Potential pitfalls and therapeutic implications of pretherapeutic radiologic staging in glottic cancers

Objectives: The aim of this study was to compare the radiologic findings with histological results of anatomically matched whole organ sections and to analyze the accuracy of pretherapeutic radiologic staging of glottic cancers. Methods: The histologic findings of surgical specimens of 30 patients who had undergone total or conservative partial laryngectomy for glottic cancers were matched and compared with the pretherapeutic radiologic findings using CT and MR imaging. The accuracy of pretherapeutic radiologic staging was assessed for specific subsites for staging of glottic cancers. Results: The overall accuracy of pretherapeutic staging with CT and MR imaging was 84.9%; 12.1% associated with false positive and 3% associated with false-negative assessments. For all subsites, the overall sensitivity was 88%, specificity 84%, positive predictive value 65%, and negative predictive value 95%. Subsites such as the anterior commissure, paraglottic space, and preepiglottic space showed lower specificity (42%, 65%, and 79% respectively) than the overall specificity. The radiologic evaluation for cartilage invasion showed the accuracy of 84.8% and yielded acceptable specificity (89%) and high negative predictive value (98%). Conclusion: Although pretherapeutic radiological examination is a very useful technique for the evaluation of tumor invasion into specific laryngeal subsites, the pretherapeutic radiologic staging can be challenging when distinguishing tumor from peritumoral inflammation.