Factors affecting the restaging accuracy of magnetic resonance imaging after preoperative chemoradiation in patients with rectal cancer

MRI at Restaging After Neoadjuvant Therapy for Rectal Cancer Overestimates Circumferential Resection Margin Proximity as Determined by Comparison With Whole-Mount Pathology

BACKGROUND

Current guidelines recommend restaging with MRI after neoadjuvant therapy for rectal cancer, but the accuracy of restaging MRI in estimating circumferential margin involvement requires additional clarification.

OBJECTIVE

The objective of this study was to measure the accuracy of circumferential resection margin assessment by MRI after neoadjuvant therapy and identify characteristics associated with accuracy.

DESIGN

MRI data were retrospectively analyzed for concordance with the findings of whole-mount pathology analysis of the corresponding surgical specimens. Univariate and multivariate logistic regression analyses were performed to identify characteristics associated with accuracy.

SETTING

This study was conducted at a comprehensive cancer center.

PATIENTS

Included in the study were consecutive patients who underwent total mesorectal excision for rectal cancer between January 2018 and March 2020 after receiving neoadjuvant therapy and undergoing restaging with MRI.

MAIN OUTCOME MEASURES

The primary outcome of this study included accuracy, sensitivity, specificity, and positive and negative predictive values for categorizing the circumferential resection margin as threatened; mean and paired mean differences were in proximity of the margin.

RESULTS

Of the 94 patients included in the analysis, 39 (41%) had a threatened circumferential resection margin according to MRI at restaging, but only 17 (18%) had a threatened margin based on pathology. The accuracy of MRI in identifying a threatened margin was 63.8%, with margin proximity overestimated by 0.4 cm on average. In multivariate logistic regression, anterior location of the margin and tumor proximity to the anal verge were independently associated with reduced MRI accuracy.

LIMITATIONS

A limitation was the retrospective design at a single institution.

CONCLUSIONS

The knowledge that MRI-based restaging after neoadjuvant therapy overestimates circumferential margin proximity may render some surgical radicality unnecessary and thereby help avoid the associated morbidity. With the recognition that MRI-based assessment of margin proximity may not be reliable for anterior margin and for distal tumors, radiologists may want to use greater caution in interpreting images of tumors with these characteristics and to acknowledge the uncertainty in their reports. See Video Abstract at http://links.lww.com/DCR/B814.

LA IRM EN LA REESTADIFICACIN LUEGO DE TERAPIA NEOADYUVANTE EN EL CNCER DE RECTO SOBRESTIMA LA PROXIMIDAD DEL MARGEN DE RESECCIN CIRCUNFERENCIAL SEGN LO DETERMINADO COMPARATIVAMENTE CON LA PIEZA DE ANATOMOPATOLOGA

ANTECEDENTES:Las pautas actuales recomiendan la re-estadificación por medio de la resonancia magnética luego de terapia neoadyuvante en los casos de cáncer de recto, pero la precisión de la reevaluación con la IRM para estimar el grado de implicación del margen circunferencial requiere aclaraciones adicionales.OBJETIVO:Medir el grado de exactitud en la evaluación del margen de resección circunferencial mediante resonancia magnética después de la terapia neoadyuvante e identificar las características asociadas con la precisión.DISEÑO:Se analizaron retrospectivamente los datos de resonancia magnética para determinar la concordancia entre los hallazgos del análisis de la pieza de anatamopatología y las muestras quirúrgicas correspondientes. Se realizó el análisis de regresión logística univariada y multivariada para identificar las características asociadas con la exactitud.AJUSTE:Centro oncológico integral.PACIENTES:Todos aquellos que se sometieron consecutivamente a una excisión total del mesorrecto por cáncer rectal entre Enero 2018 y Febrero 2020 luego de recibir terapia neoadyuvante y someterse a una re-estadificación por imágenes de resonancia magnética (IRM).PRINCIPALES MEDIDAS DE RESULTADO:La exactitud, la sensibilidad y especificidad; los valores predictivos positivos y negativos para categorizar el margen de resección circunferencial como amenazado; la diferencia media y las medias pareadas de proximidad a los margenes.RESULTADOS:De los 94 pacientes incluidos en el análisis, 39 (41%) tenían un margen de resección circunferencial amenazado según la resonancia magnética en la re-estadificación, pero solo 17 (18%) tenían un margen amenazado basado en la patología. La precisión de la resonancia magnética para identificar un margen amenazado fue del 63,8%, con la proximidad del margen sobreestimada en 0,4 cm en promedio. En la regresión logística multivariada, la ubicación anterior de los bordes de resección y la proximidad del tumor al margen anal se asociaron de forma independiente con la reducción en la precisión de la resonancia magnética.LIMITACIONES:Diseño retrospectivo en una institución única.CONCLUSIONES:El saber que la re-estadificación basada en la IRM, luego de terapia neoadyuvante sobreestima la proximidad de la lesión a los márgenes circunferenciales, hace innecesaria cierta radicalidad quirúrgica complementaria, lo que ayuda a evitar morbilidad asociada. Reconociendo que la evaluación de proximidad de los márgenes de resección basada en la resonancia magnética, no puede ser confiable en casos de márgenes anteriores y en casos de tumores distales. Los radiólogos recomiendan tener más precaución en la interpretación de imágenes de tumores con estas características y reconocen cierto desasosiego en sus informes. Consulte Video Resumen en http://links.lww.com/DCR/B814.

The American Society of Anesthesiologists score influences on postoperative complications and total hospital charges after laparoscopic colorectal cancer surgery

The aim of this study was to investigate the influence of American Society of Anesthesiologists (ASA) scores on postoperative complication rates and total hospital charges following laparoscopic surgery for colorectal cancer.All patients (n = 664) underwent laparoscopic colorectal cancer surgery. A group of patients with an ASA score of 1 or 2 (n = 575) and a group of patients with an ASA score of 3 (n = 89) were compared.The mean age was higher in the group of patients with an ASA score of 3 than in the group of patients with an ASA score of 1 or 2 (70 vs 67 years). The rate of ICU admission (27% vs 15%) was higher in the ASA score 3 group. The mean hospital stay (14 vs 12 days) was longer in the ASA score 3 group. Postoperative 30-day complications (38% vs 27%), 30-day mortality (2% vs 0%), and a Clavien-Dindo classification of ≥3 (21% vs 11%) occurred more frequently in the ASA score 3 group. Mean total hospital charges were significantly higher in the ASA score 3 group (13,906 vs 11,575 USD). Independent risk factors that affected postoperative complications were older age [≥80 years, hazard ratio (HR) = 2.8], an ASA score of 3 (HR = 1.6), and the presence of a primary rectal tumor (HR = 1.6). Postoperative complication rates were 21.9%, 28.5%, and 38.2% in the ASA score 1, 2, and 3 groups, respectively. Total hospital charges were 14,376 USD and 10,877 USD in the groups with and without postoperative complications, respectively. Mean total hospital charges were 10,769 USD, 11,756 USD, and 13,906 USD in the ASA score 1, 2, and 3 groups, respectively.Preoperative ASA scores may be a predictor of postoperative complications and hospital costs when planning laparoscopic surgery for colorectal cancer.

Pre-operative staging of rectal cancer: a review of imaging techniques

INTRODUCTION

The treatment of rectal cancer has diversified in recent years, presenting the clinician and patient with increasingly challenging management decisions. At the heart of this decision-making process are two competing interests; more radical but more morbid treatments which optimize oncological outcome, and less radical treatments which preserve organs and function but may pose a greater risk of disease recurrence.

AREAS COVERED

Imaging plays a vital role informing this decision-making process, both by providing prognostic details about the cancer before the start of treatment and by updating this picture as the cancer responds or fails to respond to treatment. There is a range of available imaging modalities, each with its strengths and weaknesses. Optimizing rectal cancer treatment requires a clear understanding of the important questions that imaging needs to answer and the optimum imaging strategy. Expert Commentary: This article provides an evidence-based review of the available imaging techniques and an expert commentary on the best imaging strategy.

Factors associated with postoperative complications and 1-year mortality after surgery for colorectal cancer in octogenarians and nonagenarians

Purpose

To identify the factors affecting 30-day postoperative complications and 1-year mortality after surgery for colorectal cancer in octogenarians and nonagenarians.

Methods

Between 2005 and 2014, a total of 204 consecutive patients aged ≥80 years who underwent major colorectal surgery were included.

Results

One hundred patients were male (49%) and 52 patients had American Society of Anesthesiologists (ASA) score ≥3 (25%). Combined surgery was performed in 32 patients (16%). Postoperative complications within 30 days after surgery occurred in 54 patients (26%) and 30-day mortality occurred in five patients (2%). Independent risk factors affecting 30-day postoperative complications were older age (≥90 years, hazard ratio [HR] with 95% confidence interval [CI] =4.95 [1.69−14.47], P=0.004), an ASA score ≥3 (HR with 95% CI =4.19 [1.8−9.74], P=0.001), performance of combined surgery (HR with 95% CI =3.1 [1.13−8.46], P=0.028), lower hemoglobin level (<10 g/dL, HR with 95% CI =7.56 [3.07−18.63], P<0.001), and lower albumin level (<3.4 g/dL, HR with 95% CI =3.72 [1.43−9.69], P=0.007). An ASA score ≥3 (HR with 95% CI =2.72 [1.15−6.46], P=0.023), tumor-node-metastasis (TNM) stage IV (HR with 95% CI =3.47 [1.44−8.39], P=0.006), and occurrence of postoperative complications (HR with 95% CI =4.42 [1.39−14.09], P=0.012) were significant prognostic factors for 1-year mortality.

Conclusion

Patient-related factors (older age, higher ASA score, presence of anemia, and lower serum albumin) and procedure-related factors (performance of combined surgical procedure) increased postoperative complications. Avoidance of 30-day postoperative complications may decrease 1-year mortality.