Background In the recent years two innovative approaches have become available for minimally invasiveen blocresections of large non-pedunculated rectal lesions (polyps and early cancers). One is... Show moreBackground In the recent years two innovative approaches have become available for minimally invasiveen blocresections of large non-pedunculated rectal lesions (polyps and early cancers). One is Transanal Minimally Invasive Surgery (TAMIS), the other is Endoscopic Submucosal Dissection (ESD). Both techniques are standard of care, but a direct randomised comparison is lacking. The choice between either of these procedures is dependent on local expertise or availability rather than evidence-based. The European Society for Endoscopy has recommended that a comparison between ESD and local surgical resection is needed to guide decision making for the optimal approach for the removal of large rectal lesions in Western countries. The aim of this study is to directly compare both procedures in a randomised setting with regard to effectiveness, safety and perceived patient burden. Methods Multicenter randomised trial in 15 hospitals in the Netherlands. Patients with non-pedunculated lesions > 2 cm, where the bulk of the lesion is below 15 cm from the anal verge, will be randomised between either a TAMIS or an ESD procedure. Lesions judged to be deeply invasive by an expert panel will be excluded. The primary endpoint is the cumulative local recurrence rate at follow-up rectoscopy at 12 months. Secondary endpoints are: 1) Radical (R0-) resection rate; 2) Perceived burden and quality of life; 3) Cost effectiveness at 12 months; 4) Surgical referral rate at 12 months; 5) Complication rate; 6) Local recurrence rate at 6 months. For this non-inferiority trial, the total sample size of 198 is based on an expected local recurrence rate of 3% in the ESD group, 6% in the TAMIS group and considering a difference of less than 6% to be non-inferior. Discussion This is the first European randomised controlled trial comparing the effectiveness and safety of TAMIS and ESD for theen blocresection of large non-pedunculated rectal lesions. This is important as the detection rate of these adenomas is expected to further increase with the introduction of colorectal screening programs throughout Europe. This study will therefore support an optimal use of healthcare resources in the future. Show less
PURPOSE: If identification of good responders to neoadjuvant chemoradiotherapy in rectal cancer is possible, there might be opportunities for local excision in selected patients. The aim of this... Show morePURPOSE: If identification of good responders to neoadjuvant chemoradiotherapy in rectal cancer is possible, there might be opportunities for local excision in selected patients. The aim of this study was to determine whether postchemoradiation MRI in rectal cancer can accurately identify ypT0 to 2/ypN0, because both features are essential for identification of good responders. METHODS: Seventy-nine patients (4 hospitals) underwent postchemoradiation MRI, 62 received a lymph node-specific contrast agent (ultrasmall superparamagnetic iron oxide). An expert and general radiologist prospectively predicted whether the tumor penetrated the mesorectal fat and whether nodes were sterilized after chemoradiation. Histology was the reference standard. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated. RESULTS: For prediction of whether a tumor penetrated the bowel wall, there was an negative predictive value of 0.90 and 0.76 for the expert and general radiologist, respectively. The negative predictive value for prediction of nodal status was 0.95 and 0.85 for expert and general radiologist, respectively. CONCLUSION: This prospective multicenter study demonstrates that MRI with a lymph node-specific contrast agent interpreted by an expert radiologist can select ypT0 to 2/ypN0 rectal cancer with low risk of undetected nodal metastases or invasion through the bowel wall. These patients could thus have been selected for local excision. However, future studies will have to prove equal outcome of such a modified surgical approach compared with current practice. Show less
