Proton Therapy and Gliomas: A Systematic Review

Background: Gliomas are primary cerebral tumors. Radiation therapy plays a key role in their treatment but with a risk of toxicity associated with the dose to and volume of normal tissue that is irradiated. With its precision properties allowing for the increased sparing of healthy tissue, proton therapy could be an interesting option for this pathology. Methods: Two reviewers performed a systematic review of original papers published between 2010 and July 2021 following PRISMA guidelines. We analyzed disease outcomes, toxicity outcomes, or dosimetry data in four separate groups: children/adults and individuals with low-/high-grade gliomas. Results: Among 15 studies, 11 concerned clinical and toxicity outcomes, and 4 reported dosimetry data. Proton therapy showed similar disease outcomes with greater tolerance than conventional radiation therapy, partly due to the better dosimetry plans. Conclusions: This review suggests that proton therapy is a promising technique for glioma treatment. However, studies with a high level of evidence are still needed to validate this finding.

Status - International Space Station (ISS) Crewmembers' Noise Exposures

Environmental noise in space vehicles, caused by onboard equipment and crew activities, has generated concerns for crew health and safety since early U.S. space missions. The International Space Station (ISS) provides a unique environment where acoustic conditions can be monitored while crewmembers from the U.S. and their international partners work and live for as long as 6 to 12 consecutive months. This review of acoustic dosimetry data collected to date reveals that the noise exposure limits of NASA's stringent noise constraint flight rule have been exceeded in 41% of these dosimetry measurements since ISS Increment 17 (2008), with undefined impacts to crew. These measurements do not take into account the effects of hearing protection devices worn by the crew. The purpose of this paper is to provide an update on ISS noise exposure monitoring approaches and hearing conservation strategies that include acoustic dosimetry data collected since the ISS Increment 55 mission (April 2018). Future directions and recommendations for the ISS noise exposure monitoring program will also be presented, including research initiatives aimed at better defining the impact of ISS noise on crew health and performance.

Radiation Dose and Fluoroscopy Time of Endovascular Treatment in Patients with Intracranial Lateral Dural Arteriovenous Fistulae

Purpose Intracranial lateral dural arteriovenous fistula (LDAVF) represents a specific subtype of cerebrovascular fistulae, harboring a potentially life-threatening risk of brain hemorrhage. Fluoroscopically guided endovascular embolization is the therapeutic gold standard. We provide detailed dosimetry data to suggest novel diagnostic reference levels (DRL). Methods Retrospective single-center study of LDAVFs treated between January 2014 and December 2019. Regarding dosimetry, the dose area product (DAP) and fluoroscopy time were analyzed for the following variables: Cognard scale grade, endovascular technique, angiographic outcome, and digital subtraction angiography (DSA) protocol. Results A total of 70 patients (19 female, median age 65 years) were included. Total median values for DAP and fluoroscopy time were 325 Gy cm2 (25%/75% percentile: 245/414 Gy cm2) and 110 min (68/142min), respectively. Neither median DAP nor fluoroscopy time were significantly different when comparing low-grade with high-grade LDAVF (Cognard I + IIa versus IIb–V; p > 0.05, each). Transvenous coil embolization yielded the lowest dosimetry values, with significantly lower median values when compared to a combined transarterial/transvenous technique (DAP 290 Gy cm2 versus 388 Gy cm2, p = 0.031; fluoroscopy time 85 min versus 170 min, p = 0.016). A significant positive correlation was found between number of arterial feeders treated by liquid embolization and both DAP (rs = 0.367; p = 0.010) and fluoroscopy time (rs = 0.295; p = 0.040). Complete LDAVF occlusion was associated with transvenous coiling (p = 0.001). A low-dose DSA protocol yielded a 20% reduction of DAP (p = 0.021). Conclusion This LDAVF study suggests several local DRLs which varied substantially dependent on the endovascular technique and DSA protocol.

Occupational low-dose irradiation and cancer risk among medical radiation workers

Background Medical workers are the largest group of workers occupationally exposed to low doses of ionizing radiation (IR) worldwide. Aims This review presents all the cohorts of medical workers exposed in the world and summarizes cancer risks associated with radiation exposure in this population. Methods Epidemiological studies on health professionals exposed to IR published from 1975 to 2019 were reviewed. Strength of evidence was assessed according to the modified Royal College of General Practitioners three-star system. Results Among the 16 epidemiological studies focusing on cancers from 11 cohorts among medical staff exposed to radiation, higher risks of cancer were observed for pre-1950 exposure and for medical workers who performed fluoroscopically guided interventional procedures or radionuclides procedures compared to those who did not. However, strength of evidence supporting the associations remains moderate as several methodological limits including the lack of dosimetry data, lifestyle factors and recent updates may obscure the link between medical occupational exposure and cancer occurrence. Conclusions Excess risk of cancer is suspected for high and former exposures. The more highly exposed professions, i.e. interventional physicians and nuclear medicine workers, should be monitored carefully. Collaborative projects aiming to increase the quantity and quality of information of the studied populations would be a key point

Occupational radiation exposures for medical workers in Pakistan – An overview

The imperative use of ionizing radiation in medicine causes the inevitable occupational exposure of the medical workers during the course of routine duties. The magnitude of health risk due to such radiation exposures has been described in terms of occupational radiation doses. In this context, it is obligatory to monitor, measure and document the radiation dose of occupationally exposed medical workers. This study aims to review the whole-body occupational radiation exposures of medical workers in Pakistan. Specifically, online literature published during 2000-2018 was reviewed for the occupational radiation exposures of Pakistani medical workers. Analysis of the extracted personal dosimetry data revealed that the total number of monitored medical occupational workers was 26046. The range of total cumulative and annual average effective doses was 94-15785 Person-mSv and 0.66-7.37 mSv, respectively. A significant number of the workers (25477; ~98%) received an annual dose below 5 mSv, while only 18 workers received an occupational exposure exceeding the annual dose limit of 20 mSv. It is expected that this study will provide a useful reference for evaluating and improving radiation protection and safety policies in the country.

OCCUPATIONAL RADIATION PROCEDURES AND DOSES AMONG NURSES IN SOUTH KOREA

This study investigated occupational radiation procedures and radiation exposures among nurses in South Korea. A total of 530 nurses were surveyed from 2012 to 2013, and the survey data were linked with the dosimetry data. Multiple regression analysis was used to identify the factors associated with radiation dose. The most frequent procedure performed by the nurses was interventional radiology, followed by fluoroscopy and routine X-ray. The average annual effective dose and the cumulative dose were 0.91 mSv and 4.66 mSv, respectively. Characteristics of nurses exposed to high radiation doses were male, completed graduate school or higher, first worked before 2000 and performing interventional procedures, nuclear medicine test and fluoroscopy. Performing nuclear medicine tests and interventional procedures had a significant positive association with high radiation exposure.

Occupational diseases caused by exposure to laser radiation

Sources of laser radiation are firmly entrenched in all spheres of human activity: different branches industry, biology, gene engineering, medicine, agriculture. In cases of gross safety violations, laser radiation can be dangerous for people working with it. Biological action of laser radiation is not completely found out. By the nature of human exposure to laser radiation, it is divided into direct, diffuse, specularly reflected and diffusely reflected. It can cause both primary effects, which include organic changes that occur in irradiated tissues, and secondary effects, which are nonspecific changes that occur in response to radiation. The «critical» organs for laser radiation are the eyes and the skin. Laser lesions are divided into acute and chronic. Acute lesions occur either in cases of gross security breaches or emergencies. The development of chronic lesions is possible in cases of prolonged work with low-intensity laser devices. Other adverse factors, such as noise, vibration, light from flash lamps, ultraviolet radiation, tiredness of visual analyzer, air pollution (ozone, oxide of nitrogen), neuro-emotional tension, affect workers during exploitation of laser radiation’s sources. Diagnostics of laser lesions is based on the occupational history data of sanitary and hygienic characteristics of working conditions as well as on the results of clinical examination and dosimetry data. There is no specific treatment for laser lesions.