Validación de la resonancia magnética pélvica como método de elección para determinar la distancia al margen anal en el cáncer de recto / Validation of pelvic magnetic resonance imaging as the method of choice to determine the distance to the anal margin in rectal cancer

Introducción: La altura exacta del tumor en el recto y sus relaciones anatómicas contribuyen a determinar la estrategia terapéutica multidisciplinar basada en la combinación de radio-quimioterapia y cirugía radical. Nuestro objetivo es valorar cuál es el método diagnóstico más preciso en la medición preoperatoria de la distancia al margen anal, y si la resonancia magnética pélvica (RM) puede sustituir a los métodos instrumentales clásicos. Métodos: Estudio prospectivo de precisión diagnóstica entre colonoscopia (CF), rectoscopia rígida (RRp) y RM en pacientes con indicación de cirugía radical. La RRp intraoperatoria fue considerada la prueba de referencia. Se analizaron las correlaciones entre las distintas técnicas y su coeficiente de determinación, así como el coeficiente de correlación intraclase y el grado de acuerdo entre los distintos test. Resultados: Se incluyeron 96 pacientes con edad media (DE) de 68 (14,1) años y predominio de varones (65%). Un 72% recibió tratamiento neoadyuvante. La distancia media al margen anal, medida mediante CF=103,5mm, fue significativamente mayor al resto, que obtuvieron valores similares: RRp=81,1, RM=77,4, RRp intraoperatoria=82,9mm (p<0,001). Se objetivó una significativa correlación intraclase y hubo un elevado acuerdo entre todas las mediciones pre e intraoperatorias a excepción de la realizada mediante CF, que sobreestimó el resultado. La RM aportó información más individualizada y precisa. Conclusiones: Existe variabilidad entre los métodos de medición, siendo la colonoscopia el menos fiable. La RM ofrece valores objetivos, comparables, precisos e individualizados que pueden sustituir a los obtenidos por RR en tumores de cualquier localización del recto. (AU)

Introduction: Distance from anal verge of rectal tumors and their anatomical relationships contribute to determine the multidisciplinary therapeutic strategy based on the combination of radio-chemotherapy and radical surgery. Our aims are to investigate which is the most accurate method for the preoperative measuring of the distance from the anal verge in rectal tumors and if the pelvic MRI can substitute the classical instrumental methods. Methods: Prospective study of diagnostic precision between flexible colonoscopy (FC), preoperative rigid rectosigmoidoscopy (pRR) and pelvic MRI in patients scheduled to radical surgery. Rigid intraoperative rectoscopy (iRR) was considered the reference test. The correlations between the different techniques and their determination coefficient as well as the intraclass correlation coefficient and the degree of agreement between the different tests were analyzed. Results: 96 patients (65% males), mean age (SD): 68 (14.1) years were included. 72% received neoadjuvant treatment. The mean distance to the anal margin measured by FC=103.5mm, was significantly greater than others, which had similar values: pRR=81.1; MRI=77.4; iRR=82.9mm (P<.001). A significant intraclass correlation was observed and there was high agreement between all pre- and intraoperative measurements except for the performed by FC, which overestimated the results. MRI provided more individualized and accurate information. Conclusions: There is variability between the measurement methods, being colonoscopy the least reliable. MRI offers objective, comparable, accurate and individualized values that can replace those obtained by pRR for tumors of any location in the rectum. (AU)

Validation of pelvic magnetic resonance imaging as the method of choice to determine the distance to the anal margin in rectal cancer.

INTRODUCTION: Distance from anal verge of rectal tumours and their anatomical relationships contribute to determine the multidisciplinary therapeutic strategy based on the combination of radio-chemotherapy and radical surgery. Our aims are to investigate which is the most accurate method for the preoperative measuring of the distance from the anal verge in rectal tumours and if the pelvic MRI can substitute the classical instrumental methods. METHODS: Prospective study of diagnostic precision between flexible colonoscopy (FC), preoperative rigid rectosigmoidoscopy (pRR) and pelvic MRI in patients scheduled to radical surgery. Rigid intraoperative rectoscopy (iRR) was considered the reference test. The correlations between the different techniques and their determination coefficient as well as the intraclass correlation coefficient and the degree of agreement between the different tests were analyzed. RESULTS: 96 patients (65% males), mean age (SD): 68 (14.1) years were included. 72% received neoadjuvant treatment. The mean distance to the anal margin measured by FC = 103.5 mm, was significantly greater than others, which had similar values: pRR = 81.1; MRI = 77.4; iRR = 82.9 mm (P < .001). A significant intraclass correlation was observed and there was high agreement between all pre- and intraoperative measurements except for the performed by FC, which overestimated the results. MRI provided more individualized and accurate information. CONCLUSIONS: There is variability between the measurement methods, being colonoscopy the least reliable. MRI offers objective, comparable, accurate and individualized values that can replace those obtained by pRR for tumours of any location in the rectum.

Validation of pelvic magnetic resonance imaging as the method of choice to determine the distance to the anal margin in rectal cancer. / Validación de la resonancia magnética pélvica como método de elección para determinar la distancia al margen anal en el cáncer de recto.

INTRODUCTION: Distance from anal verge of rectal tumors and their anatomical relationships contribute to determine the multidisciplinary therapeutic strategy based on the combination of radio-chemotherapy and radical surgery. Our aims are to investigate which is the most accurate method for the preoperative measuring of the distance from the anal verge in rectal tumors and if the pelvic MRI can substitute the classical instrumental methods. METHODS: Prospective study of diagnostic precision between flexible colonoscopy (FC), preoperative rigid rectosigmoidoscopy (pRR) and pelvic MRI in patients scheduled to radical surgery. Rigid intraoperative rectoscopy (iRR) was considered the reference test. The correlations between the different techniques and their determination coefficient as well as the intraclass correlation coefficient and the degree of agreement between the different tests were analyzed. RESULTS: 96 patients (65% males), mean age (SD): 68 (14.1) years were included. 72% received neoadjuvant treatment. The mean distance to the anal margin measured by FC=103.5mm, was significantly greater than others, which had similar values: pRR=81.1; MRI=77.4; iRR=82.9mm (P<.001). A significant intraclass correlation was observed and there was high agreement between all pre- and intraoperative measurements except for the performed by FC, which overestimated the results. MRI provided more individualized and accurate information. CONCLUSIONS: There is variability between the measurement methods, being colonoscopy the least reliable. MRI offers objective, comparable, accurate and individualized values that can replace those obtained by pRR for tumors of any location in the rectum.