Passive Monitoring Service
Medical personnel is potentially exposed to ionizing radiation emitted from medical diagnostic and therapeutic equipment or isotopes typically used in Nuclear Medicine. Thus the staff needs to be monitored with dosimeters according to the national legislative requirements.
Dosilab’s passive dosimetry service, dosiCHECK, comprises:
- Ergonomic and ready to wear whole body, extremity and eye-lens dosimeters according to your needs
- Dosimeters, sorted by department, are shipped in reusable blueBOXs used also for their return. Various shipment consolidation options available.
- Fast and accurate processing of the returned badges including timely issue of dose reports.
- dosiWEB, our web platform, lets you manage all your dosimetry needs. Nonetheless paper forms are still available to submit any service change request.
- Phone hotline available to answer any technical or administrative question.
dosiCHECK – optimized monitoring service flow
Dosilab has optimized the dosimeter badge issue and return flow between us and our clients as well as the delivery of dose reports. Our aim is to constantly reduce the administrative workload for our clients while guaranteeing high quality, fast and responsive services.
Since the dosimeter issue/return/analysis cycle is recurrent, our processes require a minimal intervention from the client: he basically needs only to exchange dosimeters and send the worn ones back for processing. The same shipping box received with the newly issued dosimeters is used for the return of the worn ones. Dosimeter issue modifications due to personnel changes are directly submitted on-line on our dosiWEB platform or via forms.
Our monitoring service optimization has following main benefits:
- dosimeters are issued and shipped “just in time” so up to the last minute clients’ change request are taken into account for the current dosimeter shipment.
- dosimeters for a department are shipped in reusable blueBOXes including a postage prepaid return label.
- changes in personnel can be submitted directly in dosiWEB or via forms
- dose reports are send with the next dosimeter shipment and can also be viewed and downloaded on dosiWEB. In addition, statistical reports are available to directly assess the overall effectiveness of the radiation protection program at the client’s facility.
- when we assess a higher dose we immediately alert the client and where required by national legislation, also the authority
- reminders of non-returned dosimeters are regularly sent to clients. This eases tracing the non-returned dosimeters before being declared as lost.
- Emergency readings: dosimeter pick-up service and fast processing when an accidental high dose exposure is suspected
dosiBADGE: the whole body dosimeter
Medical personnel potentially exposed to ionizing radiation needs to wear at least a whole body dosimeter. Dosimeters need to be worn whenever a person accesses a radiation controlled area. When not in use, the dosimeter should be stored in an especially designated spot, best on Dosilab’s dosimeter storage board.
The dosimeter badge is personalized for each wearer and each wear period with following indications
- Name and first name
- Department or function (specified via dosiWEB)
- Wear period and wear position on body
- The label colour coding changes with each issue and allows for easy identification of the wear period. Thus it is apparent when someone wears a dosimeter of the wrong wear period.
Staff members have differing requirements on how a dosimeter shall be worn, often influenced by the professional activities or personal preferences. Furthermore, organisations may also have rules on how dosimeters shall be worn.
To answer all these needs we offer a choice of dosimeter holders and attaching solutions:
- Holder available in 5 colours: yellow, blue, red, green and transparent. This aims to match the colour of dosimeter holder to a corporate colour or selecting a holder colour by department or building. The latter might ease forwarding the found dosimeters in large organizations
- ID-badge and dosimeter holder: some organisations demand that a personal ID badge shall be worn. A dual ID and dosimeter holder is available, thus avoiding multiple items clipped on the chest pocket.
- Clip or lanyard: depending on personal preference we propose a clip or a lanyard choice. Furthermore the lanyard has no metal parts thus it is ideally suited for personnel working both in X-ray and MRI environments. In surgery rooms the lanyard might be better suitable since surgical gowns often preclude dosimeter clipping.
dosiRING: the extremity dosimeter
Monitoring extremities radiation exposure, in particular fingers, is crucial for interventional radiologists and medical staff potentially exposing their fingers to radiation in the course of medical procedures. X-ray imaging and nuclear medicine procedures can cause quite high extremity doses, often close to the legal limits.
Extremity monitoring is complementary to whole body dosimeters and recommended by the ICRP and legally required in many countries. In recent years more and more surgeons and interventional radiologists started to routinely wear our extremity dosimeter since it doesn’t interfere with their finger agility due to its small size. International studies like ORAMED prove the effectiveness of ring dosimeters compared to wrist dosimeters in assessing the extremity dose. Thus, while we still offer wrist dosimeters we no longer recommend them.
Our dosimeter ring was designed to attain maximal comfort with following characteristics:
small and comfortable:
- 2 shapes to fit user’s preferences : classic and spiral
- the flexible arms fit any finger size
- ultrasound welding technology assures 100% waterproof element seeling. This enables biological decontamination / cold sterilisation of the ring by immersion in liquid decontaminants.
- wearer name and wear period provide easy and direct wearer identification.
- The ring color-coding matches the whole body wear period colour coding
thin cap to minimize beta filtration
- the cap has a minimal thickness enabling accurate beta measurements while still being sufficiently robust to resist harsh environments
Legislation varies from county to country but the European harmonisation trend is to require that persons having an elevated extremity exposure risk, normally around 20mSv/year shall wear a ring dosimeter in addition to the whole body dosimeter. The “work situational studies” performed by the radioprotection officer of your organization determines who in the organization shall wear a ring dosimeter.
Ring dosimeters are often worn under the surgical gloves. Therefore a ring needs only to be decontaminated before use at the same level as the surgeon hands. The dosimeter ring can fulfill this requirement by cold sterilization done by immersion in an appropriate decontamination / sterilization liquid.
dosiWEB: the WEB service platform
The administration of your dosimetry needs is a necessary but time consuming task. To optimize this activity, dosiWEB gives you on-line access to all the pertinent dosimetry data of your organization.
With dosiWEB you have full flexibility on when you register your modifications. Also, all changes done by the 10th of the month prior the new wear period are considered for all dosimeters issued for the next wear period.
dosiWEB lets you:
- view the list of monitored persons by department
- view the dose records and download PDF dose records by person or department. Dose records are on-line within 3-5 days from receipt of dosimeters
- add new persons and their dosimeter requirements
- cancel dosimeter issue to a wearer or interrupt the dosimeter issue for a time period (maternity leave, ….)
- transfer wearer from one department to another with a simple click
- view the status of returned dosimeters. A PDF report can be downloaded with the list of non-returned dosimeters.
- manage and view the dose measurements of your transport and ambiance dosimeters as you do for monitored persons
To access dosiWEB just a simple internet access is needed; no dedicated software required.
dosiWEB uses a secure access via the standard internet https protocol. Each client gets individualized access codes for the designated personnel, typically radioprotection officers or health physicists.
dosiBOARD: safekeeping the dosimeters during the wear cycle
Keeping dosimeter centralized when not in use during a wear period has been shown to be a good practice to minimize dosimeter losses and streamline the dosimeter exchange process at the end of a wear period. From a radioprotection perspective it is also a good practice since it assures all dosimeters of the organization are exposed to the same background radiation, avoiding possible small dose inconsistencies among wearers. Keeping dosimeters together is a legal requirement in certain countries.
dosiBOARD is the practical solution to organize and safe keep your dosimeters:
- modular panel system, each holding up-to 15 dosimeters
- dedicated dosimeter exchange rack
- ring storing solution provided: in small containers on holding racks
TLD Technology and Dose reassessing capabilities
Thermo Luminescence Dosimetry (TLD) is a well-established technology used to assess the dose resulting from radiation exposure. . As the radiation interacts with the dosimeter’s material it causes electrons in the crystal’s atoms to jump to higher energy states, where they stay trapped due to intentionally introduced crystal’s impurities. Heating the crystal causes the electrons to drop back to their ground state, while concurrently releasing photons having an energy equal to the energy difference between the trap state and the ground state. Therefore this photon (light) emission is proportional to the radiation exposure. Thus this method is called TL-Dosimetry: Thermo (the applied heat) and Luminescence (photon emission).
The dosimeters we use have 2 calcium sulphate and 2 lithium borate elements. To read the element dose the dosimeter is heated up to 370 °C by several flashes of infrared light. The TL dosimeter responds by emitting ultraviolet light, the intensity of which is measured by light sensitive detectors.
This emitted light is proportional to the Gamma, X-ray or Beta radiation the wearer was exposed to during the wearing period. This measurement is done in a TLD-Reader, an instrument which counts the photons emitted during the heating cycle and stores the measurement data. This measurement data is then processed with an algorithm which determines the dose of the exposure based on the measurements of each TLD element readings. The raw measured data (the glow curves) is kept in the database and thus available for further analysis when needed.
Once analyzed, the dosimeter can be reused since the electrons fell back to the ground energy state and therefore ready to interact with radiation again.