Positron emission tomography with [(18)F]-3'-deoxy-3'fluorothymidine (FLT) as a predictor of outcome in patients with locally advanced resectable rectal cancer: a pilot study.
OBJECTIVE
This pilot study was performed to evaluate whether tumor uptake of (18)F-labeled 3'-deoxy-3'fluorothymidine (FLT), a proliferative radiotracer, at baseline and early during therapy, is predictive of outcome in locally advanced rectal cancer.


METHODS
Fourteen patients underwent positron emission tomography (PET) with 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) and FLT before therapy and PET with FLT approximately 2 weeks after initiating neoadjuvant chemoradiotherapy. FLT and FDG uptake were evaluated qualitatively and by maximum standardized uptake value (SUV(max)). Tumor FLT and FDG uptake were correlated with disease-free survival (DFS).


RESULTS
Thirteen patients underwent surgery after therapy, one died before surgery with progressive disease. FDG-PET/computed tomography detected regional lymph node metastases in five and FLT-PET was positive in one. High pretherapy FDG uptake (SUV(max) ≥ 14.3), low during-therapy FLT uptake (SUV(max) < 2.2), and high percentage change in FLT uptake (≥60 %) were predictive of improved DFS (p < 0.05 for all three values).


CONCLUSIONS
Pretherapy FDG uptake, during-therapy FLT uptake, and percentage change in FLT uptake were equally predictive of DFS.
Division of Nuclear Medicine, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA. dehdashtif@mir.wustl.edu
Farrokh
F
Dehdashti
Perry W
PW
Grigsby
Robert J
RJ
Myerson
Ilke
I
Nalbantoglu
Changqing
C
Ma
Barry A
BA
Siegel
D000328:Adult; D000368:Aged; D059186:Chemoradiotherapy, Adjuvant; D015224:Dideoxynucleosides / Q000737:chemistry / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D010865:Pilot Projects; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D011379:Prognosis; D012004:Rectal Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000628:therapy*; D016896:Treatment Outcome
D015224:Dideoxynucleosides; C002854:alovudine