reduced white cell counts

I am getting ready to start radiation treatment on Monday.  I am 54 yrs. old and will take hormonal treatment when I complete this phase.  My B.S. is in Medical Technology so I understand the reduction in your WBC, RBC, and platelet counts during cytotoxic treatment like chemotherapy.  What I'm not understanding from my reading, is the possibility of a reduction in the WBC (especially), from radiation treatment.  This is treatment to something that is basically a gland, outside of your body cavity.  It is attacking the DNA of the nucleus of the cancer cell.  If I understand correctly, it is not "hitting" your blood stream or bone marrow.  As a Med Tech, we studied a lot about Leukemia and what chemotherapy does to the cancer that is in your blood system.  So, I'm looking for information that actually explains why it might happen in breast radiation, not just that it can happen. - Kay

[Fernando Roque, MD]

Hi.  I think it is incorrect to say that when you have radiation therapy to your breast, "it is not hitting your blood stream or bone marrow".  The machines delivering the radiation beam focus the beam and limit the radiation dose hitting tissues outside the target area, but the shielding is often not 100% foolproof.   Not all the delivered radiation dose goes solely to the target area. Some stray radiation does go to other body tissues.  If the tissue is rapidly dividing and very radiosensitive, like the bone marrow, it does not take a large radiation dose to damage it and affect its production of white blood cells.

[rockchalk76]

Thank you for your reply but it raises another question for me.  Just so you'll know, I had a lumpectomy is the upper right quadrant of the right breast.  Have they done any studies to come up with percentages comparing the localize dose administered to the breast area, compared to the systemic affect of chemotherapy in the reduction of white counts?  I've tried searching on "immunosuppression and radiation" on the internet but don't really find anything.  None of the books I've read give a %, just that it might happen.  I am supposed to get 25 treatments and then 5 treatments with a boost.  I had my flu shot earlier in the week.  I am very involved in programs at our local library.  When I read about chemotherapy, often mentioned staying away from small children.  I'm wondering about staying on the safe side and not helping with any of the children's activities for the next six weeks?  Does your WBC bounce back up to normal a few weeks after treatment ends?  

In the planning appointment, the radiation oncologist talked about the great advances they have made in the reduction of scatter since I worked in the medical field.  In the appointment I had with him a month ago he said that the skin burning I had seen 20 years ago was greatly reduced.  So I hadn't really had much level of worry about this treatment until they said they would be drawing blood each week to count my blood counts.  Suddenly that was a red flag, especially since the surgeon told me that I wasn't to have any blood pressure cuffs, injections, or blood draws in my right arm.  Although I have thin arms, the veins are not "good" in the left arm.  Please believe me when I say this, as I spent time drawing blood when I worked in the lab.  I'm afraid they will screw up my veins taking blood when its not really that big of a risk of low blood counts.  Do they still do finger sticks like we did on chemo patients 20 years ago, to save their veins?  I do not have a "port" because I did not have chemo.  Sorry, we analytical types like to see data.  Gathering data gives us a sense of comfort that is not found in general statements.  I was hoping to get more information for my appointment tomorrow.  - Kay

[Fernando Roque, MD]

Hi.  There's a study done by F. Ampil, et al (2001) in the Breast Journal (http://www3.interscience.wiley.com/journal/119028975/abstract?CRETRY=1&SRETRY=0) , wherein they investigated whether weekly blood counts of women receiving breast irradiation after lumpectomy for early stage cancer is really necessary.  Of the 73 women involved in this study, 26% developed Grade 1 neutropenia due to the radiotherapy, while 21% developed Grade 1 anemia. Because of these numbers, the authors recommended at least a baseline blood count prior to starting breast irradiation.  However, the study was not able to answer the primary research question conclusively.  The authors suggested further studies to better define the population which would benefit from weekly blood counts during breast radiotherapy.

As for your other questions: If the above study is correct and you have a 26% chance of developing at least a mild neutropenia, it might be prudent to stay away from small children for the duration of your radiation treatment since you might be immunocompromised.  If your white cell count goes down, you should start recovering around two weeks after the treatment ends.

[rockchalk76]

Thank you SO much!  This is exactly the kind of information I was looking for - numbers, not general statements.  Its good to know that the WBC count usually comes back that quickly.  I should be finished around Dec. 9th so that would give me time to be back to normal for Christmas.  Thank you for responding a 2nd time, Kay