Magnetic resonance imaging following neoadjuvant chemoradiation and transanal endoscopic microsurgery for rectal cancer

Transanal Local Excision of Rectal Cancer after Neoadjuvant Chemoradiation: Is There a Place for It or Should Be Avoided at All Costs?

Tumor response to neoadjuvant chemoradiation (nCRT) with tumor downsizing and downstaging has significantly impacted the number of patients considered to be appropriate candidates for transanal local excision (TLE). Some patients may harbor small residual lesions, restricted to the bowel wall. These patients, who exhibit major response ("near-complete") by digital rectal examination, endoscopic assessment, and radiological assessment may be considered for this approach. Although TLE is associated with minimal postoperative morbidity, a few clinical consequences and oncological outcomes must be evaluated in advance and with caution. In the setting of nCRT, a higher risk for clinically relevant wound dehiscences leading to a considerable risk for readmission for pain management has been observed. Worse anorectal function (still better than after total mesorectal excision [TME]), worsening in the quality of TME specimen, and higher rates of abdominal resections (in cases requiring completion TME) have been reported. The exuberant scar observed in the area of TLE also represents a challenging finding during follow-up of these patients. Local excision should be probably restricted for patients with primary tumors located at or below the level of the anorectal ring (magnetic resonance defined). These patients are otherwise candidates for abdominal perineal resections or ultra-low anterior resections with coloanal anastomosis frequently requiring definitive stomas or considerably poor anorectal function.

Conditional Survival in Patients With Rectal Cancer and Complete Clinical Response Managed by Watch and Wait After Chemoradiation: Recurrence Risk Over Time

OBJECTIVE

Analyze conditional recurrence-free survival (cRFS) for rectal cancer patients with complete clinical response (cCR) after neoadjuvant chemoradiation (nCRT) managed nonoperatively after each year without recurrence.

SUMMARY BACKGROUND DATA

Select patients with cCR after nCRT have been managed nonoperatively. Risk factors for local recurrence, the need for prolonged follow-up, and the risk of recurrence over time are not well defined.

METHODS

Retrospective review of patients with rectal cancer cT2-4N0-2M0 treated with nCRT. Mean follow-up was 64 months. Patients who achieved cCR were managed nonoperatively. cRFS was used to investigate the evolution of recurrence-odds, as patients remain recurrence-free after completion of nCRT. Three-year cRFS was estimated at "x" years after completion of nCRT based on the formula cRFS3 = RFS(x+3)/RFS(x).

RESULTS

One hundred ninety-seven patients with cCR after nCRT were included. Overall survival and recurrence-free survival (RFS) at 5 years were 81.9% (95% CI 74.0%-87.6%) and 60.4% (95% CI 52.5%-67.4%) respectively. Using cRFS estimates, the probability of remaining disease-free for an additional 3 years if the patient survived without disease at 1, 3, and 5 years, was 77.4% (95% CI 68.8%-83.8%), 91.0% (95% CI 81.9%-95.7%), and 94.3% (95% CI 82.9%-98.2%), respectively. In contrast, actuarial RFS rates for similar intervals were 79.1% (95% CI 72.5%-84.2%), 64.2% (95% CI 56.5%-70.8%), and 60.4% (95% CI 52.5%-67.4%). After 2 years disease-free, 3 year cRFS became similar for T2 and T3 cancers. In contrast, patients undergoing extended nCRT became less likely to develop recurrences only after initial 2 years of successful organ-preservation.

CONCLUSIONS

Conditional survival suggests that patients have significantly lower risks (≤10%) of developing recurrences after 2 years of achieving cCR following nCRT.

Comparison Between Size and Stage of Preoperative Tumor Defined by Preoperative Magnetic Resonance Imaging and Postoperative Specimens After Radical Resection of Esophageal Cancer

BACKGROUND

Our objective is to explore the accuracy of magnetic resonance imaging in determining the preoperative T and N staging, pathological stage, and the length of esophageal tumor in patients with esophageal cancer.

METHODS

This retrospective analysis included 57 patients admitted to the Department of Thoracic Surgery of The First Affiliated Hospital of Nanjing Medical University between January 2015 and December 2016. Postoperative pathological results were used as the reference to verify the accuracy of magnetic resonance imaging in evaluating tumor T and N staging, pathological stage, and tumor length. The correlation between tumor lengths-measured using magnetic resonance imaging and the surgical specimen measurements-was evaluated.

RESULTS

The mean age of the patients was 64.6 ± 7.2 years, with a range of 47 to 77 years. The overall accuracy rate of magnetic resonance imaging in T staging of esophageal cancer was 63.2%; magnetic resonance imaging was generally consistent in the N staging of esophageal cancer. Magnetic resonance imaging and surgical evaluation of tumor length were in excellent agreement (κ = .82, P < .001), while that of gastroscopy and postoperative pathology was moderate (κ = .63, P < .001).

CONCLUSION

Magnetic resonance imaging is highly accurate in determining the preoperative T and N staging, pathologic stage, and tumor length in patients with esophageal cancer, which is important in deciding the choice of preoperative treatment and the surgical approach.

Role of magnetic resonance imaging in organ-preserving strategies for the management of patients with rectal cancer

Total mesorectal excision has been the most effective treatment strategy adopted to reduce local recurrence rates among patients with rectal cancer. The morbidity associated with this radical surgical procedure led surgeons to challenge the standard therapy particularly when dealing with superficial lesions or good responders after neoadjuvant radiotherapy, to which radical surgery may be considered overtreatment. In this subset of patients, less invasive procedures in an organ-preserving strategy may result in good oncological and functional outcomes. In order to tailor the most appropriate treatment option, accurate baseline staging and reassessment of tumor response are relevant. MRI is the most robust tool for the precise selection of patients that are candidates for organ preservation; therefore, radiologists must be familiar with the criteria used to guide the management of these patients. The purpose of this article is to review the relevant features that radiologists should know in order to provide valuable information during the multidisciplinary discussion and ultimate management decision.

The Estimate of the Impact of Coccyx Resection in Surgical Field Exposure During Abdominal Perineal Resection Using Preoperative High-Resolution Magnetic Resonance

OBJECTIVE

To estimate the improvement in surgical exposure by removal of the coccyx, during abdomino-perineal resection (APR), in rectal cancer patients.

METHODS

Retrospective study of 29 consecutive patients with rectal cancer was carried out. Using MR T2 sagittal series, the solid angle was estimated using the angle determined by the anterior resection margin and the tip of coccyx (no coccyx resection) or the tip of last sacral vertebra (coccyx resection). The solid angle provides an estimate of the tridimensional surface area provided by an original angle resulting in the best estimate of the surgeon's view/exposure to the critical dissecting point of choice (anterior rectal wall). The difference ("Gain") in surgical field exposure by removal of the coccyx was compared by the solid angle variation between the two estimates (with and without the coccyx).

RESULTS

Routine removal of the coccyx determines an average 42% (95% CI 27-57%) gain in surgical field exposure area facing the anterior rectal wall at the level of the prostate/vagina by the surgeon. Fifteen (51%) patients had ≥30% (median) estimated gain in surgical field exposure by coccygectomy. There was no association between BMI, age or gender and estimated gain in surgical field exposure area.

CONCLUSIONS

Routine removal of the coccyx during APR may result in an average increase in 42% in surgical field exposure during APR's perineal dissection. Precise estimation of surgical field exposure gain by removal of the coccyx may be predicted by MR sagittal series for each individual patient.

[Clinical research for rectal carcinoma: State of the art and objectives]

The treatment of rectal carcinoma is based on multidisciplinary strategy and multimodal approaches including gastrointestinal tract specialists, medical oncologists, radiation oncologists and surgery. The different objectives should be declined according to the characteristics of the tumours. The aim of the therapist would be to select the best strategy offering to the patient to be cured with as less as possible late adverse toxicity. The challenge of the treatment of small tumours is to maintain a functional anal sphincter while minimizing the risk of local recurrence. The standard treatment of locally advanced disease is aiming firstly to cure the patient and secondly to prevent late complications. Each of these clinical presentations of the disease has to be considered as a whole taking into account the new surgical techniques and a personalized approach adapted to the tumour. Nowadays they should be studied with dedicated clinical trials.