Three-dimensional Endorectal Ultrasound Research Articles

Utility of Machine Learning Algorithms in Predicting Preoperative Lymph Node Metastasis in Patients With Rectal Cancer Based on Three-Dimensional Endorectal Ultrasound and Clinical and Laboratory Data.

We aimed to investigate the value of a machine learning (ML) algorithm in the preoperative prediction of lymph node metastasis in patients with rectal cancer. Based on the histopathological results, 126 rectal cancer patients were divided into two groups: lymph node metastasis-positive and metastasis-negative groups. We collected clinical and laboratory data, three-dimensional endorectal ultrasound (3D-ERUS) findings, and parameters of the tumor for between-group comparisons. We constructed a clinical prediction model based on the ML algorithm, which demonstrated the best diagnostic performance. Finally, we analyzed the diagnostic results and processes of the ML model. Between the two groups, there were significant differences in serum carcinoembryonic antigen (CEA) levels, tumor length, tumor breadth, circumferential extent of the tumor, resistance index (RI), and ultrasound T-stage (P < 0.05). The extreme gradient boosting (XGBoost) model had the best comprehensive diagnostic performance for predicting lymph node metastasis in patients with rectal cancer. Compared with experienced radiologists, the XGBoost model showed significantly higher diagnostic value in predicting lymph node metastasis; the area under curve (AUC) value of the receiver operating characteristic (ROC) curveof the XGBoost model and experienced radiologists was 0.82 and 0.60, respectively. Preoperative predictive utility in lymph node metastasis was demonstrated by the XGBoost model based on the 3D-ERUS finding and related clinical information. This could be useful in guiding clinical decisions on the selection of different treatment strategies.

Application of the three-dimensional endorectal ultrasonography in the rectal tumor staging before transanal endoscopic microsurgery

Objective To investigate the value of the three-dimensional endorectal ultrasonography (3D-ERUS) in the tumor staging before transanal endoscopic microsurgery (TEM) . Methods The clinical data of 30 patients with rectal cancer who underwent 3D-ERUS before TEM at the Nanjing Hospital of Traditional Chinese Medicine from April 2012 to December 2013 were retrospectively analyzed. The accuracy, sensitivity and specificity of the 3D-ERUS were evaluated according to the results of the postoperative pathological examination. The consistency of the results of the 3D-ERUS and postoperative pathological examination were compared by Kappa consistency test. Results Of 30 patients, 25 patients in stage T0, 3 in stage T1 and 2 in stage T2 were diagnosed by preoperative 3D-ERUS. There were 2 patients (stage pT0) with inflammatory polyp by postoperative pathological diagnosis, 6 patients (stage pT0) with tubular adenoma, 16 patients (stage pT0) with villioustublar adenoma, 2 patients (stage pTis) with carcinoma in situ, 2 patients (stage pT1) with rectal adenoma and 2 patients (stage pT2) with rectal adenoma. There were 2 patients with excessive tumor staging by 3D-ERUS, 1 patient in stage pT0 was misdiagnosed in stage T1 , 1 in stage pT1 was misdiagnosed in stage T2 and 1 in stage pT2 was misdiagnosed in stage T1 with insufficient tumor staging. The accuracy of 3D-ERUS in the preoperative tumors staging of TEM was 90.0% compared with the resuls of postoperative pathological examination. The accuracy, sensitivity and specificity of 3D-ERUS in stage pT0, pT1 , and pT2 of TEM were 96.7% , 90.0% , 93.3% and 96.2% , 50.0% , 50. 0% and 100.0% , 92.8% , 96.4% , respectively. There was a significant difference in the consistency between preoperative 3D-ERUS and postoperative pathological examination (κ =0. 685, P <0.05) . Conclusion 3D-ERUS is an accurate clinical method in the preoperative tumors staging of TEM, and can be used as the preoperative assessment for TEM. Key words: Rectal neoplasms; Three-dimensional endorectal ultrasonography; Tumor staging; Microsurgery

The Role of 3-D Endorectal Ultrasound in Rectal Cancer: Our Experience

In the last 20 years, endorectal ultrasound (ERUS) has been one of the main diagnostic methods for locoregional staging of rectal cancer. ERUS is accurate modality for evaluating local invasion of rectal carcinoma into the rectal wall layers (T category). Adding the three-dimensional modality (3-D) increases the capabilities of this diagnostic tool in rectal cancer patients. We review the literature and report our experience in preoperative 3-D ERUS in rectal cancer staging. In the group of 71 patients, the staging of preoperative 3-D endorectal ultrasonography was compared with the postoperative morphologic examination. Three-dimensional ERUS preoperative staging was confirmed with morphologic evaluation in 66 out of 71 cases (92.9%). The detection sensitivities of rectal cancer with 3-D ERUS were as follows: T1, 92.8%; T2, 93.1%; T3, 91.6%; and T4, 100.0%; with specificity values of T1, 98.2%; T2, 95.4%; T3, 97.8%; and T4, 98.5%. Three-dimensional ERUS correctly categorized patients with T1, 97.1%; T2, 94.3%; T3, 95.7%; and T4, 98.5%. The percentage of total overstaged cases was 2.75% and that of understaged cases was 6.87%. The metastatic status of the lymph nodes was determined with a sensitivity of 79.1% (19 of 24), specificity of 91.4% (43 of 47), and diagnostic accuracy of 87.3% (62 of 71). In our experience, 3-D ERUS has the potential to become the diagnostic modality of choice for the preoperative staging of rectal cancer.

The Value of High-Resolution Three-Dimensional Endorectal Ultrasonography in the Management of Submucosal Invasive Rectal Tumors

The aims of this prospective study were 1) to evaluate the accuracy of high-resolution three-dimensional endorectal ultrasonography in distinguishing slight from massive submucosal invasion of early rectal tumors, and 2) to determine the technology's role in treatment selection. A total of 142 consecutive patients with clinically possible pT1 rectal cancers underwent three-dimensional endorectal ultrasonography. Slight or massive irregularity of the hyperechoic submucosal layer was considered to characterize uT1-slight or uT1-massive tumors. Treatment was selected on the basis of ultrasonographic findings: endoscopic resection or full-thickness transanal local excision was selected for uT1-slight lesions, and radical resection was selected for uT1-massive tumors. Ultrasonographic staging was compared with histopathologic staging. One hundred twenty-six patients were included in the final analyses. Three-dimensional endorectal ultrasonography staged 77 lesions as uT0, 25 as uT1-slight, 20 as uT1-massive, and 4 as uT2. Histologically, adenomas were found in 75 patients and tumor invasion was found in 44 lesions (24 pT1-slight, 16 pT1-massive, 4 pT2). The overall kappa for the concordance between ultrasonographic and histopathologic stagings was 0.81 (95% confidence interval, 0.72-0.89). No invasive carcinomas remained undetected. The depth of invasion was correctly determined in 87.2% of both pT1-slight and pT1-massive lesions. Considering the complete series of 126 patients, the accuracy of this modality in selecting appropriate management was 95.2% (kappa, 0.84; 95% confidence interval, 0.71-0.96). Adequate surgery was performed in 87.5% of pT1 tumors. Three-dimensional endorectal ultrasonography is useful for assessing the depth of submucosal invasion in early rectal cancer and for selecting therapeutic options.

Three-Dimensional Endorectal Ultrasound Using a New Freehand Software Program: Results in 35 Patients with Rectal Cancer

This paper describes experience in the staging of rectal cancer using a new software program for three-dimensional endoscopic ultrasonography (EUS) that works without electromagnetic sensors and can be used even with electronic radial or linear rectal probes. From May 2003 to March 2004, 35 three-dimensional endorectal ultrasound (ERUS) examinations were carried out using this program. The indication for ERUS was local staging of rectal cancer in all cases. The three-dimensional software imaging program forms part of a new ultrasound scanning system (Hitachi 6500 or 8000) and allows reconstruction of the two-dimensional EUS images in six different scans. Thirty-five rectal cancers were assessed using two-dimensional and three-dimensional EUS. Using two-dimensional imaging, it was not possible to assess precisely the degree of involvement of the mesorectum (more or less than 50%). No differences were evident with three-dimensional EUS for superficial tumors (T1 and T2N0), but in six of 15 patients classified as having T3N0 lesions, three-dimensional EUS revealed malignant lymph nodes, a finding that was confirmed surgically in five of the six cases. Three-dimensional EUS also made it possible to assess the degree of infiltration of the mesorectum precisely in all cases, demonstrating complete invasion of the mesorectum in eight cases. These findings were confirmed in all cases by the surgical data. Two-dimensional EUS correctly assessed 25 of the 35 rectal tumors (71.4%) in relation to the T and N classifications, and three-dimensional EUS increased this figure to 31 correct evaluations out of 35 (88.6%). Three-dimensional ERUS is easy to carry out using this new software program. There is no need for an external sensor mounted at the tip of the probe, and manipulation of the rectal probe is facilitated. Three-dimensional ERUS can be carried out using linear and radial electronic probes with the same ultrasound equipment. Three-dimensional ERUS allows more precise staging of lesions and better definition of the mesorectal margins, and this has a direct impact on therapeutic decision-making in patients with rectal cancer.

Anorectal ultrasound for neoplastic and inflammatory lesions

Accurate staging of rectal and anal carcinoma is crucial for planning surgery and indicating adjuvant therapy. Although, computed tomography and magnetic resonance imaging are very sensitive in detecting metastatic disease, the local staging of rectal cancer with these techniques has been disappointing. Endorectal ultrasound (ERUS) and anal endosonography (AE) remain the most accurate methods for staging rectal and anal cancer. Anal endosonography is also of value in evaluating perianal sepsis: it can assist the surgeon in planning the surgical strategy by delineating the anatomy of fistula tracts, and can aid in puncturing abscesses in the operating room. Continued research and development has made the instrumentation for ERUS and AE more accurate and user-friendly. New techniques that have contributed significantly to the evolution of ERUS include three-dimensional ERUS, high-frequency miniprobes, transrectal ultrasound-guided biopsy techniques and hydrogen peroxide-enhanced endosonography. Further improvements can be expected from contrast enhancement with microbubbles and colour Doppler imaging. In this new millennium, new developments in ERUS and anal endosonography, such as tri-dimensional ERUS and anal endosonography and radial electronic probing, widen the role of ERUS in the staging of rectal and anal carcinoma, as well as for perianal inflammatory conditions.

Combined modality therapy for rectal cancer

Combined modality therapy for rectal cancer

Endorectal ultrasound in rectal cancer.

Accurate staging of rectal carcinoma is crucial for planning surgery and the indication for adjuvant therapy. Although computed tomography and magnetic resonance imaging are very sensitive in the detection metastastic disease, local staging of rectal cancer with these techniques has been disappointing. Endorectal ultrasound (EUS) remains the most accurate method for staging of rectal cancer. High accuracy rates in the assessment of the depth of infiltration (T stage) (80-90%) and in the determination of the lymph node status (70-80%) have been confirmed in several studies. Continued research and development has made the instrumentation for EUS more accurate and user-friendly. New techniques that have contributed significantly to the evolution of EUS include three-dimensional EUS, high-frequency miniprobes and transrectal ultrasound-guided biopsy techniques. Further improvement can be expected by contrast enhancement with microbubbles and colour Doppler imaging.

Three-dimensional endorectal ultrasonography for staging of obstructing rectal cancer

Preoperative staging of advanced carcinoma of the rectum by conventional endorectal ultrasonography is often impossible because of the presence of obstruction, which does not allow passage of the endoprobe. In a prospective study, we investigated the value of three-dimensional endorectal ultrasonography for staging of obstructing rectal cancer. This technique permits examination of obstructing rectal tumors because scan planes can be chosen deliberately within a scanned volume. Overall obstructing tumors not accessible for conventional endoprobes were found in 26 of 94 patients who were subjected to endorectal ultrasonography for staging of rectal cancer. Three-dimensional volume scanning was performed using a three-dimensional frontfire transducer or a three-dimensional bifocal multiplane transducer (7.5/10 MHz). Data of the three-dimensional scans were stored on a hard disk for subsequent evaluation with a combison 530 processor. Three-dimensional transrectal endosonography enabled visualization of local tumor spread in all 26 patients. In 18 patients, obstruction was caused by advanced primary rectal carcinoma. Endosonography accurately determined the tumor infiltration depth in three T2 tumors, eight T3 tumors, and three T4 tumors. Overall accuracy for assessment of infiltration depth was 78 percent. Accuracy for assessment of perirectal lymph node involvement was 75 percent. In eight patients, the obstruction was attributable to extramural regrowth of rectal cancer after surgery. Diameter of the lesions ranged between 3 and 6 cm. Although all lesions were clearly depicted by three-dimensional endosonography, only five lesions (62 percent) were detected by computed tomography. Three-dimensional endorectal ultrasonography provides previously unattainable scan planes and enables accurate staging of obstructing rectal tumors. This technique may improve therapy planning in advanced rectal cancer by selecting patients who require preoperative adjuvant therapy.