SBRT impact on bone marrow

[Shanti1]

Hi Everyone,

Have any of you experienced a decrease in bone marrow function of RBCs or WBCs that you attribute to SBRT treatment of bone mets?

Our radiation oncologist wants to treat my husband's 5 bone mets with SBRT (1 medium met in left sacrum and 4 small mets in, left sacrum, right 6th rib, right acetabular roof, and right ilium). Our MO is concerned that the impact to his bone marrow could limit his ability to get chemo later.

Thank you!

[Tall_Allen]

Usually, metastatic SBRT is more limited than that, and the global effect on immune function is not a concern. In fact, if he only treated one to three metastases it may have a stimulative effect on T-cell production. (This is what happened in the recent ORIOLE trial).

If the purpose of the treatment is pain palliation, docetaxel or Xofigo, may be better choices. They are also proven to extend survival (unlike SBRT to metastases). SBRT of metastases, especially when there are so many, will probably not extend survival.

[Shanti1 in reply to Tall_Allen]

Thank you, TA for the very helpful answer. We are pulling up the ORIOLE trial now.

[Tall_Allen in reply to Shanti1]

jamanetwork.com/journals/ja...

[Shanti1 in reply to Tall_Allen]

Thanks, Allen, that is kind of you to make sure we made it to the right study.

[rassusukumaran in reply to Shanti1]

I have 5 mets in all. 2 on spine, hips, ribs and shoulder joint. My onco decided that they will not do SBRT as it will be too toxic to address all mets..

[Shanti1 in reply to rassusukumaran]

In addition to TA's comment above, I looked for research on SBRT's impact to bone marrow and could find very little. A sustained drop in RBC or WBC is not listed as a side-effect on the informational sites I visited. Logically, the larger and more extensive mets are, eventually you would begin to impact bone marrow as I'm sure it is compromised or killed in the areas treated. In your case, it may be worth getting a second opinion or an opinion from a radiation oncologist who specializes in SBRT. The other debate here is if treating more advanced disease with SBRT changes OS. In our case, we are leaning toward SBRT even without that evidence as we can't help but want to do everything we can as long as the side-effect profile is acceptable.

[Hidden in reply to Shanti1]

That study used hormone sensitive men who "had not received ADT within 6 months of enrollment or 3 or more years total". Not sure if it applies to your husband or not.

Mine is castrate resistant (lupron, orchie, casodex, zytiga, xtandi) and his recent radiation to mets lowered his blood numbers. We attributed it to the radiation but didn't ask the doc to confirm. He will get bloodwork next week so it will be interesting to see if the numbers improve.

[Shanti1 in reply to Hidden]

Thanks for your reply. My husband is hormone-sensitive and just started back on ADT when his PSA reached 1 after a 2 year ADT break. He had 1 year of ADT prior. I do hope that your husband's blood counts improve, did the SBRT treatment he received include large or extensive mets?

[Hidden in reply to Shanti1]

Glad to hear your husband is still hormone sensitive. I wish him many more years of ADT success! My husband had smaller rib mets radiated. Nothing large or extensive.

[jdm3 in reply to Shanti1]

What are they using for ADT?

[Shanti1 in reply to jdm3]

Trelstar 3 month injection and Zytiga