Impact of (18)F-FDG-PET/CT on staging and irradiation of patients with locally advanced rectal cancer.
OBJECTIVE
To investigate the impact of fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) on planning of neoadjuvant radiotherapy for locally advanced rectal cancer (LARC) patients.


METHODS
From January 2003 to December 2007, a total of 36 patients with LARC underwent a retroprospective PET/CT study for radiotherapy-planning purposes. Gross tumor volume (GTV), clinical target volume (CTV) and planning target volume (PTV) were defined in a retrospective analysis by a blinded reader. The hypothetical boost volume was defined primarily on CT alone, and afterwards on the fused PET/CT dataset. The CT- and PET/CT-based GTVs were quantitatively compared and percentage of overlap (OV%) was calculated and analyzed. The impact of PET/CT on radiation treatment planning and overall patient management was evaluated.


RESULTS
PET/CT-GTVs were smaller than CT-GTVs (p < 0.05). PET/CT imaging resulted in a change of overall management for three patients (8 %). In 16 of 35 patients (46 %), PET/CT resulted in a need for modification of the usual target volumes (CT-PTV) because of detection of a geographic miss.


CONCLUSIONS
FDG-PET/CT had significant impact on radiotherapy planning and overall treatment of patients with LARC.
Department of Radiotherapy, University Hospital Münster, Germany. brigita.paskeviciute@ukmuenster.de
Brigita
B
Paskeviciute
Tobias
T
Bölling
Markus
M
Brinkmann
Ganna
G
Rudykina
Iris
I
Ernst
Lars
L
Stegger
Otmar
O
Schober
Normann
N
Willich
Matthias
M
Weckesser
Stefan
S
Könemann
D000328:Adult; D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D018714:Radiotherapy, Adjuvant / Q000379:methods; D020266:Radiotherapy, Conformal / Q000379:methods*; D012004:Rectal Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000532:radiotherapy*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18