With the continuous development and improvement of modern medical equipment and medical technology, the key population of radiation protection has undergone fundamental changes. In the interventional diagnosis and treatment of cardiovascular diseases, both the surgeon and the patient often receive high doses of ionizing radiation. Moreover, this increase in radiation doses can have an important impact on their health. However, most of the cardiovascular interventional staff have not undergone specialized training in radiation protection, lack the necessary awareness of protection in their work, and their dose levels are several times or even dozens of times that of conventional X-ray diagnostic staff. With the development of cardiovascular disease intervention in China and the increase of practitioners, the problem of radiation protection in the interventional diagnosis and treatment of cardiovascular diseases has gradually attracted everyone's attention. Compared with transguisal arterial intervention, transjunctive artery intervention has been more and more used by the majority of interventional doctors in China because of its simple operation, few complications, no need to stay in bed after surgery, and less pain for patients. However, the use of the transreidential intervention has the potential to lead to an increase in the radiation dose of the operator due to the effects of anatomical variations in its operating path that can lead to increased fluoroscopic time, as well as closer proximity to the radiation source. This has also aroused widespread concern among those involved in domestic and foreign interventions.
"1. Radiation risk of surgeons in cardiovascular interventional diagnosis and treatment
The radiation received by the surgeon in the cardiovascular interventional diagnosis and treatment is mainly scattered radiation, most of which is scattered by radiation at the patient's skin incidence, and a small part comes from the X-ray bulb and image intensifier or flat detector. The radiation effects produced are mainly random effects (tumor risk), the generation of random effects is related to cumulative effects, there is no threshold dose, and receiving the same dose of ionizing radiation multiple times can reduce the definite effect, but cannot reduce the random effect. During interventional procedures, the surgeon's head and limbs are rarely protected and therefore often receive high doses of radiation. Studies have shown that, without protection, the average incident dose of the eye, thyroid and hand can reach 120-400 μSv, 390 μSv, and 240-510 μSv per interventional procedure. Report No. 60 of the International Commission on Radiological Protection (ICRP) strictly regulates the radiation dose for occupational personnel: for 5 consecutive years, the effective dose limit for occupational radiation personnel is 100 mSv, and the maximum effective dose is 50 mSv per year; the equivalent dose for hands, feet and skin is 500 mSv for 1 year; and the equivalent dose of ophthalmos is 150 mSv for 1 year. Although during interventional procedures, the surgeon is generally not directly exposed to useful rays, so there is generally no definitive impairment. However, with the development of interventional instruments and techniques, the complexity of the procedure has increased greatly, and the radiation time required has also increased greatly. Cases of hand skin damage and ophthalmic cataracts caused by severe radiation by interventional workers have been reported. Recent studies suggest that the absorption dose threshold for the ophthalmic lens as a radiation-sensitive organ that causes radiation damage to it is much lower than previously reported (5Gy). In 2011, the ICRP issued a statement reducing the absorption dose threshold for ophthalmic lenses from 5Gy to 0.5Gy and revising the annual equivalent dose limit for ophthalmic lens irradiation under planned irradiation (150 mSv) to an average annual equivalent dose of 20 mSv for 5 consecutive years, and the equivalent dose in any single year should not exceed 50 mSv. The above suggests that the ocular lens may become a restrictive organ of the interventional operator, and the radiation protection of the ocular lens needs more attention.
Second, the effect of transreidial artery intervention on the radiation dose of the operator
As mentioned earlier, transradial intervention has the potential to lead to an increase in the radiation dose of the surgeon. A large number of studies have been done at home and abroad on the effect of trans-radial and transfessal artery interventional pathways on the radiation dose of surgeons. It has been reported that when conventional lead screens are used for protection, the radiation dose of transreidial artery route is increased by 100% compared with transfemoral artery route operators, and 50% increased by percutaneous coronary intervention (PCI). When optimized lead screen protection was adopted, the radiation dose of the surgeon was still increased in the trans-radial artery pathway, and the coronary angiography and PCI increased by 83% and 38%, respectively. Although previous studies have suggested an increase in doses in the transreidal artery pathway, this view remains somewhat controversial. This is due to the fact that in clinical practice, there are many factors that affect the radiation dose of the surgeon, such as contrast machine exposure parameters, patient anatomical variations, surgical complexity, and operator experience. Even for experienced surgeons, the radiation dose dose they receive varies greatly from one practitioner to another. This suggests that the different radiation protection strategies adopted between different practitioners have a very important impact on the comparison of radiation doses between practitioners. In addition, the use of some special protective equipment specifically for transreidial interventional radiation protection will also have an important impact on the dose of the surgeon, and foreign reports can reduce the dose of the surgeon by about 30%. At the same time, recent reports have found that the correct use of lead screens for protection can reduce the dose of the surgeon by at least 80%. Therefore, if optimized radiation protection measures are adopted, whether the dose of the surgeon is still increased by the trans-radial artery route compared with the transfemoral artery route has become a concern. Studying this question using anthropomorphic motifs can avoid the various effects of the above on the dose of the surgeon and thus obtain a more accurate answer. A model study conducted by the Department of Cardiology of the Armed Police General Hospital on the effect of transreidial artery route and transcrossal arterial route coronary angiography on the radiation dose of the surgeon found that the use of a special protective device for the transradial artery route during transradial coronary angiography can significantly reduce the radiation dose of the surgeon, despite the use of optimized radiation protection measures, the trans-radial coronary angiography still significantly increases the radiation dose of the surgeon compared with the transfessal artery, and the study also suggests that in clinical practice, The operator should adopt different radiation protection strategies according to the specific projection angle to achieve the best protective effect.
3. Radiation protection for transradial interventional therapy
Out of concern for the issue of radiation protection from occupational exposure, icrp requires all personnel involved in radiation protection to undergo radiation protection training and proposes three basic principles of radiation protection, namely the application of legitimacy, optimization and dose limits, of which the optimization principle is the core of the radiation protection system. The principle of legitimacy, i.e. any decision to change the irradiation situation should have more advantages than disadvantages. The principle of optimization, that is, the possibility of exposure, the number of people being exposed, and the size of the dose received by the individual should be controlled to the lowest possible level that can be reasonably achieved. The application of dose limits, i.e. the sum of the doses to which any individual is irradiated, except for the medical irradiation of the patient, should not exceed the corresponding limits established by the Radiological Protection Commission. Most patients undergo only a few cardiovascular interventional diagnoses and treatments in their lifetime, and cardiovascular interventional staff receive radiation every day. The dose of radiation received by the patient is closely related to the dose of the surgeon, so reducing the radiation dose of the patient to a minimum is fundamental to reducing the dose of the surgeon. In general, the dose reduction of the surgeon needs to start from three aspects, one is to minimize the exposure time of the X-ray, and the radiation dose is proportional to the individual and the radiation contact time. The shorter the exposure to the radiation source, the less the total dose received. Minimizing the number of fluorescences, fluorescence time and cinematic time is important for longer interventional procedures when meeting clinical needs. The second is to increase the distance between patients and surgeons and the radiation source. Distance protection is the simplest and most effective measure of protection. The relationship between the distance from the radioactive source and the dose rate follows the inverse square law. Increasing the distance to the radioactive source by a factor of 2 can reduce the dose rate by a factor of 4. The minimum distance between the patient's skin and the radioactive source is generally required to be 38 cm, and those who do not participate in the operation directly should stand at least 2 meters away from the radiation tube. The third is to reasonably apply shielding measures. It is important to choose the appropriate shield according to the type and use of the rays. Shielding measures mainly include lead screens, lead coats, lead bibs, lead glasses, lead caps and mobile lead screens. The cauldron chamber must be equipped with the necessary protective equipment. In addition, you should be familiar with the use of these protective equipment and use these protective equipment correctly to achieve the best protective effect. In addition, studies have shown that the radiation dose of the interventional personnel is mainly determined by the dose of unprotected organs (thyroid gland, partially active bone marrow). Therefore, there is a wireless relationship between the shielding coefficient and the effective dose of the protective clothing. Increasing the thyroid protective bib can reduce the effective dose by a factor of 3. The main measures of radiation protection for transreidial interventional therapists are shown in Table 1.
4. Summary
With the development of interventional medicine and the growth of the team of interventional practitioners, interventional staff should enhance the awareness of radiation risk and protection, always keep in mind radiation protection, protect patients is to protect themselves, and protect themselves is to protect patients. Even with optimal radiation protection measures, transradial coronary intervention therapy still significantly increases the radiation dose of the surgeon compared with the transfigual artery. Therefore, the operation of trans-radial intervention should pay more attention to radiation protection, the use of special radiation protection devices for the per-radial artery route can greatly reduce the dose of the surgeon, at the same time, the operator should take different radiation protection strategies according to the specific projection angle to achieve the best protective effect.