Staging of the neck in patients with oral cavity squamous cell carcinomas:a prospective comparison of PET, ultrasound, CT and MRI

Background: The choice of treatment in patients with oral malignancies depe nds on accurate pretreatment staging and particularly the detection of Lymp h node involvement. Therefore staging of the neck should be as accurate as possible. Patients: One hundred and six patients with histologically proven squamous cell carcinoma of the oral cavity, Study design: In a prospective study, PET using fluoro-desoxy-glucose (F-18-FDG), ultrasound, CT and MRI of head and neck were compared with the postoperative histologic tissue eva luation. Two thousand one hundred and ninety-six neck lymph nodes of 106 pa tients were investigated. In all patients the tumour was resected and a lym ph node dissection was performed. Results: The diagnostic procedures showed the following results when compared with the histological findings: PET: s ensitivity 70%, specificity 82%, accuracy 75%; Ultrasound: 84%, 68%, 76%; C T: 66%, 74%, 70%; MRI: 64%, 69% 66%, Thus PET showed the highest specificit y while ultrasound had the highest sensitivity compared with the other stag ing procedures. A non-significant correlation was found between the size of a lymph node metastasis and the ability to detect it. In 10 patients, seco nd primary tumours or distant metastases were detected by PET only, Conclus ion: Due to the high number of small lymph node metastases from oral cavity carcinoma, the non-invasive neck staging methods are limited to a maximum accuracy of 76%, Elective neck treatment should be mandatory for all patien ts with squamous cell carcinoma of the oral cavity, (C) 2000 European Assoc iation for Cranio-Maxillofacial Surgery.