High-energy Beta Research Articles

Birth of the Beta-knife Thyroidectomy: The Radiance of Saul Hertz.

This is the story of how one man's life's work allowed for Iodine-131 (I-131) to become a therapy for hyperthyroidism and thyroid cancer. What is now a standard in our times arose from Saul Hertz's rather challenging and humble beginnings. Thyroid lobectomy and total thyroidectomy were therapeutic mainstays for thyroid disease until Hertz treated his first patient with radioactive iodine (RAI) ablation therapy at Massachusetts General Hospital (MGH) on March 31, 1941. His concepts for using beta particle emission from RAI to ablate thyroid tissue were revolutionary. Hertz's RAI therapy translated to research with thyroid cancer by the mid-1940s. The high-energy beta particles produced cytolethal effects on remnant thyroid tissue left behind by total thyroidectomy, thereby accomplishing completion thyroidectomy in some patients. Progressive surgeons from the Hertz era incorporated RAI into their practice. MGH surgery resident Francis Moore took sabbatical from clinical training to do translational research with RAI and other radioisotopes. Irving Ariel of New York became known as a nuclear surgeon in the wake of Hertz's work. George Crile Jr of Cleveland became an RAI advocate for the surgical community, implementing several paradigm-changing concepts in thyroid disease along the way. Hertz was a visionary who sparked this movement, predicting many of the molecular dilemmas with RAI-tumor avidity that clinical researchers continue to navigate today. This timely history for surgical oncologists and endocrine surgeons traces the development of RAI therapy through the life of Saul Hertz, a biographical window influenced by social stigma, political controversy, and mainstream media.

Position sensitive plastic scintillator for beta particle detection

A new segmented plastic scintillator detector Tuike has been developed for recoil-beta tagging experiments at the Accelerator Laboratory of the University of Jyväskylä. The detector consists of individual plastic scintillator bars arranged in two orthogonal layers, and the scintillation light is detected using silicon photomultipliers. Performance of the new detector was tested using fusion-evaporation reaction 40Ca(36Ar, pn)74Rb, and the results are discussed here. It was found that for beta particles seen in the main silicon detector, Tuike can tag high-energy beta particles with a 48(10)% efficiency. An energy calibration method using Compton edges of gamma ray transitions is described in the present work. Tuike was demonstrated to improve the sensitivity to identify weak fusion-evaporation channels associated with beta decays having high beta end-point energy, enabling nuclear structure studies along the N = Z line.

Relevance of Internal Bremsstrahlung photons from 90Y decay: an experimental and Monte Carlo study.

Internal Bremsstrahlung (IB) is a continuous electromagnetic radiation accompanying beta decay; however, this process is not considered in radiation protection studies, particularly when estimating exposure from beta-decaying radionuclides. The aims of the present work are: i) to show that neglecting the IB process in Monte Carlo (MC) simulation leads to an underestimation of the energy deposited in a ionization chamber, in the case of a high-energy pure beta emitter such as Yttrium-90 (90Y), and ii) to determine the most reliable choice of source term for 90Y IB to be used in MC simulations. For this radionuclide, commonly employed in nuclear medicine and radiochemistry applications, experimental data acquired with a well ionization chamber have been compared with Monte Carlo (MC) calculations carried out in the GAMOS framework. Simulations that do not include the effect of the IB process, are found to give results underestimating the experimental values by 12-14%. Consequently, two models for the IB energy spectra, previously described by Italiano et al. [1], have been implemented using MC simulation and a good agreement has been achieved with one of them. We therefore conclude that inclusion of IB process in Monte Carlo simulation packages is advisable for a more accurate and complete treatment of electromagnetic interactions.

Scintillating fibre based beta spectrometer: Proof of concept by Monte-Carlo simulation and first experimental assessment

We developed a new beta measurement method based on scintillating fibres, able to discriminate incident beta particles based on their energy, using various cladding thicknesses, which could find useful applications in the field of nuclear decommissioning and dismantling (D&D). Indeed, thanks to Monte Carlo simulations, we found that high-energy beta particles were less affected by thicker cladding than medium-energy beta particles. Therefore, combining different cladding thicknesses and a deconvolution method, we were able to identify and quantify convoluted beta spectra in a simulated scenario. In this paper, we describe the Monte Carlo simulations combined with the deconvolution algorithm based on the Maximum Likelihood-ExpectationMaximization method (ML-EM), and the associated experimental setup. We demonstrated the feasibility of such a method, using both simulated and experimental data, by deconvoluting 36Cl and 90Sr–90Y spectra, considering 36Cl as a medium-energy beta emitter and 90Sr-90Y as a high-energy beta emitter. Using fibres with only one thickness of cladding, we found that we could not estimate both contributions correctly, with errors reaching up to 71% of the actual activities. However, using two different acquisitions of fibres each one with a different cladding thickness, we were able to estimate both contributions with an error of 26% for 36Cl and 10% for 90Sr-90Y. Study of the improvement of these performances is presented and could help to fine-tune activities estimated. The next step of this work would consist in designing a beta spectrometer, based on scintillating fibres, and assess its performances. Taking advantage of both deformability capacity of scintillating fibres and their potential lengths up to a few metres, we expect that such a detection system will be well adapted to the radiological characterization of large surfaces, and suitable for deployment on uneven surfaces.

Inositol pyrophosphates promote MYC polyubiquitination by FBW7 to regulate cell survival.

The transcription factor MYC regulates cell survival and growth, and its level is tightly controlled in normal cells. We report that serine pyrophosphorylation - a posttranslational modification triggered by inositol pyrophosphate signaling molecules - controls MYC levels via regulated protein degradation. We find that endogenous MYC is stabilized and less polyubiquitinated in cells with reduced inositol pyrophosphates. We show that the inositol pyrophosphate 5-IP7 transfers its high-energy beta phosphate moiety to pre-phosphorylated serine residues in the central PEST domain of MYC. Loss of serine pyrophosphorylation in the PEST domain lowers the extent of MYC polyubiquitination and increases its stability. Fusion to the MYC PEST domain lowers the stability of GFP, but this effect is dependent on the extent of PEST domain pyrophosphorylation. The E3 ubiquitin ligase FBW7 can bind directly to the PEST domain of MYC, and this interaction is exclusively dependent on serine pyrophosphorylation. A stabilized, pyrophosphorylation-deficient form of MYC increases cell death during growth stress in untransformed cells. Splenocytes from mice lacking IP6K1, a kinase responsible for the synthesis of 5-IP7, have higher levels of MYC, and show increased cell proliferation in response to mitogens, compared with splenocytes from wild type mice. Thus, control of MYC stability through a novel pyro-phosphodegron provides unexpected insight into the regulation of cell survival in response to environmental cues.

EXIRAD-HE: multi-pinhole high-resolution ex vivo imaging of high-energy isotopes

We recently developed a dedicated focusing multi-pinhole collimator for a stationary SPECT system that offers down to 120 µm (or 1.7 nL) spatial resolution SPECT images of cryo-cooled tissue samples (EXIRAD-3D). This collimator is suitable for imaging isotopes that are often used in small animal and diagnostic SPECT such as 125I (27 keV), 201Tl (71 keV), 99mTc (140 keV), and 111In (171 and 245 keV). The goal of the present work is to develop high-resolution pinhole imaging of tissue samples containing isotopes with high-energy photon emissions, for example, therapeutic alpha and beta emitters that co-emit high energy gammas (e.g. 213Bi (440 keV) and 131I (364 keV)) or 511 keV annihilation photons from PET isotopes. To this end, we optimise and evaluate a new high energy small-bore multi-pinhole collimator through simulations. The collimator-geometry was first optimised by simulating a Derenzo phantom scan with a biologically realistic activity concentration of 18F at two system sensitivities (0.30% and 0.60%) by varying pinhole placements. Subsequently, the wall thickness was selected based on reconstructions of a Derenzo phantom and a uniform phantom. The obtained collimators were then evaluated for 131I (364 keV), 213Bi (440 keV), 64Cu (511 keV), and 124I (511 + 603 keV) with biologically realistic activity concentrations, and also for some high activity concentrations of 18F, using digital resolution, mouse knee joint, and xenograft phantoms. Our results show that placing pinhole centres at a distance of 8 mm from the collimator inner wall yields good image quality, while a wall thickness of 43 mm resulted in sufficient shielding. The collimators offer resolutions down to 0.35 mm, 0.6 mm, 0.5 mm, 0.6 mm, and 0.5 mm when imaging 131I, 213Bi, 18F, 64Cu, and 124I, respectively, contained in tissue samples at biologically achievable activity concentrations.

Identification of 90Sr and 204Tl beta radiation sources by energy distribution with a 3GEM detector

This paper presents the performance of a 3GEM in terms of identification of high and low beta energy radiation sources through the energy distribution of the main beta radiation sources used for industrial application 90Sr and 204Tl. We compare the beta radiation theoretical energy loss into the drift zone with experimental energy distribution at different 3GEM voltages. The experimental results show that the Most Probable Value (MPV) of the fitted Landau distribution obtained from 90Sr and 204Tl obtained a degree of error lower than 14% in comparison to the theoretical calculation. Additionally, high energy beta radiation source (90Sr) is identified in comparison to low energy (204Tl) - taking into account the MPV and sigma values from the fitted Landau distribution. These results are essential to design and implement a new application that utilizes the performance and special characteristics of the 3GEM for beta radiation detection and identification.

Comparison of selected linear alkylbenzene and naphthalene solvents suitable for use in liquid scintillation cocktails

The chase of perfect solvents used in liquid scintillation cocktails practically resulted in the existence of two groups based on representatives of linear alkylbenzene group and a group of naphthalene derivatives. The objectives of this paper were to evaluate spectral and main detection parameters, including the pulse shape discrimination suitability, of Diethyl-, Propyl-, and Dodecylbenzene as representatives of linear alkyl benzene derivatives (LAB) and Di-iso-propyl-, and 1-methylnaphthalene in connection with the new luminophore with high Stokes shift - 1-Phenyl-3-(2,4,6-trimethyl-phenyl)-2-pyrazoline. LAB solvents exhibited similar detection efficiencies reaching up to 100% for high energy beta and alpha particles, but at the same time showed slightly worse detection efficiency for H-3. It was demonstrated that the representatives of the group of naphthalene derivatives exhibited superior pulse shape discrimination ability over the LAB representatives.

Labeling of ethylenediamine tetramethylene phosphonate with 153Sm and 177Lu,Comparison Study

Background 177Lu and 153Sm are perspective radionuclides in terms of applying to nuclear medicine. High-energy beta particles and the relative half-life of the radionuclide are used to achieve an effective palliative treatment of bone metastases. Materials and methods The absorbed doses in different organs and tissues of 177Lu and 153Sm in ionic form and labeled with EDTMP are determined by IDAC-Dose 2.1 (Internal Dose Assessment by Computer) software and WinAct software which used to calculate cumulative activity. 177Lu and 153Sm are lanthanide radionuclide which actively accumulates in liver and bone when used in ionic form. In the case of labeling with EDTMP, the distribution and elimination of the drug occur according to the kinetics of a carrier, EDTMP. The using of osteotropic (Describing any drug etc. that is attracted to, and targets bone) complex allows creating a large dose in the pathological areas and minimizing damages in healthy organs and tissues. Results The effective dose per administered activity is 0.189 mSv/MBq for 177Lu-ionic form, 0.232 mSv/MBq for 153Sm-ionic form and 0.242 mSv/MBq for 177Lu-EDTMP and 0.139 mSv/MBq for 153sm-EDTMP. Conclusion 177Lu and 153Sm labeled with EDTMP are decreasing the liver dose absorption and increasing the bone surface absorption for more effective treatment and minimize side effects.

Cherenkov Luminescence Imaging for Assessment of Radioactive Plaque Position in Brachytherapy of Uveal Melanoma: An In Vivo Feasibility Study.

PurposeTo study the feasibility of using Cherenkov luminescence imaging (CLI) to evaluate and document ruthenium-106 plaque position during brachytherapy of uveal melanoma.MethodsRuthenium-106 decays by emitting high-energy beta particles. When the electrons pass through the eye, Cherenkov radiation generates a faint light that can be captured by highly sensitive cameras. Patients undergoing ruthenium-106 plaque brachytherapy for posteriorly located choroidal melanoma were examined by CLI, which was performed in complete darkness with an electron multiplying charged-coupled device camera mounted on a fundus camera modified for long exposures.ResultsTen patients with tumors ranging from 5.8 to 13.0 mm in largest basal diameter and 2.0 to 4.6 mm in height were included. The plaques had an activity between 0.035 and 0.089 MBq/mm2 at the time of examination (1–4 days after implantation). CLI revealed the actual plaque position by displaying a circular area of light in the fundus corresponding with the plaque area. The Cherenkov light surrounded the tumor as a halo, which showed some asymmetry when the plaque was slightly displaced. The light intensity correlated positively with plaque activity and negatively with tumor pigmentation. Exposure times between 30 and 60 seconds were required to display the plaque position and delineate the tumor area. The long exposures made it difficult to maintain stable eye fixation and optimal image quality.ConclusionsCLI is a novel method to assess and document ruthenium-106 plaque position in brachytherapy for uveal melanoma.Translational RelevanceOcular CLI may provide relevant radiation data during and after implantation of radioactive plaques, thus improving the accuracy of episcleral brachytherapy.

Particles size increase assisted enhancement of thermoluminescence emission in gadolinium and dysprosium oxide doped phosphate glasses

This paper presents results of research on the influence of particles size of Gd2O3 and Dy2O3 doped phosphate glasses on the intensity of thermoluminescence (TL) signals. The obtained glasses were investigated towards potential application in high dose radiation measurements. Simultaneously, next to the glass powders, the glass/polytetrafluoroethylene composite detectors were prepared and used to study dosimetric signal dependencies and influence of glass particles size on their TL behavior. The thermoluminescence dosimetry (TLD) technique was used as the main investigation tool to study detectors dose response. Next to the sole effect of the glass particles size, the results present also an influence of the rare earth dopants on intensity of TL signal. The obtained data present the dosimetric properties of raw and doped phosphate glass (effect of particles size, dose response and radiation sensitivity). It has been found that incorporation of rare earth oxides into glass matrix changes substantially the thermoluminescent behavior of a pure phosphate glass. The highest luminescence yield was found for the samples with the largest glass particles (up to 1000 μm). The incorporation of dysprosium or gadolinium ions into the glass matrix influences both the structure of the electron traps in the glass matrix and TL emission intensity vs. particles size. The dependence of the thermoluminescence signals intensity vs. particles size for all samples can be considered as a saturation type curve. The investigated phosphate glasses exhibit good thermoluminescence properties for the high energy beta radiation dose measurement applications.

Demonstration and aging test of a radiation resistant strontium-90 betavoltaic mechanism

In this work, a betavoltaic combined with photovoltaic mechanism using strontium-90 as a radioactive source was built up. A transparent yttrium aluminum garnet ceramic doped with a cerium ion is used as an intermediate conversion layer to avoid direct irradiation to a semiconductor conversion device and translates most of the high energy beta particles into photons. The traditional crystalline silicon conversion device with an N+PP+ junction structure functions as a betavoltaic and photovoltaic conversion device simultaneously. Radiation resistance is demonstrated by a 0.9 MeV electron beam irradiation aging experiment. In the optimized betavoltaic setup with a 0.5 mm transparent yttrium aluminum garnet ceramic, the crystalline silicon conversion device can bear 5 × 1015 e/cm2 by degrading output power less than 15%. Loaded with 1.3 mCi strontium-90, this betavoltaic setup produces a short circuit current of 282 nA, an open circuit voltage of 0.168 V, a fill factor of 0.58, and a total conversion efficiency of 0.32%.

99mTc-, 90Y-, and 177Lu-Labeled Iron Oxide Nanoflowers Designed for Potential Use in Dual Magnetic Hyperthermia/Radionuclide Cancer Therapy and Diagnosis.

Development of a complex based on iron oxide nanoparticles (IONPs) for diagnosis and dual magnetic hyperthermia/radionuclide cancer therapy accomplishing high yields of radiolabeling and great magnetic heat induction is still a challenge. We report here the synthesis of citric acid, poly(acrylic acid) (PAA) and poly(ethylene glycol) coated IONPs and their labeling with three radionuclides, namely, technetium (99mTc), yttrium (90Y), and lutetium (177Lu), aiming at potential use in cancer diagnosis and therapy. Polyol-synthesized IONPs are a flowerlike structure with 13.5 nm spherically shaped cores and 24.8 nm diameter. PAA-coated nanoparticles (PAA@IONP) showed the best characteristics such as easy radiolabeling with very high yields (>97.5%) with all three radionuclides, and excellent in vitro stabilities with less than 10% of radionuclides detaching after 24 h. Heating ability of PAA@IONP in an alternating external magnetic field showed intrinsic loss power value of 7.3 nH m2/kg, which is one of higher reported values. Additionally, PAA@IONP itself presented no significant cytotoxicity to the CT-26 cancer cells, reaching IC50 at 60 μg/mL. However, under the external magnetic field, they show hyperthermia-mediated cells killing, which correlated with the magnetic field strength and time of exposure. Since PAA@IONP are easy to prepare, biocompatible, and with excellent magnetic heat induction, these nanoparticles radiolabeled with high-energy beta emitters 90Y and 177Lu have valuable potential as agent for dual magnetic hyperthermia/radionuclide therapy, while radiolabeled with 99mTc could be used in diagnostic imaging.

210Pb/210bi detection in waters by cherenkov counting – perspectives and new possibilities

The measurement of 210Pb activity concentration via its product 210Bi, high-energy beta emitter capable of producing Cherenkov radiation in waters, by liquid scintillation counter Quantulus 1220 has been explored. Without the chemical pre-treatment, the detection limits have been evaluated and possibilities to further decrease MDA value have been considered. Prolonging the counting time coupled to the sample's evaporation prior to counting can enable the achievement of the detection limits below maximal permitted levels recommended by the international legislation. The impact of sodium salicylate addition to the counting vials on the detection efficiency and consequently MDA value has been tested. Sodium salicylate application is associated with the certain complications during sample preparation, here we propose salicylate-based ionic liquids instead. We present an innovative experiment that explores the influence of the addition of a synthesized 2-hydroxypropan-1-amminium salicylate to the counting vials in order to decrease MDA parameter. Furthermore, the interference with 226Ra Cherenkov spectra was assessed and the possibility to evaluate its contribution to 210Pb/210Bi spectra has been proposed. The potential of 210Pb screening in the samples without the chemical isolation of 210Pb has not been thoroughly considered in the literature so far. 210Pb screening of a few spiked samples and real samples collected in the vicinity of mine was carried out, thus the obtained results demonstrate the method's evaluation and set its limitations.

Cherenkov luminescence imaging of shallow sources in semitransparent media.

.We experimentally investigated the Cherenkov luminescence imaging (CLI) of the isotopes with different beta particles energies (, , , , and ) in semitransparent biological equivalent media. The main focus of this work is to characterize the CLI when the sources are at the depth comparable with the range of beta particles. The experimental results were compared with Monte Carlo (MC) simulation results to fine tune the simulation parameters to better model the phantom materials. This approach can be applied to estimate the CLI performance for different phantom materials and isotopes. This work also demonstrates some unique properties of high energy beta particles that can be beneficial for CLI, including the possibility to utilize the betas escaped from the object for imaging purposes.

Investigation of fast screening LSC method for monitoring 14C activity in wastewater samples

This paper explores the possibility of a direct measurement of 14C activity concentration in wastewater without chemical pretreatment of samples, which would provide the advantages such as rapidity, low-cost, and simplicity of radioanalysis that is desirable in the case of nuclear emergencies. A method via Liquid Scintillation Counting (LSC) technique has been implemented and optimized. The method assumes mixing of the water sample with a scintillation cocktail (Permafluor E+ and Ultima Gold AB cocktails were tested). Measurements were performed on Ultra Low Level Liquid Scintillation Spectrometer Wallac 1220 Quantulus. Optimization of the method included optimal water:cocktail volume ratio, optimal counting window selection, PAC (Pulse Amplitude Comparator) parameter adjustment, based on the highest FOM (Figure of Merit) value achieved, as well as detection efficiency and detection limit evaluation. The main problem in such an approach, interference with other beta emitters that are often present in wastewater samples, has been discussed. The possibility to eliminate low-energy counts that would be generated from 3H, and to estimate the contribution of other high-energy beta emitters to obtained results of 14C content is presented as well. Method's constraints, its accuracy, and precision have been considered from the obtained results of measurements of wastewater samples. Its application is limited only to 14C screening of samples with much higher 14C activities than those of the environmental (surface and ground) waters. Presented results could be used as guiding principles of development, optimization, and implementation of the fast 14C screening method in other laboratories.

Monte Carlo based determination of dose distribution for some patch sources employed for radionuclide skin therapy

Several methods are introduced for skin cancer treatment. An encouraging method is radionuclide skin therapy, where high-energy beta emitting radionuclides such as 32P, 90Y, 188Re and 166Ho are employed for skin irradiation. This study aimed to calculate the dose distribution for mentioned radionuclides at different layers of skin phantom through Monte Carlo simulation. Depth dose distribution, transverse dose profile and isodose curves related to the patch sources under investigation were calculated by MCNPX code. All of calculations were performed inside a developed skin phantom. Obtained results were compared with those reported by other studies to evaluate the validity of simulations. The results showed that the 166Ho and 32P have steeper dose gradient within the depth which can lead to the better normal tissue sparing. Simulated depth dose distributions were in a good agreement with other published studies and confirmed the validity of performed simulations. The obtained transverse dose profiles at 0.2mm depth had acceptable symmetry and flatness that can improve the dose uniformity within the target area. Calculated isodose curves showed that the 90% isodose level covers a circular area with the diameter of around 8mm for all studied beta sources. From the results, it can be concluded that 166Ho and 32P are more effective in treatment of superficial skin lesions, while, 90Y and 188Re are more rational choices in treatment of deeply distributed skin tumors. Size of employed patch source should be based on the target area to minimize the delivered dose to the adjacent tissues.

Shielding of beta and bremsstrahlung radiation with transparent Bi2O3-B2O3-TeO2 glasses in therapeutic nuclear medicine

High-energy beta emitters (yttrium-90, strontium-89 and phosphorus-32) are nowadays increasingly used in therapeutic nuclear medicine. Beta particles and bremsstrahlung (photons produced when beta particles interact with materials) are harmful and should be shielded in order to protect the personnel and public from their harmful effects. This work determined the radiation yield, effective atomic number and range associated with the interaction of beta particles with a transparent xBi2O3-30B2O3-(70-x)TeO2 glass system (where x = 40, 50, 60 and 70 mol%) using the ESTAR database and programme; and other relevant equations. The properties of the studied glass systems were compared with transparent lead glass, which is unwanted in the medical settings because of lead’s toxicity. The result of this work showed that the studied glasses are suitable for use in making vials, syringes and other transparent materials, necessary for shielding high-energy beta particles. All the studied glass systems can replace lead glass.

OA085] CT Quantification of holmium distribution for absorbed dose calculation in a context of microbrachytherapy

Purpose Holmium 166 ( 166 Ho) is a potential candidate for internal radiotherapy due to high-energy beta radiation (1.77 and 1.85 MeV) and gamma ray (80.6 keV) adapted to SPECT imaging albeit with poor spatial resolution (cm). The spatial resolution at which activity distribution is determined impacts the absorbed dose calculation algorithm that needs to be implemented: For example, SPECT spatial resolution will often lead to the Local Energy Deposition (LED) approximation. In this study, we investigated the potential of CT for holmium quantification, and compared various absorbed dose calculation algorithms in a context of micro-brachytherapy. Methods For CT calibration, acquisitions were performed on a General Electric BrightSpeed 16 using a CIRS 62 phantom with known holmium concentration in order to get a calibration curve. We then assessed holmium concentration in brain tumours implanted in Yucatan minipigs treated by 166 Ho microbrachytherapy. Acquisition parameters were as follows: voltage = 140 kV; reconstruction filter B31s, matrix size: 512 × 512; pixel size: 0.488 × 0.488 mm 2 ; slice thickness = 0.625 mm. Holmium segmentation was based-on pre and post injection CT image subtraction. From the CT calibration curve, and with a prior knowledge of 166 Ho specific activity, it was possible to get a 3D activity distribution. Different absorbed dose computation approaches were implemented: Local Energy Deposition (LED), superposition/convolution of dose-point kernels assuming homogenous or heterogeneous media, and Monte Carlo modelling (GATE) taken as the reference. Gamma-index criteria (0.1%, 0.5 mm) were used to compare approaches. Results The LED approach was clearly not appropriated due to 166 Ho range vs. CT resolution (0.15% passing rate according to the gamma-index criteria). Homogenous and heterogeneous convolution/superposition approaches provided 78% passing rate in a situation of homogenous soft tissues, compared to GATE. Discrepancies were mainly visible in a situation of heterogeneous densities. Conclusions CT-based holmium quantification can provide relevant density information with good spatial resolution (as compared to SPECT imaging), broadening the possibilities for absorbed dose calculation algorithms. This work was partially sponsored by BPI-France under the scope of the Industrial Strategic Innovation project (projet d’Innovation Strategique Industrielle) “TheraneaM.

The Radioprotective Effects of Nano-Curcumin Against Genotoxicity Induced by Iodine-131 in Patients with Differentiated Thyroid Carcinoma (DTC) by Micronucleus Assay

Background: Iodine-131 therapy is one of the main strategies in the treatment of thyroid diseases such as hyperthyroidism and thyroid cancer. Iodine-131 emits high-energy beta particles and gamma rays. Although this technique is considered safe, there are many in vivo and in vitro studies reporting genotoxic damage induced by I-131. Induction of oxidative stress is one of the main mechanisms of therapeutic plan with I-131 and also mentioned as a side effect of it. Objectives: The aim of this study was to determine the effect of Nano-curcumin on chromosomal damages in peripheral blood lymphocyte by micronuclei (MN) assay in patients with differentiated thyroid carcinoma (DTC) after therapeutic dose of I-131 as a clinical trial. Methods: Twenty-one patients with DTC treated with I-131, activity (5.5 GBq) for destructing remnant thyroid functional tissue, were randomly selected to receive curcumin (nano-form, 160 mg/day for 10 days; n = 11) or placebo (n = 10) in a double-blind manner. We obtained blood samples from each patient before treatment and one week after radioiodine therapy. We calculated the number of MN in blood samples. The present study is the first clinical trial for investigating curcumin effectiveness to reduce genotoxicity effects by radiation after radioiodine therapy. Results: The frequency of MN in lymphocyte was significantly increased at one week after I-131 treatment in placebo and curcumin groups. The frequency of MN in the curcumin group was significantly lower than placebo group after I-131 therapy. Nevertheless, there were no significant differences between both groups in White Blood Cell (WBC), Red Blood Cell, platelets, and hemoglobin level at before and after I-131 therapy. Conclusions: The results of this study confirm that the administration of curcumin to the patients, in nano-micelle form, may prevent the genetic damage induced by I-131 in human lymphocyte.