Positron emission tomography-computed tomography in paraneoplastic neurologic disorders: systematic analysis and review

Arch Neurol. 2010 Mar;67(3):322-9. doi: 10.1001/archneurol.2009.336. Epub 2010 Jan 11.

Abstract

Objective: To evaluate the cancer detection rate of whole-body positron emission tomography-computed tomography (PET-CT) in a paraneoplastic neurologic context.

Design: Retrospective medical record review.

Setting: Mayo Clinic, Rochester, Minnesota.

Patients: Fifty-six consecutive patients with clinically suspected paraneoplastic neurologic disorders who underwent PET-CT after negative standard evaluations, including CT.

Main outcome measure: 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.

Conclusion: 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.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Early Detection of Cancer / methods*
  • Female
  • Humans
  • Male
  • Medical Records
  • Middle Aged
  • Neoplasms / diagnosis*
  • Neoplasms / therapy
  • Paraneoplastic Syndromes, Nervous System / diagnosis*
  • Paraneoplastic Syndromes, Nervous System / therapy
  • Positron-Emission Tomography / methods
  • Retrospective Studies
  • Tomography, X-Ray Computed / methods
  • Treatment Outcome
  • Whole Body Imaging