title: [Effect of radio therapy on the magnitude of iodine radioisotope half-life in the thyroid tissue remnants in patients with differentiated thyroid cancer].
abstract: The use of external irradiation in the treatment of patients with differentiated thyroid cancer is still under consideration. The aim of the study was to compare Tef in the thyroid remnants in patients with and without external irradiation prior to radioiodine treatment. 70 patients with thyroid remnants after resection of thyroid and dissection of pathological lymph nodes were treated by I-131. Patients were divided into two groups: Group 1--with external irradiation (25-60 Gy)-21 patient, and Group 2--patients who did not received external irradiation prior to radioiodine treatment (49 patients). Activities administered ranged from 1000 to 4500 MBq. I-131 kinetics was followed daily during first 4 days after activity administration on the basis of mathematical analysis of scintigraphy. T(ef) was calculated under the assumption of exponential excretion of 131-I from remnants. It was shown that in Group 1 T(eff) = 3.87 +/- 2.5 days, in Group 2 T(eff) amounted to 2.9 +/- 2.2 days. Thus, external irradiation resulted in slowing down of 131-I excretion in thyroid remnants. The probability of the full remnants ablation after the first course of 131-I treatment (p) has been calculated. It was shown that p is higher in the Group 2 in every activity interval. Teff in sequential courses of 131-I treatment has been measured at the same patients. Thus, external irradiation influences in different way at the previously irradiated and not irradiated cells.
authors.forename: O V
authors.initials: OV
authors.lastname: Kozak
authors.forename: O M
authors.initials: OM
authors.lastname: Trembach
authors.forename: L V
authors.initials: LV
authors.lastname: Romanenko
authors.forename: O I
authors.initials: OI
authors.lastname: Butrym
mesh_terms: D006207:Half-Life; D006801:Humans; D007457:Iodine Radioisotopes / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D011878:Radiotherapy / Q000379:methods; D013961:Thyroid Gland / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects / Q000601:surgery; D013964:Thyroid Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D013965:Thyroidectomy
chemical_list: D007457:Iodine Radioisotopes