Extremity exposure in nuclear medicine: preliminary results of a European study

Role of Capillaroscopy in Early Diagnosis of Ionizing Radiation Damage in Healthcare Professionals

Background and Objectives: Chronic ionizing radiation has biological effects on exposed healthcare workers, particularly on the skin. Capillaroscopy of the nail bed represents an easy, low cost, and non-invasive test to obtain information on the effects of chronic radiation exposure in healthcare workers. The aim of this study was to evaluate which capillaroscopic parameters are most associated with biological damage by chronic radiation exposure. Materials and Methods: We conducted a case-control study, in which cases were represented by healthcare workers exposed to ionizing radiations and controls by healthy subjects. We recorded anamnestic and personal data, including age and gender, before capillaroscopic examination of proximal nail folds of the fingers of both hands. Ten morphological qualitative/quantitative parameters were taken into consideration, assigning each of them a score on a scale from 0 to 3 (0 = no changes, 1 = <33% abnormal capillaries, 2 = 33-66% of abnormal capillaries, 3 = >66% of abnormal capillaries, for single magnification field at 200×). The parameters evaluated were: changes in the length, distribution and density of capillary loops, reduced visibility, decreased flow, visibility of the sub-papillary plexus, and presence of morphological atypia, such as ectasia, tortuosity, hemorrhage, and signs of neoangiogenesis. Results: We enrolled 20 cases and 20 controls. The two groups did not differ significantly for gender and age. Cases differed from controls in a statistically significant way for the following parameters: decreased capillary length (number of shortened capillaries) (p < 0.05), increased visibility of the subpapillary venous plexus (p < 0.05), tortuosity (p < 0.01), neoangiogenesis (p < 0.01), and ectasias (p < 0.001). Conclusions: We found that some capillaroscopic parameters, such as variability in length of capillaries, visibility of subpapillary venous plexus, presence of ectasias, tortuosity, and neoangiogenesis signs, are particularly associated with exposure to ionizing radiation in healthcare professionals. Alterations of these parameters may represent capillaroscopic clues of biological damage by chronic radiation exposure in healthcare professionals. Based on these observations, capillaroscopy may provide clinical data useful to the prevention and follow-up of radiation-exposed healthcare professionals.

The relative contribution of photons and positrons to skin dose in the handling of PET radiopharmaceuticals

BACKGROUND

Despite recommendations to use syringe and vial shields to reduce exposure of the hands of staff when manipulating PET radiopharmaceuticals, operators sometimes prefer to work without shields, believing that the faster handling limits the equivalent dose. The aim of this work is to show that this approach does not properly consider the contribution of positrons to the dose.

MATERIALS AND METHODS

Using the Varskin+ code, skin doses were calculated for syringes of various sizes, filled with ¹⁸F, ¹¹C or ⁶⁸Ga solution. Syringes without shielding, or shielded with 2 mm and 10 mm of tungsten were considered.

RESULTS

Dose rate values in mSv/s per MBq, averaged on a 1 cm² surface at a depth of 0.07 mm were calculated for all the above conditions. For example, in the case of 3 mL ¹⁸F syringe at 1 mm from the skin, the dose rate without shielding is 1.32E-02 and 8.63E-04 for positrons and photons respectively. For ¹¹C, the corresponding dose rates are 4.70E-02 and 8.90E-04 respectively, and for ⁶⁸Ga, 8.52E-02 and 9.48E-04.

CONCLUSIONS

Our results show that the dose due to positrons is the principal component of skin irradiation, by a factor of 3-100, depending on the conditions. The use of shields for syringes and vials is necessary to avoid unjustified skin exposures, that may challenge dose limits. In our opinion, automatic systems for dispensing and allowing injection with shielded syringes, or automatic injectors, are economically justified and should be adopted in PET.

Personal dose equivalent Hp(0.07) during 68Ga-DOTA-TATE production procedures

This work presents the exposure of hands of the personnel of a nuclear medicine department who prepare and administer ⁶⁸Ga-DOTA-TATE. Dosimetry measurements were performed during three 1-week sessions, for nine production procedures. A total of 360 measurements were made by using high-sensitivity MCP-N thermoluminescent detectors. Annealed detectors were and vacuum-packed in foil and then placed on each fingertip of both hands of five radiochemists and four nurses (one detector for one fingertip). The greatest exposure to ionizing radiation was found on the non-dominant left hand of radiochemists and nurses. A maximum H_p(0.07)/A value of 49.36 ± 4.95 mSv/GBq was registered for radiochemists during the ⁶⁸ Ga-DOTA-DATE activity dispensing procedure. For nurses performing the radiopharmaceutical injection procedure, a corresponding maximum value of 1.28 ± 0.13 mSv/GBq was measured, while the mean value for all the nurses was 0.38 mSv/GBq. The dispensing procedure accounted for approximately 60% of the total exposure of radiochemists' fingertips. Based on the results obtained it is recommended that a ring dosimeter should be routinely placed on the middle finger of the non-dominant hand of radiochemists and nurses. Furthermore, it is proposed to systematically train workers in handling open sources of ionizing radiation, with the aim of reducing the required handling time.

Occupational radiation exposure assessment during the management of [68Ga]Ga-DOTA-TOC

Background

Since it was first approved in Europe in 2016, the gallium-68 (⁶⁸Ga) radiopharmaceutical [⁶⁸Ga]Ga-DOTA-TOC has been widely used for imaging of somatostatin receptor (SSTR) positive tumours using positron emission tomography–computed tomography (PET/CT). Significant patient benefits have been reported, so its use is rapidly increasing. However, few studies have been published regarding occupational doses to nuclear medicine personnel handling this radiopharmaceutical, despite its manual usage at low distances from the skin and the beta-emission decay scheme, which may result in an increased absorbed dose to their hands. In this context, this study aims to analyse the occupational exposure during the administration of [⁶⁸Ga]Ga-DOTA-TOC for PET/CT imaging. For this purpose, extremity, eye lens and whole-body dosimetry in terms of Hp(0.07), Hp(3) and Hp(10), respectively, was conducted on six workers with both thermoluminescent dosimeters, and personal electronic dosimeters.

Results

The non-dominant hand is more exposed to radiation than the dominant hand, with the thumb and the index fingertip being the most exposed sites on this hand. Qualitative analysis showed that when no shielding is used during injection, doses increase significantly more in the dominant than in the non-dominant hand, so the use of shielding is strongly recommended. While wrist dosimeters may significantly underestimate doses to the hands, placing a ring dosimeter at the base of the ring or middle finger of the non-dominant hand may give a valuable estimation of maximum doses to the hands if at least a correction factor of 5 is applied. Personal equivalent doses for the eyes did not result in measurable values (i.e., above the lowest detection limit) for almost all workers. The extrapolated annual dose estimations showed that there is compliance with the annual dose limits during management of [⁶⁸Ga]Ga-DOTA-TOC for diagnostics with PET in the hospital included in this study.

Conclusions

Imaging with [⁶⁸Ga]Ga-DOTA-TOC is a safe process for the workers performing the administration of the radiopharmaceutical, including intravenous injection to the patient and the pre- and post-activity control, as it is highly unlikely that annual dose limits will be exceeded if good working practices and shielding are used.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40658-022-00505-8.

Assessment of extremity exposure to technologists working manually with99mTc-labelled radiopharmaceuticals and with an automatic injection system for18F-FDG

The hands of nuclear medicine (NM) personnel involved in radiopharmaceutical preparation and administration can receive significant radiation doses. The dose distribution across the hand is nonuniform and the Hp(0.07) doses obtained by an individual passive ring dosimeter do not always present a real situation. The aim of this study was to assess the extremity exposure of NM workers working with^99mTc-labelled radiopharmaceuticals and with an automatic IRIDE (COMECER, Italy)¹⁸F-FDG injection system. Hp(0.07) doses were measured using calibrated thermoluminescent dosimeters-100 (TLD-100) and were read by a RIALTO TLD (NE Technology) reader. It was found that the most exposed parts of the hand during work with¹⁸F and^99mTc radionuclides are the fingertips of the thumb, index finger and middle finger. The maximum fingertip doses were 1.3-2.4 times higher compared with the doses from the typical monitoring position (base of the middle finger of the dominant hand). When working with^99mTc, the average hand doses were relatively high, i.e. 0.17 ± 0.04 and 0.37 ± 0.13 mSv Gbq^-1for the left and the right hand, respectively, during preparation, and 58 ± 20 and 53 ± 13µSv GBq^-1for the left and the right hand, respectively, during administration of^99mTc labelled radiopharmaceuticals. Meanwhile, the lowest doses were found for hands during administration of¹⁸F-FDG (average hand dose 28 ± 13µSv GBq^-1for the left hand and 28 ± 7µSv GBq^-1for the right hand), which shows the advantages of automated injection/infusion systems, thus implementation of automatic infusion/injection in hospitals could be an expedient way to optimize Hp(0.07) doses to NM workers.

Review of extremity dosimetry in nuclear medicine

The exposure of the fingers is one of the major radiation protection concerns in nuclear medicine (NM). The purpose of this paper is to provide an overview of the exposure, dosimetry and protection of the extremities in NM. A wide range of reported finger doses were found in the literature. Historically, the highest finger doses are found at the fingertip in the preparation and dispensing of¹⁸F for diagnostic procedures and⁹⁰Y for therapeutic procedures. Doses can be significantly reduced by following recommendations on source shielding, increasing distance and training. Additionally, important trends contributing to a lower dose to the fingers are the use of automated procedures (especially for positron emission tomography (PET)) and the use of prefilled syringes. On the other hand, the workload of PET procedures has substantially increased during the last ten years. In many cases, the accuracy of dose assessment is limited by the location of the dosimeter at the base of the finger and the maximum dose at the fingertip is underestimated (typical dose ratios between 1.4 and 7). It should also be noted that not all dosimeters are sensitive to low-energy beta particles and there is a risk for underestimation of the finger dose when the detector or its filter is too thick. While substantial information has been published on the most common procedures (using^99mTc,¹⁸F and⁹⁰Y), less information is available for more recent applications, such as the use of⁶⁸Ga for PET imaging. Also, there is a need for continuous awareness with respect to contamination of the fingers, as this factor can contribute substantially to the finger dose.

Occupational radiation exposure of radiopharmacy-, nuclear medicine-, and surgical personnel during use of [99mTc]Tc-PSMA-I&S for prostate cancer surgery

Aim: The aim of this study was to estimate and subsequently measure the occupational radiation exposure for all personnel involved in the production, administration, 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 Materials and 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 technician, syringe preparation by the nuclear medicine laboratory technician, patient administration by the nuclear medicine physician, patient imaging by the nuclear medicine imaging technician, and robot-assisted laparoscopic salvage lymph node dissection attended by an anesthesiology technician, 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 1.59x10-10 µSv (imaging technician) to 9.74 µSv (scrub nurse). The measured effective dose ranged from 0 to 5 µSv for all personnel during one procedure with [^99mTc]Tc-PSMA-I&S. The highest effective dose was received by the scrub nurse (3.2±1.3 µSv), whilst the lowest dose was measured for the surgical nurse (0.2±0.5 µSv). If a single scrub nurse would perform as much as 100 procedures with [^99mTc]Tc-PSMA-I&S in a year, the total effective dose would be 3.2x10-1 mSv/year. 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 and reducing even further to 0.56±0.33 µS/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.

Occupational radiation exposure of health professionals and cancer risk assessment for Lithuanian nuclear medicine workers

BACKGROUND

Reconstruction and analysis of low doses received by the occupationally exposed medical radiation workers, especially nuclear medicine staff dealing with radioisotopes may significantly contribute to the understanding of radiation impact on individuals, assess and predict radiation related risks for the development of cancer or other specific diseases.

METHODS

A pool of 2059 annual effective doses corresponding to 272 job's positions occupied by nuclear medicine and radiology workers for a certain time period over 26 years in five Lithuanian hospitals was investigated in order to analyze the occupational exposure tendencies to medical staff. Requested data, measured in terms of whole body dose, personal dose equivalent Hp(10), was obtained from the National Register of Sources of Ionizing Radiation and Occupational Exposure. Considering that nuclear medicine staff is dealing with open sources/radioisotopes, doses to extremities, Hp(0.07), were measured using thermoluminescent dosimeters (TLD) of LiF:Mg, Ti type. Lifetime risk estimations for the development of specific cancer (thyroid cancer and leukemia) for exposed radiation workers were performed using risk models included in BEIR VII report (BEIR VII, 2006). The conservative assessment of the thyroid exposure was performed using RadRAT 4.1.1 tool.

RESULTS

Doses to radiology technologists and radiology nurses were found to be highest over the years. However, their annual doses never exceeded dose limit of 20 mSv and were following the same decreasing tendency as the doses of other personnel. There was no increase of doses to nuclear medicine staff observed after installation of two new PET/CT machines, indicating increased radiation protection culture and application of relevant technical and protective measures by the staff. Measured fingertip doses were 2-3 times higher than the hand doses measured with TLD ring and were dependent on the type and frequency of the nuclear medicine examination procedure and on the type and activity of isotopes used for examination.

CONCLUSIONS

For the first time, retrospective dose evaluation for the cohort of medical radiation workers was performed in the country. It enabled estimation of lifetime attributable risk for the development of two cancer types: thyroid and leukemia cancer among occupationally exposed medical radiation staff. Projected risk was low, ~10^-5, however it was found that the risk of thyroid cancer for female staff was 5.7 times higher than for the males. Obtained results will be used for the predictive assessment of possible radiation induced health effects to occupationally exposed medical radiation workers.

A new mobile self-dispensing and administering system for 18F-FDG: evaluation of operator dose reduction

PURPOSE

Recently new mobile systems for dispensing positron emitters have been produced, designed to guarantee dispensing cycles in an aseptic environment. The aim of the present work was to assess the advantage of one of these systems in radiation protection of operators in clinical settings.

METHODS

Recently, in our centre the new self-dispensing system named KARL₁₀₀ by Tema Sinergie was adopted for ¹⁸F-FDG radiopharmaceuticals. The system is associated with an automatic Rad-inject infuser. The system that was previously used was a fixed isolator NMC DSI (Tema Sinergie), equipped with a μDDS-An activity fractioning system, together with a pneumatic post for the syringe delivery. The dosimetric evaluations on both systems were carried out through environmental measurements with an ionisation chamber and with the use of personal dosimeters.

RESULTS

The operations of preparation and administration of ¹⁸F-FDG dose to the patient, with the use of Karl₁₀₀ + RadInject, involve exposures much lower than those obtained by the fixed isolator. The average body exposure of the technician was reduced by 31%, and for the physician by 77%. On the extremities, the equivalent dose to the hands of the technician was reduced by 78%, and for the physician by 96%. Also the additional dosimeters worn by the technician confirmed the estimated environmental assessments.

CONCLUSIONS

The exposures of the working personnel were significantly reduced with the introduction of the new KARL₁₀₀ system.

Demonstrating Compliance With Proposed Reduced Lens of Eye Dose Limits in Nuclear Medicine Settings

Based on ongoing research on ionizing radiation thresholds for cataracts, the International Commission on Radiological Protection has proposed new guidelines lowering the annual occupational lens of eye dose limit from 150 mSv to 20 mSv. The International Atomic Energy Agency has operationalized these new guidelines. Subsequently, national/regional radiation protection regulators are reviewing their lens of eye dose limits with an aim of moving towards the proposed new limits, resulting in licensees having to demonstrate compliance. In health care settings, fluoroscopic interventional practices generally have higher lens of eye doses and nuclear medicine settings generally have lower doses. A prospective cohort (n = 19) of nuclear medicine technologists wore dedicated lens of eye dosimeters for a 3 mo period synchronized with their body dosimeter schedules. The lens of eye dosimeters were validated to have a linear response in the anticipated dose ranges. The participants worked in a relatively high-volume nuclear medicine practice, which included general and cardiac, positron emission tomography/computed tomography, radiopharmacy, and cyclotron operations. The annualized dose ranges were 0.0-3.68 mSv (lens of eye) and 0.48-4.72 mSv (whole body). There was a good correlation between lens of eye and body dosimeter readings (R = 0.67). There were no significant differences in lens of eye dose by work type, worker sex, or side on which the dosimeter was worn. The findings should be generalizable to other similar practices, especially in North America, and should be sufficient to demonstrate regulatory compliance in nuclear medicine settings with the proposed new lens of eye dose limits.

Wrist dosimeter in nuclear medicine - An alternative for the ring dosimeter?

PURPOSE

Individual dosimetry is undoubtedly one of the best methods of assessing the exposure of personnel to ionizing radiation, however in case of nuclear medicine, the method applied to measure the dose does not always present a picture of the worker's actual exposure. The highly non-homogeneous dose distribution on the hand means that the ring dosimeter, routinely used to measure the Hp(0.07), provides only approximate dose values received by fingertips, the body part most exposed to ionizing radiation. This paper is an attempt to answer the question whether the wrist dosimeter used as a replacement for the ring dosimeter is able to provide information on doses for the most exposed fragments of the hand of an employee during handling procedures with the use of radiopharmaceuticals.

MATERIALS

Throughout measurements performed in five nuclear medicine facilities, high-sensitivity thermoluminescent detectors were used.

RESULTS

Correction coefficients have been determined, which constitute an amendment to be made to move from the dose recorded by the wrist dosimeter to the doses received by the most exposed hand fragments. The fingertips received on average 25 times higher doses, compared to the values recorded by the wrist dosimeter.

CONCLUSIONS

A wrist dosimeter can be used to measure the Hp(0.07) in nuclear medicine, including as a gauge of the most exposed parts of the hand - the fingertips. However, the applicability of correction coefficients makes it necessary to ensure a stable position of the wrist dosimeter during routine procedures.

ASSESSMENT OF THE LOCAL EXPOSURE OF SKIN ON HANDS OF NUCLEAR MEDICINE WORKERS HANDLING 18F-LABELLED RADIOPHARMACEUTICALS: PRELIMINARY CZECH STUDY

The article summarises some preliminary results of the assessment of the exposure of hands of workers manipulating ¹⁸F-labelled radiopharmaceuticals based on personal monitoring at two nuclear medicine clinics in the Czech Republic. The measurements were carried out using special thermoluminescence dosemeters the readings of which could be interpreted in terms of the personal dose equivalent H_p(0.07) approximating the equivalent dose to the skin at various locations on the surface of both hands. The results have shown that out of 21 workers monitored, ∼43 % (preparation and applications of radiopharmaceuticals) may reach an exposure equal to three-tenth of the annual dose limit to the skin. At the same time, it can also be concluded that in ∼10 % cases of workers, the relevant dose limit may be exceeded.

Effect of dosimeter's position on occupational radiation extremity dose measurement for nuclear medicine workers during (18)F-FDG preparation for PET/CT

Background

The recent spread of positron emission tomography-computed tomography (PET/CT) poses extremity dosimetry challenges. The question arose whether the radiation dose measured by the ring thermoluminescent dosimeter usually worn on the proximal phalanx (P1) of the index finger measures doses that are representative of the true doses received by the upper extremities of the operators. A prospective individual dosimetry study was performed in which the personal equivalent dose Hp (0.07) received during a specific 2-[¹⁸F]fluoro-2-deoxy-d-glucose (¹⁸F-FDG) manual dose-dispensing procedure was measured in a paired design by two operational personal electronic dosimeters fitted on the palm side of the index finger, namely in the P1 and distal phalanx (P3) positions. The study participants were ten nuclear medicine technologists working in two nuclear medicine departments. The personal equivalent radiation doses received by the palm side of the proximal phalanx of the index finger [Hp (0.07)_P1] and that received by the distal phalanx [Hp (0.07)_P3] were compared.

Results

The median Hp (0.07)_P3/Hp (0.07)_P1 ratio per participant varied between 1.0 and 2.5 (based on 23 to 31 measurements per participant). The 271 paired measurements revealed a crude Hp (0.07)_P3/Hp (0.07)_P1 ratio of 1.67, significantly different from 1 (p = 0.0004, 95 % CI [1.35–2.07]). When adjusted on participant’s gender and mother vial activity, the ratio was similar (1.53, p = 0.003, 95 % CI [1.22–1.92]).

Conclusions

The study demonstrated a significant disparity that may exist between the radiation doses measured in the P1 and P3 positions of operators during ¹⁸F-FDG manipulation. These findings emphasize the importance of performing workplace dosimetry studies adapted to each radiopharmaceutical and manipulation thereof, aiming to guarantee optimal workers’ dosimetry monitoring schemes.

Trial registration

Hospital Nursing and Paramedical Research Program (PHRIP, 2011–2013) from the French Ministry of Health (DGOS), http://social-sante.gouv.fr/IMG/pdf/Resultats_PHRIP_2011.pdf

A correlation study of eye lens dose and personal dose equivalent for interventional cardiologists

This paper presents the dosimetry part of the European ELDO project, funded by the DoReMi Network of Excellence, in which a method was developed to estimate cumulative eye lens doses for past practices based on personal dose equivalent values, H(p)(10), measured above the lead apron at several positions at the collar, chest and waist levels. Measurement campaigns on anthropomorphic phantoms were carried out in typical interventional settings considering different tube projections and configurations, beam energies and filtration, operator positions and access routes and using both mono-tube and biplane X-ray systems. Measurements showed that eye lens dose correlates best with H(p)(10) measured on the left side of the phantom at the level of the collar, although this correlation implicates high spreads (41 %). Nonetheless, for retrospective dose assessment, H(p)(10) records are often the only option for eye dose estimates and the typically used chest left whole-body dose measurement remains useful.

Radiation doses of employees of a Nuclear Medicine Department after implementation of more rigorous radiation protection methods

The appropriate radiation protection measures applied in departments of nuclear medicine should lead to a reduction in doses received by the employees. During 1991-2007, at the Department of Nuclear Medicine of Pomeranian Medical University (Szczecin, Poland), nurses received on average two-times higher (4.6 mSv) annual doses to the whole body than those received by radiopharmacy technicians. The purpose of this work was to examine whether implementation of changes in the radiation protection protocol will considerably influence the reduction in whole-body doses received by the staff that are the most exposed. A reduction in nurses' exposure by ~63 % took place in 2008-11, whereas the exposure of radiopharmacy technicians grew by no more than 22 % in comparison with that in the period 1991-2007. Proper reorganisation of the work in departments of nuclear medicine can considerably affect dose reduction and bring about equal distribution of the exposure.

Automated dispensing and calibration of diagnostic radiopharmaceuticals

A real-time automatic dose dispenser (RADD) has been designed and fabricated for automatic withdrawal and calibration of diagnostic radiopharmaceuticals such as those labelled with (99m)Tc. This system enhances the accuracy and precision of activity measurements and reduces personal radiation exposure. The structure, function, user-friendliness and performance of this device are described and examined for diagnostic activities of (99m)Tc ranging from 50 to 650 MBq. The results show that the RADD minimises the likelihood of miscalibration of radiopharmaceuticals due to human error and results in significantly reduced variability (i.e. higher precision) in dispensed activities of radiopharmaceuticals.

Eye lens radiation exposure to interventional cardiologists: a retrospective assessment of cumulative doses

Radiation dose to the eye lens is a crucial issue for interventional cardiologists (ICs) who are exposed during the procedures they perform. This paper presents a retrospective assessment of the cumulative eye lens doses of ICs enrolled in the O'CLOC study for Occupational Cataracts and Lens Opacities in interventional Cardiology. Information on the workload in the catheterisation laboratory, radiation protection equipment, eye lens dose per procedure and dose reduction factors associated with eye-protective equipment were considered. For the 129 ICs at an average age of 51 who had worked for an average period of 22 years, the estimated cumulative eye lens dose ranged from 25 mSv to more than 1600 mSv; the mean ± SD was 423 ± 359 mSv. After several years of practice, without eye protection, ICs may exceed the new ICRP lifetime eye dose threshold of 500 mSv and be at high risk of developing early radiation-induced cataracts. Radiation protection equipment can reduce these doses and should be used routinely.

A novel device for automatic withdrawal and accurate calibration of 99m-technetium radiopharmaceuticals to minimise radiation exposure to nuclear medicine staff and patient

A Joint Automatic Dispenser Equipment (JADE) has been designed and fabricated for automatic withdrawal and calibration of radiopharmaceutical materials. The thermoluminescent dosemeter procedures have shown a reduction in dose to the technician's hand with this novel dose dispenser system JADE when compared with the manual withdrawal of (99m)Tc. This system helps to increase the precision of calibration and to minimise the radiation dose to the hands and body of the workers. This paper describes the structure of this device, its function and user-friendliness, and its efficacy. The efficacy of this device was determined by measuring the radiation dose delivered to the hands of the nuclear medicine laboratory technician. The user-friendliness of JADE has been examined. The automatic withdrawal and calibration offered by this system reduces the dose to the technician's hand to a level below the maximum permissible dose stipulated by the international protocols. This research will serve as a backbone for future study about the safe use of ionising radiation in medicine.

Validation of a new protocol for ¹⁸F-FDG infusion using an automatic combined dispenser and injector system

PURPOSE

In nuclear medicine, radiopharmaceuticals are usually administered in unit doses partitioned from multi-dose vials. The partitioning typically takes place in a radiopharmacy, depending on local practice. Automatic, as opposed to manual, partitioning and administration should reduce radiation exposure of the personnel involved, improve the accuracy of the administration and mitigate contamination. This study set out to verify and validate the (18)F-fluorodeoxyglucose (FDG) administration procedure performed using Intego (MEDRAD, Inc., Warrendale, PA, USA), a combined dispenser and injector system. We considered maintenance of sterility and the system's potential to improve, with respect to the manual procedure, the accuracy of net administered (18)F-FDG radioactivity in patients and the radiation protection of operators.

METHODS

A media-fill procedure was used to assess whether sterility is maintained during use of the Intego system. Simulating a typical working day's setup and use of the system, we investigated the accuracy of the net administered (18)F-FDG activity obtained with Intego versus the manual dose delivery system. We also measured personnel radiation exposure during use of Intego and during manual administration and recorded and compared environmental doses in the two conditions.

RESULTS

The radiopharmaceutical remained sterile in all the tests performed. The accuracy of the net (18)F-FDG activity delivered to the patients was found to be within 3 % points, as required by European Association of Nuclear Medicine (EANM) guidelines on (18)F-FDG imaging procedures. With Intego, the residual radioactivity in the tubing was 0.20 MBq, corresponding to approximately 0.07 % of the mean activity delivered. With manual injection, the residual radioactivity in the syringe averaged 7.37 MBq, corresponding to a mean error of 2.9 % in the delivered dose. During the injection step of the positron emission tomography (PET) procedure, whole-body and extremity radiation exposures were significantly reduced with Intego by 38 and by 94 %, respectively, compared to the levels associated with manual administration (p < 0.05).

CONCLUSION

Integoaccurately partitions and administers sterile doses of (18)F-FDG from multi-dose vials. Compared with standard manual (18)F-FDG administration, the new procedure with an automatic dispensing and injection system greatly reduces the extremity dose to the operator involved in the administration of the radiopharmaceutical.