Brief Article
Copyright ©2013 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Oct 14, 2013; 19(38): 6479-6484
Published online Oct 14, 2013. doi: 10.3748/wjg.v19.i38.6479
A new endoscopic ultrasonography image processing method to evaluate the prognosis for pancreatic cancer treated with interstitial brachytherapy
Wei Xu, Yan Liu, Zheng Lu, Zhen-Dong Jin, Yu-Hong Hu, Jian-Guo Yu, Zhao-Shen Li
Wei Xu, Zheng Lu, Zhen-Dong Jin, Yu-Hong Hu, Zhao-Shen Li, Department of Gastroenterology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
Yan Liu, Department of Gastroenterology, 307 Hospital of the Chinese People’s Liberation Army, Beijing 100071, China
Jian-Guo Yu, Department of Electronic Engineering, Information Science and Engineering School, Fudan University, Shanghai 200433, China
Author contributions: Xu W, Liu Y and Lu Z contributed equally to this paper; Liu Y and Li ZS designed the research; Xu W, Liu Y, Lu Z, Jin ZD, Hu YH and Yu JG performed the research; Xu W, Liu Y and Lu Z analyzed the data; Xu W, Liu Y and Lu Z wrote the paper.
Supported by The National Natural Science Foundation of China, No. 30801362 and 81001074
Correspondence to: Zhao-Shen Li, Professor, Department of Gastroenterology, Changhai Hospital, Second Military Medical University, 168 Changhai Road, Yangpu District, Shanghai 200433, China. xuwei83419@sina.com
Telephone: +86-21-81873241 Fax: +86-21-55620081
Received: July 10, 2013
Revised: August 28, 2013
Accepted: September 4, 2013
Published online: October 14, 2013
Abstract

AIM: To develop a fuzzy classification method to score the texture features of pancreatic cancer in endoscopic ultrasonography (EUS) images and evaluate its utility in making prognosis judgments for patients with unresectable pancreatic cancer treated by EUS-guided interstitial brachytherapy.

METHODS: EUS images from our retrospective database were analyzed. The regions of interest were drawn, and texture features were extracted, selected, and scored with a fuzzy classification method using a C++ program. Then, patients with unresectable pancreatic cancer were enrolled to receive EUS-guided iodine 125 radioactive seed implantation. Their fuzzy classification scores, tumor volumes, and carbohydrate antigen 199 (CA199) levels before and after the brachytherapy were recorded. The association between the changes in these parameters and overall survival was analyzed statistically.

RESULTS: EUS images of 153 patients with pancreatic cancer and 63 non-cancer patients were analyzed. A total of 25 consecutive patients were enrolled, and they tolerated the brachytherapy well without any complications. There was a correlation between the change in the fuzzy classification score and overall survival (Spearman test, r = 0.616, P = 0.001), whereas no correlation was found to be significant between the change in tumor volume (P = 0.663), CA199 level (P = 0.659), and overall survival. There were 15 patients with a decrease in their fuzzy classification score after brachytherapy, whereas the fuzzy classification score increased in another 10 patients. There was a significant difference in overall survival between the two groups (67 d vs 151 d, P = 0.001), but not in the change of tumor volume and CA199 level.

CONCLUSION: Using the fuzzy classification method to analyze EUS images of pancreatic cancer is feasible, and the method can be used to make prognosis judgments for patients with unresectable pancreatic cancer treated by interstitial brachytherapy.

Keywords: Digital image processing, Fuzzy classification, Endoscopic ultrasonography, Pancreatic cancer, Interstitial brachytherapy, Prognosis

Core tip: Digital image processing (DIP) of endoscopic ultrasonography (EUS) images has been proven to be useful in diagnosis of malignant tumor. Currently commonly used method of DIP is only to concludes the differential diagnosis of solid tumors (“yes” or “no”), can not provide the numerical data describing the texture parameters in the EUS image. EUS-guided brachytherapy has been applied preliminarily in the study of advanced pancreatic cancer. However, prognosis judgment of these patients was still difficult. So we develop a fuzzy classification method to score texture features of pancreatic cancer in EUS images to supply more information and validated its utility in prognosis judgment of patients with unresectable pancreatic cancer treated by EUS-guided interstitial brachytherapy.