Positron emission tomography-computed tomography in paraneoplastic neurologic disorders: systematic analysis and review.
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.
McKeon
Andrew
A
Department of Neurology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA.
Apiwattanakul
Metha
M
Lachance
Daniel H
DH
Lennon
Vanda A
VA
Mandrekar
Jayawant N
JN
Boeve
Bradley F
BF
Mullan
Brian
B
Mokri
Bahram
B
Britton
Jeffrey W
JW
Drubach
Daniel A
DA
Pittock
Sean J
SJ
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