Value of spiral CT in the follow-up period of head and neck tumours after definitive radiochemotherapy.

Background: The application of spiral CT is compared with clinical/endoscop ic ear, nose, and throat (ENT) evaluation in diagnosing recurrences in pati ents with head-neck tumours treated by definitive radiochemotherapy. Patien ts and Methods: Spiral CT and clinical/endoscopic ENT evaluation in 41 pati ents who had received definitive radiochemotherapy for locally advanced squ amous cell carcinoma in nasopharynx, oropharynx or hypopharynx (average fol low-up period 7 months) were retrospectively compared regarding congruency in establishing tumours. Gold standards regarding tumour manifestation were either defined by exploratory biopsy (11/41) or by progress of examination results after additional three months (30/41). Spiral CT (5 mm collimation , 5 mm/s table speed, 4 mm reconstruction interval) was carried out after i ntravenous injection of a non-ionic contrast agent (100 ml Imagopaque(R), f low 2,0 ml/s, delay 30 s). Results: In 35/41 (85%) patients CT results and clinical/endoscopic evaluation corresponded. In 6/41 (15%) patients both re sults differed. At the time both results were compared 35/41 patients did n ot show a tumour in the area of primary manifestation. In 6/41 patients tum our tissue could be detected. Sensitivity of spiral CT in proving a recurri ng tumour was 50%, its specificity 91%. Sensitivity of ENT evaluation was 6 7%, specificity 89%. Combining both methods raised the sensitivity to 88% w ith a specificity of 86%. Posttherapeutic changes, small seize of recurring tumour (<2 cm), missing contrast agent enhancement (3/6 recurring tumours) , and superficial tumour growth affected CT diagnosis. Conclusion: These re sults stress the complementary application of spiral CT and clinical/endosc opic ENT evaluation during the follow-up period in patients with head-neck- tumours treated radiochemically.