Positron emission tomography of patients with head and neck carcinoma before and after high dose irradiation.
BACKGROUND
Positron emission tomography (PET) with labeled fluorodeoxyglucose (FDG) demonstrates increased tracer uptake in many neoplasms. This study was undertaken to define the patterns of FDG uptake in head and neck neoplasms before and after high dose irradiation.


METHODS
Twenty-five patients were evaluated prospectively with PET and standard clinical and radiographic techniques before and after irradiation.


RESULTS
Twenty-seven primary sites were confirmed pathologically in 23 patients and included the nasopharynx (four lesions), oropharynx (14 lesions), larynx (five lesions), oral cavity (two lesions), and paranasal sinuses (two lesions). Two patients had unknown primary sites. Twenty-four of 27 primary sites correlated with areas of increased tracer uptake on PET scans. Five patients had increased uptake in cervical lymph nodes that were uninvolved by radiographic or clinical criteria. Positron emission tomography seemed to be able to differentiate tumor activity from fluid-filled sinuses in two patients with paranasal sinus tumors. In two patients with unknown primary sites, increased uptake in the base of tongue after PET suggested occult primary sites. Positron emission tomography scans obtained 1 month after high dose irradiation (RT) indicated decreased levels of FDG uptake in all patients' tumors. However, these scans did not accurately reflect the status of disease in these patients. Scans obtained 4 months after RT were believed to assess more accurately the presence of malignancy.


CONCLUSIONS
Positron emission tomography is a new modality that may be useful in defining tumor activity in clinically negative areas. Appropriately timed posttreatment PET may be useful in predicting outcome after definitive RT and in distinguishing viable tumors from normal tissue changes after RT in patients with head and neck carcinomas.
Greven
K M
KM
Section Radiation Oncology, Bowman Gray School of Medicine, Winston-Salem NC 27157.
Williams
D W
DW
Keyes
J W
JW
McGuirt
W F
WF
Watson
N E
NE
Randall
M E
ME
Raben
M
M
Geisinger
K R
KR
Cappellari
J O
JO
D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000532:radiotherapy*; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000378:metabolism / Q000532:radiotherapy; D003847:Deoxyglucose / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000532:radiotherapy*; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000378:metabolism / Q000528:radiation effects; D008279:Magnetic Resonance Imaging; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D009382:Neoplasms, Unknown Primary / Q000000981:diagnostic imaging; D009959:Oropharyngeal Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism / Q000532:radiotherapy; D010255:Paranasal Sinus Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism / Q000532:radiotherapy; D011379:Prognosis; D011446:Prospective Studies; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed
D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose