Clinical significance of abdominal/pelvic PET/CT findings for staging with head and neck malignancies

Abstract

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Objectives: To evaluate the clinical significance of abdominal/pelvic PET/CT findings in initial and restaging after therapy of patient with head and neck malignancies.

Methods: A review of 292 consecutive whole-body FDG PET/CT data of various head and neck malignancies (cancer from pharyngeal; 68, laryngeal; 32, tongue; 55, gingival; 28, salivary grand; 13, external ear canal; 7, oral floor; 11 and thyroid; 78) was performed to identify metastatic lesion. PET/CT data was analyzed for the presence of metastatic disease in the neck, chest, abdomen and pelvis.

Results: Total of 292 patients with head and neck malignancy (160 females and 132 males, age 17-76 years) received initial or restaging scans. Amongst those patients for initial-staging scan (102), 8 patients (7.8%) displayed definite abnormal uptake in abdominal/pelvic area. Of those 8 patients, 2 unknown and one known bone metastases were identified. Other 5 abnormal uptakes were turned out to be minor abnormalities (physiological uptakes or adrenal incidentaloma etc.). Amongst those patients for re-staging (190), 23 patients (12.1%) displayed abnormal uptake in abdominal/pelvic area. Of those 23 patients, 3 identified additional metastases and 4 identified newly found other malignancies and 5 identified known metastases. Other 11 abnormal uptakes were turned out to be minor abnormalities. Therapy planning has been changed by FDG/PET findings of abdominal/pelvic area in 6 patients received re-staging scan and no patient for initial staging scan.

Conclusions: The utility of PET/CT scan of the lower abdomen and pelvis is limited for initial staging for head and neck malignancies, while still useful for re-staging.