Extremity Doses Research Articles

Investigation using an advanced extremity gamma instrumentation system ofoptions for shielding the hand during the preparation and injection ofradiopharmaceuticals

Staff preparing and injecting radiopharmaceuticals in hospitals may receivesignificant radiation doses to their hands. These doses may be high enough towarrant that they be classified as radiation workers. The influence of localshielding on finger doses has been investigated. Staff preparing radioactive liquidsin a radionuclide dispensary and drawing up and injecting radiopharmaceuticalsin a nuclear medicine department have been studied. Measurements have beenrecorded with an electronic extremity dose monitor, an advanced extremitygamma instrumentation system (AEGIS), worn near to the finger tip. Theelectronic dosimeter allows the pattern of doses received during differentprocedures to be determined. Doses received for individual manipulations duringmany routine sessions have been recorded for different staff members. Dosedistributions around shielded vials and syringes have also been measured usingAEGIS. In the radionuclide dispensary the vials from which radioactiveliquids are dispensed are held in tungsten shields, whereas in nuclearmedicine simple lead pots are used. Syringe shields are employed for someparts of dispensing and patient injections. Data on dose distributions havebeen used in interpretation of results from monitoring. Use of syringeshields during dispensing reduced the finger dose by 75–85%. The peaks indose rate were 60% lower, and periods of exposure to high dose rateswere reduced in length by a third because of the restriction in the regionof high dose rate. The extremity doses to staff dispensing and injectingradiopharmaceuticals in nuclear medicine were of similar magnitude. Dosesreceived during dispensing varied from 10 to 555 µGydepending upon whether the vial containing the radiopharmaceutical was directly handledor not. Dose received from individual injections varied from 1 to 150 µGydepending on the degree of difficulty experienced during the injection.

Occupational doses during the injection of contrast media in paediatric CT procedures.

The administration of intravenous contrast media by hand or power injection in paediatric computed tomography (CT) procedures is carried out at King Faisal Specialist Hospital and Research Centre for chest, abdomen and torso diagnostic examinations. Some procedures require the CT unit to commence patient scanning during the injection of the last volume of the contrast medium. During the injection, even if the nurse is wearing a 0.5 mm lead equivalent protective apron, the head region and the hand are likely to receive high doses. This study was therefore made to assess the head and extremity doses to the nurses during CT procedures where typical exposure parameters of 200 to 220 mA s and 120 kVp were used. Thermoluminescence dosemeters were deployed for three consecutive months in two CT rooms. A total of 96 procedures were performed during this period and they were included in this study. Scattered radiation measurements were done at different locations where the nurse may be positioned. Results showed that the average dose to the head region and the hands per paediatric case were 50 microSv and 80 microSv respectively. This study investigated the factors that affect the dose and found them to be the length of stay inside the room, type of CT examination. exposure parameters and location of the nurse.

Paediatric personnel extremity dose study.

Concern has been expressed in paediatric radiology regarding the magnitude of the extremity dose received by attending personnel during routine fluoroscopic procedures and CT. Common procedures that may be of short duration in adults can be quite the opposite in paediatric patients. The extremities of attending personnel are more likely to be exposed to the primary beam and for a longer period of time owing to a variety of reasons such as assisting in the procedure or physically restraining the patient during the examination. During the period mid 1998 to mid 2000, two paediatric radiologists, four senior radiographers and two paediatric nurses were monitored using ring thermoluminescent dosemeters (TLDs). Each participant wore the ring TLD on either the left or right ring finger, depending on which hand the individual favoured. Left/right asymmetrical studies were not conducted, nor were records kept of whether an examination used a grid or gridless technique. Initial apprehension about higher paediatric fluoroscopic and CT extremity doses was dispelled as a result of this quantitative dosimetric study.

Development of a real-time hand dose monitor for personnel in interventional radiology.

Medical procedures denoted as interventional radiology require operation near an X ray beam, which brings high dose exposures to the operators' hands. For the effectual control of their extremity doses, a prototype of a real-time wrist dosemeter has been developed, hand dose monitor (HDM), based on a single silicon detector. Experiments were performed to test its response to diagnostic X rays. The HDM was highly sensitive and showed a linear response down to doses of a few tens of microsieverts. Though dose rate, energy and angular dependence of the response were observed in some extreme conditions, the HDM was proved to be of practical use if it was appropriately calibrated. Since an HDM enables personnel to check their hand doses on a real-time basis, it would enable medical staff to control the exposure themselves.

IRID: Ionising Radiations Incident Database(First Review of Cases Reported and Operation of the Database)

One of the main ways accidents can be prevented is to learn lessons from previous incidents or `near-misses'. So it was that the Ionising Radiations Incident Database (IRID) was set up in 1996 by HSE, EA and NRPB (the `partners'). In essence, each radiation incident is reduced to a set of data codes on a proforma and entered onto the database by NRPB who maintain it. The data codes are grouped within 23 fields and a further one enables a written description. Fields cover such matters as doses, occupation of workers, equipment involved, nuclides, causes and follow-up. Preservation of anonymity and confidentiality are important considerations, and incidents which are sub judice are excluded. So far, only the `partners' have supplied data, some back to the 1970s, and this report gives an assessment of the first 100 (convenient for percentage descriptions!). Importantly, the incidents predominantly cover the non-nuclear sector, and exclude nuclear, transport and patient exposure incidents which are covered by other arrangements. Exposures up to 370 mSv (average 15 mSv) effective dose and 60 Sv extremity dose are reported. The report gives statistical analyses of the incidents on the basis of a number of the fields, backing this up with several tables of data. Thus it can be seen that industrial radiography is the most common cause of incidents (one third of total), followed by level/density/moisture gauges (one fifth) and scrap material processing (one tenth). Exposures are predominantly external rather than from contamination. The analyses also lead to a number of lessons for users and are backed up by examples. There are lessons for us all here, and while none of them are new, they are well worth rehearsing: `ensure proper management systems are in place'; `use a monitor'; `maintain security and supervision of radioactive materials at all times'; `train your operators'; `be prepared for incidents' and `take care of personal dosemeters'. Undoubtedly though, the main value of the report is in the descriptions of 84 case studies which take up most of its volume. These have been categorised into seven areas (e.g. unsealed radioactive materials, density gauges, recycling and scrap metal), each incident taking up just one page. Together with some drawings, they are freely available to use and reproduce, making an invaluable aid to employers, trainers, RPAs etc. This is a well structured, useful report which acknowledges that the next stage is to expand the database and get contributions from those not yet involved (i.e. the non-`partners'). To this end, there is a returnable questionnaire, but it is a pity that the report was not made freely available. The �15 price tag may well mean a biased level of response.

Characterization and minimization of extremity doses during 32P metabolic cell labeling.

A study was performed to characterize hand extremity doses received by a laboratory researcher performing a metabolic cell labeling procedure using 10-cm-diameter cell culture dishes containing GBq amounts of 32P-orthophosphate. Specifically, the optimal location for placement of thermoluminescent dosimeters on the extremities was determined as was the phase (time frame) during the cell labeling procedure when the highest dose was received. The cell labeling procedure was divided into four phases. Thermoluminescent dosimeters were placed on three fingers of each hand at the start of each phase and after the completion of that phase, collected, and sent to the processor. It was determined that in the case of this right-handed worker, the left-hand index finger should be used for determining the maximum extremity dose. The time frame during which the highest extremity dose was received was the cell lysis phase. Acrylic shielding was fabricated, which significantly reduced worker extremity dose.

Reduction of extremity dose in the radiopharmacy.

With the future introduction of legislation originating from ICRP60 in mind, the operating procedures for the radiopharmacy were reviewed, with the intention of reducing extremity radiation dose. The radiopharmacist's index fingertip dose was measured using TLDs. The radiopharmacist received a mean dose of 0.7 mSv per 10 GBq of administered activity for the right (non-dominant hand) index finger and 0.2 mSv per 10 GBq for the left (dominant hand) index finger. These doses were comparable with other publications. The radiopharmacist received the largest part of the radiation dose during the preparation of 99Tc(m)-MDP. During this preparation, the saline was withdrawn into a syringe already containing 99Tc(m)-eluate, which results in a dose to the fingers. The technique was changed so that the saline and 99Tc(m)-eluate were withdrawn and injected separately into a MDP kit. This reduced the right finger radiation dose to 0.4 mSv per 10 GBq, while the left finger radiation dose remained at 0.2 mSv per 10 GBq. This shows that radiation doses can be effectively reduced using simple changes in procedure.

Editorial - Measurement 'Quantity' for Extremity Doses - What's in a Name?

Journal Article Editorial - Measurement 'Quantity' for Extremity Doses - What's in a Name? Get access E.P. Goldfinch E.P. Goldfinch Search for other works by this author on: Oxford Academic PubMed Google Scholar Radiation Protection Dosimetry, Volume 69, Issue 3, 1 February 1997, Pages 163–164, https://doi.org/10.1093/oxfordjournals.rpd.a031900 Published: 01 February 1997

Radiation dosimetry of an accidental overexposure using EPR spectrometry and imaging of human bone

On 11 December 1991 a radiation accident occurred at an industrial accelerator facility. A description of the facility and details of the accident are reported in Schauer et al., 1993a). In brief, during maintenance on the lower window pressure plate of a 3 MV potential drop accelerator, an operator placed his hands, head, and feet in the radiation beam. The filament voltage of the electron source was turned ‘off’, but the full accelerating potential was on the high voltage terminal. The operator's body, especially his extremities and head, were exposed to electron dark current. At approx. 3 months post-irradiation, the four digits of the victim's right hand and most of the four digits of his left hand were amputated. Electron paramagnetic resonance (EPR) spectrometry was used to estimate the radiation dose to the victim's extremities. Extremity dose estimates ranged from 55.0 Gy (± 4.7 Gy) to 108 Gy (± 24.1 Gy).

Radiation safety in the central radiopharmacy

The currently increasing number of new radiopharmaceuticals and the increase in individual patient-dose activity, particularly for single photon emission computer tomography imaging, coupled with the switch toward unit doses probably contribute to an increase in the radiation burden to radiopharmacy personnel. To meet this increased need of the nuclear medicine community, a medium-sized radiopharmacy may order seven to eight 3-Ci molybdenum-99/technetium-99M generators per week and may perform 10 to 15 elutions per day. The maximum radiation exposure to radiopharmacy personnel occurs during the generator elutions, compounding (kit preparation), and unit-dose dispensing. Additional sources of radiation exposure can occur during receipt of radioactive packages, transport of prepared doses, and the process of storage and disposal of radioactive waste. Recent reports have shown extremity radiation doses to the fingers and hands at 14 to 21 rem/year. Radiation exposure can be monitored by film badges, thermoluminescent detectors, or one of the analog or digital self-reading dosimeters. Each monitoring device has advantages and the choice depends upon the personnel involved (eg, visitors) and the particular needs of the radiopharmacy. Extremity dose reductions during radiopharmacy procedures can be achieved by a number of techniques, some as simple as the use of 8- to 9-inch forceps during transfers of radioactive vials and syringes and the use of a dose-drawing syringe shield during unit-dose dispensing procedures. In preparation of unsealed doses or capsules of radioactive iodine, there is a potential for a high internal dose because of inhalation of the volitile solution. Frequent monitoring in the form of bioassays and the use of strict threshold levels will ensure early detection of exposure to radioactive iodine and quick corrective action. In pharmacies and nuclear medicine departments handling fluorine-18 for use with Anger gamma cameras, the high levels of both beta and gamma radiation present an additional set of radiation safety problems.

Patient and staff dosimetry in neuroradiological procedures.

Cerebral angiography provides valuable information for use in the clinical management of patients but can result in relatively high radiation doses to patients and staff due to the extended fluoroscopy time and number of images acquired during an examination. In this study, extremity doses to radiologists and scrub nurses working in a neuroradiological centre were monitored during a 3 month period using thermoluminescent dosemeters (TLDs). Electronic personal dosemeters were also used to monitor doses above the lead apron at chest height to the radiologists, radiographers and the scrub nurses. Patient doses were recorded using a dose-area product meter whilst patient thyroid dose was measured using TLDs. Two types of examination were studied: cerebral angiography and arterial embolization. It was deduced from the results of the study that the radiologist may expect to receive a mean dose above the lead apron at chest height of 11 microSv and 25 microSv per examination when performing cerebral angiography and arterial embolization, respectively. A radiologist mean hand dose of 19.3 microSv per examination was found, whilst the average eye dose for both radiologist and scrub nurse was 13.4 microSv per examination. The patient dosimetry results revealed a mean thyroid dose of 1.7 mSv and a dose-area product of 48.5 Gy cm2 for cerebral angiography. Average dose-area product for arterial embolization was 122.2 Gy cm2 along with a mean patient thyroid dose of 3.3 mSv. More detailed patient dosimetry was also performed using a Rando anthropomorphic phantom loaded with TLDs to measure organ doses and hence estimate effective dose. A typical four vessel angiogram was found to result in a patient effective dose of 3.6 mSv.

Modeling to Optimize Operational Practices to Limit Shallow Dose and Dose to the Lens at the Weldon Spring Site Remedial Action Project

The Weldon Spring Site Remedial Action Project (WSSRAP) began remediation of its chemical plant buildings in June 1992. The chemical plant was used by the Atomic Energy Commission in the 1950's and 1960's to process uranium ore and natural thorium. Many remaining equipment surfaces were highly contaminated with uranium and thorium product residues, which are relatively weak gamma emitters, but are strong beta emitters that deposit the majority of their energy within the first centimeter of tissue. An essential part of the remediation, therefore, is to control the dose to the skin, extremities, and the lens of the eye from the broad range of betas emitted by uranium and thorium decay series radionuclides. The WSSRAP planned to quantitatively record the dose to the skin, extremities, and the lens of the eye, when warranted, through selection and use of appropriate passive dosimeters. That would not, however, constitute control. A direct-reading instrument was needed that could be used by field technicians to anticipate and prevent work methods and situations that would otherwise result in the unnecessary commitment of dose. However, the interpretation of real-time instrument readings produced by a broad spectrum of beta energies is typically challenging at best, particularly when the shallow dose rate and the lens dose rate are both of interest. The purpose of this effort was, therefore, to (1) select a direct-reading instrument for use in the buildings that could be used to provide rule-of-thumb action levels for field technicians, which, if exceeded, would warrant worker protective measures; (2) determine the approximate conversions between the instrument readings and the shallow (including extremity) dose rate and lens of the eye dose rate; and (3) specify protective measures and dosimetry for the lens of the eye, if warranted. Methods described in the literature are used to estimate action levels for direct instrument readings and to demonstrate that lens dosimetry and special protective measures for the lens of the eye are not necessary at the WSSRAP.

Extremity Dosimetry in Nuclear Medicine Services using Thermoluminescent Detectors

Abstract The Radiation Protection and Safety Centre in Algiers provides two types of dosemeters, one for monitoring doses to the whole body and skin and the other one for monitoring doses to the extremities of the body. In nuclear medicine services and radiopharmaceutical laboratories, hands and arms are often closer to a given radiation source than the main part of the body and therefore receive greater doses. In this context, extremity doses have been measured by a ring dosemeter and by a fingertip ultra-thin dosemeter. The ring dosemeter consists of a metallic ring with a circular indentation to hold a LiF chip which is covered with a 10 mg.cm-2 shrinkable black polyamide layer. The ultra-thin dosemeter contains a 5 mg.cm-2 LiF element for measuring doses at a depth of 7 mg.cm-2. These extremity dosemeters have been characterised before their use in the field. They have also been tested using radioisotopes of various energies. The doses received by the monitored workers were correlated with the amount of the handled activity. The doses obtained using the fingertip and the ring dosemeters are presented and discussed from a radiological point of view.

Extremity Dosimetry in Nuclear Medicine Services using Thermoluminescent Detectors

The Radiation Protection and Safety Centre in Algiers provides two types of dosemeters, one for monitoring doses to the whole body and skin and the other one for monitoring doses to the extremities of the body. In nuclear medicine services and radiopharmaceutical laboratories, hands and arms are often closer to a given radiation source than the main part of the body and therefore receive greater doses. In this context, extremity doses have been measured by a ring dosemeter and by a fingertip ultra-thin dosemeter. The ring dosemeter consists of a metallic ring with a circular indentation to hold a LiF chip which is covered with a 10 mg.cm-2 shrinkable black polyamide layer. The ultra-thin dosemeter contains a 5 mg.cm-2 LiF element for measuring doses at a depth of 7 mg.cm-2. These extremity dosemeters have been characterised before their use in the field. They have also been tested using radioisotopes of various energies. The doses received by the monitored workers were correlated with the amount of the handled activity. The doses obtained using the fingertip and the ring dosemeters are presented and discussed from a radiological point of view.

Individual Thermoluminescence Dosemeters for Extremities and Eyes

Abstract An International Standards Organisation working group (ISO/TC85/SC2/WG7) has developed a draft standard specifying dosimetric performance requirements and recommending appropriate tests, for dosemeters to be used for extremity or eye dose measurements. The standard is complementary to the IEC standard Thermoluminescence Dosimetry Systems for Personal and Environmental Monitoring (IEC 1066 1991). The new draft standard is due to be circulated by ISO for international 'Member States' comments late in 1992. This paper summarises the content of the draft and gives some background to the technical requirements.

Radiation dose to the hands in nuclear medicine

Study of the distribution of radiation dose across both hands during the dispensing and administration of radiopharmaceuticals is useful in the assessment of the extremity doses received by nuclear medicine personnel. Some staff in the UK have already been designated as classified radiation workers due to the radiation doses that their hands may receive. With possible forthcoming reductions in the dose limits, it is important that as much data as possible is available on such dosimetry. By measuring the dose at nine different locations on each hand, an optimal site (the base of the second digit) to represent a more accurate 'mean hand dose' could be determined. The use of inserting different butterfly cannula into a vein, prior to radiopharmaceutical administration, was assessed in terms of the dose reduction effect to the member of staff performing the task. It was found that a long tubing cannula (300 mm) did not significantly reduce the radiation dose of the operator whereas shorter ones (95 mm) gave a very significant dose reduction.

Extremity doses during interventional radiology

Extremity doses during interventional radiology

Extremity doses during interventional radiology

Extremity doses during interventional radiology

Extremity doses during interventional radiology

The radiation doses received by the unprotected parts of a radiologist undertaking biliary and renal interventional techniques using an overcouch X-ray tube have been measured with thermoluminescent dosimeters. Mean doses to the eyes, thyroid and fingers ranged from 0.27 to 1.29 mSv per examination. The results substantiate the need for such monitoring but the study demonstrates that the doses to the radiologist can be kept to an acceptable level with careful technique.

Measurement of skin dose from low energy beta and gamma radiation using thermoluminescent discs

A thermoluminescent dosemeter is described, designed to measure the dose to the basal layer in mixed beta - and gamma -radiation fields. Very thin Teflon discs, 8.9 mg cm-2 thick and 1.27 cm diameter, loaded with LiF, provide a convenient measure of the beta -ray dose. When covered by a polyethylene window of 3.7 mg cm-2 their response is equivalent to the dose under 7 mg em-2 of tissue to within 10% for beta -rays with maximum energies of 0.15 to 2.27 MeV. The response to X- and gamma -rays above 80 keV is independent of energy and similar to the beta -ray response, but below 80 keV the sensitivity relative to beta -rays increases to a maximum of 1.5 around 30 keV. The dosemeter can be used in mixed beta - gamma radiation fields and is particularly suited to the measurement of extremity doses.