Positive Predictive Value of Computed Tomography Virtual Laryngoscopy in Detecting Laryngeal Carcinoma Taking Histopathology as Gold Standard

Background: Computed tomography virtual laryngoscopy (CTVL) is favored diagnostic tool in detecting laryngeal carcinoma because it delivers excellent temporal and spatial resolution. Objective: To determine the positive predictive value of computed tomography virtual laryngoscopy in detecting laryngeal carcinoma taking histopathology as gold standard. Methods: A cross sectional survey was conducted at department of Radiology, Mayo Hospital Lahore. The completion of study was done in six months [Feb 16, 2019 till Aug 16, 2019]. After obtaining approval from ethical committee and informed consent from subjects, 64 subjects were included in the study who presented in the Department of the Radiology having carcinoma of larynx on CTVL and then sent to department of ENT of mayo hospital, where they underwent direct laryngoscopy and afterwards biopsy obtained sent to the department of histopathology. All the subjects undergoing CT scan examination on the CT machine of hospital. Contrast injection was given to all subjects undergoing CT scan, through power injector at the rate of 4ml per min and dosage of 0.1ml/kg. Same machine was used to conduct all CT scans and was inferred through same radiologist and all the histopathology was performed by same pathologist to exclude bias. Results: The mean age of patients was 44.38 ± 9.57 years with minimum and maximum age as 22 and 60 years. There were 47(73.4%) male and 17(26.6%) female cases. On histopathology the laryngeal carcinoma was diagnosed in 56(87.5%) of the cases while it was negative in 8(12.5%) of the cases. On CT the laryngeal carcinoma was diagnosed in 59(92.2%) of the cases while it was negative in 5(7.8%) of the cases. The Positive Predictive Value of CT was 89.83%, while its sensitivity was 94.64%, specificity was 25.00%, negative predictive value was 40.00% and diagnostic accuracy was 85.94%. Conclusion: Through the findings of this study it is concluded that positive predictive value of computed tomography virtual laryngoscopy is high (89.83%) in detecting laryngeal carcinoma taking histopathology as gold standard. CT is a precise and non-invasive imaging method in detecting laryngeal carcinoma.