Prognostic value of positron emission tomography using F-18-fluorodeoxyglucose in patients with cervical cancer undergoing radiotherapy.
OBJECTIVE
The purpose of this study was to determine whether positron emission tomography (PET) using F-18-fluorodeoxyglucose (FDG) before and after radiotherapy would predict whether local control of cervical cancer had been achieved.


METHODS
FDG-PET scans were performed prior to therapy and at a mean of 4.6 months after radiation in 20 patients (pts) with histologically proven uterine cervical cancer who were undergoing a "curative" course of radiation therapy. FDG uptake was interpreted visually by two readers using a 5-point grading system (0 = normal, 1 = probably normal, 2 = equivocal, 3 = probably abnormal, and 4 = definitely abnormal). The standardized uptake values corrected by lean body mass (SUL) were calculated for suspicious areas. The percentage of residual activity (%RA) for the posttherapy SUL was also evaluated as a percentage of the pretherapy SUL.


RESULTS
At baseline before irradiation, 17 of 20 (85.0%) primary tumors were detected. Following irradiation, no or low (grade 0-2) uptake was observed in 9 pts, and none of these had local recurrence. Among the remaining 11 pts with grade 3 or 4 uptake, the correct diagnosis was made for 5 pts with active tumor; SULs (mean +/- SD = 4.17 +/- 2.52) and %RAs (57.9 +/- 16.8). Six patients without active tumor showed relatively low SULs (2.67 +/- 0.69) and %RAs (43.0 +/- 18.3). No significant differences were observed between the recurrent and nonrecurrent groups for these parameters. Overall, sensitivity, specificity, and accuracy were 100, 60, and 70%, respectively.


CONCLUSIONS
These preliminary data indicate that FDG-PET is a sensitive tool for detecting active cervical cancer after radiation, however, the method, without anatomic correlation had suboptimal specificity.
Nakamoto
Yuji
Y
Division of Nuclear Medicine, Johns Hopkins University, Baltimore, Maryland 21287-0817, USA.
Eisbruch
Avraham
A
Achtyes
Eric D
ED
Sugawara
Yoshifumi
Y
Reynolds
Kevin R
KR
Johnston
Carolyn M
CM
Wahl
Richard L
RL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000378:metabolism / Q000532:radiotherapy; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000378:metabolism; D011379:Prognosis; D019275:Radiopharmaceuticals; D014055:Tomography, Emission-Computed; D002583:Uterine Cervical Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000532:radiotherapy*
D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18