Background
Advanced low rectal cancer has a non-negligible risk of lateral pelvic lymph node (LPLN) metastasis (LPLNM) and lateral local recurrence (LR) after neoadjuvant (chemo)radiotherapy and ...total mesorectal excision. LPLN dissection (LPLND) reduces LR but increases postoperative complications and sexual/urinary dysfunction.
Objective
The aim of this study was to develop a new radiomics-based prediction model for LPLNM in patients with rectal cancer.
Methods
A total of 247 patients with rectal cancer and enlarged LPLNs treated by (chemo)radiotherapy and LPLND were enrolled in this retrospective, multicenter study. LPLN radiomic features were extracted from pretreatment portal venous-phase computed tomography images. A radiomics score of LPLN was constructed based on the least absolute shrinkage and selection operator regression in a primary cohort of 175 patients. Model performance was assessed in terms of discrimination, calibration, and decision curve analysis, and was externally validated in 72 patients.
Results
The radiomics score showed significantly better discrimination compared with pretreatment short-axis diameter measurements in both the primary (area under the curve AUC 0.91 vs. 0.83,
p
= 0.0015) and validation (AUC 0.90 vs. 0.80,
p
= 0.0298) cohorts. Decision curve analysis also indicated the superiority of the radiomics score. In a subanalysis of patients with a short-axis diameter ≥ 7 mm, the radiomics nomogram, incorporating the radiomics score and LPLN shrinkage to ≤ 4 mm, had better discrimination compared with a model incorporating only LPLN shrinkage in both cohorts.
Conclusions
Radiomics-based prediction modeling provides individualized risk estimation of LPLNM in rectal cancer patients treated with (chemo)radiotherapy, and outperforms measurements of pretreatment LPLN diameter.
Based on the finding that 15%–20% of patients with T3/T4 rectal cancer located below the peritoneal reflection (Rb) have metastases in the LPLN, the Japanese guideline recommends bilateral LPLN ...dissection in every patient with T3/4 Rb rectal cancer even in the absence of clinically suspicious LPLN metastasis. In the era of modern high‐resolution MRI and 64‐slice contrast‐enhanced helical computed tomography, the risk of LPLN involvement can be better predicted compared to the old imaging modalities. A recent large international multicenter retrospective study with 1216 patients with low cT3/4 rectal cancer treated with neoadjuvant RT/CRT demonstrated better oncological outcomes by combining LPLN dissection with RT/CRT in patients with clinically enlarged LPLN.
Background:
The clinicopathological features of ulcerative colitis‐associated colorectal cancer (UC‐CRC) have not yet been fully clarified, especially in Asian populations. This study aimed to ...clarify the prognosis and clinicopathological features of UC‐CRC in comparison with sporadic CRC in the Japanese population.
Methods:
Histologically diagnosed UC‐CRC patients between 1978 to 1998 were extracted from the Multi‐Institutional Registry of Large‐Bowel Cancer in Japan, a large nationwide CRC database, and the clinicopathological features and postoperative survival rates of UC‐CRC patients and sporadic CRC patients were compared.
Results:
Among the 108,536 CRC patients registered between 1978 and 1998, a total of 169 UC‐CRC patients were identified, including 121 patients who had been treated surgically. The proportion of UC‐CRC patients increased in the period between 1995 and 1998 compared to that between 1978 and 1994. Comparisons with the sporadic CRC patients showed that the UC‐CRC patients were younger, had a higher proportion of multiple cancer lesions, had higher proportions of superficial type lesions and invasive type lesions morphologically, and had higher proportions of mucinous or signet ring cell carcinomas. In stage III, UC‐CRC patients had a poorer survival rate than the sporadic CRC patients (43.3% versus 57.4%, P = 0.0320).
Conclusions:
UC‐CRC increased over the investigated time periods and showed a poorer survival than sporadic CRC in the advanced stage, while no difference was observed in the early stage. By detecting UC‐CRC at an early stage we can expect a similar postoperative outcomes to that of sporadic CRC. These results stress the importance of surveillance for the early detection of UC‐CRC. Inflamm Bowel Dis 2011
Background
Acquiring appropriate laparoscopic technique is necessary to safely perform laparoscopic surgery. The Endoscopic Surgical Skill Qualification System of the Japanese Society of Endoscopic ...Surgery, which was established to improve the quality of laparoscopic surgery in Japan, provides training to become an expert laparoscopic surgeon. In this study, we describe our educational system, in a Japanese highest volume cancer center, and evaluate the system according to the pass rate for the Endoscopic Surgical Skill Qualification System examination.
Methods
We assessed 14 residents who trained for more than 2 years from 2012 to 2018 in our department. All teaching surgeons, qualified by the Endoscopic Surgical Skill Qualification System, participated in all surgeries as supervisors. For the first 3 months, trainees learned as the scopist, then as the first assistant for 3 months, and then by performing laparoscopic surgery as an operator during ileocecal resection or sigmoidectomy. Trainees apply for this training in their second year of residency or later. All laparoscopic procedures in our department are standardized in detail.
Results
The cumulative pass rate was 75% (12/16), and 87% (12/14) of the trainees eventually passed, while the general pass rate was approximately 30%. On average, those who passed in their second or third year had experienced 94 procedures as the surgeon, 177 as the first assistant, and 199 as the scopist. The number of laparoscopic procedures and the learning curves did not differ between successful and failed applicants.
Conclusions
Through our educational system, residents successfully acquired laparoscopic skills with a much higher pass rate in the Endoscopic Surgical Skill Qualification System examination than the general standard. Laparoscopic practice under supervision by experienced surgeons with standardized procedures and accurate understanding of the relevant anatomy is very helpful to achieving appropriate laparoscopic technique.
Background
Lateral pelvic node (LPN) dissection (LPND) is considered a promising technique for treating low rectal cancer; however, there is insufficient evidence of its prognostic value. Using ...centrally reviewed preoperative pelvic magnetic resonance (MR) images, this study aimed to find the patient population who has benefited from LPND.
Patients and Methods
MR images of patients from 69 institutes with stage II–III low rectal cancer were reviewed by experienced radiologists. Recurrence-free survival (RFS), overall survival (OS), and short-term outcomes were measured.
Results
In total, 731 preoperative MR images were reviewed (excluding patients with short-axis LPN ≥ 10 mm). Of these, 322 underwent total mesorectum excision (TME) without LPND (non-LPND group), and 409 underwent TME with LPND (LPND group). Preoperative treatment was performed for 40% and 25% of patients in the non-LPND and LPND groups, respectively. The incidence of postoperative complications was higher in the LPND group (44.5%) than in the non-LPND group (33.2%;
P
= 0.002). Among patients with LPNs < 5 mm, OS and RFS curves were not significantly different between the groups. Among patients with LPNs ≥ 5 mm, the LPND group had significantly higher 5-year OS and RFS than the non-LPND group (OS: 81.9% versus 67.3%; RFS: 69.4% versus 51.6%). On multivariate analysis of LPN ≥ 5 mm cases, LPND was independently associated with RFS.
Conclusions
Despite the high incidence of postoperative complications, this study showed the prognostic impact of LPND on low rectal cancer patients with LPNs (≥ 5 mm, < 10 mm short axis) measured by experienced radiologists.
Trial registration
UMIN-ID: UMIN000013919
A novel fractional orthogonal frequency division multiplexing (FrOFDM)-based 100-GHz serial-to-parallel (S-P) converter is experimentally demonstrated. A 10-GHz sinusoidally modulated Nyquist-optical ...time division multiplexing serial signal, with 100-GHz repetition rate, is optically restored after S-P conversion. In addition, the performances for quadrature phase shift keying (QPSK) modulation have been numerically evaluated. Also in this case, the error vector magnitude values and the constellation map of 100-GHz QPSK serial signals demonstrate a successful S-P conversion.
BACKGROUND:Mesorectal excision with lateral lymph node dissection is the standard treatment for locally advanced low rectal cancer in Japan. However, the safety and feasibility of laparoscopic ...lateral lymph node dissection remain to be determined.
OBJECTIVE:The purpose of this study was to evaluate the safety and feasibility of laparoscopic versus open lateral lymph node dissection for locally advanced low rectal cancer.
DESIGN:This was a retrospective cohort study using an exact matching method.
SETTING:We conducted a multicenter study of 69 specialized centers in Japan.
PATIENTS:Patients with consecutive midrectal or low rectal adenocarcinoma cancer stage II to III who underwent mesorectal excision with curative intent between 2010 and 2011 were recruited.
MAIN OUTCOME MEASURES:Short-term and oncological outcomes were compared between the laparoscopic and open-surgery groups.
RESULTS:Of the 1500 eligible patients, 676 patients who underwent lateral lymph node dissection were analyzed, including 137 patients who were treated laparoscopically and 539 patients who were treated with open surgery. After matching, the patients were stratified into laparoscopic (n = 118) and open-surgery (n = 118) groups. Operative times in the overall cohort were significantly longer (461 vs 372 min) in the laparoscopic versus the open-surgery group. In the laparoscopic group, the blood loss volume was significantly smaller (193 vs 722 mL), with fewer instances of blood transfusion (7.3% vs 25.5%) compared with the open-surgery group. The postoperative complication rates were 35.8% and 43.6% for the laparoscopic and open-surgery groups (p = 0.10). The 3-year relapse-free survival rates were 80.3% and 72.6% for the laparoscopic and open-surgery groups (p = 0.07).
LIMITATIONS:The study was limited by its retrospective design and potential selection bias.
CONCLUSIONS:Laparoscopic lateral lymph node dissection is safe and feasible for cancer stage II to III low rectal cancer and is associated with similar oncological outcomes as open lateral lymph node dissection. See Video Abstract at http://links.lww.com/DCR/A334.
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