title: Role of fluorodeoxyglucose positron emission tomography (FDG PET)-computed tomography (CT) in the staging of bladder cancer.
abstract: OBJECTIVE
  To determine whether to use (18) F-fluorodeoxyglucose positron emission tomography (FDG PET) scans in the preoperative staging of bladder cancer (BC).
  
  
  METHODS
  In all, 233 patients with muscle-invasive BC (MIBC) or high-risk non-MIBC being considered for radical cystectomy (RC) between 2005 and 2011 had FDG-PET and computed tomography (CT) of the chest, abdomen and pelvis to assess for pelvic lymph node (LN) involvement or distant metastases. Sensitivity and specificity for detecting pelvic LN involvement was determined by comparing the results of the scans to the histopathology reports in patients undergoing RC. These parameters for distant metastases were determined from biopsy results or follow-up imaging. In patients who did not undergo RC, follow-up imaging was used to evaluate the sensitivity and specificity. Patients were excluded from analysis if they either had neoadjuvant chemotherapy or had <10 LNs removed at lymphadenectomy.
  
  
  RESULTS
  The PET scan was able to detect metastatic disease outside of the pelvis with a sensitivity of 54% compared with 41% for the staging CT (N = 207). Both scans had similar specificities of 97% and 98%. There were 13 PET avid lesions not visualised on the corresponding staging CT scans. These proved to be metastatic BC (six patients), a synchronous primary colonic cancer (one), colonic adenomas (one), basal cell tumour of the parotid gland (one) and inflammatory lesions (four). The sensitivity and specificity of the CT scans for pelvic LN involvement was 45% and 98%, respectively (N = 93). Using a combination of the PET and CT scan, the sensitivity for detecting metastatic disease in LNs increased to 69% with a 3% reduction in specificity to 95%.
  
  
  CONCLUSIONS
  PET when used in conjunction with a standard CT scan provides a small improvement in preoperative staging of BC. However, this advantage is not significant enough to justify the additional cost. Hence we recommend use of dual imaging only in highly selected patients.
authors.affiliation: Guy's, King's and St Thomas' Medical School, Kings College London, London, UK.
authors.forename: Henry
authors.initials: H
authors.lastname: Goodfellow
authors.forename: Zaid
authors.initials: Z
authors.lastname: Viney
authors.forename: Paul
authors.initials: P
authors.lastname: Hughes
authors.forename: Sheila
authors.initials: S
authors.lastname: Rankin
authors.forename: Giles
authors.initials: G
authors.lastname: Rottenberg
authors.forename: Simon
authors.initials: S
authors.lastname: Hughes
authors.forename: Felicity
authors.initials: F
authors.lastname: Evison
authors.forename: Prokar
authors.initials: P
authors.lastname: Dasgupta
authors.forename: Timothy
authors.initials: T
authors.lastname: O'Brien
authors.forename: Muhammad Shamim
authors.initials: MS
authors.lastname: Khan
mesh_terms: D000005:Abdomen / Q000000981:diagnostic imaging; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003362:Cost-Benefit Analysis; D015653:Cystectomy; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000191:economics / Q000379:methods; D009367:Neoplasm Staging; D018579:Patient Selection; D010388:Pelvis / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography / Q000191:economics; D011379:Prognosis; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D013909:Thorax / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D001749:Urinary Bladder Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: FDG PET/CT; bladder cancer; cystectomy; positron emission tomography; preoperative staging