title: Evaluation of fluorodeoxyglucose positron emission tomography imaging in metastatic transitional cell carcinoma with and without prior chemotherapy.
abstract: BACKGROUND
  This study was designed to determine the value of fluorodeoxyglucose (FDG) positron emission tomography (PET) in the evaluation of metastatic transitional cell carcinoma (TCC).
  
  
  METHODS
  Fifty-eight FDG PET scans were performed on 46 consecutive patients with TCC. Results were correlated with radiologic, pathologic, and histologic findings in these patients and the sensitivity of PET for detecting malignancy in untreated TCC patients (n = 48) was compared to the sensitivity in patients who had undergone prior chemotherapy (n = 10).
  
  
  RESULTS
  Of 48 scans in patients who had no prior systemic chemotherapy, 10 had increased uptake in proven metastatic TCC lesions and 3 PET studies failed to reveal metastatic TCC (sensitivity 76.9%). In patients free of metastatic disease, 33 revealed no abnormal uptake and 1 study revealed a suspicious area in a patient free of metastases (specificity = 97.1%). However, in 10 patients imaged after receiving chemotherapy, the sensitivity fell to 50% for the detection of histologically confirmed residual/recurrent tumor by PET.
  
  
  CONCLUSIONS
  FDG PET detects increased metabolic activity. After chemotherapy, viable cancer cells may still be present but with a diminished metabolic rate. As a result, PET imaging is often useful in the evaluation of untreated metastatic TCC metastasis but should be interpreted with caution in patients who have received prior chemotherapy.
authors.affiliation: Section of Urology, Veterans Affairs Palo Alto Health Care System, Palo Alto, Calif., USA.
authors.forename: I Jenna
authors.initials: IJ
authors.lastname: Liu
authors.forename: Yen-Han
authors.initials: YH
authors.lastname: Lai
authors.forename: Jocelyn I
authors.initials: JI
authors.lastname: Espiritu
authors.forename: George M
authors.initials: GM
authors.lastname: Segall
authors.forename: Sandy
authors.initials: S
authors.lastname: Srinivas
authors.forename: Matilde
authors.initials: M
authors.lastname: Nino-Murcia
authors.forename: Martha K
authors.initials: MK
authors.lastname: Terris
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002295:Carcinoma, Transitional Cell / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000556:secondary*; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007680:Kidney Neoplasms / Q000188:drug therapy / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy / Q000473:pathology*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18