Study of nuclear medicine practices in Portugal from an internal dosimetry perspective

An investigation into internal exposure management needs for nuclear medicine practitioners and temporary visitors through I-131 internal dose assessment: Focusing on large hospitals in South Korea

Purpose

To investigate the internal exposure of nuclear medicine practitioners in South Korea.

Methods

This study selected nuclear medicine practitioners among domestic hospitals and quantitatively measured their degree of internal exposure to radioisotopes, and conducted a dose assessment based on the results. For the dose assessment, 35 nuclear medicine practitioners at seven large hospitals were selected as the measurement subjects, and the measurements were obtained using the thyroid count, total body count, and a urine sample analysis. The internal exposure was measured once every two weeks, and measurements were obtained three to 15 times according to the practitioners.

Results

As a result of measuring and analyzing the radionuclides with urine samples, one or more detections above the minimum detectable activity (MDA) was identified in 52 (15%) among all 340 cases for 14 of the practitioners (43%). The committed effective doses were evaluated as have a distribution of zero to 5.4 mSv, and were mostly 1 mSv or less. There were four practitioners exceeding 1 mSv based on the whole-body measurements, whose results from a urine sample analysis and thyroid monitoring all showed exposure of 1 mSv or less. All of the practitioners participated directly in the distribution and handling of radioactive sources, and none of the nurses exceeded 1 mSv. Furthermore, it was noteworthy that, among medical assistants who do not directly handle radioisotopes and are mainly involved in the transport of contaminated patients, there was one person who exceeded the whole-body measurement standard of 1 mSv.

Conclusions

The committed effective dose of most nuclear medicine practitioners who participated in the survey was lower than 1 mSv. However, because the possibility of overexposure under special circumstances cannot be completely excluded, new strict radiation protection rules on the handling of open-source radioisotopes in hospitals are required for non-handling workers.

THYROID EXPOSURE DURING 18F-FDG PRODUCTION PROCEDURES

The production of radiopharmaceuticals for the needs of positron emission tomography (PET), in particular 18F-FDG, is a multi-step process performed most often by physicists and chemists. The monitoring of occupational exposure of staff employed in radiopharmaceutical production centres includes the measurement of the Hp(10) and Hp(0.07) values. Occupational exposure to ionising radiation means that the thyroid may be, among others, affected by the radiation field. This work analyses the exposure of the thyroid gland of employees of centres that produce the isotopes for PET, in particular fluorine-18. The analysis take into account the employment structure and work system of the discussed centres. Measurements were carried out by using high-sensitivity thermoluminescence detectors (MCP-N). The measurements covered 17 employees. Our results show that the estimated maximum annual thyroid gland exposure will not exceed 30 mSv.

Radiological protection of foetuses and breast-fed children of occupationally exposed women in nuclear medicine - Challenges for hospitals

This paper describes issues of concern for protecting foetuses and breast-fed children of occupationally exposed women in nuclear medicine from unnecessary exposure of ionising radiation. The protection principle is to ensure the same level of protection for the foetus and child as for the general public. Therefore international radiation protection standards recommend a dose constraint of 1mSv to a foetus during the remaining time of pregnancy after it is known/declared and a yearly dose constraint of 1mSv to a breast-fed child. It is not self-evident how to guarantee this level of radiation protection. The exposure situation in nuclear medicine is complex. Exploring existing reported occupational exposure levels suggests great variability between work tasks and facilities. The standards and guidelines found give no detailed advice. Therefore each facility needs to systematically review external and internal exposure levels in order to plan appropriate protection measures and issue their own guidelines and rules. One strategy might be that each facility defines tasks that do not require any restrictions and lists such duties that are not suitable to do when pregnant or breastfeeding, taking also potential exposure levels into consideration. This paper gives examples of such types of work. Information to the staff about the necessity of declaring pregnancy or breastfeeding is of fundamental importance. The internal policies issued by the hospital management should make clear the basis for taking care of pregnant and breastfeeding employees.

Necessity of Internal Monitoring for Nuclear Medicine Staff in a Large Specialized Chinese Hospital

This work intends to quantify the risk of internal contaminations in the nuclear medicine staff of one hospital in Henan province, China. For this purpose, the criteria proposed by the International Atomic Energy Agency (IAEA) to determine whether it is necessary to conduct internal individual monitoring was applied to all of the 18 nuclear medicine staff members who handled radionuclides. The activity of different radionuclides used during a whole calendar year and the protection measures adopted were collected for each staff member, and the decision as to whether nuclear medicine staff in the hospital should be subjected to internal monitoring was made on the basis of the criteria proposed by IAEA. It is concluded that for all 18 members of the nuclear medicine staff in the hospital, internal monitoring is required. Internal exposure received by nuclear medicine staff should not be ignored, and it is necessary to implement internal monitoring for nuclear medicine staff routinely.

The profile and practice of nuclear medicine technologists in Portugal: findings from a nationwide survey

OBJECTIVES

Nuclear medicine (NM) is a rapidly developing field. In Portugal, no occupational study has been conducted yet that characterizes the professional profile of NM technologists (NMTs). We investigated the clinical tasks performed by NMTs in Portugal, analysing their practices with regard to radiation protection matters and their compliance with established international guidelines for best practice.

METHODS

A questionnaire targeted at NMTs was constructed and distributed among 105 NMTs working in Portugal (an estimated 88% of the NMT population in Portugal). Questions addressed the demographic profile, academic background and professional profile of NMTs, with emphasis on practices adopted in NM tasks and radiation protection.

RESULTS

In all, 51.4% of the 105 NMTs responded. The majority (70.4%) of the NMTs studied were women, with an average age of 34.3 (± 10.4) years and 11.6 (± 10.6) years of professional experience. The reported NM tasks included radiopharmaceutical preparation (96.3%), PET (44.4%), intravenous administration (74.1%), administration with dose containers (97.7%) and administration with syringe shields (76.9%). The use of a protective lead apron was rare (2.7%). The average individual dose recorded was 3.8 (± 2.7%) mSv/year.

CONCLUSION

NMTs in Portugal are generally young women with specialized academic education, consistent with the developments in NM technology and education in Portugal since the past decade. The majority of NMT activities are focused on conventional NM. The estimated annual average individual dose is below the established legal limit. However, radiation protection practices related to staff protection are not harmonized, revealing key aspects to be considered in future education and training.