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White Blood Cell Counts Rising During Brain Radiation Therapy

White Blood Cell Counts Rising During Brain Radiation Therapy

Question
My father in law is in his last week of an intense six week radiation therapy [to the brain]. He has thus far had no major side effects [except] a little bit of swelling in the face. He was diagnosed with Glioblastoma-Multiforme brain cancer. This week however his white blood count is 15+ (over 15,0000 white cells per cubic mm) Is this a sign his body is fighting the cancer? Ordinarily, the WBC (White Blood Cell Counts) drops during radiation, and particularly chemotherapy. What would be the reason for this increase in blood count?


Answer
It is true that the blood counts typically drop during radiation therapy, especially when large volumes of marrow (the pelvic bones, for instance) are being treated. Only a small percentage of marrow is in the skull, so counts don't usually drop very much with brain radiation. An increase in the white blood cell count during brain radiation therapy can result from a number of factors. Sometimes, patients being treated with radiation to the brain are taking steroid medications to prevent or reduce swelling (decadron/dexamethasone, for instance). These drugs can cause the white cell count to rise. Another possible cause is an infection, and it is important to exclude this possibility. There may be other reasons, and as always it is best to discuss these matters with your physicians.