Evaluation of micronucleus induction in lymphocytes of patients following boron-neutron-capture-therapy: a comparison with thyroid cancer patients treated with radioiodine.

This study evaluated micronuclei induction in peripheral T-lymphocytes after BNCT (boron neutron capture therapy) irradiation of 15 brain tumor and 20 head-and-neck cancer patients. In all of these patients, the micronucleus frequency increased after BNCT; the number of micronuclei per 1000 binucleated T-lymphocytes after BNCT increased by 33.0 +/- 12.2 for brain tumor patients and 22.8 +/- 10.3 for head-and-neck cancer patients. In 14 thyroid cancer patients who were administered radioiodine (3.3-5.6 GBq) treatment, the frequency of micronuclei after internal radioiodine therapy increased to 105.0 +/- 30.5 per 1000 binucleated T-lymphocytes. The increased micronucleus frequency of BNCT patients was less than one-third that seen for thyroid cancer patients after radioiodine treatment. These results demonstrate the usefulness of BNCT for selective high-LET radiotherapy, in association with a low irradiation effect of cytological radiation damage after BNCT, which provides a high tumor target dose for each cancer patient.