RESUMO
INTRODUCTION: To investigate magnetic resonance imaging (MRI) accuracy for determining the location of rectal tumors with respect to the peritoneal reflection (PR) and its potential involvement. METHODS: Prospective study of 161 patients ongoing surgery for rectal cancer. A double-ink method has been aplied to examine surgical specimen, orange ink for the serosal surface and indian ink for the mesorrectal margin, and assess preoperative MRI accuracy. RESULTS: Twenty-two tumors were located above, 65 at and 74 below PR. MRI accuracy was 90.6% for determining tumor's location with respect to the PR and 80.5% for defining peritoneal involvement. For classifying tumors according to their intra or extraperitoneal location an accuracy of 92.5% was set for MRI. Histophatologic peritoneal involvement was found in 28.7% of tumors located above or at the PR. CONCLUSIONS: Magnetic resonance imaging accurately predicts the location of rectal tumors with respect to the PR and its potential involvement. The double-ink method is useful to assess serosal involvement (pT4a) and to distinguish mesorrectal fascia from the peritonealized surface.
Assuntos
Neoplasias Retais , Fáscia , Humanos , Imageamento por Ressonância Magnética/métodos , Peritônio/diagnóstico por imagem , Estudos Prospectivos , Neoplasias Retais/diagnóstico por imagem , Neoplasias Retais/patologia , Neoplasias Retais/cirurgiaRESUMO
INTRODUCTION: To investigate magnetic resonance imaging (MRI) accuracy for determining the location of rectal tumors with respect to the peritoneal reflection (PR) and its potential involvement. METHODS: Prospective study of 161 patients ongoing surgery for rectal cancer. A double-ink method has been aplied to examine surgical specimen, orange ink for the serosal surface and indian ink for the mesorrectal margin, and assess preoperative MRI accuracy. RESULTS: Twenty-two tumors were located above, 65 at and 74 below PR. MRI accuracy was 90.6% for determining tumor's location with respect to the PR and 80.5% for defining peritoneal involvement. For classifying tumors according to their intra or extraperitoneal location an accuracy of 92.5% was set for MRI. Histophatologic peritoneal involvement was found in 28.7% of tumors located above or at the PR. CONCLUSIONS: Magnetic resonance imaging accurately predicts the location of rectal tumors with respect to the PR and its potential involvement. The double-ink method is useful to assess serosal involvement (pT4a) and to distinguish mesorrectal fascia from the peritonealized surface.