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.
Although smaller circular staplers are easier to insert and less likely to involve the vagina and levator ani muscles when performing double stapling technique anastomosis, surgeons often consider ...that larger circular staplers would be safer in reducing the risk of postoperative anastomotic strictures.
This study aimed to investigate the safety of using 25-mm circular staplers compared with 28/29-mm staplers in the double stapling technique anastomosis regarding the development of anastomotic strictures and other complications.
This is a retrospective observational study.
This study was conducted at a single comprehensive cancer center.
Consecutive patients undergoing curative colorectal resection with double stapling technique anastomosis for stage I to III sigmoid colon and rectal cancer between 2013 and 2016 were included.
The incidence of anastomotic complications (strictures, leakage, and bleeding) was compared between the 25- and 28/29-mm circular staplers. Predictors for anastomotic strictures were investigated with multivariable logistic regression.
Small (25-mm) staplers were used in 186 (22.8%) of 815 eligible patients. The 25-mm staplers were associated with use in female patients, splenic flexure take down, high tie of the inferior mesenteric artery, and low anastomosis. Overall anastomotic complications (11.8% vs 13.7%, p = 0.51), strictures (5.9% vs 3.3%, p = 0.11), leakage (2.7% vs 3.8%, p = 0.47), and bleeding (4.8% vs 7.6%, p = 0.19) were not different between the 25- and 28/29-mm staplers. From multivariable logistic regression, independent predictors of anastomotic strictures included diverting ostomy and anastomotic leakage, but not small circular stapler use. Most of the 32 anastomotic strictures were successfully treated without surgical intervention (finger dilation, n = 25; endoscopic intervention, n = 5).
This was a single-center retrospective study.
Use of 25-mm circular staplers for double stapling technique anastomosis is safe and does not increase the risk of anastomotic strictures and other anastomotic complications in comparison with larger staplers. See Video Abstract at http://links.lww.com/DCR/B576.
ANTECEDENTES:Aunque las engrapadoras circulares más pequeñas son más fáciles de insertar y menos probable que involucren a la vagina y los músculos elevadores del ano, cuando se realiza una anastomosis con técnica de doble engrapado, frecuentemente los cirujanos consideran que las engrapadoras circulares más grandes, serían más seguras para disminuir los riesgos de estenosis anastomóticas postoperatorias.OBJETIVO:El estudio se dirigió para investigar la seguridad en el uso de engrapadoras circulares de 25 mm, en comparación con engrapadoras de 28/29 mm, en anastomosis con técnica de doble engrapado, en relación al desarrollo de estenosis anastomóticas y otras complicaciones.DISEÑO:Estudio observacional retrospectivo.AJUSTE:Centro oncológico integral único.PACIENTES:Se incluyeron pacientes consecutivos sometidos a resección colorrectal curativa, con anastomosis y técnica de doble engrapado, para cáncer de recto y colon sigmoide en estadios I-III entre 2013 y 2016.PRINCIPALES MEDIDAS DE RESULTADO:Se compararon las incidencias de complicaciones anastomóticas (estenosis, fugas y sangrados) entre las engrapadoras circulares de 25 y 28/29 mm. Los predictores para estenosis anastomóticas se investigaron con regresión logística multivariable.RESULTADOS:Entre un total de 815 pacientes elegibles, se utilizaron engrapadoras de 25 mm en 186 (22,8%). Las engrapadoras de 25 mm se asociaron con el uso en pacientes femeninas, descenso del ángulo esplénico, ligadura alta de arteria mesentérica inferior y anastomosis baja. Complicaciones anastomóticas generales (11,8% vs. 13,7%, p = 0,51), estenosis (5,9% vs. 3,3%, p = 0,11), fugas (2,7% vs. 3,8%, p = 0,47) y sangrado (4,8% vs. 7,6%, p = 0,19). No hubo diferencia entre las engrapadoras de 25 y 28/29 mm. En la regresión logística multivariable, predictores independientes de estenosis anastomóticas incluyeron ostomía derivativa y fuga anastomótica, pero no incluyeron el uso de engrapadoras circulares pequeñas. La mayoría de las 32 estenosis anastomóticas se trataron con éxito sin intervención quirúrgica (dilatación del dedo, n = 25; intervención endoscópica, n = 5).LIMITACIONES:Fue un estudio retrospectivo de un solo centro.CONCLUSIONES:El uso de engrapadoras circulares de 25 mm para la anastomosis con técnica de doble engrapado, es seguro y no aumenta el riesgo de estenosis anastomóticas y de otras complicaciones anastomóticas, cuando son comparadas con engrapadoras más grandes. Consulte Video Resumen en http://links.lww.com/DCR/B576. (Traducción-Dr. Fidel Ruiz-Healy).
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.