title: Values of (99m)Tc-methoxyisobutylisonitrile imaging after first-time large-dose (131)I therapy in treating differentiated thyroid cancer.
abstract: OBJECTIVE
  The aim of this study is to investigate the use of (99m)Tc-methoxyisobutylisonitrile (MIBI) imaging for evaluating the treatment response of differentiated thyroid cancer (DTC) after the first administration of a high dose of (131)I.
  
  
  METHODS
  Patients with DTC who received (131)I therapy underwent (99m)Tc-MIBI imaging after successive increases in the therapeutic dose of (131)I, and the serum levels of thyroglobulin (Tg) were measured.
  
  
  RESULTS
  A total of 191 patients were enrolled in the final analysis, including 65 metastases and/or thyroid remnant-positive patients (22 patients with metastases and 43 patients with thyroid remnants). The sensitivity of (99m)Tc-MIBI imaging for detecting positive cases and thyroid remnants was 56.9% and 39.5%, respectively, which was significantly lower than that of (131)I imaging (92.3% and 100%, respectively, P<0.01 for both). The sensitivity of (99m)Tc-MIBI imaging for detecting metastases was 90.9%, which was slightly higher than that of (131)I imaging (77.3%, P>0.05). The Tg levels in the positive group were significantly higher than that in the negative group (P<0.01). In addition, the Tg levels in the (99m)Tc-MIBI(+)/(131)I(-) group were significantly higher than that in the (131)I(+)/(99m)Tc-MIBI group (P<0.05).
  
  
  CONCLUSIONS
  After the first (131)I therapy, although (99m)Tc-MIBI imaging was able to detect the existence of metastatic lesions in patients with DTC better, its assessment for the removal efficiency of thyroid remnants was unsatisfactory. The results of (99m)Tc-MIBI imaging showed good correlations with the Tg level.
authors.affiliation: Department of Nuclear Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Pan
authors.affiliation: Department of Nuclear Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Dong
authors.initials: D
authors.lastname: Duan
authors.affiliation: Department of Nuclear Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Yuquan
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Nuclear Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Hua
authors.initials: H
authors.lastname: Pang
authors.affiliation: Department of Nuclear Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Lili
authors.initials: L
authors.lastname: Guan
authors.affiliation: Department of Nuclear Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
authors.forename: Zhixiang
authors.initials: Z
authors.lastname: Lv
keywords: 99mTc-MIBI imaging; differentiated thyroid cancer; therapeutic dose 131I imaging; thyroglobulin