title: The Use of 123I in Diagnostic Radioactive Iodine Scans in Children with Differentiated Thyroid Carcinoma.
abstract: BACKGROUND
  Adult studies have shown that iodine-123 ((123)I) is as effective as (131)I in detecting metastatic disease in patients with differentiated thyroid carcinoma. However, the type and administered activity of radioiodine used for diagnostic imaging of metastatic thyroid cancer has not been well studied in children. Here we describe our institution's experience with using (123)I in diagnostic radioiodine scans in children with differentiated thyroid carcinoma.
  
  
  METHODS
  Every patient with differentiated thyroid carcinoma who completed diagnostic scanning followed by radioiodine therapy at our institution over the past 8 years was included in this retrospective chart review. Patient age, sex, presentation of thyroid disease, past medical history, thyrotropin, thyroglobulin, and antithyroglobulin antibodies were recorded. A single nuclear medicine radiologist evaluated all scans.
  
  
  RESULTS
  Thirty-three subjects completed 37 pairs of scans at a mean age of 13.4 years (range 6-17 years). The majority of subjects were female (81%) and had papillary thyroid cancer (91%). For diagnostic scanning, 5 received 2 mCi of (131)I, 21 received 2 mCi of (123)I, and 11 received 3 mCi of (123)I. There was no statistically significant difference in rate of discordant scan pairs when comparing (131)I and (123)I (20% and 23% respectively, p=0.9). The detection of metastatic pulmonary disease on diagnostic scanning was not improved by increasing the dose of (123)I from 2 mCi to 3 mCi (10% rate of missed lung detection with 2 mCi (123)I vs. 20% with 3 mCi (123)I).
  
  
  CONCLUSIONS
  (123)I is effective for use in diagnostic radioactive iodine scans in children with differentiated thyroid cancer. The primary advantages of using (123)I include decreased radiation exposure and avoidance of stunning. However, in children there is a possibility of missed detection of metastatic pulmonary disease.
authors.affiliation: 1 Division of Endocrinology, Riley Hospital for Children, Department of Pediatrics, Indiana University School of Medicine Indianapolis , Indiana.
authors.forename: Melissa J
authors.initials: MJ
authors.lastname: Schoelwer
authors.affiliation: 2 Division of Endocrinology, Ann and Robert H. Lurie Children's Hospital of Chicago, Department of Pediatrics and Radiology, Northwestern University Feinberg School of Medicine Chicago , Illinois.
authors.forename: Donald
authors.initials: D
authors.lastname: Zimmerman
authors.affiliation: 3 Division of Radiology and Nuclear Medicine, Ann and Robert H. Lurie Children's Hospital of Chicago, Department of Pediatrics and Radiology, Northwestern University Feinberg School of Medicine Chicago , Illinois.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Shore
authors.affiliation: 2 Division of Endocrinology, Ann and Robert H. Lurie Children's Hospital of Chicago, Department of Pediatrics and Radiology, Northwestern University Feinberg School of Medicine Chicago , Illinois.
authors.forename: Jami L
authors.initials: JL
authors.lastname: Josefson
mesh_terms: D000293:Adolescent; D001323:Autoantibodies / Q000276:immunology; D002277:Carcinoma / Q000737:chemistry; D002291:Carcinoma, Papillary; D002648:Child; D003952:Diagnostic Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000737:chemistry*; D008297:Male; D009362:Neoplasm Metastasis; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000737:chemistry; D012189:Retrospective Studies; D013954:Thyroglobulin / Q000737:chemistry; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000737:chemistry / Q000000981:diagnostic imaging*; D013972:Thyrotropin / Q000737:chemistry
chemical_list: D001323:Autoantibodies; D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; C006606:anti-thyroglobulin; D013972:Thyrotropin; D013954:Thyroglobulin