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ORIGINAL ARTICLE
Year : 2016  |  Volume : 12  |  Issue : 8  |  Page : 241-243

The diagnostic value of contrast-enhanced computed tomography imaging for detection of colorectal tumors: A meta-analysis


Department of Radiology, Huaihe Hospital of Henan University, Kaifeng 475001, China

Date of Web Publication22-Feb-2017

Correspondence Address:
Qing Yu
Department of Radiology, Huaihe Hospital of Henan University, Kaifeng 475001
China
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0973-1482.200747

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 > Abstract 

Objective: To evaluate the application usage of contrast-enhanced computer tomography imaging for colorectal tumors diagnosis.
Methods: By searching the Medline and CNKI databases, we collected all diagnostic tests about contrast-enhanced CT imaging for colorectal tumors. Sensitivity and specificity were calculated to evaluate the usage of individual diagnostic tests. The data were analyzed using statistic software Meta-DiSc 1.4.
Results: Nine trials that included a total of 4797 patients were analyzed in this study. The summary diagnosis sensitivity and specificity of contrast-enhanced CT were 0.74 (95% confidence interval [CI]: 0.71–0.77) and 0.86 (0.85–0.87), respectively. The pooled area under the receiver operating characteristic curve was 0.90. Subgroup analysis: for intravenous contrast enhancement technology, the pooled diagnosis sensitivity and specificity were 0.63 (95% CI: 0.56–0.69) and 0.89 (95% CI: 0.86–0.92); for oral contrast enhancement technology, the pooled diagnosis sensitivity and specificity were 0.78 (95% CI: 0.74–0.81) and 0.86 (95% CI: 0.84–0.87).
Conclusion: Contrast-enhanced CT imaging can be regarded as an effective and feasible method for detection of the colorectal tumors.

Keywords: Colorectal tumors, computed tomography, diagnosis, systematic review


How to cite this article:
Yu Q, Liu J. The diagnostic value of contrast-enhanced computed tomography imaging for detection of colorectal tumors: A meta-analysis. J Can Res Ther 2016;12:241-3

How to cite this URL:
Yu Q, Liu J. The diagnostic value of contrast-enhanced computed tomography imaging for detection of colorectal tumors: A meta-analysis. J Can Res Ther [serial online] 2016 [cited 2017 Jun 26];12:241-3. Available from: http://www.cancerjournal.net/text.asp?2016/12/8/241/200747


 > Introduction Top


Enhanced computed tomography (CT) colorectal imaging is an important examination method of colorectal tumors diagnosis which has the advantages of minimally invasive, easy to operate, and relative high sensitivity and specificity.[1] However, because of relatively small number of patients included in each previous study, the statistical power of each study was relatively low. Hence, the diagnostic value of contrast-enhanced CT imaging for colorectal tumors was not conclusive. To further evaluate the application usage of contrast-enhanced CT imaging for colorectal tumors diagnosis, we collected all the published studies about contrast-enhanced CT imaging for colorectal tumors diagnosis and pooled the diagnosis sensitivity and specificity.


 > Methods Top


Inclusion and exclusion criteria

The inclusion criteria were: (1) the study type was prospective diagnostic study; (2) the patients recruited were more than 18 years old without gender or race restriction; (3) the contrast enhancement technology was intravenous or oral method; and (4) the data such as number of true positive, false positive, false negative, and true negative patients can be extracted from the original study. The exclusion criteria were: (1) case report or reviewer study; (2) without gold standard diagnosis for colorectal tumor; and (3) not enough data to pool the sensitivity and specificity.

Publication searching

By searching the Medline and CNKI databases, all diagnostic studies about contrast-enhanced CT imaging for colorectal tumors were collected. The searching procedure was carried out by two reviewers Yu Qing and Liu Jie independently. The searching terms were: CT, colorectal tumors, diagnosis, sensitivity, and specificity.

Data extraction

The data for each included studies were extracted by two reviewers independently and checked by the third reviewer. The extraction information were (1) name of first author; (2) the year of paper publication; (3) gold standard diagnosis method; and (4) number of patients for true positive, false positive, false negative, and true negative.

Statistical analysis

Statistical analysis was done by the MetaDiSc 3.0 software (http://www.biomedsearch.com/nih/ZMeta-DiSc-software- meta-analysis/16836745.html). The heterogeneity was assessed by Chi-square and I2 test. The pooled diagnosis sensitivity and specificity were calculated by fixed-effect model or random effects model. Differences with P < 0.05 were considered as statistically significant.


 > Results Top


Publication searching results

According to the previously made searching strategy, we initially found 456 correlated publications from the Medline and CNKI databases. After read in the title, abstract, and full text, 447 studies were excluded from the present meta-analysis and only 9 papers [1],[2],[3],[4],[5],[6],[7],[8],[9] were included in this study with 4797 patients. Of the included 9 studies, the publication year ranged from 2000 to 2015. Five of the studies use intravenous contrast enhancement technology and other 4 use oral contrast enhancement technology. The main information of the included 9 studies are demonstrated in [Table 1].
Table 1: The main information for included papers

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Heterogeneity for the included studies

The statistical heterogeneity was evaluated by I2. Significant statistical heterogeneity was found for diagnosis sensitivity and specificity with the I2 = 94.5% and I2 = 87.3%, respectively. Hence, the pooled sensitivity and specificity was calculated by random effects model.

Pooled sensitivity and specificity

The pooled diagnosis sensitivity and specificity were 0.74 (95% confidence interval [CI]: 0.71–0.77) [Figure 1] and 0.86 (0.85–0.87) [Figure 2], respectively, for contrast-enhanced CT by random effects model. The pooled diagnosis area under the receiver operating characteristic curve was 0.90 [Figure 3]. We still perform the subgroup analysis according to the contrast enhancement technology. For intravenous contrast enhancement technology, the pooled diagnosis sensitivity and specificity were 0.63 (95% CI: 0.56–0.69) and 0.89 (95% CI: 0.86–0.92). For oral contrast enhancement technology, the pooled diagnosis sensitivity and specificity were 0.78 (95% CI: 0.74–0.81) and 0.86 (95% CI: 0.84–0.87). The pooled diagnosis sensitivity and specificity were not significantly different for different contrast enhancement technology.
Figure 1: The forest plot of pooled diagnosis sensitivity

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Figure 2: The forest plot of pooled diagnosis specificity

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Figure 3: The area under the receiver operating characteristic curve for contrast-enhanced computed tomography in diagnosis of colorectal tumor

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 > Discussion Top


Colorectal tumors are common clinically and it was estimated 143,460 new cases of colorectal cancer and 51,690 related death were occurred in the year 2012 in the United States.[10] Colorectal cancer is the 4th most diagnosed solid malignant carcinoma.[11] For the colorectal carcinoma diagnosis, the most used method was colonoscopy which can provide information for exact diagnosis.[12] However, colonoscopy examination was not convenient and uncomfortable for the patients. Contrast-enhanced CT imaging was used for colorectal tumor diagnosis clinically for a long period of time.[4] However, because of relatively small number of patients included in each previous study, the statistical power of each study was relatively low. Hence, we collected all the open published papers and pooled the data to further evaluate the application usage of contrast-enhanced CT imaging for colorectal tumors diagnosis.

In our present meta-analysis, we finally included 9 studies with 4797 patients. Of the included 9 studies, the publication year ranged from 2000 to 2015. Five of the studies use intravenous contrast enhancement technology and other 4 studies use oral contrast enhancement technology. The pooled diagnosis sensitivity and specificity of contrast-enhanced CT were 0.74 (95% CI: 0.71–0.77) and 0.86 (0.85–0.87), respectively. The results indicated missed diagnosis rate of 17%. This means that in 100 colorectal cancer patients examined by enhanced CT scanning, 17 patients may be diagnosed as normal. The rate of misdiagnosis is 14%. This means that of 100 colorectal carcinomas diagnosed by enhanced CT, 14 cases may not have the colorectal carcinoma.

Several limitations were existed in this meta-analysis. First, we only searched the studies published in English or Chinese and papers published in other languages were not searched. This searching strategy may lead to paper inclusion bias. Second, significant statistical heterogeneity was found in this meta-analysis which may lead to decreased statistical power. Third, the general quality of included studies was relative poor especially for papers published in Chinese.

Although this study has some limitations, the results have certain clinical application value of contrast-enhanced CT imaging for colorectal tumors diagnosis. At the same time, the results also suggest that the diagnostic sensitivity and specificity were not different for intravenous or oral contrast methods. Hence, contrast-enhanced CT imaging can reduce the medical cost and shorten the examination time in the diagnosis of colorectal carcinoma.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
 > References Top

1.
Fletcher JG, Johnson CD, Welch TJ, MacCarty RL, Ahlquist DA, Reed JE, et al. Optimization of CT colonography technique: Prospective trial in 180 patients. Radiology 2000;216:704-11.  Back to cited text no. 1
    
2.
Kim YS, Kim N, Kim SH, Park MJ, Lim SH, Yim JY, et al. The efficacy of intravenous contrast-enhanced 16-raw multidetector CT colonography for detecting patients with colorectal polyps in an asymptomatic population in Korea. J Clin Gastroenterol 2008;42:791-8.  Back to cited text no. 2
    
3.
Hoppe H, Quattropani C, Spreng A, Mattich J, Netzer P, Dinkel HP. Virtual colon dissection with CT colonography compared with axial interpretation and conventional colonoscopy: Preliminary results. AJR Am J Roentgenol 2004;182:1151-8.  Back to cited text no. 3
    
4.
Wong BC, Wong WM, Chan JK, Lai KC, Hu WH, Chan CK, et al. Virtual colonoscopy for the detection of colorectal polyps and cancers in a Chinese population. J Gastroenterol Hepatol 2002;17:1323-7.  Back to cited text no. 4
    
5.
Miao Y, Amin Z, Healy J, Burn P, Murugan N, Westaby D, et al. A prospective single centre study comparing computed tomography pneumocolon against colonoscopy in the detection of colorectal neoplasms. Gut 2000;47:832-7.  Back to cited text no. 5
    
6.
Johnson CD, Chen MH, Toledano AY, Heiken JP, Dachman A, Kuo MD, et al. Accuracy of CT colonography for detection of large adenomas and cancers. N Engl J Med 2008;359:1207-17.  Back to cited text no. 6
    
7.
Pickhardt PJ, Choi JR, Hwang I, Butler JA, Puckett ML, Hildebrandt HA, et al. Computed tomographic virtual colonoscopy to screen for colorectal neoplasia in asymptomatic adults. N Engl J Med 2003;349:2191-200.  Back to cited text no. 7
    
8.
Pineau BC, Paskett ED, Chen GJ, Espeland MA, Phillips K, Han JP, et al. Virtual colonoscopy using oral contrast compared with colonoscopy for the detection of patients with colorectal polyps. Gastroenterology 2003;125:304-10.  Back to cited text no. 8
    
9.
Jiayi ZJ, Xinhua B. Value of computed tomography colonography with low radiation dose combined with enhancement scanning in the diagnosis of colorectal tumor. Chinese J New Clin Med 2015;18:262-6.  Back to cited text no. 9
    
10.
Sali L, Regge D. CT colonography for population screening of colorectal cancer: Hints from European trials. Br J Radiol 2016;89:20160517.  Back to cited text no. 10
    
11.
Siegel R, Ma J, Zou Z, Jemal A. Cancer statistics, 2014. CA Cancer J Clin 2014;64:9-29.  Back to cited text no. 11
    
12.
Torre LA, Bray F, Siegel RL, Ferlay J, Lortet-Tieulent J, Jemal A. Global cancer statistics, 2012. CA Cancer J Clin 2015;65:87-108.  Back to cited text no. 12
    


    Figures

  [Figure 1], [Figure 2], [Figure 3]
 
 
    Tables

  [Table 1]



 

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