Radiation Exposure Of Personnel Research Articles

ACCUMULATION OF RADIONUCLIDES IN REPLACEABLE PARTS AND WATER TARGET CYCLOTRON

The accumulation of unwanted long-lived radionuclides during the production of 18F-based radiopharmaceuticals using the IBA Cyclone 18/9 HC cyclotron is considered. Using high-resolution gamma-ray spectrometry with HPGe detectors, the identification of radionuclides and the assessment of activity in activated components (stripper, target entrance window) of the "medical" 18-MeV cyclotron IBA Cyclone 18/9 were carried out. More than 20 unwanted radionuclides have been identified in irradiated water. Various mechanisms for the entry of longlived radionuclides into irradiated water are described. The results obtained are of great importance for optimizing the methods of radioactive waste management in the production of radiopharmaceuticals and, as a result, minimizing the radiation exposure of personnel.

A simple, reliable and accurate approach for assessing [131I]-capsule activity leading to significant reduction of radiation exposure of medical staff during radioiodine therapy

PurposeAccording to German law, the [131I]-capsule activity has to be checked in the context of radioiodine therapy (RIT) immediately before application. The measurement leads to significant radiation exposure of the medical personnel, especially of their hands. We aimed to establish a method for estimating [131I]-capsule activity by measuring the dose rate (DR) at contact of the delivered lead closed container carrying the [131I]-capsules and to evaluate radiation exposure in comparison to conventional [131I]-capsule measurement using a dose calibrator. MethodsDR on the surface of the closed lead container was measured at two locations and correlated linearly with the [131I]-capsule activity measured in a dose calibrator to create calibrating curves. The hand and whole body (effective) doses were determined with official dose meters during validation of our method in clinical practice. ResultsThe determination coefficients (R2) of linear calibration curves were greater than 0.9974. The total relative uncertainty for estimating [131I]-capsule activity with our method was <±7.5% which is lower than the uncertainty of the nominal activity and quite close to the threshold limit for the maximum allowed uncertainty of ± 5% for measuring activity in radioactive drugs. The reduction of the hand dose caused by our method was 97% compared with the conventional measurements of the [131I]-capsules in a dose calibrator. ConclusionMeasuring DR on the surface of the closed lead containers enables the [131I]-capsules activity to be estimated simply, reliably and with sufficient accuracy leading to significant reduction of the radiation exposure for the medical staff.

Evaluation of the permissible 99Mo activity in the KL-15 cask in the design of transportation and process scheme

The demand for the use of radioactive isotopes in medicine is increasing with each coming year necessitating the increased output of radionuclide products. One of the most widely spread radionuclides used in medicine is technetium-99m (99mТс) (Feasibility of producing molybdenum-99 2015, NEA 2012, The Supply of Medical Radioisotopes 2015). The very short 99mТс life (6-hour half-life) requires its production directly on the site of medical treatment. This is achieved using molybdenum-technetium generators (Kodina and Krasikova 2014, Technical Reports No. NF-T-5.4. 2013, Technetium-99 Generator 2021) loaded with molybdenum-99 (99Мо), which uninterruptedly decays (half-life of 66 hours) yielding 99mTc. Close attention must be paid in the course of production of molybdenum-technetium generators to radiation safety during transportation of 99Мо on the territory of the manufacturing facility. The main measure for ensuring radiation safety during transportation of 99Мо is the application of special packaging kits. The Karpov Institute of Physical Chemistry JSC uses a wide range of packaging kits of types A and B for transportation of radioactive materials on the territory of the manufacturer with design features providing the required level of radiation safety. In particular, the KL-15 shipping cask loaded/unloaded from the top is used for onsite transportation of 99Мо for charging molybdenum-technetium generators. The maximum permissible activity of 99Мо is not specified in the passport of the KL-15 cask. Planned construction of a radionuclide production shop in accordance with GMP requirements will require the increase of output of target radionuclides by several times. The above considerations necessitated the evaluation of the maximum permissible activity of 99Мо planned to be transported in KL-15 casks. No other type of standard casks can be used because of their outside dimensions prohibiting the unloading of 99Мо inside the “hot” chamber. Calculation and experimental evaluation of permissible 99Мо activity during transportation inside the KL-15 cask was performed. The paper presents the calculated evaluation of the maximum permissible activity of 99Мо in a KL-15 cask to ensure the radiation exposure of personnel of group A working with the cask not exceeding the established level at the enterprise (80 μSv per shift) and not requiring the use of additional measures and means of protection. The results of the work allow us drawing the conclusion that the KL-15 cask ensures the required level of radiation safety with up to 241 Ki of 99Мо loaded in the cask.

Would your intraoperative results differ if you were a four-handed orthopedist in intramedullary nail surgery for tibial fractures?

The present study aimed to present the intraoperative results of a fixation device that assists in fracture reduction during closed intramedullary nail application in tibial shaft fractures and provides a temporary stable fixation until the last stage of surgery. The fixation device used in our study consists of two custom-made bone clamps and a joint system that connects the clamps. Patients diagnosed with closed tibial shaft fracture between 01.01.2020 and 20.12.2021 were included in our retrospective study. Twenty-one patients who underwent closed intramedullary nailing and used a fixation device in the intraoperative period (Group 1) and 21 patients who underwent closed intramedullary nailing without a fixation device (Group 2) were included in the study. Both groups were compared in terms of duration of the operation, amount of bleeding, wound infection, intraoperative fluoroscopy time, preoperative period, follow-up time, varus and valgus deformity, limb shortness, malrotation, nonunion, and deep vein thrombosis. In Group 1, the mean duration of operation was 72.62±8.78minutes; the mean amount of bleeding was 31.10±6.13ml, and the mean intraoperative fluoroscopy time was 76.81±11.83 s. In Group 2, the mean duration of operation was 87±13.12 minutes; the mean amount of bleeding was 29.81±6.01ml and the mean intraoperative fluoroscopy time was 100.71±11.50 s. Intraoperative fluoroscopy time, varus deformity, and malrotation were significantly different between the groups (p=0.001, p=0.030, p=0.001, respectively). In the study, it was observed that the intraoperative fixation device decreased intraoperative fluoroscopy time, varus, and rotational deformity. It was considered that the fixation device would reduce the radiation exposure of the health personnel in the intraoperative period and reduce the malunion rate due to varus and rotational deformity.

Robotics in Spinal Surgery

Surgical robotics have been introduced in a number of disciplines, with the aim of minimizing tissue disruption, reducing operating personnel radiation exposure, and improving dexterity and efficiency relative to human operation. In spinal surgery, robotic systems are relatively novel, applied to date largely for the placement of pedicle screw instrumentation. Only a few robotic systems have been approved for spinal surgery, and there remain significant barriers to the widespread implementation of surgical robotic techniques. This review provides an overview of robotic systems in spinal surgery and identifies current limitations that must be addressed before clinical use, including clinical merit relative to freehand navigation systems, steep learning curves, and unclear cost-effectiveness.

Robotics in spinal surgery

Surgical robotics have been introduced in a number of disciplines, with the aim of minimizing tissue disruption, reducing operating personnel radiation exposure, and improving dexterity and efficiency relative to human operation. In spinal surgery, robotic systems are relatively novel, applied to date largely for the placement of pedicle screw instrumentation. Only a few robotic systems have been approved for spinal surgery, and there remain significant barriers to the widespread implementation of surgical robotic techniques. This review provides an overview of robotic systems in spinal surgery and identifies current limitations that must be addressed before clinical use, including clinical merit relative to freehand navigation systems, steep learning curves, and unclear cost-effectiveness.

Selection of radiation tolerant commercial greases for high-radiation areas at CERN: Methodology and applications

At the European Laboratory for Particle Physics (CERN), commercial greases and oils are extensively used to lubricate moving devices operating in high-radiation areas, absorbing doses up to the MGy range. Due to their sensitivity to radiation, lubricants can become fluid or solid in operation, potentially causing component failures and compromising the operation of the accelerator complex. CERN is therefore developing methodologies to select radiation tolerant commercial lubricants for critical Beam Intercepting Devices (BIDs) such as high-power targets, dumps and collimators. A careful selection of greases is fundamental to reduce the risk of failure, to optimize equipment lifetime and to minimize maintenance and unwanted radiation exposure of personnel in high radiation areas. Three different parameters are considered to select commercial lubricants: the expected total dose absorbed in operation, the maintenance feasibility and the failure impact in terms of accelerator downtime and of personnel involvement in replacement procedures. Based on these criteria, an example of relevant application is presented: the lubrication of the new internal beam dump of the Super Proton Synchrotron (SPS). Experimental radiation damage data allowed the identification of two radiation tolerant commercial greases to lubricate the dump support jack assembly.

Abstract 11507: Radiation Reduction in Catheterization Laboratory: Single Center Experience

Introduction: Radiation reduction measures were incorporated in the Cleveland Clinic Catheterization laboratories to mitigate the hazards from radiation exposure to patients and personnel during diagnostic and interventional coronary procedures. We report our experience with these improved systems over a 10-year period. Methods: Fluoroscopes were modified in 2013 by reducing the default fluoroscopic pulse rate from 10 to 7.5 pules/s, added default low-dose acquisitions, revised field-of-view dose factors, and instructed operators to use larger fields-of-view with appropriate collimation. A retrospective data analysis of all patients undergoing diagnostic catheterization from 2009 to 2012 (pre-initiative group), and 2013 to 2019 (post-initiative group) was done using Siemens CARE analytics software. The effectiveness of radiation reduction measures was assessed by comparing the total air kerma (K a,r ), and fluoroscopy- and acquisition-mode air kerma in patients in the two groups after propensity matching them based on age, sex, BSA, and total fluoroscopic time. Results: The total fluoroscopic time for the pre-initiative group (N=18,181) was 8.02 seconds while that for the post-initiative group (N=25,868) was 8.05 seconds. After matching 18,181 patients in both the groups (mean age, 64 years; 62% males), a significant reduction (54.4%) in the mean K a,r was observed in the post- in comparison to the pre-initiative group (420.94 mGy vs. 921.21 mGy; p&lt;2.2e -16 ). Further analysis revealed a reduction in the mean acquisition- (59.3%; 217.33 mGy vs. 533.50 mGy; p&lt;2.2e -16 ) and fluoroscopy-mode (47.5%; 203.61 mGy vs. 387.71 mGy; p&lt;2.2e -16 ) air kerma in the post-initiative group. A sub-analysis of patients matched on the basis of their exact fluoroscopy and acquisition times also revealed a significant reduction in K a,r , acquisition- and fluoroscopy-mode air kerma in the post-initiative group relative to the pre-initiative group (43.95%, 44.04%, 43.78% respectively). Conclusions: Optimization of imaging systems can significantly reduce patient radiation exposures which directly affect the radiation exposure of the Cath lab personnel. Similar algorithms can be applied in other labs to achieve a reduction in radiation exposure.

Occupational Radiation Exposure of Radiopharmacy, Nuclear Medicine, and Surgical Personnel During Use of [99mTc]Tc-PSMA-I&S for Prostate Cancer Surgery.

The aim of this study was to estimate and subsequently measure the occupational radiation exposure for all personnel involved in producing, administering, or performing imaging or surgery with [99mTc]Tc-PSMA-I&S, which has been introduced for identification of tumor-positive lymph nodes during salvage prostate cancer surgery. Methods: The effective dose was estimated and subsequently measured with electronic personal dosimeters for the following procedures and personnel: labeling and quality control by the radiopharmacy technologist, syringe preparation by the nuclear medicine laboratory technologist, patient administration by the nuclear medicine physician, patient imaging by the nuclear medicine imaging technologist, and robot-assisted laparoscopic salvage lymph node dissection attended by an anesthesiology technologist, scrub nurse, surgical nurse, and surgeon. The dose rate of the patient was measured immediately after administration of [99mTc]Tc-PSMA-I&S, after imaging, and after surgery. Results: The estimated dose per procedure ranged from 1.59 × 10-10 μSv (imaging technologist) to 9.74 μSv (scrub nurse). The measured effective dose ranged from 0 to 5 μSv for all personnel during a single procedure with [99mTc]Tc-PSMA-I&S. The highest effective dose was received by the scrub nurse (3.2 ± 1.3 μSv), whereas the lowest dose was measured for the surgical nurse (0.2 ± 0.5 μSv). If a single scrub nurse were to perform as many as 100 procedures with [99mTc]Tc-PSMA-I&S in a year, the total effective dose would be 320 μSv/y. Immediately after administration, the dose rate at 50 cm from the patient was 18.5 ± 1.6 μSv/h, which dropped to 1.8 ± 0.3 μSv/h after imaging the following day, reducing even further to 0.56 ± 0.33 μSv/h after surgery. Conclusion: The effective dose for personnel involved in handling [99mTc]Tc-PSMA-I&S is comparable to that of other 99mTc-radiopharmaceuticals and therefore safe for imaging and radioguided surgery.

Rotational coronary angiography in heart transplant recipients

As a screening method for detecting coronary lesions, coronary angiography (CAG) is becoming increasingly important in the activities of transplant centers. Angiography examination of coronary arteries is performed in potential recipients of various organs, related donors, and annually in heart recipients. Given the grave condition of recipients in the early post-transplant period and annual angiographic studies, it is necessary to strive for reduction of radiation load on the body and reduction of dose of X-ray contrast agents used.Objective: to assess the possibilities of using rotational CAG in the activities of transplant centers.Materials and methods. We observed 254 patients who underwent CAG. Their ages ranged from 21 to 79 years (mean 46.92 ± 1), and 90% were men. All patients were divided into two groups: group 1 included 142 patients who underwent rotational CAG, while group 2 was the control group (where classical polyprojection CAG was performed) and included 112 patients. Group 1 was divided into 2 subgroups – the subgroup of patients after heart transplantation who underwent endomyocardial biopsy along with CAG (n = 51), and the subgroup of patients who underwent only rotational CAG.Results. In 91% of patients, CAG was performed by radial access. In group 1, stenotic lesions were detected in 33 patients: 19 had single-vessel lesions, 9 had two-vessel lesions, and 5 had three-vessel lesions. A total of 56 hemodynamically significant stenoses were detected, 9 of which were chronic total occlusions. In 83 patients (60%), performing only 2 series of rotational scans (one left and one right coronary artery) was sufficient. In 32 (23%) patients, one more clarifying projection was required, in 17 patients two and in 9 – 3–5 additional projections. In 3 cases, we switched to polyprojection CAG. The average amount of contrast agent used was 24.4 ± 0.9 ml, the average X-ray dose was 34561.3 ± 1695.2 mGycm2. The need for a contrast agent was significantly higher in the comparison group – 24.4 ± 0.9 mL and 103.5 ± 1.7 mL, respectively. The average X-ray dose in the main group was 34561.3 ± 1695.2 mGycm2, in the comparison group 41430.9 ± 4141.7 mGycm2. However, there was no significant difference between the groups. Subgroup analysis showed that patients who underwent only rotational CAG had lower radiation exposure compared to patients who underwent CAG combined with endomyocardial biopsy biopsy (EMB), as well as significantly lower load compared to the control group.Conclusion. Rotational CAG can be considered as the method of choice at transplant centers, where screening diagnostics of the state of the coronary bed is required, which is equivalent in terms of information content and safety. Rotational CAG allows to reduce the amount of injected contrast agent by more than three times, which in turn reduces the number of associated complications, as well as the radiation exposure of patients and medical personnel.

Pulsed fluoroscopy in retrograde urethrograms.

Retrograde urethrogram (RUG) is one of the corner stones for the reconstructive urologist. With hundreds of RUGs being performed yearly in busy reconstructive center, the concern for radiation exposure to the patient and the medical personnel becomes important. We propose the use of pulsed fluoroscopy to decrease the radiation exposure for patient and medical personnel. Patients presenting to our center with urethral strictures between March 2016 and March 2019 were included in our study. The fluoroscopy machine was set for pulsed fluoroscopy at a setting of 4 pulses per second. Patient information including demographics, pre-operative diagnosis, Intra-op findings, and fluoroscopy time were recorded. RUG was performed to localize the stricture pre-operatively and post-operatively. A total of 185 RUG were performed between March 2016 and March 2019. The median age was 63 (14-81). The remaining 154 RUG had 77 performed pre-operatively and 77 performed post-operatively. Pathology was identified in 77 patients. Intra-operative confirmation of pre-operative finding was found in 76 patients (98.7%). Median fluoroscopy time was found to be 2.43 seconds (0.5 sec- 6.5 sec). Pulsed fluoroscopy reduces the radiation exposure in RUG without a reduction in the diagnostic capacity of the test. Reduction of fluoroscopy can have beneficial cumulative effect as per the ALARA principle for patients and medical personnel. Further studies with randomized control trials could be of great benefit.

99mTc-labelled PSMA ligand for radio-guided surgery in nodal metastatic prostate cancer: proof of principle

PurposeIntraoperative identification of prostate cancer (PCa) lymph node (LN) metastases (LNM) detected by preoperative PSMA PET/CT may be facilitated by PSMA radio-guided surgery (RGS) with use of a γ-probe. Earlier we demonstrated excellent performance of the 111In-labelled PSMA ligand DKFZ-617 ([111In]In-PSMA-617) in RGS for ex situ distinction of LN vs LNM at lymphadenectomy (LA) at a single LN level. In comparison with indium-111, technetium-99m has better physical properties for γ-probe measurements, better availability and lower radiation exposure for patients and medical personnel. Against this background, we evaluated the uptake of 99mTc-PSMA-I&S ligand at the level of single LN and its power to discriminate between unaffected LN and LNM.MethodsSix patients with PCa with the suspicion of LNM on preoperative PSMA-PET/CT underwent [99mTc]Tc-PSMA-I&S RGS (4 salvage LA, 2 primary LA) with intravenous injection of [99mTc]Tc-PSMA-I&S 24 h prior to surgery. Resected samples were isolated manually aiming at the level of single LN. Uptake measurements were done ex situ with a high-purity germanium detector. Receiver operating characteristic (ROC) analysis was performed based on [99mTc]Tc-PSMA-I&S uptake expressed as lean body mass standard uptake value (SUL).ResultsSeparation of the tissue samples from 73 subregions resulted in 498 single samples. After final histopathology 356 LN, 160 LNM und 11 non-nodal PCa samples were identified. Median SUL of tumor-free samples (0.26) and samples with cancer (3.5) was significantly different (p < 0.0001). ROC analysis revealed an area under the curve (AUC) of 0.917 (95% CI 0.89–0.95). Using a SUL cutoff of 1.1, sensitivity, specificity, positive predictive value, and negative predictive values were 76.6%, 94.4%, 89.4% and 86.9%.ConclusionEx situ analysis of [99mTc]Tc-PSMA-I&S uptake at single LN level showed good diagnostic performance for the ex situ distinction of tumor-bearing vs tumor-free LN during RGS.

Обоснование требований к объему пускового комплекса технических средств радиационного контроля при физическом пуске энергоблоков Нововоронежской АЭС-2

The physical start-up is a stage of the power unit commissioning, which includes reactor core fuelling, achieving the first criticality and completion of all required tests and measurements at the power level. At the stages of physical start-up the priority task is to determine the scope of radiation monitoring equipment, put into operation and sufficient for absolute safety assurance and unambiguous assessment of the power unit radiation exposure of personnel, population and environment.

Navigated iliac screw placement may reduce radiation and OR time in lumbopelvic fixation of unstable complex sacral fractures

PurposeInstability of the posterior pelvic ring may be stabilized by lumbopelvic fixation. The optimal osseous corridor for iliac screw placement from the posterior superior iliac spine to the anterior inferior iliac spine requires multiple ap- and lateral-views with additional obturator-outlet and -inlet views.The purpose of this study was to determine if navigated iliac screw placement for lumbopelvic fixation influences surgical time, fluoroscopy time, radiation exposure, and complication rates.MethodsBilateral lumbopelvic fixation was performed in 63 patients. Implants were inserted as previously described by Schildhauer. A passive optoelectronic navigation system with surface matching on L4 was utilized for navigated iliac screw placement. To compare groups, demographics were assessed. Operative time, fluoroscopic time, and radiation were delineated.ResultsConventional fluoroscopic imaging for lumbopelvic fixation was performed in 32 patients and 31 patients underwent the procedure with navigated iliac screw placement. No differences were found between the groups regarding demographics, comorbidities, or additional surgical procedures.Utilization of navigation led to fluoroscopy time reduction of more than 50% (3.2 vs. 8.6 min.; p < 0.001) resulting in reduced radiation (2004.5 vs. 5130.8 Gy*cm2; p < 0.001). Operative time was reduced in the navigation group (176.7 vs. 227.4 min; p = 0.002) despite the necessity of additional surface referencing.ConclusionFor iliac screws, identifying the correct entry point and angle of implantation requires detailed anatomic knowledge and multiple radiographic views. In our study, additional navigation reduced operative time and fluoroscopy time resulting in a significant reduction of radiation exposure for patients and OR personnel.

Safety and feasibility of a 1 frame-per-second X-ray framerate in cardiac electrophysiology

BackgroundWe investigated the feasibility and safety of a framerate of 1 frame per second (“fps”) for fluoroscopy and cine-angiography, to lower radiation exposure for patients and personnel in cardiac electrophysiology (“EP”). MethodAnalysis of 2521 EP procedures, 899 (36%) with the lowest available conventional framerate (3.75 fps) and 1622 (64%) procedures performed with a framerate lowered further to 1.0 fps (by looping a 1 Hz square pulse to the ECG trigger) performed between 01/2016 and 01/2020. ResultsProcedures performed with 1.0 fps had the same acute procedural success rates (p = 0.20) and adverse event rates (p = 0.34) as the 3.75 fps group. There was no difference in total X-ray operation time (p = 0.40). The dose-area-product (DAP) was significantly reduced from 638 to 316 cGy*cm2 (p < < 0.0001) for all procedure types together, and for each subgroup. In a multivariable linear regression model, total X-ray operation time (estimate 38 cGy*cm2 /min) and body mass index (estimate 32 cGy*cm2 / index point) and a framerate of 1.0 fps (−314 cGy*cm2 against 3.75 fps) were independent predictors of a lower DAP (p-value of t-statistic for all << 0.0001). ConclusionsA framerate of 1.0 fps is safe and feasible in cardiac electrophysiology procedures. It was associated with a significant reduction of radiation exposure for patient and personnel.

Unmanned Aerial System Integrated Sensor for Remote Gamma and Neutron Monitoring.

Tools for remote radiation sensing are essential for environmental safety and nuclear power applications. The use of unmanned aerial systems (UASs) equipped with sensors allows for substantially reducing the radiation exposure of personnel. An ambient temperature Cs2LiYCl6:Ce3+ (CLYC) elpasolite scintillation sensor for simultaneous gamma and neutron measurements was designed as a user-friendly “plug and fly” module integrated into an octocopter robotic platform. Robot Operating System (ROS) was used to analyze the sensor’s data. The measured CLYC’s energy resolution was <5% at 662 keV gamma rays; neutron flux was measured using 6Li(n,α)t reaction. Time and GPS data were combined with radiation data in the ROS, supporting real time monitoring and assessment tasks, as well as radiation source search missions. Because UASs can be irradiated, radiation damage of the sensor and robot’s electronics was estimated using FLUKA code.

Minimum collective dose based optimal evacuation path-planning method under nuclear accidents

The effectiveness of the path plan is the main factor of the evacuation affecting the amount of exposure to personnel, however, the effect of the radiation field distribution has not been fully considered in current studies. In this paper, a Minimizing Collective dose based Path-Planning method (MCPP) was proposed. Among which, the accumulative dose based Dijkstra algorithm was proposed to find the optimal evacuation routes, and then the equilibrium model considering road resistance was used to formulate the optimal evacuation path plan under nuclear accidents, in which the obtained routes were reasonably arranged to evacuate all people with minimize collective dose. This paper used the Daya Bay Nuclear Power Station as an application scenario for evacuation simulation to verify the effectiveness of the method. The results showed that the path plan formulated by MCPP method could reasonably reduce personnel radiation exposure during the evacuation process.

Radiation Exposure of Patient and Operating Room Personnel by Fluoroscopy and Navigation during Spinal Surgery

Intraoperative radiography imaging is essential for accurate spinal implant placement. Hazards caused by ionizing radiation raised concern on personnel’s work life long exposure in the operating room (OR). To particularize a cumulative risk estimation of radiation of personnel and patient, depending on used methods (C-arm fluoroscopy, O-arm navigation) and patient characteristics during spinal surgery, detailed investigation of radiation exposure in a clinical setting is required. Lumbosacral dorsal spinal fusion was performed in 37 patients (19 navigated, 18 fluoroscopy) during this prospective study. Radiation exposure was measured on several body regions with thermoluminescent dosimeters on patient and OR personnel (surgeon, assistant, sterile nurse, radiology technologist). Comparison between patient characteristics and radiation exposure was included. The highest patients values were measured in the surgery field and gonads area during navigation (43.2 ± 19.4 mSv; fluoroscopy: 27.7 ± 31.3 mSv; p = 0.02), followed by the thoracic region during fluoroscopy (7.7 ± 14.8 mSv; navigation: 1.1 ± 1.0 mSv; p = 0.06), other measured regions can be considered marginal in comparison. Amongst OR personnel exposure of the surgeon was significant higher during fluoroscopy (right hand: 566 ± 560 µSv and thoracic region: 275 ± 147 µSv; followed by thyroid and forehead) compared to navigation (right finger: 49 ± 19 µSv; similar levels for all regions; p < 0.001 in all regions). When compared to the surgeon, other OR personnel had significantly lower radiation doses on all body regions using fluoroscopy, and similar dose during navigation. The highest eye’s lens region value was measured during fluoroscopy for the patient (185 ± 165 µSv; navigation: 205 ± 60 µSv; p = 0.57) and the surgeon (164 ± 74 µSv; navigation: 92 ± 41 µSv; p < 0.001). There was a significant correlation between patient BMI and radiation exposure to the surgery field during fluoroscopy. To our knowledge, these data present the first real life, detailed comparison of radiation exposure on OR personnel and patients between clinical use of navigation and fluoroscopy. Although patient’s radiation dose is approximately 3-fold during navigation compared to the fluoroscopy, we found that a spinal surgeon could perform up to 10-fold number of surgeries (10.000 versus 883) until maximum permissible annual effective radiation dose would be reached. Especially for a spinal surgeon, who is mainly exposed amongst OR personnel, radiation prevention and protection must remain a main issue.

Automatic control of cardiac ablation catheter with deep reinforcement learning method

To reduce the radiation exposure of personnel during an interventional procedure for arrhythmia, a robot has been developed and implemented herein for use in interventional procedures. Studies on the control of an electrophysiology catheter by robots are being conducted. However, controlling a catheter using a robot has limited precision owing to external forces subjected on the catheter due to blood flow and pulse inside a heart. This study implements a reinforcement learning method for automated control of a catheter by a robot. Using the reinforcement learning method, this study aims to show that such a robot can learn to manipulate a catheter to reach a target in a simulated environment and subsequently control a catheter in an actual environment. Randomization noise is used during the simulation to reduce the differences between the simulation and actual learning environments. Each environment is implemented with different movement values depending on insertion angles and steps of the catheter model. When the results from the simulated learning model are implemented in the actual environment, the success rate of catheter reaching the designated target is 73 %. In addition, the noise-implemented model shows that the success rate can be increased up to 87 %. Through these experiments, the study verifies that a simulated learning model can be implemented in a robot system to control an actual catheter as well as that the success rate of the model can be increased using randomization noise.

Лучевая нагрузка на медицинский персонал, сопровождающий пациента при близкофокусной рентгенотерапии детей

Purpose: Assessment the radiation situation in the treatment room of superficial x-ray therapy during the irradiation process in order to inform about radiation exposure of medical personnel or a relatives. &#x0D; Material and methods: In the course of the study, a procedure of superficial radiotherapy was simulated using a tissue equivalent phantom with sizes 250×250×150 mm. The radiation control protocol of measurements on the Roentgen TA-02 apparatus was compiled on the basis of SanPiN 2.6.1.1192-03. With the help of a clinical dosimeter DKS-AT1123, the ambient dose-rate of short-term x-rays was measured. In accordance with the requirements for conducting radiation monitoring, measurements were taken directly near the apparatus in areas 60×60 cm at points located at heights corresponding to the head level (160 ± 20 cm), chest level (120 ± 20 cm), gonad level (80 ± 20 cm) and the level of the legs (30 ± 20 cm). On the basis of the obtained data, the value of the effective dose-rate of x-ray radiation for the whole human body was calculated for each area. Taking into account the characteristics of the irradiation regime used in the clinic, the total effective dose received by the medical personnel accompanying the patient for the entire course of radiotherapy was calculated.&#x0D; Results: A drawn up diagram is illustrating the radiation situation in the treatment room of superficial radiotherapy. Based on the results of calculations, it can be concluded that the radiation exposure on the accompanying person during superficial x-ray therapy of children’s hemangiomas does not exceed the maximum permissible dose specified in paragraph 5.4.4 of SanPiN 2.6.1.2523-09.&#x0D; Conclusion: In exceptional cases, a parent or medical personnel may be in the treatment room to support the patient.