Proliferative activity in human brain tumors: comparison of histopathology and L-[1-(11)C]tyrosine PET.
To validate the protein synthesis rate (PSR) measured in human brain tumors using L-[1-(11)C]tyrosine (TYR) PET, the PSR was compared to histopathological parameters that reflect proliferation and protein synthesis.


METHODS
We studied 20 patients who had a brain biopsy and who also underwent a PET study with TYR. Paraffin sections were stained with the monoclonal antibody MIB 1, targeted against the core antigen Ki-67, and nucleolar organizer regions (NORs) were measured as argyrophilic NORs (AgNORs). The TYR uptake was measured by PET, and with a kinetic model, the PSR was determined.


RESULTS
PSR (nmol/ml/min) ranged from 0.44 to 1.99 (mean, 0.97), Ki-67 labeling indices (%) ranged from 0.9 to 33.5 (mean, 9.5) and AgNOR area (mm2/cm2) ranged from 0.13 to 0.85. No relationship was found between PSR and Ki-67 labeling index or AgNOR area.


CONCLUSIONS
It seems that the PSR and proliferation, as measured by Ki-67, are independent processes. The role of the PSR is uncertain, but it is likely that it can be seen as a marker for the homeostasis of the cell.
de Wolde
H
H
Department of Pathology and PET Center, University and University Hospital of Groningen, The Netherlands.
Pruim
J
J
Mastik
M F
MF
Koudstaal
J
J
Molenaar
W M
WM
D000293:Adolescent; D000328:Adult; D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm / Q000032:analysis; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology*; D002455:Cell Division; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000096:biosynthesis; D009697:Nucleolus Organizer Region / Q000473:pathology; D016622:Silver Staining; D014055:Tomography, Emission-Computed; D014443:Tyrosine / Q000378:metabolism
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D019394:Ki-67 Antigen; D009363:Neoplasm Proteins; D014443:Tyrosine