title: Positron emission tomography-computed tomography in paraneoplastic neurologic disorders: systematic analysis and review.
abstract: OBJECTIVE
  To evaluate the cancer detection rate of whole-body positron emission tomography-computed tomography (PET-CT) in a paraneoplastic neurologic context.
  
  
  METHODS
  Retrospective medical record review.
  
  
  METHODS
  Mayo Clinic, Rochester, Minnesota.
  
  
  METHODS
  Fifty-six consecutive patients with clinically suspected paraneoplastic neurologic disorders who underwent PET-CT after negative standard evaluations, including CT.
  
  
  METHODS
  Rate of cancer detection.
  
  
  RESULTS
  Abnormalities suggestive of cancer were detected using PET-CT in 22 patients (39%); 10 patients (18%) had cancer confirmed histologically. Cancers detected (limited stage in 9 of 10 patients and extratruncal in 4) were as follows: 2 thyroid papillary cell carcinomas, 3 solitary lymph nodes with unknown primary (2 adenocarcinomas and 1 small cell carcinoma), 1 tonsil squamous cell carcinoma, 3 lung carcinomas (1 adenocarcinoma, 1 small cell, and 1 squamous cell), and 1 colon adenocarcinoma. Detection of a well-characterized neuronal nuclear or cytoplasmic paraneoplastic autoantibody was associated with a successful PET-CT-directed cancer search (P < .001). Detection of limited-stage cancer facilitated early initiation of oncologic treatments and immunotherapy; cancer remission was reported in 7 patients, and sustained improvements in neurologic symptoms were reported in 5 (median follow-up, 11 months; range, 2-48 months). Combined data from 2 previous studies using conventional PET alone (123 patients) revealed that 28% of patients had a PET abnormality suggestive of cancer and that 12% had a cancer diagnosis.
  
  
  CONCLUSIONS
  In a paraneoplastic neurologic context, PET-CT improves the detection of cancers when other screening test results are negative, particularly in the setting of seropositivity for a neuronal nuclear or cytoplasmic autoantibody marker of cancer.
authors.affiliation: Department of Neurology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: McKeon
authors.forename: Metha
authors.initials: M
authors.lastname: Apiwattanakul
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Lachance
authors.forename: Vanda A
authors.initials: VA
authors.lastname: Lennon
authors.forename: Jayawant N
authors.initials: JN
authors.lastname: Mandrekar
authors.forename: Bradley F
authors.initials: BF
authors.lastname: Boeve
authors.forename: Brian
authors.initials: B
authors.lastname: Mullan
authors.forename: Bahram
authors.initials: B
authors.lastname: Mokri
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Britton
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Drubach
authors.forename: Sean J
authors.initials: SJ
authors.lastname: Pittock
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D055088:Early Detection of Cancer / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D009369:Neoplasms / Q000175:diagnosis* / Q000628:therapy; D020361:Paraneoplastic Syndromes, Nervous System / Q000175:diagnosis* / Q000628:therapy; D049268:Positron-Emission Tomography / Q000379:methods; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome; D051598:Whole Body Imaging