A computed tomography image segmentation algorithm for improving the diagnostic accuracy of rectal cancer based on U-net and residual block / 生物医学工程学杂志

As an important basis for lesion determination and diagnosis, medical image segmentation has become one of the most important and hot research fields in the biomedical field, among which medical image segmentation algorithms based on full convolutional neural network and U-Net neural network have attracted more and more attention by researchers. At present, there are few reports on the application of medical image segmentation algorithms in the diagnosis of rectal cancer, and the accuracy of the segmentation results of rectal cancer is not high. In this paper, a convolutional network model of encoding and decoding combined with image clipping and pre-processing is proposed. On the basis of U-Net, this model replaced the traditional convolution block with the residual block, which effectively avoided the problem of gradient disappearance. In addition, the image enlargement method is also used to improve the generalization ability of the model. The test results on the data set provided by the "Teddy Cup" Data Mining Challenge showed that the residual block-based improved U-Net model proposed in this paper, combined with image clipping and preprocessing, could greatly improve the segmentation accuracy of rectal cancer, and the Dice coefficient obtained reached 0.97 on the verification set.

Elastografía cualitativa por ultrasonido endoscópico en la reestadificación del tumor de recto irradiado / Qualitative elastography by endoscopic ultrasound in the restaging of the irradiated rectal tumor

Introducción: En la reestadificación del paciente con tumor de recto irradiado, la elastografía cualitativa por ultrasonido endoscópico puede identificar la fibrosis y diferenciarla del tumor residual. Objetivo: Determinar la utilidad de la elastografía cualitativa por ultrasonido endoscópico en la reestadificación del tumor de recto irradiado. Métodos: Estudio observacional y descriptivo (serie de casos), en 31 pacientes con tumor de recto irradiado, reestadificados mediante elastografía cualitativa por ultrasonido endoscópico. Para determinar la utilidad de la elastografía se calcularon: sensibilidad, especificidad, valor predictivo positivo, valor predictivo negativo, índice de Youden y concordancia diagnóstica según índice kappa, de la elastografía y del ultrasonido endoscópico por separado, estos resultados fueron comparados en ambas pruebas diagnósticas. El estudio histológico de la pieza quirúrgica fue el estándar de referencia. Resultados: El índice de concordancia del ultrasonido endoscópico (77,4 por ciento), por elastografía (87,1 por ciento). El ultrasonido endoscópico mostró mayor sensibilidad y valor predictivo negativo que la elastografía, por lo que la posibilidad de descartar presencia de tumor con un resultado negativo fue superior. La elastografía tuvo mayor especificidad (77,78 por ciento) y valor predictivo positivo (90,91 por ciento) que el ultrasonido endoscópico (22,22 y 75,86 por ciento); fue más útil para confirmar el diagnóstico de tumor. Conclusiones: La utilidad de la elastografía cualitativa asociada al ultrasonido endoscópico, en la reestadificación del tumor de recto irradiado, consiste en incrementar la especificidad del estudio y discernir mejor entre la fibrosis y el tumor residual(AU)

Introduction: Qualitative endoscopic ultrasound elastography can identify fibrosis and differentiate it from residual tumor in the re-staging of patients with irradiated rectal tumors. Objective: To determine the usefulness of qualitative endoscopic ultrasound elastography in the re-staging of the irradiated rectal tumor. Methods: An observational and descriptive study (series of cases) was carried out in 31 patients with irradiated rectal tumor, restaged by means of Qualitative elastography by endoscopic ultrasound. To determine the usefulness of elastography, the following were calculated: sensitivity, specificity, positive predictive value, negative predictive value, Youden index and diagnostic agreement according to kappa, elastography and endoscopic ultrasound separately; these results were compared in both diagnostic tests. The histological study of the surgical specimen was the reference standard. Results: The concordance index of endoscopic ultrasound (77.4 percent), that obtained by elastography (87.1 percent). Endoscopic ultrasound showed greater sensitivity and negative predictive value than elastography, so the possibility of ruling out the presence of a tumor with a negative result was higher. Elastography had greater specificity (77.78 percent) and positive predictive value (90.91 percent) than endoscopic ultrasound (22.22 and 75.86 percent); it was most helpful in confirming the tumor diagnosis. Conclusions: The usefulness of qualitative elastography associated with endoscopic ultrasound, in the re-staging of the irradiated rectal tumor, consists in increasing the specificity of the study, thus allowing a better discernment between fibrosis and residual tumor(AU)

Elastografía por ultrasonido endoscópico en el tumor de recto / Endoscopic ultrasound elastography in the rectal tumor

Introducción: Para definir una adecuada estrategia terapéutica en el cáncer de recto es preciso una correcta estadificación. El ultrasonido endoscópico es un método de estadiaje preciso que define la profundidad del tumor y el estado nodal. En los tumores tratados con radioterapia disminuye su rentabilidad por la fibrosis que se origina en la pared rectal; indistinguible de los elementos de malignidad. La elastografía brinda la posibilidad de resolver esta limitación. Objetivo: Ofrecer una actualización sobre la elastografía por ultrasonido endoscópico en el diagnóstico del paciente con tumor rectal. Desarrollo: La elastografía se basa en las alteraciones que en la elasticidad del tejido inducen la fibrosis y el cáncer. Determina si un tejido es maligno o benigno mediante el análisis de su dureza. Se obtienen imágenes que se expresan en un mapa de colores superpuestas a la imagen convencional del ultrasonido endoscópico. Muchas investigaciones demuestran su elevada sensibilidad y especificidad en tumores de páncreas y ganglios linfáticos, algunas en tumores de esófago, sin embargo muy pocas en el cáncer rectal. Conclusiones: La elastografía ha mejorado el diagnóstico y seguimiento oncológico del paciente con tumor rectal(AU)

Introduction: To define an adequate therapeutic strategy in rectal cancer, a correct staging is necessary. For this, advanced diagnostic means have been developed to evaluate the rectal wall. Endoscopic Ultrasound a fundamental technique; combines endoscopic image with ultrasound; in tumors treated with radiotherapy, its profitability decreases due to fibrosis that originates in the rectal wall; indistinguishable from the elements of malignancy. Elastography offers the possibility of resolving this limitation. Objective: To offer an update on elastography by endoscopic ultrasound in the diagnosis of the patient with rectal tumor. Development: Elastography is based on the alterations that fibrosis and cancer induce in the elasticity of the tissue. Determine if a tissue is malignant or benign by analyzing its hardness. Images are obtained that are expressed on a color map superimposed on the conventional endoscopic ultrasound image. Many investigations demonstrate its high sensitivity and specificity in tumors of the pancreas and lymph nodes, some in esophageal tumors, however very few in rectal cancer. Conclusions: Elastography has improved the diagnosis and oncological follow-up of the patient with rectal tumor(AU)

ELAPE: rol actual en el tratamiento del cáncer de recto bajo / ELAPE: current role in the treatment of low rectal cancer

Resumen En este artículo se discute el origen del concepto ELAPE ( extralevator abdominoperineal excision) en el tratamiento quirúrgico del cáncer del recto bajo, las variantes técnicas asociadas con la resección "cilíndrica", las indicaciones actuales, las limitaciones técnicas asociadas y los resultados publicados en la literatura mundial. Considerando la evidencia actual se propone la utilización en casos seleccionados de acuerdo al estudio clínico y por imágenes, donde la resonancia magnética de la pelvis tiene un rol predominante. La técnica tradicional de la amputación abdominoperineal (comúnmente asociada a Miles) se mantiene como una alternativa válida en el manejo quirúrgico de algunos pacientes con un tumor localmente avanzado del recto bajo.

This article discusses the origin of the ELAPE concept (abdominoperineal excision extralevator) in the surgical treatment of low rectal cancer, the technical variants associated with "cylindrical" resection, current indications, associated technical limitations and the results published in the world literature Considering the current evidence, the use is proposed in selected cases according to the clinical study and imaging, where the magnetic resonance of the pelvis has a predominant role. The traditional abdominal-perineal amputation technique (commonly associated with Miles) remains a valid alternative in the surgical management of some patients with a locally advanced tumor of the lower rectum.

Tecnología y globalización en el pronóstico de pacientes con cáncer rectal / Technology and globalization on the prognosis of patients with rectal cancer

Desde el siglo XX hasta la fecha, el proceso de globalización ha caracterizado el desarrollo de la economía mundial. En este contexto los países desarrollados son los que tienen directamente el manejo y dominio tecnológico, mientras que los subdesarrollados han sido afectados con la introducción acelerada de las nuevas tecnologías y su alto costo. El desarrollo tecnológico en la sociedad actual es un factor importante en el manejo de enfermedades como el cáncer. El tumor de localización rectal constituye el tercer tipo de cáncer más comúnmente diagnosticado y la tercera causa de muerte por cáncer para ambos sexos. Para su estadificación se han desarrollado varios medios diagnósticos, dentro de estos, la elastografía por ultrasonido endoscópico es una técnica de elevado impacto. En Cuba se cuenta con esta tecnología de avanzada, a disposición de todos los pacientes, lo cual demuestra que es posible enfrentar los desafíos que la globalización impone al desarrollo tecnológico. En este trabajo se exponen las opiniones de los autores, relacionadas con la influencia que tiene la política de globalización en el desarrollo tecnológico y su repercusión en el pronóstico de los pacientes con cáncer de recto(AU)

From the 20th century to the present, the process of globalization has characterized the development of the world economy. In this context, the developed countries are those that have direct management and technological control, while the underdeveloped countries have been affected by the accelerated introduction of new technologies and their high cost. The technological development in today's society is an important factor in the management of diseases such as cancer. The rectal tumor is the third most commonly diagnosed type of cancer and the third cause of cancer death for both sexes. For its staging, several diagnostic means have been developed, within these, endoscopic ultrasound elastography is a high impact technique. In Cuba, this advanced technology is available to all patients, which shows that it is possible to face the challenges that globalization imposes on technological development. This paper presents the opinions of the authors, related to the influence of the globalization policy on technological development and its impact on the prognosis of patients with rectal cancer(AU)

Excisão total de mesorreto transanal combinada à dissecção laparoscópica: resultados perioperatórios e avaliação da qualidade do mesorreto / Transanal total mesorectal excision combined with laparoscopic dissection: perioperative results and assessment of the mesorectal quality

RESUMO Objetivo: avaliar os resultados perioperatórios e pós-operatórios relacionados à excisão total do mesorreto transanal, bem como, qualidade dos espécimes obtidos pela excisão total do mesorreto transanal através da análise histopatológica da qualidade do mesorreto, acometimento das margens proximal e distal e positividade da margem circunferencial. Métodos: estudo prospectivo, descritivo, em pacientes consecutivos portadores de adenocarcinoma de reto localizados até 10cm da borda anal, sem metástase à distância, submetidos ou não à quimioterapia e radioterapia neoadjuvantes. Foram avaliados a presença de dificuldades técnicas, índice de conversão para via abdominal, tempo cirúrgico e intercorrências intra e pós-operatórias. A qualidade do mesorreto foi classificada em ressecção completa, parcialmente completa ou incompleta. Resultados: entre dezembro de 2016 e maio de 2019, 41 pacientes foram submetidos à excisão total do mesorreto transanal, dos quais 75% foram classificados como estágio clínico III, 13% estágio clínico II e 12% estágio clínico I. A média de distância entre borda anal e borda inferior do tumor foi de 6,2cm. Quarenta por cento dos tumores encontravam-se na parede retal anterior e 17% foram classificados como circunferenciais. A média de tempo operatório foi de 189 minutos. A média de internação hospitalar foi de 4,6 dias. Não houve óbitos intra-hospitalares. Oitenta e dois por cento dos espécimes foram classificados como ressecção completa. Conclusão: a excisão total do mesorreto transanal demonstra adequada qualidade do mesorreto e adequadas margens cirúrgicas, estando associada a baixos índices de complicações perioperatórias, tempo cirúrgico aceitável e curto tempo de hospitalização.

ABSTRACT Objective: to assess the perioperative and postoperative results of transanal total mesorectal excision, as well as the quality of the specimens obtained by this technique. Methods: we conducted a prospective, descriptive study in consecutive patients with rectal adenocarcinoma located up to 10cm from the anal verge, without distant metastasis, subjected or not to neoadjuvant chemoradiotherapy. We evaluated the presence of technical difficulties, conversion to open abdominal route, surgical time and intra and postoperative complications. Through histopathological analysis, we assessed the quality of the mesorectum, involvement of the proximal and distal margins and positivity of the circumferential, classifying quality of the mesorectum as complete, partially complete or incomplete resection. Results: between December 2016 and May 2019, 41 patients underwent transanal total mesorectal excision, of which 75% were classified as clinical stage III, 13% clinical stage II and 12% clinical stage I. The average distance between the anal verge and the lower border of the tumor was 6.2cm. Forty percent of the tumors were in the anterior rectal wall and 17% were circumferential. The average operative time was 189 minutes. The average hospital stay was 4.6 days. There were no in-hospital deaths. Eighty-two percent of the specimens were classified as complete resection. Conclusion: transanal total mesorectal excision demonstrates adequate specimen quality and surgical margins, being associated with lower rates of perioperative complications, acceptable surgical time and short hospitalization.

Manejo no operatorio del cáncer de recto con respuesta clínica completa luego de quimiorradioterapia neoadyuvante: experiencia en 8 casos / Non-operative management of rectal cancer with complete clinical response after neoadjuvant chemoradiotherapy: experience in 8 cases

Introducción: Se diagnostican hasta 13000 nuevos casos de cáncer colorrectal por año, y esto va en aumento. El cáncer de recto debe ser tratado mediante un abordaje multimodal. Luego de la implementación del tratamiento neoadyuvante y de la aparición de la respuesta patológica completa se implementó el manejo no operatorio. Nuestro objetivo es describir nuestra experiencia con el manejo inicial no operatorio de pacientes con cáncer de recto, que recibieron neoadyuvancia y desarrollaron una respuesta clínica completa inicial. Diseño: Estudio observacional, descriptivo, retrospectivo. Pacientes y Métodos: 49 pacientes con diagnóstico de cáncer de recto bajo (< 8 cm), recibieron tratamiento neoadyuvante con radioquimioterapia (RQT). Se realizó radioterapia (RT), a una dosis de 5040 cGy por un total de 5 semanas, y concomitante a esta, quimioterapia (QT) con 5-Fu-leucovorina en las semanas 1 y 5. Aquellos pacientes en los cuales se encontró cCR inicial a la neoadyuvancia, y la cirugía resectiva implicaba alto riesgo quirúrgico debido a sus comorbilidades y/o imposibilidad de la conservación de esfínteres se planteó la posibilidad de tomar una conducta no operatoria. Resultados: Se incluyeron 8 pacientes con cCR. El promedio de edad de los pacientes fue de 70 años (mediana 69,5 años), el promedio de altura del tumor fue de 5,8 cm; todos en estadio IIa. La mediana de seguimiento fue de 72,5 meses. 3 pacientes presentaron recaídas, todas endoluminales, 2 fueron tempranas (9 y 12 meses) y una tardía (18 meses), los cuales fueron operados, 2 de ellos se encuentran actualmente libres de enfermedad y el tercero óbito a los 30 días POP. La sobrevida global de los pacientes fue de un 87,5% y se evitó una cirugía mayor en 5 pacientes (62,5%). Conclusión: La implementación del tratamiento inicial no operatorio del cáncer de recto en aquellos pacientes que desarrollaron cCR luego del tratamiento neoadyuvante puede ser seguro, siempre y cuando estos pacientes estén incluidos en un programa de seguimiento estricto que permita una cirugía de rescate. El tratamiento conservador sin cirugía debe ser reservado para pacientes de alto riesgo quirúrgico o en los que la cirugía implique la necesidad de una cirugía de amputación abdominoperineal. (AU)

Introduction: 13000 new cases of colorectal cases are diagnosed per year. Rectal cancer must be treated with a multimodal approach. After the administration of neoadjuvant treatment and the appearance of a pathologic complete response, nonoperative management was implemented. Our objective is to describe our experience with nonoperative management of patients with rectal cancer that received neoadjuvant therapy and developed an initial complete clinical response. Design: Retrospective descriptive observational study. Patients and Methods: Forty-nine patients with low rectal cancer (< 8 cm) received neoadjuvant radiochemotherapy. Radiotherapy was performed with a total dose of 5040 cGy for 5 weeks, and concomitant 5-FU-leucovorin-based chemotherapy in weeks 1 and 5. Nonoperative management was attempted on patients experiencing initial cCR to neoadjuvant therapy and with a higher surgical risk due to their comorbidity and/or impossibility of conserving the sphincters. Results: Eight patients with cCR were included. The average age of the patients was 70 years; the average height of the tumor was 5.8 cm; all of them at stage IIA. Median follow-up was 72.5 months. Two patients developed an early endoluminal recurrence (after 9 and 12 months) and one had a late recurrence (18 months). All of them had surgery. Two of them are disease-free and one died 30 days after surgery. Conclusion: Implementation of initial nonoperative treatment of rectal cancer in patients that developed cCR after neoadjuvant therapy can be safe, provided that those patients are included in a strict monitoring programme that would allow for a rescue surgery. Conservative treatment without surgery must be reserved for patients with a higher surgical risk or who require an abdominoperineal resection. (AU)

Eficacia de la ultrasonografía endoscópica en la estadificación de tumores del recto / Endoscopic ultrasound efficacy in the staging of rectal cancer

Introducción: el cáncer rectal representa un problema de salud en el mundo y la estadificación clínica constituye la llave para definir la conducta a seguir. Objetivo: determinar la eficacia de la ecoendoscopia en el estadiaje T y N del cáncer rectal. Métodos: se realizó un estudio descriptivo, desde enero del 2014 hasta marzo del 2016, se seleccionaron un total de 33 pacientes que se habían realizado ecoendoscopia y que luego fueron intervenidos quirúrgicamente. Se comparó la estadificación mediante ecoendoscopia con el informe anatomopatológico de la pieza quirúrgica obtenida. Se calculó concordancia global y eficacia diagnóstica en los diferentes estadios del cáncer rectal. Resultados: la concordancia global para la etapa T fue 57,6 por ciento y 87,9 por ciento para N. La precisión diagnóstica en pacientes que recibieron adyuvancia resultó del 47,1 por ciento y 82,4 por ciento para las etapas T y N respectivamente. La eficacia diagnóstica por subetapas T resultó en valores respectivos de sensibilidad y especificidad de 71,43 por ciento (95 por ciento CI 64 por ciento-79 por ciento) y 84,6 por ciento (95 por ciento CI 82 por ciento-86 por ciento) en T1; 76,9 por ciento (95 por ciento CI 73 por ciento-81 por ciento) y 70,0 por ciento (95 por ciento CI 67 por ciento-73 por ciento) en T2; y 42,8 por ciento (95 por ciento CI 35,5 por ciento-50,2 por ciento) y 96,2 por ciento (95 por ciento CI 94,2 por ciento-98,1 por ciento) en T3. Conclusiones: la concordancia global en T resultó inferior a lo reportado en la literatura consultada así como la eficacia diagnóstica de la técnica, debido a que 17 pacientes tuvieron tratamiento adyuvante previo. No hubo resultados significativos en la evaluación de la etapa N(AU)

Introduction: Rectal cancer represents a health problem nowadays worldwide, for that reason an accurate clinical staging of the disease is fundamental to define the proper behavior to follow. Objective: To determine the efficacy of endoscopic ultrasound for staging rectal cancer. Methods: A descriptive study was carried out, from January 2014 to March 2016 in Cuban National Center of Minimal Access Surgery in 33 patients (17 men and 16 women) who had undergone endoscopic ultrasound and who underwent surgery too. Their endoscopic ultrasound staging were compared with their anatomopathological reports of the surgical pieces obtained. Global concordance and diagnostic efficacy were calculated. Results: The overall concordance for stage T was 57.6 percent and 87.9 percent for N. The diagnostic accuracy in the patients that received adjuvant treatment previously was lower than the group of patients that not received it. The diagnostic efficacy by sub-steps T resulted in respective values of sensitivity and specificity of 71.43 percent and 84.6 percent in T1; 76.9 percent and 70.0 percent in T2; and 42.8 percent and 96.2 percent in T3. Conclusions: The overall concordance in T was lower than that reported in the literature consulted as well as the diagnostic efficacy of the technique, because 17 patients had previous adjuvant treatment. There were no significant results in the evaluation of stage N(AU)

Linfoma difuso de células grandes B rectal en un paciente con colitis ulcerosa / Rectal diffuse large B cell lymphoma appearing after immunosuppression for ulcerative colitis: report of one case

Primary colorectal lymphoma is a rare form of presentation of gastrointestinal tract lymphomas. Inflammatory bowel disease and its treatment are risk factors for its development. We report a 47-year-old male patient with Ulcerative Colitis of two years of evolution, treated initially with azathioprine and later on with infliximab. Due to a relapse in symptoms after the second dose of infliximab, a new coloncoscopy was performed showing a rectal ulcerative lesion, corresponding to a large cell Non-Hodgkin's Lymphoma. The patient was successfully treated with RCHOP chemotherapy (Rituximab cyclophosphamide doxorubicin vincristine prednisone). He is currently in disease remission.

Valor pronóstico de la invasión vascular extramural por resonancia magnética en pacientes con cáncer de recto: cohorte retrospectiva / Prognostic value of extramural vascular invasion by magnetic resonance imaging in patients with rectal cancer: retrospective cohort

El objetivo fue evaluar si existe asociación entre la presencia del signo de invasión vascular extramural constatado por resonancia magnética (IVErm) con el período libre de enfermedad (PLE) a los 3 años, en pacientes con cáncer de recto (CR). Se realizó un estudio de cohorte retrospectiva. Se incluyeron 64 pacientes seguidos en nuestra institución con diagnóstico histológico de CR, evaluados inicialmente con RM, los cuales recibieron esquema de quimio-radioterapia neoadyuvante y cirugía curativa. Se analizó, mediante un análisis multivariable a través de una regresión de Cox, para ajustar por potenciales variables de confusión como la estadificación por tamaño tumoral (Trm) en la resonancia magnética (RM) basal, la asociación entre IVErm y el PLE a los tres años. Treinta pacientes (49.5%) sufrieron progresión o recaída, de los cuales 20 (60.6%) presentaron signos de IVErm. La presencia de IVErm se asoció con duplicación del riesgo de mala evolución (HR: 2.11; p = 0.054; IC: 1.00 - 4.51). Luego de ajustar por Trm esta tendencia se mantuvo. La presencia del signo IVErm se asocia con disminución del PLE a 3 años. Es mandatorio incorporarlo en los informes radiológicos a fin de contribuir al manejo de dicho grupo de pacientes (AU)

The aim was to evaluate whether there is an association between the presence of extramural vascular invasion sign found in the magnetic resonance (mrEMVI) and three years' disease-free survival (DFS) in patients with rectal cancer (RC). A retrospective cohort study was performed. Sixty four patients with proven RC, who had been initially evaluated with magnetic resonance (MR), had undergone neoadjuvant chemoradiotherapy and curative surgery, and had been followed for at least 3 years at our institution were included. Association between mrEMVI and reduced DFS was analyzed by logistic regression. Thirty patients (49.5 %) had reduced DFS, of whom 20 (60.6%) had signs of mrEMVI. The presence of mrEMVI duplicated the odds of reduced prognosis (HR: 2.11; 95% CI: 1.00 - 4.51; p < 0.054). The mrEMVI increases the likelihood of reduced DFS in patients with RC (AU)

Impact of neoadjuvant therapy in downstaging of lower rectal adenocarcinoma and the role of pelvic magnetic resonance in staging / Impacto da terapia neoadjuvante na diminuição do estádio no adenocarcinoma de reto baixo: papel da ressonância magnética da pelve na determinação do estádio

ABSTRACT Objective: to evaluate the effect of neoadjuvant therapy on the stage (TNM) of patients with rectal adenocarcinoma and validate the use of MRI as a method of determining locoregional stage. Methods: we conducted a retrospective study of 157 patients with lower rectum adenocarcinoma, whom we divided into two groups: Group 1, 81 patients (52%) who had undergone surgical treatment initially, with the purpose to analyze the accuracy of locoregional staging by pelvic magnetic resonance imaging throug the comparison of radiological findings with pathological ones; Group 2, 76 patients (48%), who had been submitted to neoadjuvant therapy (chemotherapy and radiation) prior to definitive surgical treatment, so as to evaluate its effects on the stage by comparing clinical and radiological findings with pathology. Results: In group 1, the accuracy of determining tumor depth (T) and lymph node involvement (N) was 91.4% and 82.7%, respectively. In group 2, neoadjuvant therapy decreased the T stage, N stage and TNM stage in 51.3%, 21% and 48.4% of cases, respectively. Conclusion: neoadjuvant therapy in patients with rectal adenocarcinoma is effective in decreasing disease stage, and pelvic magnetic resonance imaging is effective for locoregional staging.

RESUMO Objetivo: avaliar o efeito da terapia neoadjuvante, nos pacientes portadores de adenocarcinoma de reto, sobre o estádio (TNM) e validar o emprego da ressonância magnética como método de determinação do estádio locorregional. Métodos: estudo retrospectivo de 157 pacientes com diagnóstico de adenocarcinoma de reto baixo, que foram divididos em dois grupos: Grupo 1, 81 pacientes (52%), submetidos ao tratamento cirúrgico de princípio, cuja finalidade foi analisar a acurácia da determinação do estádio locorregional pela ressonância magnética da pelve, através da comparação entre os achados radiológicos e os achados anatomopatológicos; Grupo 2, 76 pacientes (48%), encaminhados à terapia neoadjuvante (quimioterapia e radioterapia), antes do tratamento cirúrgico definitivo, com o intuito de avaliar seus efeitos sobre o estádio, através da comparação dos achados clínico-radiológicos com os anatomopatológicos. Resultados: no grupo 1, a acurácia da determinação da profundidade da lesão (T) e do comprometimento linfonodal (N), foram de 91,4% e 82,7%, respectivamente. No grupo 2, a terapia neoadjuvante diminuiu o estádio T, estádio N e o estádio TNM em 51,3%, 21% e 48,4% dos casos, respectivamente. Conclusão: a terapia neoadjuvante nos pacientes com adenocarcinoma de reto é efetiva na diminuição do estádio e a ressonância magnética da pelve é eficaz na determinação do estádio locorregional.

Preoperative staging of rectal cancer with MRI: correlation with pathologic staging

Introduction: An accurate preoperative rectal cancer staging is crucial to the correct management of the disease. Despite great controversy around this issue, pelvic magnetic resonance (RM) is said to be the imagiologic standard modality. This work aimed to evaluate magnetic resonance accuracy in preoperative rectal cancer staging comparing with the anatomopathological results. Methods: We calculated sensibility, specificity, positive (VP positive) and negative (VP negative) predictive values for each T and N. We evaluated the concordance between both methods of staging using the Cohen weighted K (Kw), and through ROC curves, we evaluated magnetic resonance accuracy in rectal cancer staging. Results: 41 patients met the inclusion criteria. We achieved an efficacy of 43.9% for T and 61% for N staging. The respective sensibility, specificity, positive and negative predictive values are 33.3%, 94.7%, 33.3% and 94.7% for T1; 62.5%, 32%, 37.0% and 57.1% for T2; 31.8%, 79%, 63.6% and 50% for T3 and 27.8%, 87%, 62.5% and 60.6% for N. We obtained a poor concordance for T and N staging and the anatomopathological results. The ROC curves indicated that magnetic resonance is ineffective in rectal cancer staging. Conclusion: Magnetic resonance has a moderate efficacy in rectal cancer staging and the major difficulty is in differentiating T2 and T3. (AU)

Introdução: Um estadiamento pré-operatório do Câncer do Reto (CR) é essencial na gestão da doença. Apesar de grande controvérsia, a ressonância magnética pélvica (RM) é apontada como modalidade imagiológica standard. Com este trabalho pretendeu-se avaliar a acuidade da RM no estadiamento do CR, comparando com os resultados anatomopatológicos da peça cirúrgica. Materiais e métodos: Calculou-se a sensibilidade, especificidade, valor preditivo positivo (VP positivo) e negativo (VP negativo) para T e N. Avaliou-se a concordância entre ambas as formas de estadiamento através do valor de K de Cohen ponderado (Kw) e, através de curvas ROC, avaliou-se a precisão do estadiamento por RM. Resultados: 41 doentes cumpriram os critérios de inclusão. Obteve-se uma eficácia de 43.9% para T e 61% para N. Verificou-se uma sensibilidade, especificidade, VP positivo e negativo, respectivamente, de 33.3%, 94.7%, 33.3% e 94.7% para T1, 62.5%, 32%, 37.0% e 57.1% para T2, 31.8%, 79%, 63.6% e 50% para T3, 27.8%, 87%, 62.5% e 60.6% para N. A concordância calculada foi pobre para T e N. As curvas ROC indicaram que o estadiamento do CR por RM foi ineficaz. Conclusão: A RM apresenta acuidade moderada no estadiamento do CR, onde a maior dificuldade está na distinção entre T2-T3. (AU)

Pre-operative staging of rectal cancer using multi-detector row computed tomography with multiplanar reformations: Single center experience.

BACKGROUND: Technical advancement in imaging has helped to stage and plan treatment modality for carcinoma rectum with still some objectives controversial. AIMS: The aim of our study was to evaluate the accuracy of multidetector row computed tomography (MDCT) with multiplanar reformations in the pre‑operative staging of rectal carcinoma and correlation with intraoperative and histopathologic staging of retrieved specimen with respect to the depth of tumor invasion (T‑staging), lymph node metastasis (N‑staging) and mesorectal fascia (MRF) involvement. MATERIALS AND METHODS: The study was a prospective one and consisted of 52 patients with biopsy proved rectal carcinoma. MDCT studies were performed on a 64‑slice computed tomography system. Images were reconstructed in axial, coronal and sagittal planes. MDCT findings were compared with intraoperative and pathologic (reference standard) findings. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were assessed. RESULTS: The diagnostic accuracy of MDCT for T1/T2, T3 and T4 lesions was 77%, 86.5% and 100%, respectively. For perirectal lymph node metastasis (N+), the diagnostic accuracy of MDCT was 84.1%. The diagnostic accuracy of MDCT for MRF involvement was 91%. CONCLUSION: MDCT is a reliable radiological tool for local staging of rectal cancer with excellent accuracy rates for T and N‑staging of rectal cancer.

Two Cases of Electrocautery Incision Therapy Using an Insulated-tip Knife for Treatment of Symptomatic Benign Short-segment Colonic Stenosis Following Colonic Resection / 대한소화기학회지

Anastomotic stenosis of the colon is not an uncommon finding; however, its frequency varies from one study to another. Traditionally, postoperative colonic stenosis is managed surgically. However, endoscopic therapy has recently become the preferred treatment modality over traditional surgery. Good short-term success has been achieved with use of endoscopic balloon dilation; however, restenosis may occur over time in 14% to 25% of patients. The current report showed the effectiveness and usefulness of an insulated-tip knife (IT-knife) for electrocautery therapy of a patient with symptomatic anastomotic colonic stenosis.

Imaging Diagnosis of Locally Advanced Rectal Cancer: Tumor Staging before and after Preoperative Chemoradiotherapy / 대한소화기학회지

Recently, treatment strategy of rectal cancer has changed dramatically. The application of total mesorectal excision (TME) and preoperative chemoradiation therapy (PCRT) has become standard procedure for locoregional and locally advanced rectal cancer, respectively. For the planning of patient-specific therapy, both functional and morphological radiologic evaluation as well as multidisciplinary approach is essential. In other words, the needs for more accurate T- and N-staging and assessment of circumferential resection margin, both before and after PCRT, are increasing rapidly. Although so far there is no consensus on the role of diagnostic imaging (endorectal ultrasound, CT, MRI) in the evaluation of rectal cancer patient, MRI with diffusion-weighted image is emerging as an essential imaging modality, especially in the assessment of tumor response and depiction of complete remission after PCRT. In this review, we intended to demonstrate the present diagnostic role of various imaging modalities in tumor assessment of locally advanced rectal cancer before and after PCRT, with the introduction of new emerging imaging tool.

Challenges on imaging follow-up for rectal neuroendocrine tumor endoscopic local resection: case report / Desafios no acompanhamento de imagens de tumor neuroendócrino retal com ressecção endoscópica local: relato de caso

We report a case of neuroendocrine tumor in rectum that was endoscopically resected and discuss the need of imaging follow-up for the early detection of cancer comorbidities to improve prognosis.

Relato de um caso de tumor neuroendócrino no reto, que foi submetido à ressecção endoscópica e avaliada a necessidade de imagens de acompanhamento para a detecção precoce de câncer como comorbidade para melhorar o prognóstico.

retrospective comparison of concurrent bolus 5-fluorouracil or raltitrexed in preoperative chemoradiation for locally advanced rectal cancer

5-fluorouracil [FU] is commonly used in preoperative chemoradiation in locally advanced rectal cancer, but not all patients cooperate in taking the 5-day continuous infusion regimen. Raltitrexed [RA], a thymidylate synthase inhibitor, is one of the agents used in place of FU in such cases. We retrospectively compared the toxicity, tumor downstaging, pathologic response and relapse rate with bolus FU or RA during concurrent radiotherapy [RT] to assess the role of RA in place of FU. We conducted a retrospective analysis of response rates and toxicity data on 59 patients diagnosed with locally advanced rectal cancer and treated with surgery following preoperative chemoradiation with either concurrent FU or RA between January 1999 and December 2004. Median follow-up was 38 months [range, 1-70]. Ten patients [10%] had grade 3 gastrointestinal [GIS] toxicity during chemoradiation. The pathologic complete response rates were 6% with FU and 7% with RA [P=0.844], while 66.7% of patients treated with FU and 37.1% with RA had downstaging of the T stage after chemoradiation [P=0.026]. The sphincter preservation rates were 45.8% with FU and 51.4% with RA [P=0.912]. The 5-year local control rates were 79.2% for patients treated with RT+FU and 85.76% for patients treated with RT+RA [P=0.510]. Compared with the RT+RA regimen, the incidence of downstaging was greater with RT+FU but RT+FU was associated with a correspondingly greater rate of acute grade 2 GIS toxicity. However, no significant differences were seen in sphincter preservation, pathologic complete response, local control and distant recurrences rates among patients. FU seems to be the best therapeutic choice, while RA seems to be as effective as bolus FU

Squamous cell carcinoma of colon and rectum

Primary squamous cell carcinoma SCC of the colon and rectum is a rare malignancy. Less than 100 cases have been reported in literature. We report 2 cases of pure SCC involving the rectum and sigmoid colon. A review of literature has been made starting from the first report in 1919 to the present. We have examined the theories regarding the etiology, available treatment modalities, and prognosis for this variant of colorectal carcinoma. We conclude that this tumor presents later than adenocarcinoma and follows an aggressive course. With a greater awareness among surgeons and pathologists, more cases may become known leading to a better estimation of prevalence and clinicopathological behavior of this tumor

An appraisal of invertograms and distal colostograms in the management of anorectal malformations.

OBJECTIVES: To determine the accuracy of two main radiologic tools currently employed in the clinical management of anorectal malformations, the invertogram and the distal colostogram. The data will be useful as a basis for quality assurance as well as for future comparisons in case there are innovations to be considered. MATERIAL AND METHOD: Radiological materials and clinical records of infants with anorectal malformations operated on in Songklanagarind Hospital from 1995 to 2001 were retrieved. Each record was blindly reviewed by two radiologists and one pediatric surgeon. Using operative findings as the gold standard, the accuracy of an invertogram in diagnosing low anomalies and the accuracy of a distal colostogram in screening cases that needed a laparotomy and in detecting internal fistulas were determined. The quality of the films was also categorized and poor quality studies were excluded from the analysis. Cases of common cloaca were not included in the level reading analysis. RESULTS: Radiologic materials from 59 patients were examined, including 26 invertograms and 49 distal colostograms. Among 52 cases whose neonatal history could be traced, 29 (55.8%) cases exhibited clinical evidence of anomalies level. Two invertograms and 5 colostograms were graded as poor quality and excluded from the analysis. The overall sensitivity of invertograms in detecting low anomalies was 33.3%, whereas, specificity was 66.7%. Analyzing only infants with a blind rectal pouch, the sensitivity and specificity to detect low anomalies were 33.3% and 75.0%, respectively. The sensitivity of distal colostograms in detecting a fistula was 60.0% in males and 62.5% in females. Distal colostograms diagnosed 'high-type anomalies' in 7 cases and correctly detected 2 cases of vesical fistula which needed APSARP. No prostetic-urethral fistulas showed a radiological high level. CONCLUSION: The study found poor diagnostic sensitivity of invertograms in detecting low type anomalies which deserved primary anoplasty. However, the data support the role of a distal colostogram in diagnosing high anomalies, despite its low sensitivity in detecting urethral fistulas.