| BackgroundCervical cancer is the most common gynecological malignancies, which came top of list in developing country. According to the worldwide statistics, there are about500thousands new happened every year, developing countries account for80percent and a third of these are Chinese. Most cervical cancer is the result of precancerous lesions of uterine cervix which means cervical intraepithelial neoplasia (CIN) through year of slow development. So early diagnosis of cervical lesion is the key to prevent and cure the cervical cancer. At present, cytology examination, colposcopy and histology biopsy which known as three stepwise diagnosis procedure is a standard model for diagnosing CIN and cervical cancer. Nowadays, the differentiating methods between benign and malignant cervical lesions concentrate to imaging and cytology test. As a non-invasive method, imaging examinations includes ultrasound, computer tomography, nuclear magnetic resonance imaging, and radioisotope scanning, et al. Computer tomography and radioisotope scanning are radioactive, NMRI is expensive. Those methods could not be applied widely. Among all the imaging examinations, ultrasound has become a routine cervical cancer screening method because of its non-invasive, real-time, repeatability and other advantages.An important property of tissue is its intrinsic elasticity, which may change under the influence of pathologic processes, such as inflammation and tumor developments. Ultrasonic elastography (UE) was known as the only way that can provide information of the elasticity of lesions, accurately reflect the relative softness and hardness of the lesion and normal tissue around it. Ultrasonic elastography contains three types (compressive elastography, intermittent elastography and vibration elastography). Compressive elastography is applicable to diagnose the nodular diseases of the superficical organs (e.g., mammary gland, thyroid gland, prostate, etc.). Some scholars did ultrasonic elastography for prostate lesions by transrectal probe (intracavitary probe) and achieved results. So ultrasonic elastography on cervical lesions through transvaginal probe (intracavitary probe) may have the feasibility in theory. Previous elasticity imaging techniques use scoring method. However, in clinic practices, we have occasionally found that the score of a lesion would be biased by uncertain subjective factors. For example, a lesion was scored consistently by different doctors who interpreted the same condition. The strain ratio measure method may solve this problem. It was employed to evaluate the softness and hardness of the cervical tissue semi-quantitatively, which can be much more objective than scoring method.This study was designed to investigate the value of ultrasonic elastography in diagnosing cervical lesions by detecting changes of stiffness (strain ratio was calculated and compared between the benign and malignant lesions), and compare with the most common clinical screening method named thinprep cytology test, TCT.ObjectiveThe purpose of this study was to evaluate the diagnostic value of strain ratio measure method and TCT for C SOL, and help the clinical to improve the diagnosis of cervical cancer.MethodsFrom March,2010to September,2011,116patients with116suspected cervical lesions were examined with TCT and ultrasonic elastography in Xiangya Hospital, Central South University, including outpatient and inpatient treatment. All lesions were removed by surgeons and were done histopathological examination. Elastographic images were obtained by using a HV-900scanner (Hitachi Medical, Tokyo) equipped with transvaginal probe. The pathologic diagnosis was as golden standard. The diagnostic performances of the two methods were evaluated with receiver operating characteristic curve (ROC).Results1. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the TCT in the differential diagnosis of cervical polyp, cervical intraepithelial neoplasia and cervical cancer lesions were68.24%(58/85),18.18%(4/22).57.94%(62/107)、76.32%(58/76)、12.90%(4/31), respectively.2. Strain ratio value of benign lesions was much lower than that of malignant lesions (mean value,2.56±1.94vs.6.88±2.03). The differences were statistically significant (P<0.01). According to the ROC, the best cut-off point of strain ratio value was4.045. When the strain ratio of a cervical lesion was greater than or equal to4.045, it is confidential to be diagnosed as malignant. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the strain ratio measure method in the differential diagnosis of CSOL were84.21%(64/76),87.5%(35/40),85.34%(99/116),92.75%(64/69),74.47%(35/47), respectively.3. The area under ROC curve (AUC) values were statistically different for the strain index0.846and TCT0.775. The differences were statistically significant (P<0.05). ConclusionStrain ratio measure method was a semi-quantitative method that provided information about the softness and hardness of a cervical lesion, and had a better diagnostic performace than TCT. So, it was clinical valuable for transvaginal ultrasonic elastography in differentiating benign and malignant cervical lesions. BackgroundUltrasound is a kind of examination method with non-invasive, real-time and repeatability. The conventional ultrasound, including two-dimensional ultrasound for appearance and color Doppler ultrasound for vascularity. The two-dimensional ultrasound could detect the number, size, shape, location, cover, inner echo (cystic or solid or calcification), and relation with the closing tissue and so on. Color Doppler ultrasound could provide the inner or rounding vascularity of lesions, including the distribution, volume, velocity. However, the multifocal pathological structure of cervical space-occupying lesions brings the complication of image, so that the overlap existence of the benign and malignant lesions influences the diagnosis. Conventional ultrasound could provide appearance about the benign and malignant lesions except showing the relative softness or hardness. Thus, it is confined in the differentiation of CSOL to some extent. Ultrasonic elastography is a fine non-invasive and convenient supplement to traditional ultrasound.An important property of tissue is its intrinsic elasticity, which may change under the influence of pathologic processes, such as inflammation and tumor developments. Elastography was known as the only way that can demonstrate the information of tissue hardness visually. Ultrasonic elastography has showed its superiority in several fields and has a high clinical value. However, almost no effort was done on the detection cervical cancer until now.This essay is aimed at the study of Adler flow grading combined with Doppler spectrum resistance index (resistance index, RI), elasticity scores, strain ratio, ultrasonography comprehensive scoring method (ultrasonography comprehensive score, DCS) in the differential diagnosis of CSOL. The study will propose the analysis of using the ultrasonography comprehensive score and comparison of each individual standard to provide more theoretical basis for clinical diagnosis. ObjectiveTo evaluate the diagnostic performance of ultrasonography comprehensive scoring method for the differentiation of benign and malignant CSOL. Methods116patients underwent a sonographic examination of the cervix using two-dimensional ultrasound and elastography. The process began with conventional ultrasound imaging of the target lesions, After that, the system was switched into elastography mode to evaluate the stiffness of the cervix and the lesions. We measured and recorded these parameters: Adler flow grading combined with RI. They then underwent real-time ultrasonic elastography. The observer produced slight and steady compression of the target lesion, finally stored the fine elastogram, which reflected each layer tissue clearly. Elasticity scores and strain ratio of each CSOL were calculated, and we also measured and recorded ultrasound scoring method of each CSOL. The pathologic diagnosis was as golden standard. By analyzing the ROC curve, we researched wether the ultrasonography comprehensive scoring method was more accurate than each parameter and which was the best cut-off value for differential diagnosis of CSOL.Data were represented as mean±standard error and analyzed using the SPSS13.0and MedCalc12.1.3.0statistic software. The comparation of area under the curve (AUC) was analyzed by Z test. A2-tailed P<0.05was considered to be statistically significant. The diagnostic performance of the index was evaluated by ROC curve.ResultThe following results were diagnosed by histopathology after operation as the gold standard for comparison.1. The benign lesions had a Adler flow grade of0-1, the malignant lesions had a Adler flow grade of2-3. When RI≥0.50was benign, RI<0.50was malignant. The sensitivity, specificity, accuracy, positive predictive, and negative predictive values of Adler flow grading combined with RI in the differential diagnosis of CSOL were82.89%(63/76),85.0%(34/40),83.62%(97/116),91.30%(63/69),72.34%(34/47), respectively.2. The benign lesions had a elasticity score of1-3, the malignant ones had a elasticity score of4-5. The sensitivity, specificity, accuracy, positive predictive, and negative predictive values of the elasticity score method in the differential diagnosis of CSOL were77.63%(59/76),82.5%(33/40),79.31%(92/116),89.39%(59/66),66.0%(33/50), respectively.3. The best cut-off point of strain ratio value was4.045. The sensitivity, specificity, accuracy, positive predictive, and negative predictive values of the best cut-off point were84.21%(64/76),87.5%(35/40),85.34%(99/116),92.75%(64/69),74.47%(35/47), respectively.4. The diagnostic performance of the index was evaluated by ROC curve. The data of AUC by using Adler flow grading combined with RI, elasticity scores and strain ratio method were0.775,0.791,0.846, respectively. There were no statistical differences in the elasticity scores and strain ratio methods (P>0.05). There were statistical differences in strain ratio method and Adler flow grading combined with RI (P> 0.05).There were no statistically different for Color Doppler Adler flow grading and spectral Doppler resistance index (P<0.05).5. The range of ultrasonography comprehensive score was0-4. According to the ROC curve analysis, the cutoff point of ultrasonography comprehensive score was determined as3. So, the benign lesions had a ultrasonography comprehensive score of0-2, the malignant ones had a score of3-4. The sensitivity, specificity, accuracy, positive predictive and negative predictive values of ultrasonography comprehensive scoring method in the differential diagnosis of CSOL were90.79%(69/76),92.5%(37/40),91.38%(106/116),95.83%(69/72),84.09%(37/44), respectively. The data of AUC by using ultrasonography comprehensive scoring method was0.935. The diagnostic accuracy of ultrasonography comprehensive scoring method was higher than the other of each method and their difference was statistically significant (P<0.05). Conclusion1. Using Adler flow grading combined with RI, elasticity score and strain ratio method, ultrasonography comprehensive scoring method to identify benign and malignant cervical lesions all have a certain diagnostic value. 2. It is obvious that strain ratio method yielded better results than elasticity score method, the former is semi-qualitiative, and the latter is qualitative.3. Ultrasonography comprehensive scoring method can improve the diagnostic sensitivity of cervical malignant lesions and early cervical cancer detection rates and can possibly realize the early detection, early diagnosis,early treatment. The accuracy of CSOL, ultrasonography comprehensive score method which put conventional ultrasound and ultrasound elasticity imaging detect each single,index into quantitative and comprehensive analysis is higher than the single ultrasound. Main Innovative Points:1.To our knowledge, this is the first study on the comparison between strain ratio method and TCT. The results showed the strain ratio method for the diagnosis of CSOL is better than TCT. It provided a new ultrasound method for clinical to improve the diagnostic rate.2. Based on the clinical demand, this is the first study in vestigating the clinical value of ultrasonography comprehensive score in preoperating diagnosis of cervical cancer on a sufficient number of patients. It can greatly increase the diagnostic sensitivity, specificity and accuracy of differentiation of benign and malignant cervical lesions. So ultrasonography comprehensive score is a simple, practical and accurate new method which is worthwhile for clinical application. |
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