[Pulmonary microcirculation after distant gamma-therapy of breast and thyroid cancer (perfusion pulmoscintigraphy...

A study was made of an effect of irradiation on pulmonary microcirculation using perfusion pulmoscintigraphy indicators. Altogether 13 breast cancer patients (9 with left-side and 4 with right-side involvement) and 9 thyroid cancer patients were examined before and after radiation therapy. Absorbed doses in breast cancer were determined by phantom measurements, for thyroid cancer by calculation. Perfusion pulmoscintigraphy with labeled albumin macroaggregate preceded and followed radiotherapy. Accumulation of the radioactivity of the drug in different pulmonary zones was taken into account. Slight changes of the microcirculation index found after irradiation, lead to a conclusion that in radiation therapy of breast cancer one can observe improvement of the blood flow in the pulmonary arterial system whereas in thyroid cancer a similar effect in the irradiated upper pulmonary zone was not marked. Irradiation of the root of the lung produces a more powerful effect on the pulmonary blood flow. Taking into account a sharp suppression of the arterial blood flow in some lung cancer patients (decreasing chemotherapy efficacy) it is suggested that change of the blood content developing after irradiation be used in the planning of combined therapy of lung cancer.