Tag: dosimetry

18 Dec 2023
Large size motorized 3D water phantom system for dose distribution measurement of radiation therapy beams in real daily routine practice used as a part of quality control of radiation therapy.

What’s Inside Matters Most: Internal Dosimetry

Medical physics has been an integral part of medicine and healthcare over the greater part of the last century. Applying physics theory, concepts, and methods, scientists have created patient imaging, measurement, and treatment techniques that revolutionized the medical world. One product of medical physics has been the evolving specialty called radiopharmaceutical dosimetry, the calculation of absorbed dose and optimization of radiation dose delivery in cancer treatment. Today, we address internal dosimetry, the subset of medical physics that aims to optimize treatment and protect the patient from any undesirable side effects.

What is internal dosimetry?

Dosimetry is the measurement of radiation energy imparted to body organs and tissues. Radionuclides emit beneficial ionizing radiation that is useful for both diagnostic imaging of various diseases as well as for cancer treatment. Thus, medical internal dosimetry is the assessment of internal radiation dose from incorporated radionuclides associated with such life-saving radiopharmaceuticals.1 Radiation dose is the amount of energy imparted by radiations emitted during disintegration of radioactive atoms that constitute part of the radiopharmaceutical chemistry. Dose to organs of the body is quantified per unit mass (or weight) irradiated tissue. Dosimetry provides the fundamental quantities needed for several important purposes, including record-keeping, radiation protection decision-making, risk assessment, and cancer-treatment planning.2 The purpose and objective is to optimize medical benefit while minimizing potential radiation damage to body cells, tissues, and organs.

Dosimetry is a complex physical and biological science. Internal dosimetry provides critical information needed to better understand the biological mechanisms governing radionuclide uptake, translocation, and excretion from the body. The radiation dose imparted depends on the type, amount, and distribution of radionuclides, as well as specific nuclear properties, such as energy emitted.

Internal dosimetry differs from ā€œexternalā€ dosimetry, which deals with the radiation dose from sources outside the body. Devices such as dosimeters measure external dosimetry directly, while internal dosimetry relies on indirect methods of radioactivity inside the patient using bioassay and imaging measurements.3 Bioassay is the measurement of the activity or concentration of radionuclides in biological samples. Samples can include urine specimens, feces, blood, or breath. Imaging techniques, such as whole-body counters or gamma cameras, can detect the radiation emitted by the radionuclides inside the body. This helps to provide information on their location and quantity.1

When is internal dosimetry used in healthcare?

Internal dosimetry mainly benefits patients who receive radionuclide therapy, a treatment that involves administering radioactively labeled proteins, such as monoclonal antibodies, to target specific types of cancer.3 It also helps to evaluate and account for unique patient variations in biodistributionā€”the way that different subjects respond to treatment. Internal dose assessments analyze radionuclide behavior in both normal (healthy) organs, as well as tumors. For example, imaging measurements provide physicists with important information to determine tumor uptake, retention, and clearance. In doing so, administered activity can be tailored according to patient health status, age, size, sex, and basal metabolic rates.

How does internal dosimetry produce useful data?

The main challenge of internal dosimetry is to track and follow the uptake, redistribution, metabolism, and clearance of the administered radiopharmaceutical inside the body over extended time periods after administration.4 Tracking sometimes involves mathematical modeling to describe the absorption, distribution, metabolization, and excretion of radionuclides by the body. Biokinetic models may be developed from the study of population groups, knowledge of radionuclide behavior in different organs, and the unique chemistry of each radiopharmaceutical. Biokinetic models incorporate mathematical compartments representing a particular organ or a tissue, and descriptions of the transfer rates that reflect the movement of radionuclides from one body compartment to another.1

Summary

Internal dosimetry is an important tool for radiation protection, especially in the fields of nuclear medicine, occupational health, and environmental monitoring. Dosimetry helps to customize or personalize nuclear medicine in cancer patients. In a broader sense, internal dosimetry is also applied to occupational and environmental health to prevent or reduce the exposure to radionuclides, by providing information on the sources, pathways, and levels of intake, and by suggesting appropriate measures, such as respiratory protection, contamination control, or dose limits. Internal dosimetry can also help to verify the adequacy of workplace controls, to demonstrate regulatory compliance, and to provide medical and legal evidence in case of accidental or intentional exposure.

Special software tools have been developed for the clinical nuclear medicine setting to facilitate medical imaging and calculate internal doses.

QDOSEĀ® Multi-purpose Voxel Dosimetry (Personalized Dosimetry in Molecular Radiotherapy) is a complete, one-stop solution software for all internal dosimetry needs with multiple parallel workflows. With USFDA 510(k) clearance granted in August 2023, QDOSEĀ® has proven its quality and compliance. To learn more, visit our QDOSEĀ® webpage or schedule a meeting with our team.

Sources

  1. Sudprasert W, Belyakov OV, Tashiro S. Biological and internal dosimetry for radiation medicine: current status and future perspectives. J Radiat Res. 2022;63(2):247-254. doi:10.1093/jrr/rrab119
  2. Bartlett R, Bolch W, Brill AB, et al. MIRD Primer 2022: A Complete Guide to Radiopharmaceutical Dosimetry. Society of Nuclear Medicine & Molecular Imaging; 2022.
  3. Chapter 7 External and Internal Dosimetry. Accessed November 15, 2023. https://www.nrc.gov/docs/ML1121/ML11210B523.pdf
  4. What is Internal Dosimetry – Definition. Radiation Dosimetry. Published December 14, 2019. Accessed November 16, 2023. https://www.radiation-dosimetry.org/what-is-internal-dosimetry-definition/

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06 Oct 2021
Odyssey Personnel Dosimetry module dashboard

Odyssey “How To” Series: Personnel Dosimetry Module

Join us for an interview with our Odyssey Implementation Analyst Katelyn Waters, where we discuss how to carry out certain functions of the Personnel Dosimetry module and answer some of your frequently asked questions.

Odyssey is a radiation safety software suite designed to help RSOs, EHS managers, and Radiation Safety Specialists manage affordable and efficient programs.

KB 00:10: Welcome to Part 1 of our Odyssey how-to series, where we highlight some frequently asked questions about the cloud-based radiation safety software suite and its application in real-world radiation safety programs. Over the next 12 weeks, weā€™ll be addressing each of Odysseyā€™s modules, and breaking them down to give a better idea of how they work. My name is KB, and today Iā€™m joined by Odyssey Implementation Analyst Katelyn Waters to discuss the Personnel Dosimetry Module. Thanks for joining me, Katelyn!

Katelyn 00:37: Thanks KB, Iā€™m happy to be here and hopefully we can help answer some of the frequently asked questions that we get for the Personnel Dosimetry module in Odyssey.

KB 00:46: So, the personnel dosimetry module is a key feature of the Odyssey platform. It features customizable widgets and reporting tools that help RSOs and EHS professionals managing a badge program do so in a very efficient way. But how exactly is dosimetry data made available in the module?

Katelyn 01:05: Thatā€™s an excellent question, and one of the first that we get whenever we are doing different demonstrations of the software. So, personnel dosimetry does support data from any vendor, but it is primarily designed for Mirion and Landauer. So what it actually does is the software uses a login to either AMP for Mirion or MyLDR for Landauer to view and import that dosimetry information into your account. And so this import happens automatically, we set it up to be daily for Mirion and monthly for Landauer, and so everythingā€™s going to be automatically pulled into the software for you.

KB 01:43: If I have multiple dosimetry accounts can I use this module to manage them?

Katelyn 01:48: Yeah, absolutely. So, it is designed to help aid in the management of multiple accounts. So, whether those accounts are all through one vendor, being Mirion or Landauer, or if theyā€™re from both vendors, this is very beneficial for managing those. You can change the dashboard, thatā€™s what weā€™re currently looking at here for the module, and this dashboard is a quick at a glance view of your dosimetry account. And you can change what account youā€™re looking at from this first dropdown menu here that Iā€™m hovering over currently, and you can also change it to look at specific locations or subaccounts, and thatā€™s from the second dropdown menu here.

Additionally, we also have something called a Common Wearer Profile, and what that does is it’s going to combine dosimetry information from more than one account. So if you have a wearer that has a badge from both vendors, or maybe they have two badges that are under different locations or subaccounts, you can combine that information into one profile to make viewing that dosimetry history a lot easier for that wearer.

KB 02:50: So, if I wanted to add or remove any of those multiple badges on my account, can I do so from within Odyssey?

Katelyn 02:57: Yeah, great question. So, the actual addition or editing of any of the badges for wearers for your program will still take place in your vendor portal, whether thatā€™s Mirion, Landauer, or another party. So this particular module is designed to give you some additional features that arenā€™t available in those vendor portals. Some of those features include ALARA reporting, easy form 5 access, different alerts and reminders, shipping, different management for some of those high-level activities that youā€™re going to need to do for your program.

KB 03:31: I see. What about this dashboard? Is it possible to change any of the information thatā€™s displayed here?

Katelyn 03:38: Yes. I definitely recommend that when you start utilizing this module in the software thatā€™s something you do right away because it makes it very beneficial for you, and you can do that by selecting this gear icon here, itā€™s going to take us to show us all of the settings. So each of these boxes we refer to as a widget, and each widget has its own settings for what you want to view on your dashboard. A good example here is the Recently Viewed widget in the top right-hand corner. I have what I want to see available for selection with these checkboxes, I have some drop-down menus for the number of things that I want to see here for the Read activity widget I can choose the time periodā€¦ so depending on what it is they each have their own settings for these particular widgets, and that way you can really make it for what you need to see for your program.

In addition to that, you can also click and drag things to more prominently display them. So, if I want to have this graph of Read Activity–these are doses that are coming in each day–I can put this at the very top so I can see that a more prominent position. You can also hide things if they arenā€™t useful to your program. So, say you donā€™t want this recently viewed widget, I can select the eye icon and hide that and if I were to save these settings it would remove that from my dashboard. So, itā€™s very customizable.

KB 04:59: You mentioned read activity. Is there a place that I can see who hasnā€™t read their badge?

Katelyn 05:06: Yeah, so we have a query data section which I can actually go to and show you here. And this section allows you to do some really in-depth searches on your dosimetry data. You can choose to select what you want to search for, so with your example, I would go and search for different personnel, and ones that donā€™t have a badge reading. And then I come down to this section where it says Include or Exclude and I can choose things that I want to either include in my search or exclude from my search. And for us today, Iā€™ll go ahead and add in an inclusion statement to include people for the current account that weā€™re looking at, just as an example, and then I can exclude people who have readings and we will only be left with those who do not, so Iā€™ll go ahead and exclude people who have a reading for this year by putting in the date of January 1st.

So we can hit this play button here and itā€™s going to then search through all of your dosimetry records and give you the corresponding data for your filters. Once it does so, you have a table result at the bottom. And so, the format of this data is a little odd due to the fact that weā€™re looking at primarily, or not primarily, exclusively demo data. So you can see the employee IDs are very long. But this is what the format of that table would look like for you, just have your own dosimetry data displayed in it.  

And these are linked to other areas of the software. So for these wearers, I can actually select them to go to their profiles, and in addition, we have a list of contact information here that if you were to select this mail icon for it would actually put all of these people into a mailing list for you so you can easily communicate with them. So if we do want to reach out to this group and say hey, you need to please read your badge for 2021, you can do so by this easy feature there.

KB 07:02: Well that seems pretty easy to do. Is there any way for me to receive notification of individuals with high doses?

Katelyn 07:10: Absolutely. So that is actually one of my favorite features that we have added into the Personnel Dosimetry module and it exists in this reporting section. So Iā€™ll go ahead and select that and weā€™ll take a look at that.

The reporting section has a tab called ALARA. The module has the ability to add in different custom ALARA thresholds. For this particular demo dosimetry account, we have two thresholds added in. Iā€™ve added in an ALARA 1 and an ALARA 2. These are both quarterly thresholds but you can also have them trigger on a single dose, they can be monthly, quarterly, or annually. So, you have a variety of options there. They can also be scoped to particular badge regions that a badge is assigned to. Since these are quarterly thresholds, this next filter of the period gives me the option to choose a quarterly time period but that will change depending on your threshold. And if I do put in last quarter as an example and select run report, what thatā€™s going to do is give me a table of results of individuals that have surpassed that threshold for the chosen time period. So we have these three demo people who have surpassed the ALARA 1 Threshold,  and then one person additionally also surpassed the ALARA 2, so this table is really nice because if they did surpass other thresholds it will let you know that. So if you only want to follow up on the higher of the two you absolutely can do that.

It will tell you the time period that weā€™re covering currently, and then the cumulative dose for that time period, and then the stage that youā€™re at in the process. So this will allow you to email each of these individual wearers either notification that they went over this dose threshold or a questionnaire ā€“ that form that they actually get sent is completely customizable ā€“ and the wearer will receive that via email. Once they do, they will open and view that, if they have any questions they can fill that out, it requires a signature and dates it for them automatically, and then that gets sent back to Odyssey. Once it does get sent back, this pie chart progresses and shows you where this process is. So it will change to being yellow for ā€œwaiting for RSO response.ā€ So if youā€™re an RSO, a radiation safety representative, you can come in here, review that questionnaire, and the responses, and sign off on that to complete the process.

And to get back to your initial question about alerts for these items, throughout this entire process youā€™re going to be receiving in-software alerts which can optionally be email alerts as well. So when a wearer initially goes over the threshold, any of these thresholds you have set up, youā€™re going to get an alert that looks like a post-it note like one of these. And then when they fill it out they also will trigger an alert and itā€™ll let you know they have it filled out so that way you can come in and review that as soon as possible. And so youā€™re always going to be notified of each stage of the process there as this progresses.

KB 10:07: Well that all sounds great! Thanks, Katelyn, for helping us address some frequently asked questions about Odysseyā€™s Personnel Dosimetry module. Join both of us next week for part 2 where weā€™re going to be talking about the inventory tracking module and its ability to assist with tracking radioactive materials in your radiation safety program.

Katelyn 10:26: Thanks, KB.


Schedule an in-depth demo with our Odyssey team to discuss how the software can assist you with your radiation safety management needs, or visit our website to learn more about Odyssey’s radiation safety modules.