title: Effects of Dosimetrically Guided I-131 Therapy on Hematopoiesis in Patients With Differentiated Thyroid Cancer.
abstract: The objective of the study was to evaluate the effects of dosimetrically guided I-131 prescribed activities on hematopoiesis reflected by changes in complete blood counts (CBCs).
  
  
  
  This was a retrospective analysis.
  
  
  
  The study was conducted at an academic center.
  
  
  
  A total of 152 patients with differentiated thyroid cancer who had 185 dosimetrically guided I-131 treatments.
  
  
  
  There were no interventions.
  
  
  
  Repeated-measure ANOVA was used for the analysis of the differences in the averages of CBCs that were documented at baseline and 1, 6, 12, 24–36, and 48–60 months after I-131 treatment.
  
  
  
  All parameters decreased to their respective nadir at 1 month and then gradually returned toward baseline values. White blood cells (WBCs) and platelets (PLTs) were the most significantly affected cells. At 1 month, the decrease was 29.6% (P < .0001) for WBCs and 25% (P < .0001) for PLTs, whereas at 12 months, the decrease was 15.5% (P < .0001) and 13% (P < .0001), respectively. Lymphocytes appeared to be more susceptible to I-131 than neutrophils (ANCs). The decreases were small in absolute numbers for red blood cells, hematocrit and hemoglobin not surpassing 10%. Multivariate analysis demonstrated that the ratio of administered prescribed activity-to-maximum tolerated activity was associated with the decreases in WBCs (P = .0038), ANCs (P = .0063), and red blood cells (P = .029), with borderline significance for PLTs (P = .057) and hemoglobin (P = .057).
  
  
  
  Dosimetrically guided I-131 resulted in statistically significant decreases in CBC parameters, which were more prominent in WBCs and PLTs. Lymphocytes were more severely affected than ANCs, whereas all parameters reached a nadir at 1 month and then gradually returned toward baseline values over the 5-year follow-up of our study.
authors.affiliation: Division of Endocrinology (A.B., K.D.B., L.W.), Department of Medicine, MedStar Health Research Institute (A.B., S.D., M.M.), and Division of Nuclear Medicine (M.S., F.A., D.V.N.), MedStar Washington Hospital Center, Washington, DC 20010.
authors.forename: Athanasios
authors.initials: A
authors.lastname: Bikas
authors.affiliation: Division of Endocrinology (A.B., K.D.B., L.W.), Department of Medicine, MedStar Health Research Institute (A.B., S.D., M.M.), and Division of Nuclear Medicine (M.S., F.A., D.V.N.), MedStar Washington Hospital Center, Washington, DC 20010.
authors.forename: Mark
authors.initials: M
authors.lastname: Schneider
authors.affiliation: Division of Endocrinology (A.B., K.D.B., L.W.), Department of Medicine, MedStar Health Research Institute (A.B., S.D., M.M.), and Division of Nuclear Medicine (M.S., F.A., D.V.N.), MedStar Washington Hospital Center, Washington, DC 20010.
authors.forename: Sameer
authors.initials: S
authors.lastname: Desale
authors.affiliation: Division of Endocrinology (A.B., K.D.B., L.W.), Department of Medicine, MedStar Health Research Institute (A.B., S.D., M.M.), and Division of Nuclear Medicine (M.S., F.A., D.V.N.), MedStar Washington Hospital Center, Washington, DC 20010.
authors.forename: Frank
authors.initials: F
authors.lastname: Atkins
authors.affiliation: Division of Endocrinology (A.B., K.D.B., L.W.), Department of Medicine, MedStar Health Research Institute (A.B., S.D., M.M.), and Division of Nuclear Medicine (M.S., F.A., D.V.N.), MedStar Washington Hospital Center, Washington, DC 20010.
authors.forename: Mihriye
authors.initials: M
authors.lastname: Mete
authors.affiliation: Division of Endocrinology (A.B., K.D.B., L.W.), Department of Medicine, MedStar Health Research Institute (A.B., S.D., M.M.), and Division of Nuclear Medicine (M.S., F.A., D.V.N.), MedStar Washington Hospital Center, Washington, DC 20010.
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Burman
authors.affiliation: Division of Endocrinology (A.B., K.D.B., L.W.), Department of Medicine, MedStar Health Research Institute (A.B., S.D., M.M.), and Division of Nuclear Medicine (M.S., F.A., D.V.N.), MedStar Washington Hospital Center, Washington, DC 20010.
authors.forename: Leonard
authors.initials: L
authors.lastname: Wartofsky
authors.affiliation: Division of Endocrinology (A.B., K.D.B., L.W.), Department of Medicine, MedStar Health Research Institute (A.B., S.D., M.M.), and Division of Nuclear Medicine (M.S., F.A., D.V.N.), MedStar Washington Hospital Center, Washington, DC 20010.
authors.forename: Douglas
authors.initials: D
authors.lastname: Van Nostrand
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001792:Blood Platelets / Q000528:radiation effects; D002648:Child; D005260:Female; D006410:Hematopoiesis / Q000528:radiation effects*; D006801:Humans; D007457:Iodine Radioisotopes / Q000494:pharmacology / Q000627:therapeutic use*; D007962:Leukocytes / Q000528:radiation effects; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000532:radiotherapy*; D055815:Young Adult
chemical_list: D007457:Iodine Radioisotopes