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Interested in the dosimetrist career path

  1. Jun 3, 2012 #1
    Hi everyone. I know there are some medical dosimetrists and physicists in this forum who have provided useful advice. I still have some questions, if you don't mind.

    Basically, my background consists of a B.S. and M.Sc in physics with not so stellar grades (~3.0 GPA). I graduated almost 7 years ago with no work experience in the discipline. I've worked in some finance and am currently in IT. I'm looking to apply to some dosimetry programs but it seems my chances are slim compared to applicants who come from a radiation therapy background.

    I did apply to a radiation therapy program at a reputable institution some time ago but was declined because they felt I was too shy and reserved to be able to interact with patients. I wasn't too happy about that but they're the professionals who know what it takes so I understand.

    So I figured perhaps I could go straight into dosimetry. I'm in the process of taking Biology and Anatomy/Physiology to fulfill program prerequisites and then, hopefully, intern at a clinic to get some experience. Provided I can find one willing to take me.

    My question is if it's worth sacrificing my current job to proceeds with my aspirations. I know this is something I want to do and was in awe when I shadowed a dosimetrist for a day. I have the utmost respect for the radiation oncology team and what they do. I don't have a radiation therapy background. I don't have a radiology background. I don't have any healthcare background. I'm just a prospective applicant in my early 30's looking to switch careers.

    I know determination (which I will need) is one thing. But from the perspective of the admissions committee, or any future employers looking at a candidate with no experience, that weighs much greater in my eyes.

    I've been asked why not medical physics. Well, my grades speak for themselves. Plus, I think it's an even harder road to take relative to dosimetry. So, for now, that's out of the question.

    I would appreciate if anyone could chime in. Thanks.
  2. jcsd
  3. Jun 4, 2012 #2


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    I think there's another thread about this somewhere.

    In my experience all CMDs I know have been therapists first. Experience as a therapist is in my opinion, a necessary prerequisite. That's no to say that you can't do it. I'm sure there's a program out there that would accept you. But you have to remember that as a dosimetrist, at some point you'll be called out to the floor with a group of therapists looking at you asking how to set the patient up given that the mask used on the planning CT doesn't fit the same way now as it did in simulations.

    My advice would be to try again to get into an RT program and work up from there.
  4. Jun 6, 2012 #3
    I don't know that I would agree with you completely. To be sure, having some basic knowledge as an RTT would help, but it's not necessary. Remember the days when the RTT needed to be an RTR first? Not anymore. More significantly, the dosimetrist's boss and teacher is a physicist. In 30 plus years, I've never met even one physicist that was an RTT first. Yes, I'm sure there are some, but my point is, if a physics or biology major can make it in graduate school as a Medical Physicist, I see no reason a physics major couldn't make it in dosimetry school. As for the "set up" type questions, the present clinical time requirements will take care of that.

    BTW, this is from an e-mail exchange with a JRCERT program head "The students that do the best in our program are the ones with a BS in Physics or RT(T). Our program is a 12 month program which consist of our Professional Curriculum for Medical Dosimetry. Our instructors are PhD Physicist, Master Degree Physicist and Certified Medical Dosimetrist."
  5. Sep 8, 2012 #4
    Need further information regarding dosimetry

    I'm interested in reading more about this field but seems the resources are limited.

    The MDCB website is pretty much restricted to members.

    How can I find information relating to this profession. I'd like to read about the workings of their daily routine. And the technical aspects of what they do and how they plan treatment.

  6. Sep 8, 2012 #5


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    I did a quick google and found a lot of information.
  7. Sep 8, 2012 #6
    I hope you're not being facetious. What search terms did you use?
  8. Sep 9, 2012 #7


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    Re: Need further information regarding dosimetry

    You may want to start here:

    The best way to really get a good picture of their daily routine is to organize a job shadow of some sort.

    If you have any specific questions, there are a number of medical physicists that post here regularly who can probably give you some good answers.
  9. Sep 9, 2012 #8
    Re: Need further information regarding dosimetry

    Thanks for your post! I already read through the website and feel I already have a grasp of the general outlay of the profession. I already shadowed once and have another appointment soon to shadow another dosimetrist.

    I just wanted to find some technical info on what they're actually doing and the workings of the treatments and software they use so I can have a better understanding when I visit. This is so they don't have to explain every single thing to me and waste their time and I can actually follow along
  10. Sep 10, 2012 #9
    Re: Need further information regarding dosimetry

    If a medical dosimetrist is willing to have you shadow them for a bit then I doubt that they would mind answering whatever questions you have as they work.

    However, a very brief and general overview of how the process typically works is as follows:

    Treatment planning -- the domain of the medical dosimetrist -- occurs after the patient has been seen by the radiation oncologist and has typically had some form of treatment simulation performed. Simulations are usually performed by radiation technologists or radiation therapists under the direction of the physician (and with the help of dosimetrists and medical physicists, as needed).

    Dosimetrists usually plan treatments for external beam radiotherapy. External beam radiotherapy (EBRT) will typically use mechanically produced radiation from linear accelerators. Depending on where you are, the dosimetrist may also perform or help with treatment planning for brachytherapy procedures. Brachytherapy refers to the placement of small radioactive sources inside of or very near to the area being treated. I won't talk about brachytherapy in this post since it is less likely that you would be involved with it while shadowing.

    For EBRT, the treatment simulation is usually a medical imaging procedure where a computed tomography scan (CT scan, also known as CAT scan) is performed. The patient will be positioned in a way that is identical to how they will be positioned during their treatments. The diseased area (plus some extra volume) is imaged via CT and the images are transferred to the treatment planning system, which is the software used by the medical dosimetrists.

    Once the CT scan images are available in the treatment planning software, the radiation oncologist will identify and draw (aka contour, or delineate) the area that they wish to be treated. The oncologist will also specify a treatment prescription that includes (among other things) the amount of radiation they wish to give, the treatment technique they wish to use, and also any limitations on the amount of radiation that nearby healthy tissue can receive. Nearby organs that have limitations on the amount of radiation they can receive are known as critical structures, or organs-at-risk. These structures are also drawn/contoured on the CT images, usually by the dosimetrist but sometimes by the radiation oncologist.

    Once the planning directions have been given to the dosimetrist from the radiation oncologist, the dosimetrist can begin treatment planning. The dosimetrist will specify the directions from which they wish to give targeted radiation as well as the shape of the radiation beam. The number of beams may range from 1-4 for simple procedures, or might be as many as 10 or more for more complex treatments. As the treatment plan is put together, the dosimetrist is able to visualize the quantity and location of deposited radiation dose on the CT images to verify that the target (the cancer) is receiving the prescribed amount while the critical structures (the healthy tissue) is being appropriately spared from excess dose.

    Once a candidate treatment plan is finished, it is presented to the radiation oncologist for review and approval. Alternatively, the oncologist may request that further work done to improve the treatment plan if they have reason to believe that it does not satisfy the goals of the treatment.

    Throughout the process the medical physicist may be involved to assist with generating and critiquing the treatment plan.

    The technical aspects of the treatment planning software are handled by the medical physicist. Among other things, this includes the modeling of the mechanical aspects of the treatment machines (the linear accelerators) in the planning software so that the positioning of the patient and the available beam directions and shapes in the software agree physically with the treatment machine, the modeling of the radiation beams themselves so that the algorithms that compute deposited dose yield correct results, and periodic quality checks that ensure that everything continues to perform correctly over time.

    Feel free to continue to ask whatever questions you like.

    Good luck!
    Last edited: Sep 10, 2012
  11. Sep 11, 2012 #10
    This is the most informative resource I read so far and exactly what I'm looking for. Thanks!
  12. Sep 26, 2012 #11
    I've been contacting several clinics about volunteering or observing part-time but haven't been getting favorable, if any, responses. My thought was to accumulate all these hours in a clinic so I have a relatively strong application when it comes to applying to several dosimetry schools.

    I just came back from observation with a CMD (for the second time, and the only clinic that would allow me to come in). I learned a little more about the software but it seems my hopes have been dashed for now.

    The CMD I observed today was willing to help out but told me it would hurt him more than help me since it would take away from his work explaining things to me. This is the dilemma. How am I supposed to show I really want to commit to this in my dosimetry program applications if I'm getting turned down for volunteer experience?

    And to counter Choppy's statement about all dosimetrists he knew being therapists before, the CMD said that he only knew one dosimetrist that was previously a therapist. Haha!
  13. Sep 26, 2012 #12
    Just curious, where are you located?
  14. Sep 26, 2012 #13
    from NYC
  15. Sep 26, 2012 #14


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    Did you happen to get his sample size?

    Mine's about 50, though to be fair, the population is largely limited to Canada. Things may be slightly different in the US. Back on the other and I have actually discussed this issue with several of the American dosimetrists that I've met and was given the impression that it is still most common for dosimetrists to have come up through the RT ranks.

    Anyway, that doesn't really matter. Your dilemma right now is how to bolster your application. You've done a second job shadow and want to volunteer more. This shows that you've done some serious investigation into the career and probably puts ahead of most other applicants to the program. I'm not sure it there really is much volunteer opportunity a dosimetry department would be able to offer to a volunteer.

    One possible option is that you might contact a medical physics department. Occassionally they may have projects that could benefit from the assistance of a volunteer.
  16. Sep 28, 2012 #15
    Sorry, I didn't get a sample size. Probably not as large as yours though.

    Are there any highly recommended books for me to get started on?

    I guess these are pretty good, right?

    Physics of Radiation Therapy by Khan
    Radiation Therapy Planning by Bentel
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