Role of three-dimensional anorectal ultrasonography in the assessment of rectal cancer after neoadjuvant radiochemotherapy: preliminary results

Abstract

3-DAUS can aid significantly in the choice of surgical approach following RCT. However, a greater sample of patients is required to establish sufficiently accurate post-RCT 3-DAUS parameters.

Criteria for three-dimensional anorectal ultrasound assessment of response to chemoradiotherapy in rectal cancer patients

“…New imaging techniques, such as PET, MRI and 3D-AUS, have been developed for the assessment of tumour response to chemoradiotherapy [15][16][17][18][19][20][21]23]. PET scanning can detect a complete response and residual cancer in the rectal wall and in the mesorectum.…”

“…Hypoechoic (or tumour-like) areas with irregular borders were considered to be metastatic lymph nodes. In contrast, oval structures with regular borders and a central hyperechoic area (corresponding to the hilum) were suggestive of an inflammatory lesion [23]. The examination included the measurement of tumour length in cm (the distance from the proximal edge to the distal edge of the tumour), total tumour volume in cm 3 (the sum of microsections) and anal canal invasion or the distance between the distal tumour edge and the proximal edge of the anal canal muscle, corresponding to the internal anal sphincter in the posterior quadrant ( Figs.…”

“…Advances in ultrasound scanning technology over the past few years include the development of high-frequency three-dimensional 360°rotating anorectal ultrasonography (3D-AUS), with increased focal distance and automatic image acquisition in multiple planes [22]. In a study of patients with rectal cancer who underwent treatment with preoperative neoadjuvant chemoradiotherapy and evaluation by 3D-AUS, Murad-Regadas et al [23] identified residual tumour and complete response with a high degree of accuracy. 3D-AUS can help in the choice of surgical approach by providing important information on the distance between the lower border of the tumour and the upper anal sphincter.…”

Ultrassom anorretal tri-dimensional pode selecionar pacientes com tumor no reto após neoadjuvância para cirurgia de preservação esfincteriana?

“…Não foi realizado o re-estadiamento ultrassonográfico (uT) baseado no TNM. Entretanto, foram avaliados quanto à resposta ao tratamento neoadjuvante, identificando regressão completa, regressão parcial, sem regressão de acordo com os padrões radiológicos previamente descrito (27) . Foi mensurado novamente a distância (cm) entre a borda distal do tumor (qualquer quadrante) até a borda proximal do EAI no quadrante posterior visando selecionar pacientes que poderiam submeter-se a cirurgia com preservação esfincteriana.…”

“…Evidenciaram ainda que a visualização das camadas da parede retal sugere regressão completa da lesão. MuradRegadas e cols (27) demonstraram em estudos preliminares o papel do ultrassom anorretal tridimensional na avaliação dos tumores de reto pós quimioradioterapia definindo padrões radiológicos na identificação de lesão residual ou resposta completa assim como as vantagens da modalidade multiplanar e aquisição automática das imagens. Portanto, esse estudo objetiva avaliar a resposta pós-QT no tratamento das neoplasia malignas no reto médio e inferior utilizando o ultrassom anorretal tridimensional visando definir a estratégia cirúrgica adequada comparando com o histopatológico.…”