Detection Of Extramural Venous Invasion Research Articles

Diagnostic accuracy of state-of-the-art rectal MRI sequences for the diagnosis of extramural vascular invasion in locally advanced rectal cancer after preoperative chemoradiotherapy: dos or maybes?

The aim of this study was to determine the accuracy of three state-of-the-art MRI sequences for the detection of extramural venous invasion (EMVI) in locally advanced rectal cancer (LARC) patients after preoperative chemoradiotherapy (pCRT). This retrospective study included 103 patients (median age 66years old [43-84]) surgically treated with pCRT for LARC and submitted to preoperative contrast-enhanced pelvic MRI after pCRT. T2-weighted, DWI, and contrast-enhanced sequences were evaluated by two radiologists with expertise in abdominal imaging, blinded to clinical and histopathological data. Patients were scored according to the probability of EMVI presence on each sequence using a grading score ranging from 0 (no evidence of EMVI) to 4 (strong evidence of EMVI). Results from 0 to 2 were ranked as EMVI negative and from 3 to 4 as EMVI positive. ROC curves were drawn for each technique, using histopathological results as reference standard. T2-weighted, DWI, and contrast-enhanced sequences demonstrated an area under the ROC curve (AUC) respectively of 0.610 (95% CI: 0.509-0.704), 0.729 (95% CI: 0.633-0.812), and 0.624 (95% CI: 0.523-0.718). The AUC of DWI sequence was significantly higher than that of T2-weighted (p = 0.0494) and contrast-enhanced (p = 0.0315) sequences. DWI is more accurate than T2-weighted and contrast-enhanced sequences for the identification of EMVI following pCRT in LARC patients. MRI protocol for restaging locally advanced rectal cancer after preoperative chemoradiotherapy should routinely include DWI due to its higher accuracy for the diagnosis of extramural venous invasion compared to high-resolution T2-weighted and contrast-enhanced T1-weighted sequences. • MRI has a moderately high accuracy for the diagnosis of extramural venous invasion in locally advanced rectal cancer after preoperative chemoradiotherapy. • DWI is more accurate than T2-weighted and contrast-enhanced T1-weighted sequences in the detection of extramural venous invasion after preoperative chemoradiotherapy of locally advanced rectal cancer. • DWI should be routinely included in the MRI protocol for restaging locally advanced rectal cancer after preoperative chemoradiotherapy.

MRI-based radiomics model for preoperative prediction of extramural venous invasion of rectal adenocarcinoma.

Extramural venous invasion (EMVI) is an important prognostic factor of rectal adenocarcinoma. However, accurate preoperative assessment of EMVI remains difficult. To assess EMVI preoperatively through radiomics technology, and use different algorithms combined with clinical factors to establish a variety of models in order to make the most accurate judgments before surgery. A total of 212 patients with rectal adenocarcinoma between September 2012 and July 2019 were included and distributed to training and validation datasets. Radiomics features were extracted from pretreatment T2-weighted images. Different prediction models (clinical model, logistic regression [LR], random forest [RF], support vector machine [SVM], clinical-LR model, clinical-RF model, and clinical-SVM model) were constructed on the basis of radiomics features and clinical factors, respectively. The area under the curve (AUC) and accuracy were used to assess the predictive efficacy of different models. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were also calculated. The clinical-LR model exhibited the best diagnostic efficiency with an AUC of 0.962 (95% confidence interval [CI] = 0.936-0.988) and 0.865 (95% CI = 0.770-0.959), accuracy of 0.899 and 0.828, sensitivity of 0.867 and 0.818, specificity of 0.913 and 0.833, PPV of 0.813 and 0.720, and NPV of 0.940 and 0.897 for the training and validation datasets, respectively. The radiomics-based prediction model is a valuable tool in EMVI detection and can assist decision-making in clinical practice.

Synthetic phase-sensitive inversion-recovery vessel for assessing extramural venous invasion in patients with rectal cancer: imaging quality and added value to T2-wighted imaging.

To evaluate the imaging quality of a synthetic phase-sensitive inversion recovery (SyPSIR) vessel and to add value to T2-weighted imaging (T2WI) for extramural venous invasion (EMVI) detection in patients with rectal cancer. Participants in this retrospective study underwent preoperative synthetic MRI between October 2020 and April 2022. SyPSIR image reconstruction was performed with a single inversion time of 10 ms. A junior and a senior radiologist evaluated the imaging quality, including overall imaging quality scores, motion artifact scores, and relative image signal intensity contrast between the tumor and peritumoral vessels (SItumor-vessel), of both T2WI and SyPSIR vessels. Differences in imaging quality between the two methods were assessed using the Wilcoxon signed-rank test and two-sample t-test. EMVI scores were recorded for T2WI and T2WI+SyPSIR vessel. The area under the receiver operating characteristic curve (AUC) was calculated to evaluate the diagnostic performance. A total of 106 patients (35 EMVI+ and 71 EMVI-) were evaluated. There were no statistically significant differences in the overall image quality scores, motion artifacts, or SItumor-vessel (p = 0.08-0.93) between the T2WI and SyPSIR vessels. On combining T2WI and SyPSIR vessels, the AUC for pathological EMVI+ diagnoses increased from 0.65 to 0.88 for the junior radiologist and from 0.86 to 0.96 for the senior radiologist. Furthermore, the sensitivity of the analyses by junior and senior radiologists increased from 0.40 to 0.77 and 0.49 to 0.86, respectively. A SyPSIR vessel can provide additional information to improve the diagnostic efficiency of pathological EMVI in rectal cancer, which may be beneficial for individualized clinical treatment. • SyPSIR vessel and T2WI had similar imaging quality. • EMVI evaluation in SyPSIR vessel has a high inter-observer agreement. • The SyPSIR vessel has the potential to improve the diagnostic efficiency of EMVI detection in rectal cancer.

Extramural venous invasion (EMVI) revisited: a detailed analysis of various characteristics of EMVI and their role as a predictive imaging biomarker in the neoadjuvant treatment response in rectal cancer.

To assess whether size, diameter, and large vein involvement of MR-detected extramural venous invasion (MR-EMVI) have an impact on neoadjuvant therapy response in rectal adenocarcinoma. 57 patients with locally advanced rectal adenocarcinoma scanned with MRI before and after neoadjuvant therapy were included. Two abdominal radiologists evaluated the images with special emphasis on EMVI, on initial staging and after neoadjuvant treatment. The sensitivity and specificity of MRI for detection of rest EMVI were determined. The association of various MR-EMVI characteristics including number, size, and main vein involvement with treatment response was investigated. In subjects with discordance of radiology and pathology, elastin stain was performed, and images and slides were re-evaluated on site with a multidisciplinary approach. At initial evaluation, 17 patients were MR-EMVI negative (29.8%) and 40 were MR-EMVI positive (70.2%). Complete/near-complete responders had less number (mean 1.45) and smaller diameter of MR-EMVI (mean 1.8mm), when compared with partial responders (2.54 and 3.3mm; p < 0.005). The sensitivity of MRI for rest EMVI detection was high, specificity was moderate, and in one patient elastin stain changed the final decision. In five patients with rest MR-EMVI positivity, carcinoma histopathologically had a distinctive serpiginous perivascular spread, growing along the track of vascular bundle, although it did not appear in intravascular spaces. This study demonstrates that not only the presence, but also size and number of EMVI that may be significant clinically and thus these parameters also ought to be incorporated to the MRI evaluation and prognostication of treatment response. From pathology perspective, tumors growing alongside major vessels may also reflect EMVI even if they are not demonstrably "intravascular."

Prognostic Importance of MRI-Detected Extramural Venous Invasion in Rectal Cancer: A Literature Review and Systematic Meta-Analysis.

Extramural venous invasion (EMVI) is recognized as a poor prognostic factor in rectal cancer. There are well-documented limitations associated with pathology detection of EMVI, including variable reporting and the inability to use it preoperatively to guide neoadjuvant treatment. Magnetic resonance imaging (MRI)-detected EMVI (mrEMVI) has been proposed as an imaging biomarker. This review assesses the prognostic significance of mrEMVI on survival outcomes and whether regression of mrEMVI after neoadjuvant therapy is associated with improvements in survival. An electronic search was carried out using MEDLINE and EMBASE databases using the search terms "rectum," "cancer,", "MRI," and "outcomes." A systematic review and meta-analysis were carried out in accordance with Preferred Reporting for Systematic Reviews and Meta-Analyses guidelines using Review Manager software. A qualitative review was performed. A total of 7399 articles were identified, of which 33 were relevant to the review question. After a qualitative assessment, 20 articles were included in the meta-analysis. Baseline mrEMVI positivity is associated with significantly worsened overall survival (hazard ratio [HR] 1.84; 95% confidence interval [CI], 1.33-2.54; P=.0001) and significantly worsened disease-free survival (HR 2.41; 95% CI, 2.02-2.89; P < .00001). After neoadjuvant treatment, a positive mrEMVI status is associated with a significantly worsened overall and disease-free survival. Only 3 papers specifically looked at mrEMVI regression, but the results show that persistent mrEMVI-positive status after treatment is associated with significantly worsened disease-free survival compared with a change in mrEMVI from positive to negative (HR 1.93; 95% CI, 1.39-2.68; P < .0001). A subgroup analysis of MRI-detected lymph node metastases showed no significant association with survival, with a hazard ratio of 1.33 (95% CI, 0.98-1.80; P=.06). mrEMVI is significantly associated with worsened survival outcomes, both at baseline and after neoadjuvant treatment. Additionally, there is evidence that regression of mrEMVI after neoadjuvant treatment is associated with improved survival compared with mrEMVI persistence. The findings of this review emphasize the need for accurate and consistent reporting of mrEMVI status before and after neoadjuvant treatment and support the inclusion of mrEMVI into staging systems preferentially over lymph node metastases.

Multifocal extramural venous invasion detected with an elastin stain as a predictor of cancer-specific outcomes in stage I-III resected colorectal cancer (CRC).

114 Background: ExtraMural Venous Invasion (EMVI) is considered an indicator of poor prognosis in patients who have undergone resection of primary CRC, but its use has not been widely adopted in staging systems or nomograms. Staining for elastin may facilitate the accurate detection of EMVI and minimize interobserver variability, as well as enable the assessment of specific features of EMVI including focality and size. We examined the prognostic potential of EMVI detected by elastin staining at a tertiary center that performs a high volume of CRC resections. Methods: This is a single-institution, observational study of consecutive patients who underwent resection of primary CRC between 01/2011 and 12/2016 (n=556). All pathology specimens were re-assessed by expert reviewers who were blinded to patient outcomes. Venous invasion was detected using an elastin trichrome stain and classified as IntraMural or ExtraMural. The number of VI foci, as well as the maximum foci width and length, were also determined. Disease-specific and recurrence-free survival (DSS, RFS) were estimated using the Kaplan-Meier method and group differences were assessed using the log-rank test. Cox proportional-hazard models were used to calculate hazard ratios (HR) and 95% CI. For the present analysis, patients with stage IV (n=86) CRC were excluded. Results: The cohort for analysis included 470 patients (264M, 206F; TNM 8th edition Stage I/II n=291; Stage III n=179) with a median follow-up time of 63 months (0.1-114). EMVI was detected in 33% of all cases (20% in Stage I/II vs. 55% in Stage III; p&lt;0.0001). For the entire cohort, DSS and RFS at 5 years were 86% and 76%, respectively. The presence of EMVI was associated with significantly worse DSS and RFS at 5-years (73% and 54%) compared to patients with no VI (92% and 85%) or IMVI alone (93% and 89%; p&lt;0.0001). The majority of EMVI was multifocal (69%) vs. unifocal (31%). Interestingly, multifocal EMVI was prognostic for worse 5-year DSS (65%), whereas unifocal EMVI was similar to the absence of EMVI (91% and 92%, respectively; p&lt;0.0001). A Cox-proportional hazards model showed worsening DSS with increasing number of detected EMVI foci (1 focus: HR 1.1, 2-4 foci: HR 3.3, &gt;4 foci: HR 7.9; p&lt;0.0001). A similar trend was observed for RFS. Neither the maximum width or length of EMVI foci were prognostic of DSS or RFS. Conclusions: To our knowledge, the prognostic role of EMVI focality in CRC has not been previously explored. In this cohort of Stage I - III CRC patients, multifocal EMVI as assessed by elastin staining was a powerful predictor of cancer-specific death and recurrence-free survival. Elastin staining, which improves the accuracy and objectivity of EMVI detection, may allow validation of EMVI as an independent prognostic variable that should be incorporated into staging systems and nomograms.

High-Resolution T2-Weighted MRI to Evaluate Rectal Cancer: Why Variations Matter.

MRI has been used to image rectal cancer for over two decades and there is extensive research on this imaging technique. The 1999 seminal paper by Brown et al. [1] demonstrated the accuracy of thin-slice MRI in identifying the depth of extramural tumor in 28 patients with rectal cancer. MRI has also been shown to predict involvement of the circumferential resection margin in total mesorectal excision surgery, which is extremely useful to surgeons who may otherwise have produced an R2 resection [2,3]. MRI has enabled the stratification of patients into high- and low-risk and the selection of appropriate patients for neoadjuvant chemoradiotherapy. It has previously been demonstrated that the thin section, or high-resolution (HR) T2 imaging provided promising results in the assessment of lymph nodes, detection of extramural venous invasion, and differentiation of tumors from fibrosis on post-treatment imaging, which continue to be extensively studied [4,5,6]. The majority of publications assessing MRI in rectal cancer describe the use of HR T2 sequences, and the term ‘HR T2’ has been generally accepted to represent HR imaging. There have been a variety of results regarding the accuracy of rectal MRI, particularly the T2 sequence alone, and it has been regularly assessed against other techniques including diffusion, post-contrast, and radiomics. On more in-depth methodological assessment, there is significant heterogeneity in the resolution of the HR T2 sequences across many publications, and this may have an impact on the results.

P-133 Extramural venous invasion detected with an elastin stain is a powerful predictor of cancer-specific mortality in STAGE I-IIIB resected colorectal cancer

Extramural venous invasion (EMVI) is considered an indicator of poor prognosis in patients who have undergone resection of primary colorectal cancer (CRC), but its use has not been widely adopted in staging systems or nomograms. In particular, EMVI is not reported in most large case series, is not included in most large CRC databases, and is not incorporated into the current AJCC TNM staging system. Staining for elastin may facilitate the accurate detection of EMVI and minimize inter-observer variability. We examined the prognostic potential of EMVI detected by elastin staining at a tertiary center that performs a high volume of CRC resections. This is a single-institution, observational study of consecutive patients who underwent resection of primary CRC between 01/01/2011 and 31/12//2016. All pathology specimens were re-assessed by reviewers who were blinded to patient outcomes. Venous invasion was detected using an elastin trichrome stain and classified as Intramural or Extramural. Overall and disease-specific survival (OS, DSS) were estimated using the Kaplan-Meier method. Differences between groups were assessed using the Mantel-Cox log-rank test. For the present analysis, we excluded all patients with stage IV (n=80) or IIIC (n=34) CRC. The cohort for analysis included 428 patients (248M, 190F; AJCC 8th edition Stage I n=107; Stage II n=185; Stage IIIA and B n=146) with a median follow-up time of 61 months (0.1-104). For the entire cohort, OS and DSS at 5 years were 82% and 90%, respectively. AJCC stage (p=0.04), but not T stage (p=0.08) or N stage (p=0.09), was prognostic of DSS. Neither grade (p=0.1) nor IMVI (p=0.4) were prognostic, whereas EMVI was highly prognostic of inferior DSS (p< 0.001). In this cohort of Stage I - III CRC patients with complete follow-up, EMVI as assessed by elastin staining was a powerful predictor of death from CRC. Elastin staining, which improves the accuracy and objectivity of EMVI detection, may allow validation of EMVI as an independent prognostic variable that should be incorporated into staging systems and nomograms. Accurate assessment of EMVI would permit refinement of risk estimation, and inform individualized decision-making regarding adjuvant therapy in patients who have undergone resection of CRC.

Primary and post-chemoradiotherapy MRI detection of extramural venous invasion in rectal cancer: the role of diffusion-weighted imaging.

To assess the added value of diffusion-weighted imaging (DWI) to high-resolution T2-weighted sequences (HRT2w) in MRI detection of extramural venous infiltration (EMVI), according to the previous experience of radiologists. A cross-sectional study of a retrospective database including 1.5T MRI records from 100 patients with biopsy-proven rectal cancer (2011-2016; 75 male/25 female, average 63 y/o), which included primary staging (54) and post-chemoradiotherapy follow-up MRIs (46). The reference standard was histology of surgical specimens. All cases were individually blindly reviewed by ten radiologists: three specialists in abdominal radiology, three specialized in different areas and four residents. In each case, the presence of EMVI was assessed twice: first, using just HRT2w; second, with DWI added to HRT2w. The results were pooled by experience, analyzing sensitivity, specificity, accuracy (area under ROC curve), likelihood ratios, predictive values and overstaging/understaging. Addition of DWI improved diagnostic performance by specialists radiologists, particularly post-chemoradiotherapy (accuracy 0.74-0.84; positive likelihood ratio 3.9-9.1; overstaging 16-8%), less so at primary staging (specificity 76-87.2%; overstaging 21-11%). Non-specialist radiologists also improved, but only at primary staging (accuracy 0.59-0.63). Residents showed small changes, except for notably increased sensitivity in both primary staging (35.7-43%) and post-chemoradiotherapy (41.7-58.3%) staging, at the expense of increased overstaging. The addition of DWI improved the diagnostic performance of EMVI by experienced radiologists, downgrading overstaging, especially in post-chemoradiotherapy follow-up. It resulted in fewer changes for inexperienced radiologists (enhanced primary staging) and residents (increased sensitivity).

Evaluation of Extramural Venous Invasion by Diffusion-Weighted Magnetic Resonance Imaging and Computed Tomography in Rectal Adenocarcinoma

PurposeThe aim of this study is to evaluate the diagnostic contribution of diffusion-weighted magnetic resonance imaging (MRI) and computed tomography (CT) to distinguish extramural venous invasion (EMVI) in rectal adenocarcinoma. Materials and MethodsFifty-eight patients who had been diagnosed with rectal adenocarcinoma (30 patients with EMVI and 28 patients without EMVI) were enrolled in the study. Apparent diffusion coefficient (ADC) values of the tumour and the EMVI (+) vein, the lengths of the tumours were measured on MRI. The diameters of the superior rectal vein (SRV)-inferior mesenteric vein (IMV) and distant metastatic spread were evaluated on CT. The ability of these findings to detect EMVI was assessed using receiver operating characteristic (ROC) analysis. Pathology was accepted as the reference test for EMVI. ResultsMean diameters of the SRV (4.9 ± 0.9 mm vs 3.7 ± 0.8 mm) and IMV (6.9 ± 0.8 mm vs 5.4 ± 0.9 mm) were significantly larger (P < .001) and tumour ADC values were significantly lower (0.926 ± 0.281 × 10−3 mm2/s vs 1.026 ± 0.246 × 10−3 mm2/s; P = .032) in EMVI (+) patients. Diameters of 3.95 mm for the SRV (area under the curve [AUC] ± standard error [SE]: 0.851 ± 0.051, P < .001, sensitivity: 93.3%, specificity: 67.9%) and 5.95 mm for the IMV (AUC ± SE: 0.893 ± 0.040, P < .001, sensitivity: 93.3%, specificity: 71.4%) and an ADC value of 0.929 × 10−3 mm2/s (AUC ± SE: 0.664 ± 0.072, P = .032 sensitivity: 76.7%, specificity: 57.1%) were found to be cutoff values, determined by ROC analysis, for detection of EMVI. Distant metastases were significantly more prevalent in EMVI (+) patients (P < .001). ConclusionThe measurement of ADC values and SRV-IMV diameters seems to have contribution for diagnosis of EMVI in rectal adenocarcinoma. EMVI (+) patients appear to have higher risks of distant metastases at diagnosis.

The Impact of Extramural Venous Invasion in Colorectal Cancer: A Detailed Analysis Based on Tumor Location and Evaluation Methods

This study aimed to elucidate the prognostic implications of extramural venous invasion (EMVI) in colorectal cancer (CRC) through a meta-analysis. Eighteen eligible studies were included in this meta-analysis. Data on the prevalence of EMVI and the correlation between EMVI and survival were collected from these studies. In addition, a subgroup analysis was conducted based on tumor location and evaluation methods. The estimated prevalence of EMVI was 28.3% (95% confidence interval [CI] = 23.1% to 34.0%) in patients with CRC. The estimated prevalence of EMVI in patients with colon cancer and rectal cancer was 23.0% (95% CI = 17.6% to 29.6%) and 35.7% (95% CI = 22.3% to 51.6%), respectively. Based on the evaluation method, the estimated prevalence of EMVI were 28.3% (95% CI = 23.2% to 34.1%) and 27.3% (95% CI = 8.4% to 60.6%) in pathologic and radiologic examinations, respectively. The correlation of EMVI with worse overall and disease-free survival rates was significant (hazard ratio = 1.773, 95% CI = 1.483-2.120, and hazard ratio = 2.059, 95% CI = 1.683-2.520, respectively). However, in the subgroup analysis with radiologic examination, there was no significant difference in survival rates between patients with and without EMVI. Our study showed that EMVI was frequently detected in 28.3% of patients with CRC and was correlated to worse survival. The detection of EMVI can be useful for predicting the prognosis of patients with CRC.

The Diagnostic Performance of MRI for Detection of Extramural Venous Invasion in Colorectal Cancer: A Systematic Review and Meta-Analysis of the Literature.

OBJECTIVE. The purpose of this article is to perform a systematic review and meta-analysis regarding the diagnostic test accuracy of MRI for detecting extramural venous invasion (EMVI) in patients with colorectal cancer. MATERIALS AND METHODS. PubMed and EMBASE were searched up to November 9, 2018. We included diagnostic accuracy studies that used MRI for EMVI detection in patients with colorectal cancer, using pathologic analysis as the reference standard. The methodologic quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Sensitivity and specificity were pooled and plotted in a hierarchic summary ROC plot. Metaregression analysis using several clinically relevant covariates was performed. RESULTS. Fourteen studies (n = 1751 patients) were included. Study quality was moderate in general. Pooled sensitivity was 0.61 (95% CI, 0.49-0.71), and pooled specificity was 0.87 (95% CI, 0.79-0.92). There was substantial heterogeneity according to the Cochran Q test (p < 0.01) and Higgins I2 heterogeneity index (98% and 95% for sensitivity and specificity, respectively). Publication bias was present (p = 0.01). Higher rates of advanced T category, use of high-resolution MRI, and use of antispasmodic drugs were shown to significantly affect heterogeneity (p < 0.01). Location of primary tumor, preoperative treatment status, study design, definition of reference standard, magnetic field strength, and use of functional MRI were not statistically significant (p = 0.17-0.92). CONCLUSION. MRI shows moderate sensitivity and good specificity for the detection of EMVI in colorectal cancer. The use of high-resolution MRI may improve diagnostic performance.

Added value of diffusion-weighted imaging for evaluation of extramural venous invasion in patients with primary rectal cancer.

To evaluate the added value of diffusion-weighted imaging (DWI) to T 2 weighted imaging (T 2WI) for detection of extramural venous invasion (EMVI) in patients with primary rectal cancer. 79 patients (50 men, 29 females, mean age 67.4 years, range 37-87 years) who had undergone rectal MRI and subsequently received surgical resection were included. The rectal MRI consisted of T 2WI in three planes and axial DWI (b-values, 0, 1000 s mm-2). Two radiologists blinded to the pathologic results independently reviewed the T 2WI first, and then the combined T 2WI and DWI 4 weeks later. They recorded their confidence scores for EMVI on a 5-point scale (0: definitely negative and 4: definitely positive). The diagnostic performance of each reading session for each reader was compared by pairwise comparison of receiver operating characteristic curves. The area under the ROC curve (AUC) was considered as the diagnostic performance. The result of a histopathological examination served as the reference standard for EMVI. For both readers, the diagnostic performance was not significantly different between the two image sets (for reader 1, AUC, 0.828 and 0.825, p = 0.9426 and for reader 2, AUC, 0.723 and 0.726, p = 0.9244, respectively). There was no added value of DWI to T2WI for detection of EMVI in patients with primary rectal cancer. High-resolution T2WI alone is sufficient to assess EMVI and a supplementary DWI has no added value in patients with primary rectal cancer.

Incidence of extramural venous invasion in colorectal carcinoma as determined at the invasive tumor front and its prognostic impact

Extramural venous invasion (EMVI) is prognostic for colorectal cancer; however, veins are only detected partially by normal perpendicular preparation. Therefore, reported findings are conflicting and standardization is required. A total of 239 resection specimens were examined by tangential preparation of the extramural veins at the invasive tumor front. Average follow-up was 39 months. The relationship of EMVI to metachronous hematogenic metastasis (MHM) was evaluated. With this method, a high prevalence of EMVI beginning in stage II is apparent. In stage I, 66% of patients with EMVI developed MHM; in stage II, 25%; and in stage III, 49%. In stage III, the number of tumor-invaded veins is crucial. In the absence of detection of EMVI, MHM occurred in 1 of 29 patients in stage II and in 2 of 13 patients in early stage III. By tangential sectioning at the invasive tumor front, we found a high incidence of EMVI beginning in stage II, which increases with tumor stage. Especially in stages II and III, the correct determination of absent EMVI has a high negative predictive value for MHM. In stage I, EMVI defines a patient group with increased risk for MHM. The quantification of EMVI is an important issue for standardization.

Extramural venous invasion in rectal cancer: overview of imaging, histopathology, and clinical implications.

Extramural venous invasion (EMVI) is an independent prognostic factor for prediction of overall unfavorable outcomes in rectal cancer. While EMVI has traditionally been detected in postoperative pathologic specimens, MRI can provide this important piece of information preoperatively. This article reviews the methods of EMVI detection and their clinical implications for treatment and outcomes of rectal cancer. EMVI has fundamental implications for rectal cancer prognosis and long-term outcomes. Since MRI has the advantage of preoperative detection of EMVI, it has been suggested that MRI-detected EMVI be incorporated for preoperative chemoradiotherapy (CRT) treatment stratification of rectal cancer for better patient triage and outcomes.

Clinical value of MRI-detected extramural venous invasion in rectal cancer.

Extramural venous invasion (EMVI) is associated with a poor prognosis and a poor overall survival rate in rectal cancer. It can independently predict local and distant tumor recurrences. Preoperative EMVI detection in rectal cancer is useful for determining the treatment strategy. EMVI status is beneficial for the post-treatment evaluation and analysis of rectal cancer. Magnetic resonance imaging (MRI) is a non-invasive diagnostic modality with no radiation effects. High-resolution MRI can detect EMVI with high accuracy. In addition, MRI results are equal to or even better than pathological results in the detection of medium to large EMVI in rectal cancer. MRI-detected EMVI (mrEMVI) can be used as a potential biomarker that facilitates treatment methods. This review highlights the importance of MRI before and after rectal cancer treatment. In addition, we analyze the prognostic correlation between mrEMVI and circulating tumor cells (CTC) in rectal cancer. This article may help shed light on the significance of mrEMVI.

Effect of gadolinium contrast-enhanced T1-weighted magnetic resonance imaging for detecting extramural venous invasion in rectal cancer.

To evaluate the performance of gadolinium contrast-enhanced T1-weighted magnetic resonance imaging (CET1WI) in addition to high-resolution T2-weighted imaging (HRT2WI) for preoperative detection of extramural venous invasion (EMVI) in rectal cancer. Fifty-nine patients with rectal cancer who underwent preoperative MRI were included in this study. The likelihood of EMVI was retrospectively scored by two readers on CET1WI, HRT2WI, and HRT2WI+CET1WI, using a subjective five-point scale ranging from 0 to 4. The pathological status of EMVI was used as a standard reference. Diagnostic parameters, including area under the receiver operating curve (AUC), sensitivity, and specificity, were calculated, and the diagnostic performances of HRT2WI and HRT2WI+CET1WI were compared. Interobserver variance was also evaluated. Eighteen (30.5%) patients showed pathological EMVI. During EMVI detection, reader A obtained an AUC of 0.768, sensitivity of 72.5%, and specificity of 73.2% from HRT2WI alone; after combination with CET1WI, these values improved to 0.864, 83.3%, and 75.6%, respectively. Differences in AUC between these techniques were not significant (p=0.056). Reader B obtained an AUC of 0.833, sensitivity of 77.8%, and specificity of 73.2% from HRT2WI alone; after combination with CET1W1, these figures were adjusted to 0.720, 50%, and 78%; differences in AUC between techniques were significant (p=0.027). Interobserver agreement during EMVI scoring was good for HRT2WI (κ=0.603) and moderate for HRT2WI+CET1WI (κ=0.413). Although interobserver agreement decreased, combination of CET1WI with HRT2WI could improve EMVI detection.

MRI Detection of Extramural Venous Invasion in Rectal Cancer: Correlation With Histopathology Using Elastin Stain.

The purpose of this article is to evaluate the diagnostic performance of MRI for detection of extramural venous invasion (EMVI) compared with histopathologic analysis using elastin stain. Forty-nine patients with rectal cancer who had undergone surgical resection with preoperative MRI were identified. Thirty-seven patients had received preoperative chemoradiation therapy (CRT). Sixty-nine MRI studies were independently reviewed by two blinded radiologists for EMVI using a score of 0-4. Comparison was made with histopathologic results obtained by two pathologists reviewing the elastin-stained slides in consensus. EMVI status was also correlated with other tumoral and prognostic features on imaging and pathologic analysis. Statistical analysis was performed using Fisher exact and McNemar tests. EMVI was present in 31% of the pathology specimens. An MRI EMVI score of 3-4 was 54% sensitive and 96% specific in detecting EMVI in veins 3 mm in diameter or larger. Inclusion of a score of 2 as positive for EMVI increased the sensitivity to 79% but decreased the specificity to 74%, with poor positive predictive value. Preoperative CRT had no significant effect on the diagnostic performance of MRI. Contrast-enhanced MRI increased reader confidence for diagnosis or exclusion of EMVI compared with T2-weighted imaging. EMVI status correlated with depth of extramural invasion and proximity to mesorectal fascia. Despite an anticipated increase in sensitivity for EMVI detection by histopathologic analysis using elastin compared with H and E staining, MRI maintains a high specificity and moderate sensitivity for the detection of EMVI.

The evolution in the detection of extramural venous invasion in rectal cancer: implications for modern-day practice

SUMMARY Venous invasion has been considered a poor prognostic factor in rectal cancer for over half a century. This term has evolved in recent years and now applies specifically to tumor invasion into extramural veins – extramural venous invasion. This distinction from intramural venous invasion is important as it is more clinically relevant. Extramural venous invasion can be identified by histopathology and MRI but until recently there has been a lack of consistency in definitions and detection techniques. This paper reviews the historical evidence for the prognostic importance and detection of venous invasion in rectal cancer.