Assessing The Value Of MSCT In The Preoperative Classification And Staging Of Laryngeal Carcinoma

As the pronunciation organ and breathing passage, larynx plays asignificant role in the respiratory system. Dysphagia and respiratory disorderscaused by laryngeal carcinoma brings great trouble to patients. Laryngealcarcinoma is treated by major surgery complex treatment nowadays, and thedominant surgical method is partial laryngectomy which would reserve or thereconstruct laryngeal function. The principle of the operation is to retain orreconstruct laryngeal vocal function under the premise of excise the tumorradically, in order to improve patients’ quality of life. To achieve those purpose,it’s critical to assess the location and extended range of the tumor, and thesituation of peripheral vascular, lymphatic metastasis and other relations(namely laryngeal type and stage).Electronic laryngoscope, spiral CT, MRI, are commonly used to detectlaryngeal carcinoma. Electronic laryngoscope, which may show the location,size and shape of the tumor visually, and taking biopsy instantly, can notdemonstrate the depth of invasion, metastasis of lymph node, destruction ofcartilage. With the improvement of CT scanning technology in recent years,lesions can be observed from many different perspectives via multilayer spiralCT scanning and post-processing techniques. The location, range, adjacentstructure, and vascular relationship with lesions can be displayed overall byaxial images together with MPR and3D CTVE, providing imaging informationcomprehensively.Objective: To explore the utility of MSCT in preoperative typing andstaging of laryngeal carcinoma, and to provide more valuable information forthe choice or formulation of treatment plan and assessment of prognosis. Subjects and methods: collect56patients, all of whom were performedplain and enhanced scan using Siemens64slice spiral CT, from January2011to January2012with laryngeal carcinoma determined as laryngeal carcinomasuspicion by electronic laryngoscope in outpatient department and thenconfirmed by surgery and pathology.Those patients, whose age were from37to87years and median age were61years, whose course of disease were from1month to2years, and amongwhich38were male and18were female, were without any treatment beforeoperation, and both their biopsy taken via electronic laryngoscope and theirpostoperative pathological diagnosis were squamous cell carcinoma. Allpatients were treated with the Germany Siemens dual-source spiral CT(Somatom Definition). To reduce breathing motion artifacts, swallow, speech,and deep breathing were prohibited during scanning. As soon as55secondsafter injecting nonionic contrast agent (omnipaque300or Ultravist300)100mlat the rate of3.0ml/s into antecubital vein, the enhancement scanning wereperformed with American Medrad double cylinder high pressure injector. Thescanning range were from the mandibular rim to thoracic entrance.Scanningparameters: collimation64x0.625, slice distance5mm, slice thickness5mm,tube voltage120KV, tube current260-320mAs, table speed12mm/s,rotationtime0.7s. The original scanning data was reconstructed to1mm thickness andis transmitted to Siemens workstation for multiplanar reconstruction (MPR),Computed tomography virtual endoscopy (CTVE) after scanning. The axialimages of CT and a variety of post-processing images are used to analyze thelocation, size, shape, depth of invasion,lymph node metastasis of laryngeal, andpreoperative stage. CT evaluation data were compared with the data of pathologyin the operation, and were analyzed statistically by SPSS18.0statistical analysissoftware. The paper aims at evaluating the consistency between the preoperativestage from MSCT and the pathology results after operation. Results:1. The location, size, shape and extent of laryngeal carcinomacan well displayed by MSCT. Among56cases, there were25supraglottic,24glottic,4subglottic and3transglottic. Postoperative typing were in accordancewith preoperative CT typing.2. The CTVE were strongly consistent with the result of electroniclaryngoscope in the observation of lesions of aryepiglottic folds and epiglottis,room, anterior commissure, subglottic (Kappa=0.8565,0.9176,0.8903,0.9141); and the consistency between CTVE and laryngoscopy for observationlesions of room, laryngeal were also strong(Kappa=0.7717,0.7366).3. The preoperative CT typing in T1and T4were strongly consistent withpostoperative pathology typing (Kappa=0.8993,0.8048); for T2, T3, theconsistency between the preoperative stage and the pathology results afteroperation were also strong (Kappa=0.7558,0.7623). With consistent rate of100%, CT scanning performed extremely strong consistency in the diagnosis oflymph node metastasis in stage N2of laryngeal carcinoma pathology; and theconsistency were less strong in the diagnosis of lymph node metastasis in stageN1(Kappa0.7286), leading parts of the lymph node misdiagnosed easily.Conclusion: Combining MSCT axial images with post-processing imagescan well display the laryngeal location, size, shape, boundary, degree ofenhancement,depth of invasion, laryngeal cartilage with or withoutdestruction,the relationship between tumor and adjacent vessels and cervicallymph node metastasis. it is relatively accurate to diagnose preoperative type,stage, to provide evidences for clinical treatment and prognosis evaluation.And the CT scan has the advantages of simple operation and short-timecompletion, so it can be popularized in the clinical application.