title: The clinical significance of 18F-FDG-PET/CT in early detection of second primary malignancy in cancer patients.
abstract: OBJECTIVE
  This retrospective study evaluated the diagnostic value of integrated whole-body (18)F-fluorodeoxyglucose positron-emission tomography and computed tomography ((18)F-FDG-PET/CT) in early detection of second primary malignancies in cancer patients.
  
  
  METHODS
  From June 2007 to October 2008, 677 cancer patients who had undergone a whole-body (18)F-FDG-PET/CT imaging for the purpose of initial tumor work-up were included in this study. We retrospectively analyzed the follow-up results of patients with newly detected lesions presented on the (18)F-FDG-PET/CT images, which had not been previously detected by other modalities. We diagnosed suspected second primary malignancies by considering PET/CT images and clinical information as well. With the pathological results as the golden standard and complementary clinical follow-up investigations, the sensitivity and the positive-predictive value (PPV) of diagnosis of a second primary malignancy were calculated.
  
  
  RESULTS
  We retrospectively analyzed the follow-up results of 338 patients with newly detected lesions. Twenty-one patients were finally diagnosed with second primary malignancies. In addition, the second primary malignancies of 17 patients were diagnosed at an early stage (P = 0.007). Thirteen patients were without any related symptoms which are indicative of second primary malignancies (P = 0.38). The median Karnofsky performance status scale of these patients in the last follow-up study was 80 points. The sensitivity of (18)F-FDG-PET/CT in detecting a second primary malignancy was 95.24%, the PPV was 74.07%, which was much higher than the PPV of diagnosing with no clinical information.
  
  
  CONCLUSIONS
  (18)F-FDG-PET/CT is a useful tool in detecting second primary malignancies in an early stage and can improve the therapeutic effects experienced by the patients.
authors.affiliation: Department of Nuclear Medicine, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197, Rui Jin Er Road, 200025, Shanghai, People's Republic of China.
authors.forename: Haoping
authors.initials: H
authors.lastname: Xu
authors.forename: Miao
authors.initials: M
authors.lastname: Zhang
authors.forename: Ge
authors.initials: G
authors.lastname: Zhai
authors.forename: Biao
authors.initials: B
authors.lastname: Li
mesh_terms: D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D009369:Neoplasms / Q000150:complications* / Q000473:pathology; D016609:Neoplasms, Second Primary / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000473:pathology; D049268:Positron-Emission Tomography / Q000379:methods*; D011379:Prognosis; D012004:Rectal Neoplasms / Q000150:complications / Q000601:surgery; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D019788:Fluorodeoxyglucose F18