Use of single MRI and 18F-FDG PET-CT scans in both diagnosis and radiotherapy treatment planning in patients with head and neck cancer: advantage on target volume and critical organ delineation.
BACKGROUND
The use of a single MRI and 18F-fluoro deoxyglucose positron emission tomography-CT (18F-FDG PET-CT) was evaluated, both in diagnostic procedure and radiotherapy planning, in patients with head and neck cancer.


METHODS
Thirty-five patients with nasopharyngeal and oropharyngeal tumors were studied. The MRI and 18F-FDG PET-CT were used for both diagnostic work-up and gross tumor volume and critical structure delineation. The interobserver variation (IOV) of volumes determined on MRI and CT by a radiotherapist and by a radiologist were compared as well as their impact on dose distribution.


RESULTS
The CT-MRI decreased the IOV of parotid glands in 12 of 35 and target volume in 15 of 35 patients. The use of 18F-FDG PET-CT changed the treatment design in 6 of 21 patients.


CONCLUSIONS
Diagnostic imaging performed in the treatment position can improve the accuracy of radiotherapy planning in case of intracranial tumor extension, heavy dental work, or contraindication for contrast-enhanced CT, but not in the absence of these conditions.
Gardner
Miriam
M
Service de Radiothérapie, Centre René Huguenin, Saint-Cloud, France. gardner@crhl.org
Halimi
Philippe
P
Valinta
Danielle
D
Plantet
Marie-Madeleine
MM
Alberini
Jean-Louis
JL
Wartski
Myriam
M
Banal
Alain
A
Hans
Stephane
S
Floiras
Jean-Louis
JL
Housset
Martin
M
Labib
Alain
A
D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000175:diagnosis / Q000532:radiotherapy*; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000532:radiotherapy; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis / Q000532:radiotherapy*; D009959:Oropharyngeal Neoplasms / Q000175:diagnosis / Q000532:radiotherapy*; D010306:Parotid Gland / Q000000981:diagnostic imaging / Q000473:pathology / Q000528:radiation effects; D019275:Radiopharmaceuticals; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D014057:Tomography, X-Ray Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18