title: Utility of Tc-PEG4-E[PEG4-c(RGDfK)]2 in Posttherapy Surveillance of Patients with Reelevated Carcinoembryonic Antigen Levels.
abstract: OBJECTIVE
  To evaluate the efficacy of (99m)Tc-PEG4-E[PEG4-c (RGDfK)]2 ((99m)Tc-3PRGD2) single photon emission computed tomography (SPECT) in monitoring the recurrence of malignancies.
  
  
  METHODS
  (99m)Tc-3PRGD2 SPECT was performed on 28 patients (10 females and 18 males; median age 49.2 years) suspected of recurrent malignancies due to an asymptomatically reelevated carcinoembryonic antigen level. The SPECT was performed 0.5 h after an intravenous injection of 11.1 MBq/kg (0.3 mCi/kg) of (99m)Tc-3PRGD2. The SPECT and concurrent contrast-enhanced computed tomography (ceCT) findings were analyzed with reference to the histopathological findings and/or clinical follow-up data.
  
  
  RESULTS
  Recurrences were identified in 20 out of the 28 patients (prevalence 71.4%) with altogether 26 lesions. Fifteen lesions were confirmed by histopathological findings, and the other 11 lesions were confirmed by serial radiological or clinical follow-up. Of the 20 patients with recurrent malignancies, 12 (60%) were correctly identified by (99m)Tc-3PRGD2 SPECT. In the patient-based analysis, the sensitivity and specificity of (99m)Tc-3PRGD2 SPECT were 60 and 100%, respectively, and the positive and negative predictive values were 100 and 50%, respectively. In the lesion-based evaluation, the sensitivity and specificity were 62 and 100%, respectively. The sensitivity and specificity of the ceCT in the patient-based evaluation were 60 and 75%, respectively, and the positive and negative predictive values were 86 and 40%, respectively. In the lesion-based evaluation, the sensitivity and specificity of the ceCT were 70 and 84%, respectively.
  
  
  CONCLUSIONS
  (99m)Tc-3PRGD2, as a new SPECT tracer targeting the integrin αvβ3 receptor, was more useful in distinguishing recurrences as compared to ceCT.
authors: Department of Nuclear Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, PR China.
authors: Rui
authors: R
authors: Gao
authors: Guangjian
authors: G
authors: Zhang
authors: Ling
authors: L
authors: Chen
authors: Zhaohui
authors: Z
authors: Zhu
authors: Fan
authors: F
authors: Wang
authors: Aimin
authors: A
authors: Yang
mesh_terms: D000328:Adult; D000368:Aged; D002272:Carcinoembryonic Antigen / Q000032:analysis*; D003287:Contrast Media; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000473:pathology; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000473:pathology; D015609:Organotechnetium Compounds; D011859:Radiography; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D002272:Carcinoembryonic Antigen; D003287:Contrast Media; D015609:Organotechnetium Compounds