A Serial Of Research And Production Of Protect Device And Its Effect Evaluation In Interventional Treatment

Objective:Interventional Radiology (interventional radiology, IVR) is one image-based diagnosis and treatment approach for variety of difficult diseases. Assisted by medi-cal image diagnosis devices, by using the puncture technique, this approach can carry special catheters, following blood vessels and other body lumen, into a person's various organs. This approach can be conducted without open-surgeries, which characterizes interventional diagnosis and treatment as minimally invasive, small operation wound, repeated treatment available and preferable treatment effect. Therefore this approach is more receivable by medical practitioners and patients. At present, more and more diseases can be dealt with by IVR, and the application of IVR is conducted in almost every subject of clinic and imaging pathology. With the development Intervention devices and new material of biology engineering, invention diagnosis and treatment techniques will have a promising future However, protection during interventional diagnosis and treatment causes worries because medical practitioners are exposed to radial directly, and for long time. As for patients, because of limited devices and sometimes, and also because of the lack of protection knowledge of medical practitioners, patients are exposed to X-rays for long time, especially, healthy parts of patient's body are also exposed to X-rays. Meanwhile, radio protection management and training is lagged. This lag and the limited equipments can not meet the need of rapid development. The radiation dose of IVR practitioners is the highest one in medical industry. By now, IVR is conducted with the sacrifice of health of medical practitioners. Taking the cost as well as benefit into consideration, radiation problem will eventually pull back the application of IVR. Faced by the problem of poor protection for people during interventional diagnosis, the fact that medical staff, as well as patients, are over-irradiated as 10 or even several 10 times over national standard, and the great difficulties in applying the protection due to the popular use of clinical use of interventional treatment, In order to verify the unsatisfying situation of Interventional Radiology Radiation Protection, and to set up theoretical basis for the practical production of serial protect devices, we first make epidemic investigation for the radiation dose in selected intervention radiation area of Xinjiang. The necessary material of intervention treatment X-ray machines, such as small-sized and large-sized C-brachial X-ray machines, vessel photograph machines, etc., is fully obtained. To collect the material, we conduct cluster sampling combined with stratified sampling in all Urumqi's hospitals equipped with Interventional Radiology ray devices. We conduct the measurement in different stand positions of patients by testing their ESD (entrance skin dose), focusing on four representative parts of their body:eye lens, hypothyroids, gonads and knees. The present protection measures and devices are far from enough for the rapid development of IVR. The bottle-neck which impedes IVR is the lack of protection knowledge of most medical practitioners and the radiation protection workers are not familiar with diagnosis. By now, serial and affordable protection devices are not provided yet in the radiation protection industry. Based on her many years of observation and accumulation in this area, by conducting serial R&D of interventional protective devices, selecting three representative intervention diagnosis X-ray machines and modifying these machines, aims to reduce largely the level of irradiation of IVR practitioners, and also to reduce the radiation of non-treatment body parts of patients. With the technical breakthrough of protection equipment manufacture, the application of IVR could be better promoted. With economic, practical and easy to promote the purpose of developing the three main protective device, to provide the basis for the series of promotional. Method: 1) Epidemic Investigation:To collect data of radiation dose of staff and patients by means of cluster sampling and stratified sampling, for radiation equipments used in interventional treatment in Xinjiang. The radiation dose of staff includes the dose in stand positions and the accumulated absorbed dose using thermoluminescence dosimeters. Radiation dose of patients includes ESD of subjects, DAP, and CD. Location of test: locate in operating stand positions, four parts of body of patients, including eye lens, hypothyroids, gonads and knees. The way to measure includes:①Site-measure by X-ray Survey Meter;②Take back data collected by thermoluminescence dosimeters to labs for further measurement;③Mathematic model formula to calculate by using radiation dose data and workload; finally, calculate annual absorbed dose of staff by statistical analysis of these three kinds of data mentioned above. Measurement of patient:①Useful harness the air kemarate measurement.②The operation will be preceded by film placed in the radiation field incident X hamess the dorsal skin of patients;③Using the TL elements on the surface of the skin of patients after surgery to recover laboratory measurements; 2) Manufacture of protect box or protect cover:①Through the "half-layer" ("half-layer" is to the original ray exposure rate to reduce by half the thickness of the material, the main barrier of high energy radiation), "half-value layer" (in the X-Ray beam exposure of a point rate reduction absorb half of the standard required slice thickness the main absorption of low energy rays.X-Ray machine on the half-value layer measurements and calculations needed to ensure the normal operation of the machine) is calculated. The preliminary estimate in millimeters of aliuminum or lead thickness. Then according to lead and aluminum materials, the actual amount of lead in aluminum calculated about thickness.Calculate the thickness of lead by half-price layer method and that of aluminum by HVL considering the voltages of different machines. Determine the thickness range of lead and aluminum in material. Find the smallest thickness which in accordance with protect standard;②Make R&D of three types of protective devices dealing with different interventional operations concerning equipments of variety of types. Make further adjustments according to machine room and shapes of tubes:①Screen or curtain protection taking interventional radiation machine as sample, in the concept of "restriction, collection and screening";②Develop intervention protect device under-tube taking under-tube X-ray machine as subject;③Develop interventional protect device applicable in both above and under tube condition, taking above-tube X-ray machine as subject;④After protect box installed, make a self-comparison analysis by using same method in same positions with the same equipment for measuring;⑤Compare the two results by SPSS. Then make self-comparison and group-comparison.⑥Collected before and after the intervention modified X-ray machine operator's blood, as compared. The difficult problem existing in protect device manufacture is solved due to successful R&D of above-tube interventional X-ray protect cover. This design is made considering machine type, which makes interventional treatment protect device a serial products and hence can be better promoted. Result:1) Radiation dose of epidemic investigators and patients:①Skin absorbed dose of patients:2.17μGy/h～205 mGy/h, DAP 28.5Gycm2～525 Gycm2; ED 1.67mSv 181mSv under the test environment of 0.3mA,43kV～363.9mA,66kV. The dose of cardiovascular patients taking interventional treatment is:dose-area product 1233.4 mGycm2, surface radiation of subject 637mGy, and medium value of efficient dose 20.27mSv;②Radiation dose of medical workers:3.37mSv/a～82.56mSv/a Principle surgeon:with range (1.0～14000)μSvh"1, Dose of principal operators is 63.4% over standard, Secondary surgeon:with range (1.80～8830)μSv·h-1,51.6% over standard.Third surgeon:with range (0.5～2200)μSv·h-1,30.4% over standard. Principle surgeon for machine-above-bed (807.4±42.5)μSv/a. Surgeon for machine-under-bed (527.4±102.4)μSv/a; 2) Systematic R&D of Protect Device:The thickness range of lead is determined as 2mm～6mm by half-price layer method. The thickness range of aluminum is determined as 2mm～4mm by half-value layer method. The three kinds of protect device is designed taking consideration of voltage, machine type and surgery type. They are:protective shield devices, under-tube protect device, and above-tube protect device. After the designing, the search for manufacturer is carried out. By help of manufacturer through their test, the art of manufacture of the protect device is improved as nice-looking, good adaptation of pit and fissure, light, the most important, the final design will not hinder the operation of staff; 3) Evaluation of the effect of three types protect devices:①Protective shield devices:without this device, the absorbed dose in 13 test positions:(382±113)μSv·h-1 range (160～567)μSv·h-1. Conservatively calculate, 1000 patients will take the treatment within one year,20 minutes each one, the average absorbed dose, before the protection can reach 127.3mSv/a; after the protection, dose around operating beds in perspective in erect positions is (49.7±32.2)μSv·h-1 with the rage (40～156.7)μSv·h- After the comprehensive protection, the average dose is predicted as 16.6mSv/a. By comparison, the statistical difference is P<0.05. Before the protection, dose in the 13 test positions all are over 43μSv·h-1, disqualification rate is 100%; after the protection, it is bigger than 43μSv·.h-1 in each position. The disqualification rate is 7.7%. The protective efficiency:93.3%;②under-tube protect device:before the protection, dose in the 23 test positions of perspective and lying space is (3.32±3.93) mGy/h, ranging 0.56～12.78 mGy/h, the highest 6.21 mGy/h, specially in the operating position, such as those parts:gonads, knees and legs, the dose is extremely over the standard. Accumulatively, annual absorbed dose is 102.88mSv. After the protection, the dose of the 23 positions is (0.67±1.56) mGy/h, with range of 0.0006～5.22 mGy/h. Specially, dose in the lower parts of operators body, below abdomen, is reduced to the bottom limitation, annual dose reduced to 20.76mSv. By comparison, the statistically difference is P<0.05. Dose of operators is reduced to 1/5 of previous. Taking stand positions of radiation workers into sole consideration, the dose before:(1.78±2.07) mGy/h, with the range (0.21～6.27) mGy/h; the dose after:(0.00021±0.00035) mGy/h, with the range of (0～0.008) mGy/h. The statistical difference is P<0.05. Patients absorbed dose is also reduced, thus their healthy body parts are protected;③Above-tube protect cover:the cover is installed to the tube directly. Results show that dose of principle surgeon is (5825±1755)μSv·h-1 before protection, range (3580～7580)μSv·h-1, while (112±56)μSv·h-1 with the protection, and range (56～129)μSv·h-1. For secondary surgeon, (250±34)μSv·h-1, and range (216-282) uSvh-1.Before the protection, (62±5)μSv·h-1, and range (56～67)μSv·h-1. For the principle surgeon in front, (3270±1243)μSv·h-1, without this protection and range (123～8730)μSv·h-1, while after the protection, (202.5±37.5)μSv·h-1, range (112～278)μSv·h-1. Before this protection, radiation of eye lens at the head of bed is 4.57mSv/h, hypothyroid 11mSv/h, abdomen 527μSv/h. With the installation of protection, radiation of eye lens at the head of bed is 0.418mSv/h, hypothyroid 0.427mSv/h, abdomen 52μSv/h. There is statistic difference in the absorbed radiation dose before and after the protection. Conclusion:1) Epidemic Investigation of Radiation Dose Prediction on patient's ESD, DAP and ED is in accordance with reported data. Radiation dose of medical staff:the absorbed radiation dose of most interventional treatment staff is over the standard of 20mSv. The dose in more than 60% test positions is over the Space Air Kerma Rate 0.05 mGy/h on the test space of perspective in erect position. Most radiation dose in interventional treatment area shows:the principal operators' dose>the secondary operators'>the third operators, the dose of under-bed tube>the dose of above-bed tube. Dose of principal operators is 63.4% over standard, with highest 17.5mSv/h. Dose of secondary operators is 51.6%, with highest 8.84mSv/h. Dose of the third operators:30.4% over standard, with highestmSv/h. Radiation dose of operators in surgery stand positions is big also under the condition of using high reference air kerma, but there is no definite correlation. The reason is that radiation of patients is direct from X-ray machines, while operators'radiation is mainly caused by scattering rays; 2) R&D of protect device By repeated experiments using half-value layer and half-price-layer calculation, three types of protective device are designed, considering various voltage, machine type and surgery type. The three are:the protective shield devices, protective equipment under the tube and above-tube. Make design of device and look for producer. After experimenting again and again the problem of manufacture is solved thus the bottleneck in protect device operating is no longer existed; 3) Effect of protect device:①Protective shield devices:applicable in intervention treatment X-ray machine involved in under-tube operation, esp. in X-ray machines with non-movable under-tubes, such as those in digest department, orthopaedics and gravel etc. The absorbed radiation dose of principle operators and their assistants can be efficiently reduced to the national standards in 20mSv/a after comprehensive protection. The health of interventional radiation people is better protected.②Protective equipment under the tube:applicable in under-tube machines. Before the equipment, radiation practitioners' radiation dose is severely over standard. After the equipment, the dose is down to the standard (≤20mSv/a). Specially, the dose in perspective-in-erect position meets the standard (≤43μSv/h). Meanwhile, dose in patients' other parts are also reduced;③Protective equipment above the tube:applicable in both above and under tube. It is equipped directly into machine's head. After this, radiation of practitioners and patients' healthy parts are all reduced obviously. After installment protective equipment, the dosage will fall to the national standards in 20mSv/a. The biggest advantage of this device is that it solves the problem of hindering the operation while protecting. Therefore this protect cover is more practicable and can be better promoted.