以高解晰度內視鏡合併i-Scan系統鑑別小於一公分之大腸瘜肉效力之評估

Abstract

摘要 研究背景: 在台灣地區，大腸癌的發生率不斷攀升，已成為國人十大癌症死因的第二位，早期診斷以及治療大腸癌可提高病患的存活率及生活品質。大腸腺瘤性瘜肉是大腸的癌前病灶，早期偵測到這些腺瘤性瘜肉並將其切除，已被證實可以減少大腸癌發生的機率。因此如何鑑別大腸瘜肉對內視鏡醫師而言是非常重要的課題。腺瘤性瘜肉因為有癌變的可能性，所以必須切除。而增生性瘜肉則不需要被切除。不必要的瘜肉切除不但會大幅增加醫療成本，也會增加因為瘜肉切除而產生的併發症(例如:出血及穿孔)發生的可能性。內視鏡影像強化偵測模式是近年來所發展出的技術，可以有效增加病灶檢出率以及診斷的準確度。i-Scan系統是一種新發展出來的內視鏡影像對比強化模式，它合併高解晰度內視鏡(high definition endoscope)對於大腸瘜肉之診斷效力仍有待研究。 研究目的: 評估高解晰度內視鏡合併i-Scan系統對於大腸瘜肉之診斷效力，包括效度及信度。 研究方法:自2009年3月到2010年3月間，共120名來台大醫院雲林分院接受高解晰度內視鏡合併i-Scan系統大腸鏡檢查的病患。對照檢查中發現之大腸瘜肉之內視鏡診斷及病理診斷結果，計算內視鏡診斷之敏感性、特異性及準確度。接下來選擇直徑小於1公分的45個瘜肉在i-Scan的三種不同模式(表面加強模式，色調加強模式之腺口型態分析模式，色調加強模式之大腸模式)下的影像，將這些影像打散並請四位年輕內視鏡醫師判讀其為癌性息肉(neoplastic)或是非癌性息肉(non-neoplastic)。判讀的結果將以病理診斷結果為準則，計算每一位醫師診斷之敏感性、特異性及準確度。並計算內視鏡醫師間的判讀差異及同一判讀者判讀結果之一致性。 研究結果:表面加強模式，色調加強模式之大腸模式、色調加強模式之腺口型態分析模式之整體的敏感度、特異性及準確度分別為87.7% (95% 信賴區間為: 81.3-94.1%), 84.1% (95%信賴區間為: 76.9-91.3%), 及 86.1% (95%信賴區間為: 79.4- 92.8%)。針對每種不同的模式來看,表面加強模式的敏感度、特異性、及準確度分別75.0%(68.7-81.3%),82.7%(77.2-88.2%)和77.2% (71.1-83.3%)。色調加強模式之大腸模式的敏感度、特異性、及準確度分別為71.1% (64.5-77.7%), 78.8% (72.8-84.8%) 和73.3% (66.8-79.8%)。色調加強模式之腺口型態分析模式的敏感度、特異性、及準確度分別為75.0% (68.7-81.3%), 80.8% (75.0-86.8%) 及76.7% (70.5-82.9%)。不同判讀者之間判讀結果之一致性尚可(κ值範圍: 0.522-0.568)及同一判讀者之重複判讀結果一致性良好(κ值範圍: 0.605-0.694)。當同一位判讀醫師在不同模式下評估同一位病灶時，在總共挑選出的45個小於1公分的瘜肉中，共有8個(17.8%)瘜肉有不一致的判讀結果，其中以色調加強模式之大腸模式診斷錯誤率最高。 結論:在沒有使用擴大內視鏡的情況下、高解晰度內視鏡合併i-Scan系統在預測小於1公分之大腸瘜肉的組織學上的結果是令人滿意的。主要的助益大部分是來自腺口型態分析模式。

Abstract Background: Image-enhanced endoscopy (IEE) compromises various means of enhancing contrast during endoscopy using dye, optical, and/or electronic methods. IEE allows improved visualization of lesions and can be used to gain insight into the pathology of the lesions. Recent progress in optics and computerized processing of endoscopic images, such as narrow band image (NBI) and Fuji intelligent Chromoendoscopy (FICE), provide an optical and/or electronic enhancement of the mucosal structures. Most recently, the i-Scan system, a novel endoscopic post-processing light filter technology, can provide detailed analysis based on surface architecture (surface enhancement), vascular change (i-Scan colon mode), or pit pattern (i-Scan p mode). However, it remains unclear whether this technology can distinguish neoplastic colon polyps from non-neoplastic ones when the polyps are less than 1 cm without magnification. Aims: Evaluate the efficacy of high definition endoscopy combined with i-Scan system in differential diagnosis of colon polyps Patients and methods: Images of colorectal polyps less than 1 cm in diameter were recruited from 54 patients who underwent non-magnified colonoscopy with surface enhancement (SE) and tone enhancement (TE). We calculated the sensitivity, specificity and accuracy in the prediction of histology. Inter- and intra-observer consistencies were evaluated by inviting 4 endoscopists to rate 45 static images. Results: Overall sensitivity, specificity, and accuracy following the sequence of SE, TE-colon, and TE-pit pattern modes were 87.7% (95% confidence interval [CI]: 81.3-94.1%), 84.1% (76.9-91.3%), and 86.1% (79.4-92.8%), respectively. For each modality, the results were 75.0% (68.7-81.3%), 82.7% (77.2-88.2%) and 77.2% (71.1-83.3%) for SE; 71.1% (64.5-77.7%), 78.8 (72.8-84.8) and 73.3% (66.8-79.8%) for TE-colon mode; and 75.0% (68.7-81.3%), 80.8% (75.0-86.8%) and 76.7% (70.5-82.9%) for TE-pit pattern mode; their inter- and intra-observer agreements were all fair (κ range: 0.522-0.568) and good (0.605-0.694), respectively. When the same rater evaluated the same lesion under different modalities, eight out of 45 (17.8%) polyps yielded discordant interpretations and the possibility of incorrect diagnoses was highest with the TE-colon mode. Conclusion: The use of high definition endoscopy combined with i-Scan system is satisfactory in predicting the histology of small colon polyps without the need of magnification. This advantage is mostly related to the pit-pattern enhancement.