Radiotherapy response in head and neck cancer - evaluation of the primary tumour site.
CONCLUSIONS
PET-CT scans seem to be sufficient to rule out residual tumour at the primary site. Patients with positive or equivocal PET findings should be scheduled for endoscopy with biopsy or a second PET-CT scan.


OBJECTIVE
Assessment of remission at the primary site, in patients treated with organ preservation therapy with curative intent, is important to identify residual tumours requiring treatment with salvage surgery. The aim of this study was to evaluate the diagnostic accuracy of fluorodeoxyglucose positron emission tomography (FDG-PET) after radiotherapy with or without chemotherapy in assessing primary site response in patients with head and neck cancer.


METHODS
A total of 82 patients, with a positive baseline PET-CT scan before start of treatment, were evaluated with a PET-CT scan 6-7 weeks post-radiotherapy and with a clinical examination/endoscopy with or without biopsy 1-2 weeks later. The majority of patients had p16-positive oropharyngeal tumours.


RESULTS
Post-treatment, 77% of the patients had no visible hypermetabolism. If equivocal PET scans are regarded as positive, the sensitivity, specificity, negative (NPV) and positive predictive value (PPV) and accuracy were 100%, 78%, 100%, 6% and 78%, respectively. Eight patients suffered from relapses involving the primary site during the 9-month follow-up.
Department of ORL-Head and Neck Surgery, Clinical Sciences.
Johanna
J
Sjövall
Eva
E
Brun
Helen
H
Almquist
Elisabeth
E
Kjellén
Peter
P
Wahlberg
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000532:radiotherapy*; D004724:Endoscopy; D005260:Female; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D018365:Neoplasm, Residual; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
Squamous cell carcinoma; endoscopy; positron emission tomography; treatment outcome