Short-term effect of irradiation on the peripheral lymphocyte populations in patients treated with high-energy photon beam.

Changes in lymphocyte populations wee studied in 22 patients with testicular cancer before and after a single 2-Hy dose of high-energy photon beam. Absolute lymphocyte counts as sell as total T-and active T cells markedly decreased immediately after irradiation, whereas no significant alterations in Fc receptor-bearing lymphocytes and B cell counts were produced. Recovery of lymphocyte populations was relatively rapid, reaching pre-irradiation values by 24 hours.