PRETHERAPEUTIC STAGING OF LARYNGEAL CARCINOMA CLINICAL FINDINGS, COMPUTED-TOMOGRAPHY, AND MAGNETIC-RESONANCE-IMAGING COMPARED WITH HISTOPATHOLOGY

BACKGROUND. An accurate pretherapeutic staging of laryngeal carcinoma is required for most treatment planning as well as for evaluation and comparison of the results of different treatment modalities. Neoplasti c invasion of the laryngeal cartilage may have important therapeutic i mplications. To our knowledge, no data are available comparing the imp act of endoscopic examination, computed tomography (CT), and magnetic resonance (MR) imaging on pretherapeutic staging accuracy. The purpose of our study was to determine which imaging should be used as an adju nct to other clinical examinations in the pretherapeutic staging of la ryngeal carcinoma. METHODS. In this study, 40 consecutive patients wit h neoplasms of the larynx, who were treated surgically, were included in a prospective pretherapeutic staging protocol that included indirec t laryngoscopy, direct microlaryngoscopy, contrast-enhanced CT, and ga dolinium-diethylenetriamine pentaacetic acid-enhanced MR imaging at 1. 5 Tesla. The surgical specimens were cut in whole-organ slices paralle l to the plane of the axial CT and MR images. The histologic findings were compared with the clinical findings including the CT and MR image s. The impact of each diagnostic method on pretherapeutic staging was analyzed. RESULTS. Clinical/endoscopic evaluation failed to correctly stage 17 tumors due to invasion of the paraglottic space (1 tumor), pr eepiglottic space (2 tumors), and extralaryngeal soft tissues (14 tumo rs), resulting in a pretherapeutic staging accuracy of 57.5%. Neoplast ic invasion of cartilage was present in 28 patients and absent in 12 p atients. Although MR imaging was more sensitive in detecting neoplasti c invasion of cartilage than CT (94% vs. 67%; P = 0.001), MR imaging w as less specific than CT (74% vs. 87%; P = 0.007). There was no differ ence between the overall accuracy of CT and MR imaging in detecting ne oplastic invasion of cartilage (80% vs. 82%). The accuracy of combined clinical/endoscopic examination and CT staging was 80% and the accura cy of combined clinical/endoscopic examination and MR imaging staging was 87.5%; the difference was not statistically significant. CONCLUSIO NS. Clinical/endoscopic examination alone failed to identify tumor inv asion of the laryngeal cartilages and of the extralaryngeal soft tissu es, resulting in a low staging accuracy (57.5%). Many pT4 (according t o the International Union against Cancer TNM Staging System) tumors we re clinically unrecognized. The combination of clinical/endoscopic eva luation and an additional radiologic examination, either CT or MR imag ing, resulted in significantly improved staging accuracy (80% vs. 87.5 %). MR imaging is significantly more sensitive but less specific than CT in detecting neoplastic cartilage invasion. Therefore, MR imaging t ends to overestimate neoplastic cartilage invasion and may result in o vertreatment, whereas CT tends to underestimate neoplastic cartilage i nvasion and may lead to inadequate therapy. (C) 1996 American Cnncer S ociety.