Diagnostic evaluation of malignant head and neck cancer by F-18-FDG PET compared to CT/MRI

Aim: Evaluation of F-18-FDG PET in comparison to CT/MRI as diagnostic tool in primary and recurrent head and neck cancer. Methods: 78 F-18-FDG PET stu dies were performed in 71 patients with known or suspected primary (n=48) o r recurrent (n=30) head and neck cancer and compared to CT (n=75) or MRI in vestigations (n=3) concerning detection of the primary or recurrent tumor a nd detection of regional lymph node metastases in the ipsilateral and contr alateral neck sides. Glucose uptake (SUV) of PET findings was correlated to tumor location, grading and dignity of the lesion. Results: Sensitivity an d specificity for PET in detection of primary tumors were 87%* and 67%, res pectively (CT/MRI 67%* and 44%) (*p<0.05), in detection of local recurrence 86% and 75%, respectively (CT/MRI 57% and 92%), in detection of necks affe cted by lymph node metastases 80% and 92%, respectively (CT/MRI 80% and 84% ). Laryngeal, buccal (cheek) and salivary gland tumors had significant lowe r glucose uptake (SUV) when compared to tumors of the hypopharynx (p<0.05). G1-tumors (mean SUV 4.26) had significant (p<0.05) lower glucose uptake wh en compared to G2- a nd GS-tumors (mean SUV 7.73 and 8.19, respectively). M ean SUV of malignant PET findings (7.88) was significant (p<0.05) higher th an mean SUV of benign PET findings (5.70). However, a SUV threshold to impr ove diagnostic accuracy could not be defined. Conclusion: F-18-FDG PET is s ignificantly more accurate than CT/MRI for detection of head and neck cance r. Both methods are valuable for detection of cervical lymph node metastase s Glucose uptake shows correlation to histological grading. A quantitative SUV analysis does not improve diagnostic accuracy.