Addressing glucose sensitivity measured by F-18 FDG PET in lung cancers for radiation treatment planning and monitoring.
OBJECTIVE
To address glucose sensitivity in lung cancers before and after radiation treatment (Tx).


METHODS
Twelve patients were each studied with two pre-Tx positron emission tomography (PET) scans and 3 patients each with one post-Tx PET scan, with glucose concentration [Glc] and maximum standard uptake value (SUV) recorded. The pre-Tx glucose sensitivity, g from SUV1/SUV2= {[Glc]1/[Glc]2}g and Tx index, tau from SUVpost-Tx/SUVpre-Tx = {[Glc]post-Tx/[Glc]pre-Tx}tau was calculated by linear regression. Pre-Tx SUVs were corrected to post-Tx Glc with g (SUV'pre-Tx) for a pure Tx effect, R = ln(SUVpost-Tx/SUV'pre-Tx).


RESULTS
There were no significant differences in SUV but [Glc] were different (96.4 +/- 10.9 vs. 88.3 +/- 10.5, p = 0.015) between two pre-Tx PET scans. Linear regression yielded g = -0.79 and tau = -1.78 to -2.41 (p < 0.0005 in all). The %DeltaSUV after Tx for 3 patients without vs. with g correction were different by -12%, 0%, and + 7%, suggesting varying effects from glucose. R values were also different and mean R (-0.81 +/- 0.38) was significantly different from zero (p = 0.03), consistent with successful Tx as confirmed by clinico-radiologic follow-up.


CONCLUSIONS
The extra dimension of glucose sensitivity, g besides SUV incorporated in the combined Tx-derived tau may be a useful global Tx evaluation index even with differing [Glc].
Wong
Ching-Yee Oliver
CY
Department of Nuclear Medicine, William Beaumont Hospital, Royal Oak, MI 48073-6769, USA. owong@beaumont.edu
Thie
Joseph
J
Gaskill
Marianne
M
Kestin
Larry
L
Yan
Di
D
Cheng
Vincent
V
Nagle
Conrad
C
D000368:Aged; D000465:Algorithms; D001786:Blood Glucose / Q000378:metabolism*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D016014:Linear Models; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000532:radiotherapy; D008297:Male; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*
D001786:Blood Glucose; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18