Indications for Lateral Pelvic Lymph Node Dissection Based on Magnetic Resonance Imaging Before and After Preoperative Chemoradiotherapy in Patients with Advanced Low-Rectal Cancer

Abstract

MRI before CRT is useful to predict LPLN metastasis and to determine the indications for LPLD.

Prognostic Impact of Neutrophil-to-Lymphocyte Ratio in Patients with Advanced Low Rectal Cancer Treated with Preoperative Chemoradiotherapy

“…Between July 2004 and December 2012, 219 consecutive patients with locally advanced (cT3-4 or cN+ and without distant metastasis at surgery) low rectal adenocarcinoma were treated with long-course NACRT followed by surgery at our institute [24][25][26][27] . Low rectal cancer is defined as a tumor located below the peritoneal reflection, which is equivalent to within 8 cm from the anal verge (AV).…”

Correlations between the Recurrence Patterns and Sizes of Lateral Pelvic Lymph Nodes before and after Chemoradiotherapy in Patients with Lower Rectal Cancer

“…Oh et al [16] investigated 66 patients with mid/low rectal cancer who had suspected LPN metastases and who underwent preoperative CRT and LPN dissection; they found that the overall and disease-free survival rates of patients with persistently enlarged LPNs after CRT were poorer. In contrast, Akiyoshi et al [11] reported no association between LPN size and prognosis after analyzing 77 patients with low rectal cancer. Our data showed that LPN size before CRT correlated with liver metastasis while that after CRT correlated with lung metastasis; the fact that the previous studies did not investigate sites of metastases may have contributed to their discrepant outcomes.…”

“…In a study of patients who did not undergo neoadjuvant CRT, the sensitivity and specificity of LPN size as a predictor of metastasis were 68.6-87% and 79.7-81.0%, respectively [9,10]. In a study of patients who did receive neoadjuvant CRT, the sensitivity and specificity of postneoadjuvant CRT LPN size were reported to be 67.7 and 84.8%, respectively [11]. Because most institutions do not perform lateral LPN dissection for all patients who undergo neoadjuvant CRT, it is difficult to preoperatively diagnose LPN metastasis accurately.…”

Correlations between the sizes of lateral pelvic lymph nodes and metastases in rectal cancer patients treated with preoperative chemoradiotherapy

“…We consider that the LLN size after CRT might be more diagnostic for the final pathological status than the size before CRT, because we previously reported that, when measured with CT or MRI, pathologically negative LLNs had significantly reduced in size in response to CRT; however, in contrast, pathologically positive LLNs had not. 16 However, as mentioned above, the sizes of lymph nodes cannot be correctly examined on CT or MRI cross sections when these sections fail to capture the maximum dimensions the lymph nodes; this can lead to underestimating the sizes of lymph nodes and skewing of the data. 14 However, concerns have been raised regarding the diagnostic reliability of lymph node size as determined via imaging.…”