Preoperative Staging Of Rectal Tumors Research Articles

Significance of MRI in rectal carcinoma therapy optimization - correlation of preoperative T- and N-staging with definitive histopathological findings.

In past decades, both prognosis and therapy of rectal cancer patients showed significant improvement, on the other hand, the incidence of rectal carcinoma continues to have a rising tendency. According to current UICC classification, patients in stage II rectal cancer or higher are indicated for neoadjuvant chemoradiotherapy (nCRT). Magnetic resonance imaging (MRI) is currently the most common diagnostic method used for preoperative staging of rectal cancer. Several studies already pointed out the inaccuracy of preoperative lymph node staging in patients with rectal cancer. The present study analyzed overall accuracy of MRI staging of rectal cancer and thus its accuracy in neoadjuvant therapy indication, by comparing preoperative MRI staging with definitive histopathologic results from resected tumors. This study evaluated cases of 92 patients with rectal tumor that underwent MRI examination followed by surgical resection. Tumors included in the analysis were ranging from T1 to T3b according to TNM staging, with free circumferential resection margin (CRM), distance form mesorectal fascia more than 5 mm, negative intersphincteric plane and also negative extramural venous invasion (EMVI), while the N stage was not decisive. In all cases both N-staging and T-staging were evaluated histologically and compared with preoperative MRI results. Significant difference in preoperative and postoperative N-staging was shown in 51 patients (61.45%). In majority of cases MRI lead to overstaging, which was observed in 44 cases (53.1 %), with complete negativity of lymph nodes proven by histological examination in 34 cases. On the other hand, understaging of lymph nodes was observed only in 7 cases (7.4 %). The T-staging did not show significant differences. Results from this study confirm that MRI plays an important role in T-staging of rectal tumors, however, there are admittedly issues in N-staging of tumors, which should lead to reevaluation of neoadjuvant therapy indication in patients with positive lymph nodes according to MRI examination. Based on the results of this study, we see the future of preoperative staging of rectal tumors in precise T-staging together with accurate assessment of CRM and distance of tumor from mesorectal fascia as well as evaluation of intersphinteric plane and EMVI.

Clinical value of radial endorectal ultrasound in the assessment of preoperative staging of rectal carcinoma

To evaluate the clinical value of radial endorectal ultrasound (ERUS) in the assessment of preoperative staging of rectal carcinoma. One hundred and ten patients with rectal cancer underwent preoperative endorectal ultrasound (ERUS) examination in our hospital from February 2010 to September 2011. ERUS was performed using a Hitachi 900, Hitachi HI Vision Preirus US scanner, with a 5 - 10 MHz rigid rotating radial transducer and a focal length of 2 - 5 cm. The size, shape, echo pattern, infiltration depth, degree of circumferential involvement, extra-rectal invasion of the lesions and lymph node involvement were observed. The results of ERUS staging were compared with histopathological findings of the surgical specimens. The accuracy of ERUS for T staging was 91.4%. The accuracy of ERUS in diagnosing stage T1, T2, T3, T4 cancers was 92.7%, 88.2%, 88.2% and 96.4%, respectively. The sensitivity of ERUS in diagnosing stage T1, T2, T3, T4 cancers was 92.3%, 72.7%, 85.4% and 71.4%, respectively. The specificity of ERUS in diagnosing stage T1, T2, T3, T4 cancer was 92.9%, 92.0%, 90.3% and 100.0%, respectively. Comparing the consistency of preoperative T-staging and postoperative pathological results, the Kappa value was 0.75, with a considerable consistency. The sensitivity, specificity, and accuracy of ERUS in the assessment of lymph node metastasis were 74.2%, 89.9% and 85.5%, respectively. Comparing the consistency of preoperative N-staging and postoperative pathological results, the Kappa value was 0.64, with a considerable consistency. ERUS is a practical and accurate tool in assessment of preoperative staging of rectal tumors in regard to tumor invasion depth (T) and regional lymph node status (N), with advantages of simple operation, less pain, and high accuracy.

Confocal chromolaser endomicroscopy: a supplemental diagnostic tool prior to transanal endoscopic microsurgery of rectal tumors?

Due to diagnostic advancements, preoperative staging of rectal tumors was significantly improved. However, difficulties in obtaining accurate results can sometimes be observed in the staging of adenomas and early rectal carcinomas (pT1/2). The aim of this study was to test if confocal chromolaser endomicroscopy (cCLEM) can help minimize this diagnostic gap. cCLEM generates optical transversal sections at x1,000 magnification and allows for evaluation of the mucosal microarchitecture and differentiation of normal mucosa from adenomas and carcinomas. Cases with conflicting preoperative findings (adenoma vs. > or =uT2 categories), undetectable tumors after inadequate (R1/RX) snare polypectomy of carcinomas, and extremely flat adenoma areas were studied. By cCLEM, in > or =uT2 carcinomas with an adenoma histology, malignoma-suspicious areas were identified and selected biopsies were done. In addition, re-epithelialized polypectomy areas of carcinomas were visualized and targeted reoperations could be carried out. Furthermore, the dignity and extension of extremely flat adenomas were determined and marked by clips for additional therapy. In cases with rectal tumors, conflicting or unclear findings, and flat extending adenomas, the utilization of cCLEM should be considered. Especially in cases with early rectal carcinomas, unnecessary second operations and also recurrences can be minimized or even avoided by selective usage of cCLEM.

Comparison of intrarectal filling with water and idling in rubber sheath with water in endoluminal ultrasonography for preoperative staging of rectal tumors

Objective To compare the value of intrarectal filling with water and filling in rubber sheath with water in endoluminal uhrasonography for preoperative staging of rectal tumors. Methods 215 cases of rectal tumors were divided into two groups. 120 cases using the method of filling in rubber sheath with water and 95 cases using intrarectal filling with water were diagnosed with uhrasonography. The results were compared with corresponding pathologic results for the judgment of their accuracy. Results The accuracy for the diagnosis of infiltration depth was 60.0 % in the first group and was 73.7 % in the second. The difference was statistically significant (P 0.50). Conclusion Intrarectai filling with water is better than filling in rubber sheath with water in the diagnosis of infiltration depth of rectal tumors, while there is no difference in the diagnosis of metastasis of perirectal lymph nodes. Key words: Rectal neoplasms; Endosonography; Intrarectal filling with water; Filling in rubber sheath with water

Impact of Biopsy on the Accuracy of Endorectal Ultrasound Staging of Rectal Tumors

Endorectal ultrasound is a well-established method for the preoperative staging of rectal tumors. This prospective study was performed to establish whether obtaining a biopsy before endorectal ultrasound has an influence on staging accuracy. Between 1990 and 2003, a total of 333 rectal tumors were examined preoperatively by using endorectal ultrasound. All patients underwent rectal resection, and the specimens were sent for histologic evaluation. Thirty-three were not biopsied, the remaining at various times before endorectal ultrasound. The chi-squared test or Fisher's exact test were used for statistical analysis to compare the accuracies. The overall staging accuracy was 71 percent but differed significantly (P = 0.004) between the groups as a function of time elapsed since biopsy. The best results were seen in tumors that were not biopsied before endorectal ultrasound, which were correctly staged in 85 percent of the cases. The least accurate staging (53 percent) was noted when endorectal ultrasound was performed in the third week after biopsy, mostly as a result of overstaging. Biopsy did not have a significant effect on nodal staging. Biopsy before endorectal ultrasound significantly affects its accuracy. To achieve the most accurate staging, biopsy should be performed after endorectal ultrasound. Endorectal ultrasound staging performed in the first week after biopsy is the second best option but should be interpreted with caution in the second or third week.

Preoperative Staging of Rectal Tumors: Comparison of Endorectal Ultrasound, Hydro-CT, and High-Resolution Endorectal MRI

Aim: The aim of this study was to compare transrectal ultra-sound (TRUS), hydro-computed tomography (hydro-CT), and endorectal magnetic resonance imaging (MRI) in the preoperative staging of rectal cancer. Patients and Methods: 23 patients with rectal adenocarcinoma underwent TRUS, hydro-CT, and MRI (1 Tesla) with endorectal coil. The results were correlated with the histopathological findings based on the TNM classification. Results: T staging with TRUS, hydro-CT, and endorectal MRI correlated with the histopa-thological findings in 83% of patients (19/23). Tumors were overestimated by TRUS in 2/23 patients, by CT in 3/23, and by MRI in 3/23 patients. Tumor size was underestimated by TRUS in 2 patients, by CT and MRI in 1 case each. Local lymphatic node involvement was correctly diagnosed with CT and MRI in 87% and 83%, respectively. Using TRUS, false-negative results in the staging of lymph node involvement were seen in 3/23 patients, whereas 1 patient was over-staged. Using hydro-CT as well as endorectal MRI, overstaging of the local lymph nodes took place in 2/23 patients. Conclusion: All methods are limited because peritumoral inflammation cannot be precisely distinguished from infiltration by the tumor. Correct lymph node staging is hampered in advanced disease using TRUS. In these patients, further cross-sectional imaging may be required.

The Role of Endorectal Ultrasound in Therapeutic Decision-Making for Local vs. Transabdominal Resection of Rectal Tumors

In rectal tumors, preoperative biopsies frequently fail to diagnose an invasive carcinoma. Endorectal ultrasound is considered a useful adjunct in preoperative staging of rectal tumors. However, feasibility of endorectal ultrasound and its role in therapeutic decision-making in presumed rectal adenomas is sparsely studied. Endorectal ultrasound was performed in 268 tumors referred for local excision because biopsies showed tubulovillous adenoma. Feasibility of endorectal ultrasound was studied and ultrasound staging was compared with definite histopathologic findings. In 231 tumors, endorectal ultrasound was technically feasible (86 percent). Median distance from the dentate line was 11 cm in nonassessable tumors and 7 cm in assessable tumors (P < 0.001). In 21 tumors, endorectal ultrasound was not conclusive, mainly in tumors being recurrent or after recent endoscopic manipulation (P < 0.001). With endorectal ultrasound the rate of preoperative missed carcinomas could be reduced from 21 to 3 percent (P < 0.01). In diagnosing tubulovillous adenomas, sensitivity and specificity of endorectal ultrasound was 89 and 86 percent, respectively. Endorectal ultrasound is technically feasible in almost all presumed rectal adenomas, referred for local excision. Proper endorectal ultrasound interpretation is possible in 78 percent of all presumed rectal adenomas. Endorectal ultrasound is very reliable in diagnosing tubulovillous adenomas, and therapeutic decision-making regarding local excision vs. radical surgery based on endorectal ultrasound is valid.

Single nucleotide polymorphism array analysis of chromosomal instability patterns discriminates rectal adenomas from carcinomas

Total mesorectal excision (TME) is the standard treatment for rectal cancer, while transanal endoscopic microsurgery (TEM) is a recently introduced surgical approach for the treatment of rectal adenomas. Incorrect preoperative staging before TEM is a problem. To identify genetic changes that might correlate with tumour stage and could lead to optimized treatment selection we performed a genome-wide chromosomal instability search in a homogeneous, clinical cohort of rectal tumours. 78 rectal tumours during different clinical stages were analysed with 10K single nucleotide polymorphism (SNP) arrays. Logistic regression was performed to build a quantitative model of specific chromosomal aberrations. Overall, most cases (95%) had one or more chromosomal aberrations. We observed a clear correlation between the total number of aberrations and the different tumour stages. Specifically, the chromosomal events: gain of 8q22-24, 13q and 20q, and loss of 17p and 18q12-22, were far more abundant in carcinoma than in adenoma. In adenoma fractions from cases with a carcinoma (infiltrating at least in the submucosa), twice the amount of such 'malignant aberrations' was observed, compared to pure adenomas. Furthermore, combined aberrations such as gain of 13q and loss of 18q were only found in adenomatous fractions of carcinomas and not in benign lesions. Based on these five genomic events associated with carcinoma, a clear distinction between adenoma and carcinoma tissue could be made. These data should be validated further in order that they may be used in preoperative staging of rectal tumours.

Accuracy of endorectal ultrasonography in the preoperative staging of rectal cancer

Preoperative staging of rectal tumours is considered essential to tailoring treatment for individual patients. The aim of the present study was to evaluate the accuracy of 3-D-endorectal ultrasonography for the preoperative staging of rectal cancer. Three hundred and fifty-seven patients with rectal adenocarcinomas underwent an endorectal ultrasonography evaluation during a period of eight years. The evaluation was performed by four surgeons. We compared the endorectal ultrasonography staging with the pathology findings. Patients with preoperative chemoradiation were excluded from the study. Overall accuracy in assessing the level of rectal wall invasion was 77.3%, with 9.3% of the tumours overstaged and 8.1% understaged. Accuracy in assessing nodal involvement in 313 patients treated with radical surgery was 74.9%, with 8.9% overstaged and 8.9% understaged. The accuracy of 3-D-endorectal ultrasonography in assessing the depth of tumour infiltration is good, but it is lower than previously reported. The technique is precise in distinguishing between benign tumours and invasive cancer. The results depend on the experience of the surgeon.

Selection of patients with rectal tumors for local excision based on preoperative diagnosis. Results of a consecutive evaluation study of 552 patients

The aim of our study was to evaluate the accuracy of clinical staging (CS), biopsies, and endoluminal ultrasonic examination (EUS) in preoperative staging of rectal tumors treated with transanal local excision. This local excision is an adequate procedure for benign rectal polyps and low-risk T1 carcinoma. The study included 552 patients with rectal adenocarcinoma, villous adenoma, or tumors with other histologic characteristics who underwent a transanal excision (transanal endoscopic microsurgery n=513 or transanal excision n=39). We compared the results of CS, biopsies, and EUS with postoperative pathology findings. Preoperative histological diagnosis of the rectal carcinoma depended on tumor size (52% in cancers <3 cm, 25% in cancers >3 cm; p=0.001) and was correct in 56% of cases. Transanal ultrasonography (uT0/1) had superior sensitivity (95% vs 78%) and a higher positive predictive value (93% vs 85%) than clinical staging (CS I) in detecting adenoma or T1 rectal carcinoma, whereas specificity was similar in both (62% vs 58%). In patients in whom preoperative histological analysis revealed adenomas, transanal ultrasonography was accurate (uT0/1) for the postoperatively assessed adenoma pT1 in 97%, whereas diagnosis (uT0/1) was correct in only 71% of cases in which preoperative histological analyses showed rectal carcinomas. In patients with rectal tumors, preoperative staging with transanal ultrasonography and biopsy is essential for the indication and allows selection of patients for transanal local excision.

Accuracy of endorectal ultrasonography in preoperative staging of rectal tumors.

Preoperative staging of rectal tumors is considered essential to tailor treatment for individual patients. The aim of the present study was to evaluate the accuracy of endorectal ultrasonography in preoperative staging of rectal tumors. Eleven hundred eighty-four patients with rectal adenocarcinoma or villous adenoma underwent endorectal ultrasonography evaluation at a single institution during a ten-year period. We compared the endorectal ultrasonography staging with the pathology findings based on the surgical specimens in 545 patients who had surgery (307 by transanal excision, 238 by radical proctectomy) without adjuvant preoperative chemoradiation. Comparisons between groups were performed using chi-squared tests and logistic regression analysis. Overall accuracy in assessing the level of rectal wall invasion was 69 percent, with 18 percent of the tumors overstaged and 13 percent understaged. Accuracy depended on the tumor stage and on the ultrasonographer. Overall accuracy in assessing nodal involvement in the 238 patients treated with radical surgery was 64 percent, with 25 percent overstaged and 11 percent understaged. The accuracy of endorectal ultrasonography in assessing the depth of tumor invasion, particularly for early cancers, is lower than previously reported. The technique is more precise in distinguishing between benign tumors and invasive cancers and between tumors localized to the rectal wall and tumors with transmural invasion. Differences in image interpretation may in part explain discrepancies in accuracy between studies.

Endosonography for preoperative staging of rectal tumors : Nielsen MB, Qvitzau S, Pedersen JF, Christiansen J (Radiology, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenaghen O, Denmark). Acta Radiol 1996;37:799–803

Endosonography for preoperative staging of rectal tumors : Nielsen MB, Qvitzau S, Pedersen JF, Christiansen J (Radiology, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenaghen O, Denmark). Acta Radiol 1996;37:799–803

Endosonography for preoperative staging of rectal tumours.

The aim of this study was to evaluate the use of rectal endosonography for preoperative staging of tumour extension and lymph node involvement in rectal tumours. Over a 4-year period 100 patients with rectal tumours were studied with sonography using 7 MHz endoprobes. Tumour spread was assessed according to the TNM classification, and the number and maximum size of perirectal lymph nodes were registered. The sonographic findings were compared with the surgical and histological findings. The overall accuracy of endosonography in assessing local tumour extension was 85% (76-91%; 95 percent confidence limits). T4 tumours with a large contact surface to an adjacent organ tended to be nonresectable. Lymph node assessment could be made in 81 patients who underwent radical resection: sonography showed lymph nodes in 49 patients, 30 of whom had nodal metastases; the histological examination showed lymph nodes in the remaining 32 patients, 8 of whom had nodal metastases. The number of lymph nodes at the histological examination was markedly higher than the number depicted by preoperative ultrasound. This study confirmed the use of endoluminal ultrasound in the preoperative evaluation of local tumour spread. However, endosonographic assessment of perirectal nodal involvement seems to be too unreliable to be used for the preoperative selection of patients.

Endosonography for Preoperative Staging of Rectal Tumours

Endosonography for Preoperative Staging of Rectal Tumours

Transrectal ultrasound of rectal tumors

Since preoperative staging of rectal tumors is important in planning treatment, we evaluated transrectal ultrasound (TRUS) staging of rectal neoplasms. In 35 consecutive rectal tumors, we compared TRUS staging results with final pathologic staging. TRUS predicted the degree of tumor invasion in 19 of 24 patients (79%) and the presence or absence of lymph node metastasis in 11 of 15 patients (73%). TRUS overestimated the degree of tumor invasion in four patients (17%) and underestimated invasion in one patient (4%). The depth of tumor invasion was correctly predicted in all 14 tumors located within 6 cm from the anal verge, but, beyond 6 cm, only 5 of 10 tumors (50%) were staged correctly (p = 0.005). In the group of 11 patients who underwent preoperative radiotherapy, pretreatment TRUS predicted the depth of tumor invasion in only six patients (55%) and overestimated tumor invasion in five patients (45%), suggesting that nearly half of these tumors were downstaged by radiotherapy. TRUS accurately predicts the degree of tumor invasion, especially in tumors closer to the anal verge, allowing for better treatment planning in patients with low to middle rectal neoplasms.

Endorectal ultrasound for control of preoperative radiotherapy of rectal cancer.

Endorectal ultrasound (EUS) is known to be a reliable method for preoperative staging of rectal tumors. In this study, EUS was used to select patients with rectal cancer suitable for preoperative radiation therapy. By performing EUS before and after radiation, the aim of the study was to evaluate the role of EUS in monitoring the effects of preoperative radiation therapy. In 17 patients with large T3 or T4 rectal tumors, a complete staging by EUS was done before and after radiation therapy. Beside a shrinkage of the tumor, there was a change of echopattern to more hyperechoic gray levels to be observed in the irradiated tumor. The rectal wall lost its normal architecture, and lymph nodes disappeared or changed their echopattern from echopoor to echorich. There was no down-staging of a tumor seen by EUS. Complete preoperative staging was correct in 13 of 17 patients because of endosonographic examination before and after preoperative radiation therapy. New interpretation criteria are given for evaluation of patients with rectal cancer treated by radiation therapy.

Endorectal ultrasound in the preoperative staging of rectal tumors

The preoperative staging of rectal cancer has important implications for treatment as local therapies become increasingly utilized. Seventy-seven patients underwent preoperative staging using endorectal ultrasonography. All patients had complete pathologic staging and none had preoperative radiotherapy. Depth of invasion of the tumor was accurately predicted in 75 percent of cases in the entire group, with 22 percent overstaged and 3 percent understaged. Accuracy improved greatly over the study period, and in the past six months, 95 percent have been accurately staged for depth of invasion with 5 percent overstaged. Lymph nodes have been properly classified into positive and negative groups in 88 percent of cases in the past year, with a specificity of 90 percent and a sensitivity of 88 percent. Endorectal ultrasound is an accurate preoperative staging modality. Accuracy is improved greatly with increased experience and it has been found that the 5-layer anatomical model facilitates accurate staging. Introduction of the ultrasound probe through a previously placed proctoscope ensures complete scanning of the entire lesion and should be used for the majority of examinations.

Ultrasound in preoperative staging of rectal tumours.

A dynamic ultrasound sector scanner with 5.0 and 7.5 MHz transducers was used for examination of resected bowel specimens with rectal carcinoma. Pathologic structures, i.e. tumour extension into or beyond the bowel wall, and perirectal lymph nodes, were marked. Corresponding parts of the tissue were embedded in paraffin and a detailed comparison between the findings at ultrasound and those in the histopathological sections was made. There was a good accordance between the histopathologic and ultrasonic findings which makes it possible to perform an exact preoperative staging of rectal carcinomas with ultrasound. Twenty patients with primary tumours of the rectum preoperatively underwent ultrasonography with a prototype transrectal probe with the same type of crystals and frequencies. In the 14 cases, however, where ultrasound findings could be compared with the histopathologic findings only six (43%) were correctly staged at ultrasonography. Certain difficulties were encountered in the preoperative examinations with a rigid probe as used in this study.