. © Copyright 2012, Mary Ann Liebert, Inc

Comparison of Thyroglobulin Concentrations Measured by Two Immunoradiometric Assay

Circulating thyroglobulin measurements is a highly specific test in the management of patients affected by differentiated thyroid cancer after total thyroidectomy, followed by radioiodine ablation. The aim of our study was to compare two thyroglobulinimmunoradiometric assays (INEP, Serbia and Cisbio Bioassays, France). Study included 42 patients of both genders with DTC. The subjects were on suppres¬sive doses of levothyroxine and followed up. Results showed concordance between the two assay methods for determining serum thyroglobulin for 39 (92.85%) patients. Statistical analysis showed that there was a direct correlation between two IRMA tests, with a positive correlation coefficient r=0.613 (p 0.05). We concluded that there is good agreement between the two thyroglobulin assays compared in this study

Alarm system for surveillance of patients receiving high doses of radioiodine (¹³¹I) therapy in the case of unauthorised abandoning of a controlled area

© 2018, Vinca Inst Nuclear Sci. All rights reserved. After receiving high doses of radioiodine the patients have to remain isolated within the “restricted area”, until the radioactivity of the body drops below a certain level. The aim of this paper was to present our alarming system designed to discover patients who attempt to abandon the “restricted area” and inform medical staff about the event. The system consists of a survey-meter with a pancake probe directed towards the corridor. The survey-meter is connected to a trigger circuit which gives a signal in the case when the measured count rate exceeds a pre-set value. This signal sets “on” the alarm device, blinking light, programmable siren and IP camera, in order to warn the patient and inform the personnel when such a case occurs. In order to test the consistency and sensitivity of our system we measured ten times the ambient dose equivalent, H*(10), from the source of 925 MBq (25 mCi)131I, kept at a distance of 1 m. The average ambient dose equivalent was 77.73 ± 31.57 (0.084 μSvh–1 per MBq, or 3.1 μSvh–1 per mCi). We measured ten times the same source at various distances (1-2.25 m) from the probe. In each position, the system was triggered. Also we tested the system on 40 patients treated with radioiodine instructed to pass through the corridor. Each of their attempts triggered the system. According to our experience gained over the past few years, this alarm system intended for patients receiving radionuclide therapy ensures a high level of safety for both the patients and medical staff

Calculation of absorbed dose due to the ⁹⁰ Y-DOTATOC peptide receptor radionuclide ther apy by MCNP5/X

© 2018; Vinca Inst Nuclear Sci. All rights reserved. Strong beta emitters, like 90 Y, 177 Lu labelled peptide, are used for treatment of neuroendocrine tumours where there is a good expression of somatostatin receptors. In this work, MCNP5/X computer software and ORNL human phantoms were used lo calculate absorbed dose due to 90 Y labelled DOTATOC in the peptide receptor radionuclide therapy. Tumour was considered as a sources of beta radiation and represented as a sphere with diameter of 1-4 cm and 5 cm in liver, pancreas, and lungs. Results are expressed as absorbed dose per unit of cumulated activity, S -value in units mGy(MBq.s) -1 . The far largest dose is in tumour itself, then in organ which contains the tumour. Doses in other organs, where the metastasis are the most frequent, due lo the bremsslrahlung radiation, are much smaller and could be neglected. The largest dose, 8.66.10 -3 mGy.(MBq.s) -1 was obtained lor tumour with size of 3 cm

Clinical usefulness of^99mtc-hynic-toc and¹³¹i-mibg scintigraphy in the evaluation of adrenal tumors

© 2019, University of Kragujevac, Faculty of Science. All rights reserved. Disorders and morphological abnormalities affecting the adrenal gland, could lead to profound clinical consequences, owing to its biochemical structure-activity and morphological characteristics. The recent focus on theranostic approach has led to a need for tumors characterization and early diagnosis at the molecular level. Many radiotracers have been developed with specific imaging characteristics for the adrenal tumors, by exploiting different physiological mechanisms of uptake and metabolism. The aim of present study is to provide a prospective confirmation of131I-MIBG and99mTc-HYNIC-TOC scintigraphy, for the evaluation of patients with known or suspected tumors of the adrenal region. The research is designed as a cross-sectional observational study of the clinical correlates and diagnostic accuracy of radionuclide-based imaging methods in relation to in vitro analysis, clinical manifestations and morphological characteristics of these tumors. Furthermore, the present study also evaluates the usefulness and the clinical impact of each radiopharmaceutical for the detection and management of tumors, and functional imaging modality as well. Visual scintigraphic appearance of an increased focal tracer uptake in the suspected tumor site revealed that99mTcHYNIC-TOC is highly sensitive and reliable tumor-seeking radiotracer for adrenal tumors, but does not distinguish between adenoma and pheochromocytoma, and the existence of hormone secreting adrenocortical tumor cells. However,131IMIBG scintigraphy is highly sensitive and specific method only in differentiating catecholamine-secreting adrenal tumors. Clinical significance of this research is in the accurate localization of adrenal tumors, and is of paramount importance for an algorithmic diagnostic approach and management, and provide the rationale to different therapeutic possibilities

The opposite effects of nandrolone decanoate and exercise on anxiety levels in rats may involve alterations in hippocampal parvalbumin-positive interneurons.

The aim of this study was to evaluate the behavioral effects of chronic (six weeks) nandrolone decanoate (ND, 20 mg/kg, s.c., weekly in single dose) administration (in order to mimic heavy human abuse), and exercise (swimming protocol of 60 minutes a day, five days in a row/two days break), applied alone and simultaneously with ND, in male rats (n = 40). Also, we evaluated the effects of those protocols on hippocampal parvalbumin (PV) content and the possible connection between the alterations in certain parts of hippocampal GABAergic system and behavioral patterns. Both ND and exercise protocols induced increase in testosterone, dihydrotestosterone and estradiol blood levels. Our results confirmed anxiogenic effects of ND observed in open field (OF) test (decrease in the locomotor activity, as well as in frequency and cumulative duration in the centre zone) and in elevated plus maze (EPM) test (decrease in frequency and cumulative duration in open arms, and total exploratory activity), that were accompanied with a mild decrease in the number of PV interneurons in hippocampus. Chronic exercise protocol induced significant increase in hippocampal PV neurons (dentate gyrus and CA1 region), followed by anxiolytic-like behavioral changes, observed in both OF and EPM (increase in all estimated parameters), and in evoked beam-walking test (increase in time to cross the beam), compared to ND treated animals. The applied dose of ND was sufficient to attenuate beneficial effects of exercise in rats by means of decreased exercise-induced anxiolytic effect, as well as to reverse exercise-induced augmentation in number of PV immunoreactive neurons in hippocampus. Our results implicate the possibility that alterations in hippocampal PV interneurons (i.e. GABAergic system) may be involved in modulation of anxiety level induced by ND abuse and/or extended exercise protocols