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)

Revisión pictográfica de las anomalías de los conductos de Müller por resonancia magnética / Pictographic review of Müllerian duct anomalies by magnetic resonance imaging

Las anomalías útero-vaginales o müllerianas son un grupo de patologías congénitas que se originan por un defecto del desarrollo, fusión o canalización de los conductos de Müller en la etapa embrionaria, excepcionalmente pueden deberse a una alteración adquirida. La mayoría se diagnostica en forma tardía, como resultado de estudios de infertilidad o complicaciones obstétricas tempranas o tardías. La resonancia magnética (RM) es un examen no invasivo, que no utiliza radiación ionizante, con una alta resolución de contraste, que permite la evaluación multiplanar de las malformaciones müllerianas, permitiendo su aproximación diagnóstica y caracterización, complementando otras técnicas de imágenes como la histerosalpingografía y la ecografía ginecológica. El radiólogo debe estar familiarizado con las alteraciones anatómicas de los genitales femeninos y su representación en RM permitiendo un diagnóstico diferencial apropiado, oportuno y en consecuencia, un tratamiento adecuado. Este artículo describe los hallazgos en este grupo de malformaciones según la clasificación de la American Fertility Society, la más utilizada en la literatura actual.

The uterus-vaginal or Müllerian anomalies are a group of congenital diseases that are caused by a developmental defect, merger or channeling of Müllerian ducts in the embryonic stage, exceptionally may be due to an acquired disorder. Most belatedly diagnosed as a result of studies of infertility or early or late obstetric complications. Magnetic resonance imaging (MRI) is a noninvasive test that does not use ionizing radiation, with high contrast resolution, which allows multiplanar evaluation of Müllerian malformations, allowing its diagnostic approach and characterization, complementing other imaging techniques such as hysterosalpingography and gynecological ultrasound. The radiologist should be familiar with the anatomical abnormalities of the female genitalia and its representation in MRI, allowing an appropriate and timely differential diagnosis, and consequently, an appropriate treatment.

Sharp Pelvic Dissection for Abdominoperineal Resection for Distal Rectal Cancer Based on Anatomical and MRI Knowledge

Even though sphincter saving surgery such as coloanal anastomosis or intersphincteric resection have been popular in era of Total Mesorectal Excision (TME) in distal rectal cancer, unreasonable sphincter saving surgery might cause a couple of troublesome complications in terms of oncologic or functional outcomes. Since preoperative staging work up recently have been developed with MRI or MDCT, it is important to assess whether rectal cancer invaded into surrounding sphincter or levator ani muscle based on MRI or MDCT coronal image study. If tumor is located at a very close distance or has invaded the adjacent sphincter muscle, the need of abdominoperineal resection is definite without any hesitation for curative resection. But, the actual number of cases of APR have been decreased in favor of sphincter preserving surgery even APR remains an important therapeutic option in the surgical treatment of low rectal cancer. Indication case for APR have become a intersphincteric resection or ultralow anterior resection and coloanal anastomosis Even patients who showed invasion of sphincter underwent sphincter saving surgery, lately proven safe in terms of recurrence and defecation functions. On practical view points on operative techniques, abdominal phase are same as TME techniques. Sharp pelvic dissection must be carried out along the visceral fascia enveloping the mesorectum to the levator ani muscle with preservation of pelvic autonomic nerve. Perineal phase dissection is a key process in APR. During perineal dissection, inadequate resection margin and blunt tissue dissection along the nonanatomical plane encourage implantation of a malignant cell and local recurrence. Moreever, it could lead to serious complications such as prostatic urethral injury, vaginal wall perforation, perineal sinus and fistula. Massive bleeding from pelvic side wall major vessels injury. Especially in males with very narrow pelvis, pelvic dissection is very difficult due to deep narrow and blunt sacral curvature of the pelvis. It is nearly impossible to reach the levator ani muscle and result in perineal dissections performed on excessively high levels. For colorectal surgeons with insufficient experience, it is difficult to dissect the rectum from the perineum upto the seminal vesicle level. In the classic pattern, anterior and lateral dissection from the prostate or vagina after the completion of posterior dissection. The dissected proximal colon was delivered outward through the perineal wound and with traction of the delivered portion of the colon, anterior dissection was performed. However, in patients with narrow pelvis, such delivery of the proximal colon through perineal wound can result in fractured tumor and local recurrence due to limited operation field. Therefore, it is mandatory that specimen must be delivered in situ after posterior, anterior and lateral dissection. During posterior dissection, gluteus muscle must be observed and removal of the ischiorectal fat tissue should be accomplished. In lateral dissection, levator ani muscle must be divided near the bony insertion. Finally, during anterior dissection, seminal vesicle and prostate gland must be exposed and neurovascular bundle observed at the 10 and 2 o'clock direction. In addition to TME on abdominal phase, Sharp Anatomical Perineal Dissection (SAPD) empowered by 3D concept based on MRI is a key process for prevention of local recurrence in APR.

Assessment of Tumor Regression by Consecutive Pelvic Magnetic Resonance Imaging and Dose Modification during High- Dose-Rate Brachytherapy for Carcinoma of the Uterine Cervix / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: To assess tumor regression, as determined by pelvic magnetic resonance imaging (MRI), and evaluate the efficacies and toxicities of the interim brachytherapy (BT) modification method, according to tumor regression during multi-fractionated high-dose-rate (HDR) BT for uterine cervical cancer. MATERIALS AND METHODS: Consecutive MRI studies were performed pre-radiotherapy (RT), pre-BT and during interfraction of BT (inter-BT) in 69 patients with cervical cancer. External beam radiotherapy (EBRT) was performed, using a 10 MV X-ray, in daily fraction of 1.8 Gy with 4-fields, 5 d/wk. Radiation was delivered up to 50.4 Gy, with midline shielding at around 30.6 Gy. Of all 69 patients, 50 received modified interim BT after checking the inter-BT MRI. The BT was delivered in two sessions; the first was composed of several 5 Gy fractions to point A, twice weekly, using three channel applicators. According to the three measured orthogonal diameters of the regressed tumor, based on inter-BT MR images, the initial BT plan was modified, with the second session consisting of a few fractions of less than 5 Gy to point A, using a cervical cylinder applicator. RESULTS: The numbers of patients in FIGO stages Ib, IIa, IIb and IIIb+IVa were 19 (27.5%), 18 (26.1%), 27 (39.2%) and 5 (7.2%), respectively. Our treatment characteristics were comparable to those from the literatures with respect to the biologically effective dose (BED) to point A, rectum and bladder as reference points. In the regression analysis a significant correlation was observed between tumor regression and the cumulative dose to point A on the follow-up MRI. Nearly 80% regression of the initial tumor volume occurred after 30.6 Gy of EBRT, and this increased to 90% after an additional 25 Gy in 5 fractions of BT, which corresponds to 73.6 Gy of cumulative BED10 to point A. The median total fraction number, and those at the first and second sessions of BT were 8 (5~10), 5 (3~7) and 3 (1~5), respectively. The median follow-up time was 53 months (range, 9~66 months). The 4-year disease-free survival rate of all patients was 86.8%. Six (8.7%) patients developed pelvic failures, but major late complications developed in only two (2.9%). CONCLUSION: Our study shows that effective tumor control, equivalent survival and low rates of major complications can be achieved by modifying the fraction size during BT according to tumor regression, as determined by consecutive MR images. We recommend checking the follow-up MRI at a cumulative BED10 of around 65 Gy to point A, with the initial BT modified at a final booster BT session.