The role of baseline mesorectal fascia status and its change after neoadjuvant therapy in predicting prognosis in locally advanced rectal cancer / 中华放射学杂志

Objective:To analyze the role of baseline mesorectal fascia (MRF) status and the correlation between MRF changes and prognosis after neoadjuvant therapy in patients with locally advanced rectal cancer.Methods:Totally 321 patients with locally advanced rectal cancer were retrospectively analyzed from January 2014 to December 2016 in Peking University Cancer Hospital. All patients underwent surgery after neoadjuvant radiotherapy and chemotherapy, and were followed up regularly after surgery. The MRF status, extramural vascular invasion (EMVI) status, tumor location, tumor stage and lymph node status were evaluated on baseline MRI. For patients with positive baseline MRF, preoperative MRF status was also evaluated. Chi-square test or independent t test were used to compare the characteristics between MRF positive and negative patients. Kaplan-Meier curve, log-rank test and multivariate Cox regression were used to analyze the correlation between imaging features and prognosis. Results:In all of the 321 subjects, 193 (60.1%) had positive baseline MRF, 54 (28.0%) of the 193 patiens had negative MRF after neoadjuvant therapy, and 139 (72.0%) of them still had positive MRF preoperatively. The postoperative pathological T and N stages were significantly higher in patients with positive baseline MRF than those with negative MRF, and the proportion of patients achieving complete pathological response was significantly lower than those with negative MRF (all P<0.05). The postoperative pathological T and N stages of patients with MRF negative conversion were significantly lower than those without MRF negative conversion. In patients with negative baseline MRF and patients with negative MRF conversion after neoadjuvant therapy, the proportion of positive MRI EMVI was significantly lower (all P<0.05). Univariate survival analysis showed that overall survival and metastasis free survival were poorer in patients with positive MRF at baseline, with a hazard ratio of 3.33 and 1.69, respectively. There was no significant correlation between negative MRF conversion after neoadjuvant therapy and overall survival, metastasis free survival and recurrence free survival. Multivariate Cox analysis showed that baseline MRF and EMVI status were independent factors for overall survival and metastasis free survival, with a risk ratio of 2.15 and 3.35 for overall survival, 1.13 and 2.74 for metastasis free survival, respectively. Conclusions:Baseline MRF status is one of the independent prognostic predictors in locally advanced rectal cancer patients with neoadjuvant therapy. However, the role of the change in MRF status after neoadjuvant therapy is uncertain for predicting prognosis.

Endorectal ultrasound in evaluation on mesorectal fascia invasion in preoperative rectal cancer / 中国医学影像技术

Objective To evaluate the value of endorectal ultrasonography (ERUS) in assessment of mesorectal fascia (MRF) invasion in rectal cancer.Methods Data of 44 patients who accepted preoperative ERUS and total mesorectal excision surgery within a week were retrospective analyzed.There were 18 patients who accepted preoperative neoadjuvant chemotherapy and 26 patients didn't acceped.Taking the pathological diagnosis of circumferential resection margin (CRM) as the gold standard,the diagnostic efficiency of ERUS for the MRF invasion in rectal cancer was evaluated.Results The final pathological T staging was T1 in 2 cases,T2 in 17 cases and T3 in 25 cases.There were 2 cases of CRM positive results,and 42 cases of CRM negative results.With regard to the location of tumor,there were 16 cases located in low,and 28 cases in mid rectum.There were 26 cases located in anterior or antero-lateral wall of rectum,13 cases in posterior or postero-lateral wall,and 5 cases with a circle of rectum.The diagnostic accuracy were 83.33 ％ (15/18) and 92.31％ (24/26) for cases of accepting and not accepting the preoperative neoadjuvant chemotherapy;80.77％ (21/26) for cases located in anterior or antero-lateral wall,and 100％ (13/13) for cases located in posterior or postero-lateral wall;75.00％ (12/16)and 96.43 ％ (27/28) for low position and mid position tumors.The total diagnostic accuracy was 88.64％ (39/44).Conclusion ERUS can be an effective method in preoperative assessment of the MRF invasion in rectal cancer.

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.

MR Study on the Mesorectum and Mesorectal Fascia / 实用放射学杂志

Objective To study MR imaging manifestations of the mesorectum and mesorectal fascia. Methods 100 cases were divided into five groups according to the age. All MR images were retrospectively observed and analyzed by two radiologists.The observing contents included: ①exhibition of the mesorectal fascia, ②the signal intensity of the mesorectum and the pelvic fat and ③the thickness ratio of the mesorectum and the subcutaneous fat in different ages. All data were dealed with SPSS 10.0 software. Results The showing rate of the anterior, posterior, left and right mesorectal fascia respectively were 77, 100, 91 and 93 by MR imaging. The signal intensity of the mesorectum(550.8843) was significantly higher than that(469.8693) of pelvic fat in all five groups(P﹤0.05) and the signal difference between the mesorectum and the pelvic fat could be detected by naked eye. The thickness of the mesorectum and the subcutaneous fat had no association with ages.Conclusion MRI can display the mesorectum and mesorectal fascia clearly. The signal intensity of the mesorectum is significantly higher than that of pelvic fat in five groups. The thickness of the mesorectum and the subcutaneous fat have no association with ages.