Prediction of the originating site of sinonasal inverted papilloma by preoperative magnetic resonance imaging and computed tomography

Abstract

Precise localization and excision of the originating site of a sinonasal inverted papilloma (SNIP) is essential for decreasing tumor recurrence. In this study we evaluated the use of preoperative computed tomography (CT) and magnetic resonance imaging (MRI) to pinpoint the attachment/originating sites of SNIPs in 143 patients. Osteitis signs in CTs and convoluted cerebriform pattern (CCP)–based reverse tracings from MRIs of 143 SNIP patients were analyzed preoperatively to predict the originating site of SNIPs. The predicted sites were compared with actual SNIP attachment sites determined by surgery, and patients were followed-up for evaluation of SNIP recurrence rates over a mean period of about 4 years. Osteitis signs in CT accurately predicted the actual tumor attachment site in 49.7% of all patients. In comparison, convoluted cerebriform pattern (CCP)–based reverse tracings in MRI and combination CT plus MRI accurately predicted the SNIP originating sites in 84.1% and 86% of the patients, respectively. Sensitivity and specificity in predicting the SNIP originating site were: CT, 54.6% and 69.2%; MRI, 93.1% and 76.9%; and CT+MRI, 94.6% and 92.3%, respectively. A single postoperative recurrence occurred in 4.2% of the patients. Preoperative combination of MRI and CT provides a better option to accurately predict the SNIP originating site, and thus may facilitate accurate and complete excision of the SNIP.