Preoperative assessment of rectal cancer: an accurate MRI protocol a radiological template (original) (raw)
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Pretreatment High-Resolution Rectal MRI and Treatment Response to Neoadjuvant Chemoradiation
Diseases of the Colon & Rectum, 2012
Background-Use of rectal MRI evaluation of patients with rectal cancer for primary tumor staging and for identification for poor prognostic features is increasing. MR imaging permits precise delineation of tumor anatomy and assessment of mesorectal tumor penetration and radial margin risk. Objective-To evaluate the ability of pre-treatment rectal MRI to classify tumor response to neoadjuvant chemoradiation. Design-Retrospective, consecutive cohort study, central review. Setting-Tertiary academic hospital. Patients-62 consecutive patients with locally advanced (stage cII-cIII)rectal cancer who underwent rectal cancer protocol high resolution MRI prior to surgery(12/09-3/11). Main Outcome Measures-Probability of good (ypT0-2N0) vs. poor (≥ypT3N0) response as a function of mesorectal tumor depth, lymph node status, extramural vascular invasion, and grade assessed by uni-and multi-variate logistic regression. Results-Tumor response was good in 25, 40.3% and poor in 37, 59.7%.Median interval from MRI to OP was 7.9weeks (IQR: 7.0-9.0). MRI tumor depth was <1 mm in 10 (16.9%), 1-5 mm in 30 (50.8%), and >5 mm in 21(33.9%). LN status was positive in 40 (61.5%) and vascular invasion was present in 16 (25.8%). Tumor response was associated with MRI tumor depth (P=0.001), MRI lymph nodes status (P=<0.001)and vascular invasion (P=0.009). Multivariate regression indicated >5mm MRI tumor depth (OR=0.08, 95% CI=0.01-0.93, p=0.04) and MRI LN positivity (OR=0.12, 95% CI=0.03-0.53, p=0.005) were less likely to achieve a good response to neoadjuvant chemoradiotherapy.
European Journal of Radiology, 2020
To provide a practical overview regarding the state-of-the-art of the magnetic resonance imaging (MRI) protocol for rectal cancer imaging and interpretation during primary staging and restaging after neoadjuvant chemoradiation therapy (CRT), pointing out technical skills and findings that radiologists should consider for their reports during everyday clinical activity. Method: Both 1.5T and 3.0T scanners can be used for rectal cancer evaluation, using pelvic phased array external coils. The standard MR protocol includes T2-weighted imaging of the pelvis, high-resolution T2-weighted sequences focused on the tumor and diffusion-weighted imaging (DWI). The mnemonic DISTANCE is helpful for the interpretation of MR images: DIS, for distance from the inferior part of the tumor to the anorectal-junction; T, for T staging; A, for anal sphincter complex status; N, for nodal staging; C, for circumferential resection margin status; and E, for extramural venous invasion. Results: Primary staging with MRI is a cornerstone in the preoperative workup of patients with rectal cancer, because it provides clue information for decisions on the administration of CRT and surgical treatment. Restaging after CRT is crucial for treatment planning, and findings on post-CRT MRI correlate with the patient's prognosis and survival. It may be useful to remember the mnemonic word "DISTANCE" to check and describe all the relevant MRI findings necessary for an accurate radiological definition of tumor stage and response to CRT. Conclusions: "DISTANCE" assessment for rectal cancer staging and treatment response estimation after CRT may be helpful as a checklist for a structured reporting.
MR imaging of rectal cancer before and after chemoradiation therapy
La Radiologia medica, 2012
This study was done to determine the diagnostic accuracy of magnetic resonance (MR) imaging in patients with rectal carcinoma by comparing post-chemoradiation MR imaging with pathological specimens. We enrolled 39 patients with locally advanced rectal cancer. All patients received chemoradiation therapy before surgery and neoadjuvant chemoradiation therapy followed by MR imaging. MR images were analysed by a team of two expert radiologists unaware of the clinical and histopathological findings. Following neoadjuvant chemoradiation therapy, the analysis of MR images showed 23 (59%) patients with a rectal disease staged ≤T2 and 16 (41%) with a disease staged >T2. Post-treatment histological staging (TNM) revealed 13 patients with a disease >T2 and 26 patients with a disease ≤T2. Cohen's kappa to measure concordance between post-chemoradiation MR staging and histological response showed 83.6% concordance for disease confined to the serosa (≤T3): concordance was 97.22% for dis...
Preoperative MRI accuracy after neoadjuvant chemoradiation for locally advanced rectal cancer
Medicine and Pharmacy Reports
Background and aims. To evaluate the performance of magnetic resonance imaging (MRI) in restaging locally advanced rectal cancers (LARC) after neoadjuvant chemoradiotherapy (nCRT), with pathologic correlation. Methods. 80 patients with LARC treated with neoadjuvant therapy, with restaging MRI and surgery, were enrolled and prospectively reviewed. The diagnostic accuracy of the restaging MRI was assessed for tumor (ymrT), nodal status (ymrN), circumferential resection margin (ymrCRM), extramural vascular invasion (ymrEMVI) and tumoral deposits (ymrN1c) by calculating the sensitivity (Se), specificity (Sp), negative predictive values (NPV) and positive predictive values (PPV). Response to treatment was classified as good response (complete/near complete) vs. poor response (poor/partial response). The agreement between the tumor regression grade at MRI (mrTRG) and pathology (pTRG) was reported, as well the performance of mrTRG to identify good responders. The correlation between restag...
Current Topics in Colorectal Surgery [Working Title], 2021
Rectal cancer is one of the most common types of cancer in both men and women. In recent years, the importance of magnetic resonance imaging (MRI) has greatly increased in the multidisciplinary treatment of patients with rectal cancer. MRI has a particularly important role in the most accurate preoperative staging of these patients, both in terms of assessing the local invasion of the tumor and in terms of assessing the status of pelvic lymph nodes. Many patients with rectal cancer, especially those in the advanced stage of the disease, in the preoperative period undergo neoadjuvant radio chemotherapy. The evaluation of the clinical response of these patients to neoadjuvant therapy is of crucial importance both in terms of personalized treatment and in terms of their prognosis. In this regard, MRI has its clearly defined role at present in evaluating the efficacy of neoadjuvant therapy, as well as in postoperative follow-up.
Pretherapy Imaging of Rectal Cancers: ERUS or MRI?
Surgical Oncology Clinics of North America, 2010
Surgical treatment of rectal cancer has been plagued by a high local recurrence rate, until in the last decades the role of a good surgical technique and adjuvant (chemo)radiation was fully appreciated. 1 Additionally it was shown that (chemo)radiation was more effective when given before rather than after the resection. 2 Whereas previously most decisions on whether or not to give adjuvant treatment were based on the risk assessment for recurrence through histologic evaluation of the tumor and the lymph nodes, the decisions on neoadjuvant treatment now have to be based mainly on risk assessment through imaging. Although modern CT techniques are improving and are to some extent able to provide information for locoregional staging, endorectal ultrasonography (ERUS) and MRI are considered as the 2 best locoregional staging methods for rectal cancer. When comparing ERUS with MRI, there are several issues that require consideration. In addition to the accuracy in predicting a certain risk factor for local recurrence, there is the treatment strategy that dictates what information will have a clinical consequence, and there are also issues of expertise, availability, and cost. Currently, there is also a trend to study alternative treatment options after a good response to treatment, such as a local excision, or even a nonoperative wait-and-see approach. It is clear that imaging will play an important role in the selection and follow-up of these patients. This new role of imaging to detect small volumes of residual disease in the bowel wall and lymph nodes, sometimes within fibrotic scar tissue, is beyond the scope of this article.
The British Journal of Radiology, 2016
To identify the MRI parameters which best predict complete response (CR) to neoadjuvant chemoradiotherapy (CRT) in patients with locally advanced rectal cancer (LARC) and to assess their diagnostic performance. Methods: This was a prospective study of pre-and post-CRT MRI and diffusion-weighted imaging (DWI) of 64 patients with LARC who underwent neoadjuvant CRT and subsequent surgery. Histopathological tumour regression grade was the reference standard. Multivariate regression analysis was performed to identify the best MRI predictors of CR to neoadjuvant CRT, and their diagnostic performance was assessed. Results: The study cohort comprised 48 males and 16 females (n 5 64), with mean age of 49.48 6 14.3 years, range of 23-74 years. 11 patients had pathological complete response. The following factors predicted CR on univariate analysis: low initial (pre-CRT) tumour volume on T 2 weighted high-resolution (HR) images and DWI, tumour volume-reduction rate (TVRR) of .95% on DWI and CR on post-CRT DWI (ydwiT0) as assessed by the radiologist. However, the best MRI predictors of CR on multivariate regression analysis were CR on post-CRT DWI (ydwiT0) as assessed by the radiologist and TVRR of .95% on DWI, and these parameters had an area under the curve (95% confidence interval) of 0.881 (0.74-1.0) and 0.843 (0.7-0.98), respectively. The sensitivity, specificity, positive-predictive value, negative-predictive value and accuracy of DWI in predicting CR was 81.8%, 94.3%, 75%, 96.1% and 76%; the sensitivity, specificity and accuracy of TVRR of .95% as a predictor of CR was 80%, 84.1% and 64.1%, respectively; however, this difference was not statistically significant. The interobserver agreement was substantial for ydwiT0. Conclusion: Visual assessment of CR on post-CRT DWI and TVRR of .95% on DWI were the best predictors of CR after neoadjuvant CRT in patients with LARC, and the former being more practical can be used in daily practice. Advances in knowledge: In rectal cancer, ydwiT0 as assessed by the radiologist was the best and most practical imaging predictor of CR and scores over standard T2W HR images.
Journal of Magnetic Resonance Imaging, 2012
Purpose: To evaluate rectal cancer volumetry in predicting initial neoadjuvant chemotherapy response. Materials and Methods: Sixteen consecutive patients who underwent neoadjuvant chemotherapy (CX) before chemoradiotherapy (CRT) and surgery were enrolled in this retrospective study. Tumor volume was evaluated at the first magnetic resonance imaging (MRI), after CX and after CRT. Tumor volume regression (TVR) and downstaging were compared with histological results according to Tumor Regression Grade (TRG) to assess CX and CRT response, respectively. Results: The mean tumor volume was 132 cm 3 6 166 before and 56 cm 3 6 71 after CX. TVR after CX was significantly different between patients with poor histologic response (TRG1/2) and those with good histologic response (TRG3/4) (P ¼ 0.001). An optimal cutoff of TVR >68% (area under the curve [AUC]: 0.9, 95% confidence interval [CI]: 0.65-0.98, P ¼ 0.0001) to predict good histology response after CX was assessed by receiver operating characteristic curve. According to previous data and this study, we defined 70% as the best cutoff values according to sensitivity (86%), specificity (100%) of TVR for predicting good histology response. In contradistinction, MRI downstaging was associated with TRG only after CRT (P ¼ 0.04). Conclusion: Our pilot study showed that MRI volumetry can predict early histological response after CX and before CRT. MRI volumetry could help the clinician to distinguish early responders in order to aid appropriate individually tailored therapies.