A new era in surgical oncology: preliminary insights into the hinotori™ surgical robot system's role in rectal surgery using the double bipolar method.

BACKGROUND: The da Vinci™ Surgical System, recognized as the leading surgical robotic platform globally, now faces competition from a growing number of new robotic surgical systems. With the expiration of key patents, innovative entrants have emerged, each offering unique features to address limitations and challenges in minimally invasive surgery. The hinotori™ Surgical Robot System (hinotori), developed in Japan and approved for clinical use in November 2022, represents one such entrant. This study demonstrates initial insights into the application of the hinotori in robot-assisted surgeries for patients with rectal neoplasms. METHODS: The present study, conducted at a single institution, retrospectively reviewed 28 patients with rectal neoplasms treated with the hinotori from November 2022 to March 2024. The surgical technique involved placing five ports, including one for an assistant, and performing either total or tumor-specific mesorectal excision using the double bipolar method (DBM). The DBM uses two bipolar instruments depending on the situation, typically Maryland bipolar forceps on the right and Fenestrated bipolar forceps on the left, to allow precise dissection, hemostasis, and lymph node dissection. RESULTS: The study group comprised 28 patients, half of whom were male. The median age was 62 years and the body mass index stood at 22.1 kg/m2. Distribution of clinical stages included eight at stage I, five at stage II, twelve at stage III, and three at stage IV. The majority, 26 patients (92.9%), underwent anterior resection using a double stapling technique. There were no intraoperative complications or conversions to other surgical approaches. The median operative time and cockpit time were 257 and 148 min, respectively. Blood loss was 15 mL. Postoperative complications were infrequent, with only one patient experiencing transient ileus. A median of 18 lymph nodes was retrieved, and no positive surgical margins were identified. CONCLUSIONS: The introduction of the hinotori for rectal neoplasms appears to be safe and feasible, particularly when performed by experienced robotic surgeons. The double bipolar method enabled precise dissection and hemostasis, contributing to minimal blood loss and effective lymph node dissection.

Multiparametric MRI-based radiomic model for predicting lymph node metastasis after neoadjuvant chemoradiotherapy in locally advanced rectal cancer.

OBJECTIVES: To construct and validate multiparametric MR-based radiomic models based on primary tumors for predicting lymph node metastasis (LNM) following neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer (LARC) patients. METHODS: A total of 150 LARC patients from two independent centers were enrolled. The training cohort comprised 100 patients from center A. Fifty patients from center B were included in the external validation cohort. Radiomic features were extracted from the manually segmented volume of interests of the primary tumor before and after nCRT. Feature selection was performed using multivariate logistic regression analysis. The clinical risk factors were selected via the least absolute shrinkage and selection operator method. The radiologist's assessment of LNM was performed. Eight models were constructed using random forest classifiers, including four single-sequence models, three combined-sequence models, and a clinical model. The models' discriminative performance was assessed via receiver operating characteristic curve analysis quantified by the area under the curve (AUC). RESULTS: The AUCs of the radiologist's assessment, the clinical model, and the single-sequence models ranged from 0.556 to 0.756 in the external validation cohort. Among the single-sequence models, modelpost_DWI exhibited superior predictive power, with an AUC of 0.756 in the external validation set. In combined-sequence models, modelpre_T2_DWI_post had the best diagnostic performance in predicting LNM after nCRT, with a significantly higher AUC (0.831) than those of the clinical model, modelpre_T2_DWI, and the single-sequence models (all p < 0.05). CONCLUSIONS: A multiparametric model that incorporates MR radiomic features before and after nCRT is optimal for predicting LNM after nCRT in LARC. CRITICAL RELEVANCE STATEMENT: This study enrolled 150 LARC patients from two independent centers and constructed multiparametric MR-based radiomic models based on primary tumors for predicting LNM following nCRT, which aims to guide therapeutic decisions and predict prognosis for LARC patients. KEY POINTS: The biological characteristics of primary tumors and metastatic LNs are similar in rectal cancer. Radiomics features and clinical data before and after nCRT provide complementary tumor information. Preoperative prediction of LN status after nCRT contributes to clinical decision-making.

Utility of abbreviated MRI in the post-treatment evaluation of rectal cancer.

BACKGROUND: Post-treatment evaluation of patients with rectal cancer (RC) using magnetic resonance imaging (MRI) burdens medical resources, necessitating an exploration of abbreviated protocols. PURPOSE: To evaluate the diagnostic performance of abbreviated MRI (A-MRI) for the post-treatment evaluation of RC patients. MATERIAL AND METHODS: This retrospective study included RC patients who underwent non-contrast rectal MRI and standard liver MRI, as well as abdominal contrast-enhanced computed tomography (CECT) for post-treatment evaluation. A-MRI comprised diffusion-weighted imaging (DWI) and T2-weighted imaging of the upper abdomen and the pelvic cavity. Three radiologists independently reviewed A-MRI, CECT, and standard liver MRI in the detection of viable disease. The diagnostic performances were compared using a reference standard considering all available information, including pathology, FDG-PET, endoscopic results, and clinical follow-up. RESULTS: We included 78 patients (50 men, 28 women; mean age=60.9 ± 10.2 years) and observed viable disease in 34 (43.6%). On a per-patient-basis analysis, A-MRI showed significantly higher sensitivity (95% vs. 81%, P = 0.04) and higher accuracy (93% vs. 82%, P < 0.01), compared to those of CECT, while A-MRI showed comparable sensitivity (91% vs. 91%, P = 0.42) and accuracy (97% vs. 98%, P = 0.06) to that of standard liver MRI. On a per-lesion-based analysis, A-MRI exhibited significantly superior lesion detectability than that of CECT (figure of merit 0.91 vs. 0.77, P < 0.01) and comparable to that of standard liver MRI (figure of merit 0.91 vs. 0.92, P = 0.75). CONCLUSION: A-MRI exhibited higher sensitivity and diagnostic accuracy than those of CECT in the post-treatment evaluation of RC, while it showed comparable performances with standard liver MRI. A-MRI provides diagnostic added value in the follow-up of RC patients.

R2* mapping and reduced field-of-view diffusion-weighted imaging for preoperative assessment of nonenlarged lymph node metastasis in rectal cancer.

The aim of the current study is to investigate the diagnostic value of R2* mapping versus reduced field-of-view diffusion-weighted imaging (rDWI) of the primary lesion of rectal cancer for preoperative prediction of nonenlarged lymph node metastasis (NLNM). Eighty-one patients with pathologically confirmed rectal cancer underwent preoperative R2* mapping and rDWI sequences before total mesorectal excisions and accompanying regional lymph node dissections. Two radiologists independently performed whole-tumor measurements of R2* and apparent diffusion coefficient (ADC) parameters on primary lesions of rectal cancer. Patients were divided into positive (NLNM+) and negative (NLNM-) groups based on their pathological analysis. The tumor location, maximum diameter of the tumor, and maximum short diameter of the lymph node were assessed. R2* and ADC, pT stage, tumor grade, status of mesorectal fascia, and extramural vascular invasion were also studied for their potential relationships with NLNM using multivariate logistic regression analysis. The NLNM+ group had significantly higher R2* (43.56 ± 8.43 vs. 33.87 ± 9.57, p < 0.001) and lower ADC (1.00 ± 0.13 vs. 1.06 ± 0.22, p = 0.036) than the NLNM- group. R2* and ADC were correlated to lymph node metastasis (r = 0.510, p < 0.001 for R2*; r = -0.235, p = 0.035 for ADC). R2* and ADC showed good and moderate diagnostic abilities in the assessment of NLNM status with corresponding area-under-the-curve values of 0.795 and 0.636. R2* provided a significantly better diagnostic performance compared with ADC for the prediction of NLNM status (z = 1.962, p = 0.0498). The multivariate logistic regression analysis demonstrated that R2* was a compelling factor of lymph node metastasis (odds ratio = 56.485, 95% confidence interval: 5.759-554.013; p = 0.001). R2* mapping had significantly higher diagnostic performance than rDWI from the primary tumor of rectal cancer in the prediction of NLNM status.

Applying the fragility index to randomized controlled trials evaluating total neoadjuvant therapy for rectal cancer: A methodological survey.

BACKGROUND: Recently, there has been significant interest in, and adoption of, total neoadjuvant therapy (TNT) for locally advanced rectal cancer (LARC). We designed the present study to assess the robustness of the randomized controlled trials (RCTs) evaluating contemporary TNTs for LARC using the fragility index (FI). MATERIALS AND METHODS: Relevant articles were identified through a review article by Johnson et al. in the Canadian Journal of Surgery. Dichotomous outcomes within these RCTs were eligible for inclusion if the reported effect size had a p-value < 0.05. The main outcome was FI for each included outcome. Walsh et al.'s method of calculating FI was utilized. Correlations between FI and research characteristics were assessed using the Spearman's rank correlation coefficients. Risk of bias was assessed using Cochrane recommended tools. RESULTS: Ten RCTs were identified with 25 outcomes having statistically significant differences between groups. Eleven outcomes were time-to-event outcomes, while the remainder were dichotomous outcomes. Approximately half (n = 13) were oncologic outcomes. The median FI was 2 (interquartile range [IQR] 1-16). The number of patients lost to follow-up exceeded the FI in 17 outcomes (68.0 %) and thus these results were considered "fragile". Lower FI was associated with high risk of bias (rho = -0.5594) and greater loss to follow-up (rho = -0.4394), while higher FI was associated with large study size (rho = 0.5120). CONCLUSIONS: The robustness of outcomes from trials assessing TNT for LARC was found to be questionable. Most outcomes were fragile, as determined by the FI. This survey is limited by the number of included studies.

Effect of Extralevator Abdominoperineal Excision on Biomechanics of Female Pelvic Floor: A Finite Element Analysis / 肿瘤防治研究

Objective To explore the effects of four extralevator abdominoperineal excision (ELAPE) procedures on the biomechanics of female pelvic floor through finite element analysis. Methods Six finite element models of the female pelvic floor were established, including a normal model, an ELAPE model, and four individual models. The maximum stress in each model was measured under the same pressure, and the stress distribution was observed. Results The maximum stress of non-levator ani muscle tissues on the partially reserved side and totally removed side of the levator ani muscle were 3.101±0.133 and 4.868±0.123 MPa in individual model 1, respectively, which were lower than the maximum stress in the ELAPE model (5.111±0.081 MPa; both P<0.01). The maximum stress in the non-levator ani muscle tissue were 5.138±0.091 MPa on both sides in individual model 2, which were not significantly different from that in the ELAPE model (P>0.05). The maximum stress of non-levator ani muscle tissues were 4.700±0.105 and 3.653±0.156 MPa in individual models 3 and 4, respectively, which were lower than the maximum stress in the ELAPE model (both P<0.01). Conclusion Three ELAPE procedures, including ELAPE with unilateral levator ani muscle resection plane close to the rectum, and the bilateral pubococcygeal muscle lateral resection of levator ani muscle and levator ani muscle in front of the rectum preserved could decrease stress in the non-levator ani muscle tissue on both sides. The effect is evident on the levator ani muscle partially reserved side of ELAPE with unilateral levator ani muscle resection plane close to the rectum. ELAPE with unilateral levator ani muscle resection plane close to the pelvic wall has no significant reduction effect on the non-levator ani muscle tissue on either side.

Preoperative sequential short-course radiation therapy and FOLFOX chemotherapy versus long-course chemoradiotherapy for locally advanced rectal cancer: a multicenter, randomized controlled trial (SOLAR trial).

BACKGROUND: Preoperative (chemo)radiotherapy has been widely used as an effective treatment for locally advanced rectal cancer (LARC), leading to a significant reduction in pelvic recurrence rates. Because early administration of intensive chemotherapy for LARC has more advantages than adjuvant chemotherapy, total neoadjuvant therapy (TNT) has been introduced and evaluated to determine whether it can improve tumor response or treatment outcomes. This study aims to investigate whether short-course radiotherapy (SCRT) followed by intensive chemotherapy improves oncologic outcomes compared with traditional preoperative long-course chemoradiotherapy (CRT). METHODS: A multicenter randomized phase II trial involving 364 patients with LARC (cT3-4, cN+, or presence of extramural vascular invasion) will be conducted. Patients will be randomly assigned to the experimental or control arm at a ratio of 1:1. Participants in the experimental arm will receive SCRT (25 Gy in 5 fractions, daily) followed by four cycles of FOLFOX (oxaliplatin, 5-fluorouracil, and folinic acid) as a neoadjuvant treatment, and those in the control arm will receive conventional radiotherapy (45-50.4 Gy in 25-28 fractions, 5 times a week) concurrently with capecitabine or 5-fluorouracil. As a mandatory surgical procedure, total mesorectal excision will be performed 2-5 weeks from the last cycle of chemotherapy in the experimental arm and 6-8 weeks after the last day of radiotherapy in the control arm. The primary endpoint is 3-year disease-free survival, and the secondary endpoints are tumor response, overall survival, toxicities, quality of life, and cost-effectiveness. DISCUSSION: This is the first Korean randomized controlled study comparing SCRT-based TNT with traditional preoperative LC-CRT for LARC. The involvement of experienced colorectal surgeons ensures high-quality surgical resection. SCRT followed by FOLFOX chemotherapy is expected to improve disease-free survival compared with CRT, with potential advantages in tumor response, quality of life, and cost-effectiveness. TRIAL REGISTRATION: This trial is registered at Clinical Research Information under the identifier Service KCT0004874 on April 02, 2020, and at Clinicaltrial.gov under the identifier NCT05673772 on January 06, 2023.

Rectal Tropism: An Extremely Rare Case of Prostate Cancer Recurrence With Metastasis to the Rectum Postradical Prostatectomy.

Prostate cancer is the most common noncutaneous cancer affecting men in the United States. It is a slow-growing tumor that can be missed during the nascent phase. Prostate cancer commonly metastasizes to the bones and nearby lymph nodes. However, cases of metastatic prostate cancer to the rectum are exceptionally rare. Such metastases may cause obstructive or malabsorption symptoms similar to those observed in primary rectal carcinoma. We present a very rare case of prostate cancer recurrence with rectal metastasis in an elderly male with a history of castration-resistant prostate carcinoma status postradical prostatectomy.

Pretreatment MRI-detected extramural venous invasion as a prognostic and predictive biomarker for neoadjuvant chemoradiotherapy in non-metastatic rectal cancer: a propensity score matched analysis.

OBJECTIVES: This study evaluated pretreatment magnetic resonance imaging (MRI)-detected extramural venous invasion (pmrEMVI) as a predictor of survival after neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer (LARC). MATERIALS AND METHODS: Medical records of 1184 patients with rectal adenocarcinoma who underwent TME between January 2011 and December 2016 were reviewed. MRI data were collected from a computerized radiologic database. Cox proportional hazards analysis was used to assess local, systemic recurrence, and disease-free survival risk based on pretreatment MRI-assessed tumor characteristics. After propensity score matching (PSM) for pretreatment MRI features, nCRT therapeutic outcomes according to pmrEMVI status were evaluated. Cox proportional hazards analysis was used to identify risk factors for early recurrence in patients receiving nCRT. RESULTS: Median follow-up was 62.8 months. Among all patients, the presence of pmrEMVI was significantly associated with worse disease-free survival (DFS; HR 1.827, 95% CI 1.285-2.597, p = 0.001) and systemic recurrence (HR 2.080, 95% CI 1.400-3.090, p < 0.001) but not local recurrence. Among patients with pmrEMVI, nCRT provided no benefit for oncological outcomes before or after PSM. Furthermore, pmrEMVI( +) was the only factor associated with early recurrence on multivariate analysis in patients receiving nCRT. CONCLUSIONS: pmrEMVI is a poor prognostic factor for DFS and SR in patients with non-metastatic rectal cancer and also serves as a predictive biomarker of poor DFS and SR following nCRT in LARC. Therefore, for patients who are positive for pmrEMVI, consideration of alternative treatment strategies may be warranted. CLINICAL RELEVANCE STATEMENT: This study demonstrated the usefulness of pmrEMVI as a predictive biomarker for nCRT, which may assist in initial treatment decision-making in patients with non-metastatic rectal cancer. KEY POINTS: • Pretreatment MRI-detected extramural venous invasion (pmrEMVI) was significantly associated with worse disease-free survival and systemic recurrence in patients with non-metastatic rectal cancer. • pmrEMVI is a predictive biomarker of poor DFS following nCRT in patients with LARC. • The presence of pmrEMVI was the only factor associated with early recurrence on multivariate analysis in patients receiving nCRT.

MRI in rectal cancer: An institutional real life analysis of technical parameters.

INTRODUCTION: MRI plays a key role in the preoperative staging of rectal cancers and choice of neoadjuvant radiochemotherapy. Yet, the acquisition and interpretation of rectum magnetic resonance imaging (MRI) turn out to be unequal, impacting patients'care. The present study aims at evaluating the quality of the acquisition of technical parameters of the rectal MRI performed by comparing them according to the various guidelines. METHODS: The medical MRI reports of all consecutive patients with locally advanced rectal cancer treated in a curative intent, by preoperative RCT and completion surgery were retrospectively reviewed over two periods (January 2010-December 2014 and January 2018 and December 2020) according to international 2012 and 2016 ESGAR and 2017 SAR MRI recommendation reports. RESULTS: During the first period (69 MRI performed), 58% of these MRI abided by the recommendations and 75% of essential criteria could be found in 25.5% of MRI reportings. During the second period (73 MRI performed), the protocol used by 6.8% of MR images abided by the 2016 Society of Gastrointestinal and Abdominal Radiology (ESGAR) recommendations and 39.7% abided by the Society of Abdominal Radiology (SAR) recommendations. 75% of essential criteria could be found in 52.3% of MRI reportings and 90% of essential criteria could be found in 6.2% of MRI reportings. DISCUSSION: In an era of increasing individualized patient care and conservative treatment focused on tumour response and prognostic factors, the present study showed that compliance to MRI protocols and reporting guidelines needs improving to upgrade patient care.

Influence of proton pump inhibitors on the pathological response of rectal cancer: a multicentre study.

Background: The standard neoadjuvant therapy for rectal cancer involves fluoropyrimidines and radiotherapy and, most recently, total neoadjuvant therapy (TNT). A drug-drug interaction between fluoropyrimidines and proton-pump inhibitors (PPI) was suggested, with a negative impact on oncological outcomes in breast, colon and gastric cancers. Little is known about such an effect on rectal tumours. We aimed to evaluate the impact of PPI utilisation on the pathological response after chemoradiation for rectal cancer. Materials and methods: Retrospective multicentre study of rectal cancer patients treated with neoadjuvant chemoradiotherapy with capecitabine (cohort 1) or 5-fluororuracil (5-FU) (cohort 2); TNT with oxaliplatin-based regimens was allowed. The pathological response was considered a complete (ypCR) or complete + partial (ypCR + ypPR) according to American Joint Committee on Cancer. PPI use was considered at any time during the neoadjuvant period if concomitant to fluoropyrimidines. Results: From January 2007 to November 2020, 251 patients received capecitabine and 196 5-FU. The rates of PPI use in cohorts 1 and 2 were 20.3% and 26.5%, respectively. TNT was offered to 18.3% in cohort 1. PPI use did not influence ypCR in cohort 1 (yes versus no: 29.4% versus 19.5%; p = 0.13) or 2 (yes versus no: 25.0% versus 26.4%; p = 1.0). Similar ypCR + ypPR were observed in both cohorts 1 (76.5% versus 72.0%; p = 0.60) and 2 (86.5% versus 76.4%; p = 0.16). PPI use was not associated with pathological response in multivariable analysis. PPI users experienced more grade 3 or higher diarrhoea and infections. Conclusion: PPI concomitant to capecitabine/5-FU chemoradiation did not influence the pathological response in rectal cancer but was associated with more treatment-related adverse events.

External validation of the Moroccan Arabic version of the European Organization for Research and Treatment of Cancer colorectal (CR29) module: Monocentric study.

BACKGROUND: Quality of life (QoL) outcomes are a focal endpoint of cancer treatment strategies. AIM: To externally validate the Moroccan Arabic version of the European Organization for Research and Treatment of Cancer (EORTC) QoL Questionnaire (QLQ) for colorectal cancer (CRC) patients (CR29). METHODS: Both Moroccan Arabic modules of QLQ-CR29 and QLQ-C30 were administered to Moroccan CRC. Psychometric properties were retested by measuring Cronbach's alpha coefficient for reliability and Intraclass correlation coefficient (ICC) to examine test-retest reproducibility. The multitrait-scaling analysis was performed to demonstrate the validity of the instrument and known-groups comparison was used to test the score's ability to discriminate between different groups of patients. RESULTS: In total, 221 patients were included in our study and 34 patients completed the questionnaire twice. The Urinary Frequency scale and Stool Frequency scale had good internal consistency with alpha Cronbach coefficients of 0.79 and 0.83 respectively, while the same coefficients were moderately lower for the Blood and Mucus in Stool scale (0.61) and the Body Image scale (0.67). The ICCs ranged from 0.88 to 1 indicating good to excellent reproducibility. In multitrait scaling analyses, the criterion for item convergent and divergent validity was satisfactory. The known-group comparison showed statistically significant differences between patients according to age, gender, stoma status, tumor location, and radiotherapy. CONCLUSION: The Moroccan Arabic version of the EORTC QLQ-CR29 is a valid and reliable tool that can be used safely for research and clinical purposes in Moroccan CRC patients.

Chemical Shift-Encoded Sequence (IDEAL-IQ) and Amide Proton Transfer (APT) MRI for Prediction of Histopathological Factors of Rectal Cancer.

To investigate whether parameters from IDEAL-IQ/amide proton transfer MRI (APTWI) could help predict histopathological factors of rectal cancer. Preoperative IDEAL-IQ and APTWI sequences of 67 patients with rectal cancer were retrospectively analyzed. The intra-tumoral proton density fat fraction (PDFF), R2* and magnetization transfer ratio asymmetry (MTRasym (3.5 ppm)) were measured according to the histopathological factors of rectal cancer. The relationship between MR parameters and histopathological factors were analyzed, along with diagnostic performance of MR parameters. PDFF, R2* and MTRasym (3.5 ppm) were statistically different between T1+T2/T3+T4 stages, non-metastatic/metastatic lymph nodes, lower/higher tumor grade and negative/positive status of MRF and EMVI (p < 0.001 for PDFF, p = 0.000-0.015 for R2* and p = 0.000-0.006 for MTRasym (3.5 ppm)). There were positive correlations between the above parameters and the histopathological features of rectal cancer (r = 0.464-0.723 for PDFF (p < 0.001), 0.299-0.651 for R2* (p = 0.000-0.014), and 0.337-0.667 for MTRasym (3.5 ppm) (p = 0.000-0.005)). MTRasym (3.5 ppm) correlated moderately and mildly with PDFF (r = 0.563, p < 0.001) and R2* (r = 0.335, p = 0.006), respectively. PDFF provided a significantly higher diagnostic ability than MTRasym (3.5 ppm) for distinguishing metastatic from non-metastatic lymph nodes (z = 2.407, p = 0.0161). No significant differences were found in MR parameters for distinguishing other histopathological features (p > 0.05). IDEAL-IQ and APTWI were associated with histopathological factors of rectal cancer, and might serve as non-invasive biomarkers for characterizing rectal cancer.

Technique, sedation, and clinical outcome of endoscopic submucosal dissection for rectal tumor with involvement of dentate line: A retrospective cohort study.

Background: Endoscopic submucosal dissection (ESD) of rectal tumors involving the dentate line (RT-DL) is challenging because of the anatomical features of the anal canal. This study aimed to identify optimal techniques and sedation and to determine the clinical outcomes of ESD for RT-DL. Methods: We retrospectively collected medical records and endoscopic results of patients who underwent ESD for rectal tumors between January 2012 and April 2021. Patients were divided into RT-DL and rectal tumors not involving the dentate line (RT-NDL) groups, as per involvement of the dentate line. The treatment results and clinical outcomes of the two groups were evaluated and analyzed. Additionally, subgroup analysis was performed in the RT-DL group for the sedation method involved. Results: In total, 225 patients were enrolled and 22 were assigned to the RT-DL group. The complete resection rate (90.9% vs. 95.6%, P =0.336), delayed bleeding (13.6% vs. 5.9%, P =0.084), perforation (0% vs. 3.9%, P = 0.343), hospital stays (4.55 vs. 4.48 days, P = 0.869), and recurrence (0% vs. 0.5%) showed no significant group differences. However, in RT-DL group, the procedure time (78.32 vs. 51.10 min, P = 0.002) was longer and there was more perianal pain (22.7% vs. 0%, P = 0.001). The subgroup analysis revealed that deep sedation using propofol reduced perianal pain during the procedure (0/14 vs. 5/8, P = 0.002). Conclusions: ESD of RT-DL is a safe and effective treatment despite the challenges of requiring a high level of technique and longer procedure time. In particular, ESD under deep sedation should be considered in patients with RT-DL to control perianal pain.

Assessing the histopathological features of rectal adenocarcinoma with chemical shift-encoded sequence (CSE)-MRI and diffusion-weighted imaging (DWI).

Background: It is of clinical importance to assess the histopathological features of rectal cancer. The adipose tissue microenvironment is closely associated with tumor formation and progression. The chemical shift-encoded magnetic resonance imaging (CSE-MRI) sequence can noninvasively quantify adipose tissue. In this study, we aimed to investigate the feasibility of using CSE-MRI and diffusion-weighted imaging (DWI) to predict the histopathological features of rectal adenocarcinoma. Methods: In this retrospective study, 84 patients with rectal adenocarcinoma and 30 healthy controls were consecutively enrolled at the Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology. CSE-MRI and DWI sequences were performed. The intratumoral proton density fat fraction (PDFF) and R2* of rectal tumors and normal rectal walls were measured. The histopathological features, including pathological T/N stage, tumor grade, mesorectum fascia (MRF) involvement, and extramural venous invasion (EMVI) status were analyzed. The Mann-Whitney test, Spearman correlation, and receiver operating characteristic (ROC) curves were used for statistical analyses. Results: Patients with rectal adenocarcinoma demonstrated significantly lower PDFF and R2* values than did the control participants (5.35%±1.70% vs. 11.55%±3.41%, P<0.001; 35.60 s-1±7.30 s-1 vs. 40.15 s-1±5.72 s-1, P=0.003). PDFF and R2* were significantly different in the discrimination of T/N stage, tumor grade, and MRF/EMVI status (P=0.000-0.005). A significant difference was only noted in the differentiation of the T stage for the apparent diffusion coefficient (ADC) (1.09±0.26×10-3 mm2/s vs. 1.00±0.11×10-3 mm2/s; P=0.001). PDFF and R2* exhibited positive correlations with all the histopathological features (r=0.306-0.734; P=0.000-0.005), while ADC was negatively correlated with the T stage (r=-0.380; P<0.001). PDFF demonstrated diagnostic ability, with a sensitivity of 95.00% and a specificity of 87.50%, while R2* had a sensitivity of 95.00% and a specificity of 79.20% in differentiating T stage; both demonstrated a better diagnostic performance than did ADC. Conclusions: Quantitative CSE-MRI imaging might serve as a noninvasive biomarker for assessing the histopathological features of rectal adenocarcinoma.

Specific Septic Complications after Rectal Cancer Surgery: A Critical Multicentre Study.

The postoperative septic complications in gastrointestinal surgery impact immediate as well as long-term outcomes, which lead to reinterventions and additional costs. The authors presented the experience of three surgery clinics in Romania regarding the specific septic complications occurring in patients operated on for rectal cancer. The study group comprised 2674 patients who underwent surgery over a 5-year period (2017-2021). Neoplasms of the middle and lower rectum (76%) were the majority. There were 85% rectal resections and 15% abdominoperineal excisions of the rectum. In total, 68.54% of patients were operated on laparoscopically, and 31.46% received open surgery. Without taking wound infections into account, 97 (3.67%) patients had abdominal-pelvic septic complications. The aim was to evaluate the causes of the complications. The percentage of suppurations after surgery of the rectum treated by radiochemotherapy was considerably higher than after surgery of the non-radiated upper rectum. The fatality rate was 5.15%. The risk of fistulas was significantly associated with the preoperative treatment, tumour position and type of intervention. Sex, age, TNM stage or grade were not significant at 0.05 the threshold. The risk of fistulas is reduced with low anterior resection, but the gravity of these complications is higher in the lower rectum compared with the superior rectum. Preoperative radiochemotherapy is a contributing factor to septic complications.

Rectal bleeding as a symptom of solitary rectal ulcer syndrome mimicking rectal neoplasm on colonoscopy: A case report.

Patients complaining of rectal bleeding, constipation, and a suspicious mass in colonoscopy should undergo biopsy. Histological features such as fibromuscular obliteration in the lamina propria favor SRUS, a benign disorder.

Prognostic score for synchronous metastatic rectal cancer: A real-world study.

BACKGROUND: Prognostic factors of metastatic rectal cancer are not well known. AIM: The objective of this study was to identify prognostic factors of overall survival (OS) in a cohort of patients with non-resectable synchronous metastatic rectal cancer. METHODS: Patients were retrospectively enrolled from 18 French centres. Univariate and multivariate analyses were performed to identify prognostic factors for OS. A simple score was derived from this a development cohort RESULTS: A total of 243 patients with metastatic rectal cancer were included in the study. Median OS was 24.4 months, 95% CI [19.4-27.2]. Among patients with non-resected metastases (n=141), six independent prognostic factors associated with better OS were identified in multivariate analysis: primary tumour surgery, WHO score 0-1, middle or upper rectal tumour, lung metastases only, systemic chemotherapy and targeted agent in first line. A prognostic score individualized three groups, each factor counting for one point in the score (<3, = 3 et > 3). Their median OS were respectively 27.9 months, 95% CI [21.7-35.1], 17.1 months [11.9-19.7] (HR2/1=2.08, 95%, CI [1.31-3.30], p2/1=0.002) and 9.1 months [4.9-11.7] (HR3/2=2.32, 95% CI [1.38-3.92], p3/2=0.001). CONCLUSION: A prognostic score for non-resectable synchronous metastatic rectal cancer can be proposed to classify patients in three prognostic groups.

Operative and oncological outcomes after robotic rectal resection compared with laparoscopy: a systematic review and meta-analysis.

BACKGROUND: Most studies comparing robotic and laparoscopic surgery, show little difference in clinical outcomes to justify the expense. We systematically reviewed and pooled evidence from studies comparing robotic and laparoscopic rectal resection. METHOD: Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica (EMBASE), and Cochrane databases were searched for studies between 1996 and 2021 comparing clinical outcomes between laparoscopic and robotic rectal surgeries involving total mesorectal excision. Outcome measures included operative times, conversions to open, complications, recurrence and survival rates. RESULTS: Fifty eligible studies compared outcomes between robotic and laparoscopic rectal resections; three were randomized trials. Pooled results showed significantly longer operating times for robotic surgery but lower conversion and complications rates, shorter lengths of stay in hospital, better rates of complete mesorectal resection and better three-year overall survival. However, the low number of randomized studies makes most data subject to bias. CONCLUSION: Available evidence supports the safety and ongoing use of robotic rectal cancer surgery, while further high-quality evidence is sought to justify the expense.

External validation and comparison of MR-based radiomics models for predicting pathological complete response in locally advanced rectal cancer: a two-centre, multi-vendor study.

OBJECTIVES: The aim of this study was two-fold: (1) to develop and externally validate a multiparameter MR-based machine learning model to predict the pathological complete response (pCR) in locally advanced rectal cancer (LARC) patients after neoadjuvant chemoradiotherapy (nCRT), and (2) to compare different classifiers' discriminative performance for pCR prediction. METHODS: This retrospective study includes 151 LARC patients divided into internal (centre A, n = 100) and external validation set (centre B, n = 51). The clinical and MR radiomics features were derived to construct clinical, radiomics, and clinical-radiomics model. Random forest (RF), support vector machine (SVM), logistic regression (LR), K-nearest neighbor (KNN), naive Bayes (NB), and extreme gradient boosting (XGBoost) were used as classifiers. The predictive performance was assessed using the receiver operating characteristic (ROC) curve. RESULTS: Eleven radiomics and four clinical features were chosen as pCR-related signatures. In the radiomics model, the RF algorithm achieved 74.0% accuracy (an AUC of 0.863) and 84.4% (an AUC of 0.829) in the internal and external validation sets. In the clinical-radiomics model, RF algorithm exhibited high and stable predictive performance in the internal and external validation datasets with an AUC of 0.906 (87.3% sensitivity, 73.7% specificity, 76.0% accuracy) and 0.872 (77.3% sensitivity, 88.2% specificity, 86.3% accuracy), respectively. RF showed a better predictive performance than the other classifiers in the external validation datasets of three models. CONCLUSIONS: The multiparametric clinical-radiomics model combined with RF algorithm is optimal for predicting pCR in the internal and external sets, and might help improve clinical stratifying management of LARC patients. KEY POINTS: • A two-centre study showed that radiomics analysis of pre- and post-nCRT multiparameter MR images could predict pCR in patients with LARC. • The combined model was superior to the clinical and radiomics model in predicting pCR in locally advanced rectal cancer. • The RF classifier performed best in the current study.