Role of PET Scan in Initial Staging of Oral Squamous Cell Carcinoma
Role of PET Scan in Initial Staging of Oral Squamous Cell Carcinoma
Steel, D., Kalayeh, M., McClure, S.
The sensitivity of FDG-PET in detecting primary tumors of the head and neck has been extensively studied. Hannah et. al1reported a sensitivity of 88% for PET in the detection of known primary tumors and 51% for CT in detection of oral squamous carcinoma in their series. PETs are reported to be not as specific (75%)2 for follow up and re-staging. The goal of this study is to determine whether PET scans would change our surgical approach when comparing initial clinical staging with PET scan to final pathology.
An exempt classification was granted by each hospital’s institutional review board. Medical records of 160 head and neck cancer patients from the Department of Oral and Maxillofacial Surgery at Nova Southeastern University College of Dental Medicine from 2007 to 2013 were evaluated. Demographic data including age, sex, and sites of primary tumor were collected. Clinical staging, PET results, surgical treatments, and final pathology were compared. Statistical analysis was used to evaluate whether PET up-staged or down-staged the initial clinical staging when compared to final pathology.
This study involved 160 patients with head and neck malignancies who presented for initial staging and work up. Patient cohort consisted of average age of 61 with 117 (73%) male and 43 (27%) female. Most common sites for primary were lateral tongue 34 (21%) followed by floor of mouth 25 (16%) and retro molar fossa 18 (11%).
PET scans were obtained in 127/160 (79.3%), 109 patients underwent surgery. Patients without PET scans 33/160 (20.6%), 30 underwent surgery.
PET findings did change the surgical plan for one subject due to positive PET findings in contralateral neck nodes, prompting a bilateral neck dissection. Final pathology revealed no nodal disease bilaterally.
Clinical and PET staging was consistent in 64% of subjects when compared to final pathology. PET staging was different in 52/160 (32.5%) comparing final pathology with 14/52 (8.75%) upstaging the initial clinical staging compared to final pathology. Down staging 35/52 (21%) initial clinical staging compared to the final pathology.
Traditional work up for head and neck cancer consists of clinical exam, CT scan and PET scan to determine initial staging. Clinicians with good knowledge and understanding of the disease process and its treatment modalities, gain minimal benefit from the use of a PET. With the increased exposure to radiation, cost, and minimal added benefit bring into question the need for PET scans in initial work up for oral cancer.
References:
Hannah, A., Scott, A.M., Tochon-Danguy, et. al. Evaluation of 18F-Fluorodeoxyglucose Positron Emission Tomography and Computed Tomography With Histopathologic Correlation in the Initial Staging of Head and Neck Cancer
H., J. Ann Surg. 2002 August; 236(2): 208–21
Di Martino, E., Nowak, B., Krombach, G.A., et al. (2000) Results of Pretherapeutic Lymph Node Diagnosis in Head and Neck Tumors. Clinical value of 18-FDG positron emission tomography (PET). Laryngorhinootologie 79, 201–6.