title: A randomized clinical trial comparing 50mCi and 100mCi of iodine-131 for ablation of differentiated thyroid cancers.
abstract: OBJECTIVE
  To compare the efficacy of low (50 mCi) and high dose (100 mCi) Iodine-131 in ablation of differentiated thyroid cancer remnants.
  
  
  METHODS
  Baseline serum thyroglobulin (sTg), thyroglobulin antibody (Tg Ab) and diagnostic whole body iodine scan with 2 mCi of I-131 were performed in each individual. After 6 months serum Tg, Tg Ab (of-thyroxin) and WB iodine scan with 10 mCi of I-131 were done to assess the efficacy of the low and high dose of I-131. Iodine ablative therapy (IAT) was considered successful (complete ablation) if the I-131 whole body scan was negative and sTg level was undetectable. In case of positive scan and/or sTg level detectable the patient was considered as unsuccessfully/partially ablated.
  
  
  RESULTS
  In group A, (high dose) successful IAT was seen in 12/20 (60%) patients. Of these 5/7 (71%) had follicular Carcinoma on histopathology and 7/13 (54%) had papillary Ca. In group B, (low dose) successful IAT was seen in 8/20 (40%) patients, out of which 3/10 (30%) had follicular Carcinoma on histopathology and had successful IAT. 5/10 (50%) patients with papillary Carcinoma had successful IAT. As far as histopathology is concerned, in group A, response to high dose I-131 was better in follicular type than papillary type. Whereas in group B, response to low dose I-131 was better in patients with papillary type than follicular.
  
  
  CONCLUSIONS
  100 mCi of radioactive Iodine-131 (I-131) is a more effective therapeutic dose than 50 mCi (I-131) in the treatment of differentiated thyroid cancer remnants. Furthermore, follicular Carcinoma respond better to 100 mCi I-131 than 50 mCi while papillary Carcinoma showed an almost equal response to both.
authors.affiliation: Karachi Institute of Radiotherapy and Neuclear Medicine, Jinnah Postgraduate Medical Centre.
authors.forename: Maseeh uz
authors.initials: Mu
authors.lastname: Zaman
authors.forename: Rafia
authors.initials: R
authors.lastname: Toor
authors.forename: Shahid
authors.initials: S
authors.lastname: Kamal
authors.forename: Minhaj
authors.initials: M
authors.lastname: Maqbool
authors.forename: Salman
authors.initials: S
authors.lastname: Habib
authors.forename: Khalid
authors.initials: K
authors.lastname: Niaz
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000097:blood / Q000532:radiotherapy*; D000328:Adult; D002291:Carcinoma, Papillary / Q000097:blood / Q000532:radiotherapy*; D003131:Combined Modality Therapy; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D018365:Neoplasm, Residual; D013954:Thyroglobulin / Q000097:blood; D013964:Thyroid Neoplasms / Q000097:blood / Q000532:radiotherapy*; D013965:Thyroidectomy
chemical_list: D007457:Iodine Radioisotopes; D013954:Thyroglobulin