Relationship between non-small cell lung cancer FDG uptake at PET, tumor histology, and Ki-67 proliferation index.
BACKGROUND
We compared primary non-small cell lung cancer (NSCLC) F-fluorodeoxyglucose (FDG) uptake at positron emission tomography (PET) to tumor histologic features and Ki-67 proliferation index. This large, prospectively-recruited patient cohort has previously been analyzed based on differences in FDG uptake across stage groups; the current analysis adds further dimensions to this characterization.


METHODS
One hundred seventy-eight patients with potentially-resectable NSCLC were scanned with FDG PET before therapy. A partial volume correction algorithm was used to correct FDG uptake values for their dependence on tumor size. Primary tumor resection specimens, core biopsies, and biopsies of metastatic lymph nodes were used to assess each tumor's NSCLC histologic subtype, degree of differentiation, and Ki-67 proliferation index.


RESULTS
Bronchioalveolar carcinomas were found to have lower FDG uptake at PET and lower Ki-67 scores than any other histologic subtype. Non-bronchioalveolar adenocarcinomas had lower FDG uptake and Ki-67 scores than squamous cell carcinomas or large cell undifferentiated carcinomas. Better differentiated NSCLCs had lower FDG uptake and Ki-67 scores than more poorly differentiated NSCLCs. There was a significant positive correlation between FDG uptake and Ki-67 scores. Partial volume correction increased the strength of this correlation, while also diminishing the strong positive correlation between FDG uptake and tumor size.


CONCLUSIONS
There are significant differences in NSCLC FDG uptake across histologic subtypes and differentiation groups. These differences parallel nearly identical differences in Ki-67 scores, implying that differences in NSCLC tumor cell proliferation may give rise to commensurate differences in tumor glucose metabolism.
Vesselle
Hubert
H
Department of Radiology, University of Washington, Seattle, Washington, USA. vesselle@u.washington.edu
Salskov
Alexander
A
Turcotte
Eric
E
Wiens
Linda
L
Schmidt
Rodney
R
Jordan
C Diana
CD
Vallières
Eric
E
Wood
Douglas E
DE