title: Comparison of MRI and PET-CT in detecting the loco-regional recurrence of soft tissue sarcomas during surveillance.
abstract: OBJECTIVE
  To investigate the diagnostic performance of MRI and PET-CT for the detection of loco-regional recurrences after soft tissue sarcoma (STS) excision.
  
  
  METHODS
  From Dec 2003 to Aug 2014, 394 patients with STSs, who were included in the electronic patient registry for initial or repeated surgery at our hospital, were retrospectively reviewed. We identified 152 patients who underwent regular postoperative follow-ups with both MRI and PET-CT, obtained within a 3 month period of each other. We analyzed differences in the performance of MRI and PET-CT for the diagnosis of loco-regional recurrences using McNemar's test. The receiver-operating characteristic curves and calculations of the area under the curve were used.
  
  
  RESULTS
  Twenty patients were found to have a loco-regional recurrence after tumor excision. For MRI and PET-CT, the sensitivities were 90.0 and 95.0 %, and the specificities 97.7 and 95.5 %, respectively, with positive predictive values of 85.7 and 76.0 % and negative predictive values of 98.5 and 99.2 %, respectively. No significant difference was detected between the sensitivities of MRI and PET-CT (p = 0.125). The area under the receiver-operating characteristic curve for PET-CT (0.952) was not significantly greater than that for MRI (0.939; p = 0.6).
  
  
  CONCLUSIONS
  MRI of the area of interest is recommended for evaluation of tumor recurrence after surgical excision of STS. PET-CT was shown to be effective for detection of STS recurrence, and comparable to MRI. However, if PET-CT or MRI findings are inconclusive, the other modality may be helpful in differentiating tumor recurrence from post-therapeutic tissue change.
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea.|Department of Radiology, Hallym University Sacred Heart Hospital, Gwanpyeong-ro 170 beon-gil, Dongan-gu, Anyang-si, Gyeonggi-do, 14068, Republic of Korea.
authors.forename: Sun-Young
authors.initials: SY
authors.lastname: Park
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea. chung@amc.seoul.kr.
authors.forename: Hye Won
authors.initials: HW
authors.lastname: Chung
authors.affiliation: Department of Nuclear Medicine, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea.
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Chae
authors.affiliation: Department of Orthopedic Surgery, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea.
authors.forename: Jong-Seok
authors.initials: JS
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging* / Q000473:pathology / Q000517:prevention & control; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012509:Sarcoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D012680:Sensitivity and Specificity; D018571:Sentinel Surveillance; D012983:Soft Tissue Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D016896:Treatment Outcome
keywords: Magnetic resonance imaging; Paired comparison; Positron emission tomography; Recurrence; Soft tissue sarcoma