Low energy contact X-ray brachytherapy for treatment of rectal cancer: a health technology appraisal by Health Technology Wales.

AIM: Health Technology Wales sought to evaluate the clinical and cost-effectiveness of contact X-ray brachytherapy (CXB) for early-stage rectal cancer. METHODS: Relevant studies were identified through systematic searches of MEDLINE, Embase, Cochrane Library and Scopus. A cost-utility model was developed to estimate the cost-effectiveness of CXB in National Health Service Wales, using results of the Organ Preservation in Early Rectal Adenocarcinoma (OPERA) trial. Patient perspectives were obtained through the Papillon Patient Support group and All-Wales Cancer Network. RESULTS: The OPERA randomized controlled trial showed that CXB improved complete response and organ preservation rates compared with external-beam boost for people with T2-3b, N0-1, M0 rectal cancer who are fit for surgery. Managing more of this population non-operatively after CXB was estimated to provide 0.2 quality-adjusted life years at an additional cost of £887 per person. CXB was cost effective compared with external-beam boost at a cost of £4463 per quality-adjusted life year gained. This conclusion did not change in scenario analysis and CXB was cost effective in 91% of probabilistic sensitivity analyses. Patients valued receiving clear information on all available options to support their individual treatment choices. The detrimental impact of a stoma on quality of life led some patients to reject the idea that surgery was their only option. CONCLUSION: This evidence review and cost-utility analysis indicates that CXB is likely to be clinically and cost effective, as part of a watch and wait strategy for adults fit for surgery. Wider access to CXB is supported by patient testimonies.

From burden to relief: The economic and quality-of-life advantages of pseudo continent perineal colostomy in ultra-low rectal cancer patients.

BACKGROUND AND OBJECTIVE: Pseudo Continent Perineal Colostomy (PCPC) is an alternative technique to left iliac colostomy (LIC) after abdominoperineal resection for ultra low rectal cancer (ULRC). It allows placing the stoma in the perineum to preserve patients' body image. However, concerns about its impact on quality of life and management costs have limited its adoption. We aimed to compare the early outcomes and financial burden of PCPC and LIC in ULRC patients in Morocco, a low-middle-income country. METHODS: From January 2018 to December 2019, all patients who underwent abdomino-perineal resection (APR) with LIC or PCPC were prospectively enrolled. For each patient, baseline characteristics, and in hospital and 90 days morbidity with a focus on perineal complications were reported. Quality of life (QOL) was assessed using the validated EORTC-C30 and CR29 questionnaires. Financial burden to patients was reported using declarative out-of-pocket costs (OOPC) analysis. RESULTS: Among 49 patients who underwent APR, 33 received PCPC and 16 received definitive LIC. Similar rates of early perineal complications were observed between the two groups (p = 0.49). Readmission rate at POD90 was higher in the LIC-group due to perineal sepsis (p = 0.09). QOL analysis at 6 months revealed that patients with PCPC had a higher global health status (p = 0.006), a better physical functioning and reported fewer symptoms of flatulence and fecal incontinence (p = 0.001). Patients with a LIC reported more financial difficulties with higher median OOPC of stoma management up to €23 versus €0 per month for PCPC (p = 0.0024). PCPC was the only predictive factor of improved patient reported outcomes. CONCLUSIONS: PCPC is a cost-effective alternative to the standard definitive colostomy without alteration of the QOL or additional perineal complications during the first 6 months following the surgery. These findings may help convince surgeons to offer this option to patients refusing definitive LIC.

Costs Related to Diverting Ileostomy After Rectal Cancer Surgery: A Population-Based Healthcare Cost Analysis Based on Nationwide Registers.

Low anterior resection for rectal cancer often includes a diverting loop-ileostomy to avoid the severe consequences of anastomotic leakage. Reversal of the stoma is often delayed, which can incur health-care costs on different levels. The aim is to, on population basis, determine stoma-related costs, and to investigate habitual and socioeconomic factors associated to the level of cost. Multi-register design with data from the Swedish Rectal Cancer Registry, the National Prescribed Drug Register, Statistics Sweden and cost-administrative data from the National Board of Health and Welfare. Data was gathered for 3564 patients with rectal cancer surgery 2007 to 2013, for 3 years following the surgery. Factors influencing the cost of inpatient care and stoma-related consumables were assessed with linear regression analyses. All monthly costs were higher for females (consumables P < .001 and in-patient care P = .031). Post-secondary education (P = .003) and younger age (P = .020) was associated with a higher cost for consumables while suffering a surgical complication was associated with increased cost for inpatient care (P < .001). Patients who had their stoma longer had lower monthly costs (consumables P < .001 and in-patient care P < .001). Female gender, longer duration of stoma, young age, and higher education are associated with higher costs for the care of a diverting stoma after rectal cancer surgery. This study does not allow for analyses of causality but the results together with deepened analyses of underlying reasons form a proper basis for decisions in health care planning and allocation of resources. These findings may have implications on the debate of equal care for all.

Cost associated with diverting ostomy after rectal cancer surgery: a transnational analysis.

BACKGROUND: Diverting ileostomy and colostomy after total mesorectal excision reduces the risk of complications related to anastomotic leakages but is associated with a reduction in health-related quality of life and long-term economic consequences that are unknown. Our objective was to estimate the lifetime costs of stoma placement after rectal cancer resection in the U.S., England, and Germany. METHODS: Input parameters were derived from quasi-systematic literature searches. Decision-analytic models with survival from colorectal cancer-adjusted life tables and country-specific stoma reversal proportions were created for the three countries to calculate lifetime costs. Main cost items were stoma maintenance costs and reimbursement for reversal procedures. Discounting was applied according to respective national guidelines. Sensitivity analysis was conducted to explore the impact of parameter uncertainty onto the results. RESULTS: The cohort starting ages and median survival were 63 and 11.5 years for the U.S., 69 years and 8.5 years for England, and 71 and 6.5 years for Germany. Lifetime discounted stoma-related costs were $26,311, £9512, and €10,021, respectively. All three models were most sensitive to the proportion of ostomy reversal, age at baseline, and discount rate applied. CONCLUSION: Conservative model-based projections suggest that stoma care leads to significant long-term costs. Efforts to reduce the number of patients who need to undergo a diverting ostomy could result in meaningful cost savings.

High-resolution integrated dynamic shimming diffusion-weighted imaging (DWI) in the assessment of rectal cancer.

OBJECTIVES: To investigate the feasibility of high-resolution integrated dynamic shimming echo planar imaging (iEPI) applied to rectal cancer. METHODS: A total of seventy-eight patients with non-mucinous rectum adenocarcinoma were enrolled in this study. Using a prototype high-resolution iEPI sequence, high-resolution single-shot EPI (sEPI) sequence, and sEPI sequence, subjective and objective assessment and apparent diffusion coefficient (ADC) value were measured for comparison. The spearman rank correlation analysis test and the receiver operating characteristic curve were performed to evaluate correlation between tumor ADC values, corresponding T stage, and differentiation degree of rectal cancer. RESULTS: The subjective assessment of the image quality (IQ) of high-resolution iEPI was rated superior to high-resolution sEPI and sEPI by both readers (p < 0.001). Signal-to-noise ratio, contrast-to-noise, and signal-intensity ratio were significantly higher in high-resolution iEPI than the other two sequences (p < 0.001). There was no significant difference of tumor ADC values among three EPI sequences in the group of low- to well-differentiated rectal cancer. An inverse correlation was noted between ADC values on three DWI sequences and pathological T stage of rectal cancer (r = - 0.693, - 0.689, - 0.640, p < 0.001). The AUC values of high-resolution iEPI, high-resolution sEPI, and sEPI in predicting well-differentiated rectal cancer were 0.910, 0.761, and 0.725 respectively. CONCLUSIONS: In conclusion, the high-resolution iEPI provided significantly higher IQ and stable ADC compared to another two sequences. High-resolution iEPI has the highest efficacy among three examined sequences in differentiation of rectal cancer with different degrees of differentiation. KEY POINTS: • High-resolution iEPI provided a significantly better IQ than high-resolution sEPI and sEPI when assessing rectal cancer. • The AUC of high-resolution sEPI was the highest among three EPI sequences in predicting well-differentiated rectal cancer.

Effectiveness of simultaneous multislice accelerated readout-segmented echo planar imaging for the assessment of rectal cancer.

PURPOSE: To investigate the effectiveness of simultaneous multislice (SMS) accelerated readout-segmented echo planar imaging (RESOLVE) DWI for assessing rectal cancer in the clinic. METHOD: Sixty consecutive histologically proven rectal cancer patients were enrolled. They all received MRI examinations, including both SMS-RESOLVE and RESOLVE sequences. Two readers visually assessed the overall image quality, distinction of anatomical structures, lesion conspicuity, and artifacts of two sequences by using a qualitative 4-point Likert scale. The quantitative ADC value, lesion contrast, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and temporal SNR (tSNR) were independently calculated in rectal cancer on the largest slice of the tumor. RESULTS: The scan time was shortened from 3 min and 50 s to 1 min and 47 s. The interobserver agreement of visual and quantitative assessments between the two readers was good overall. There were no differences in overall image quality, lesion conspicuity or artifact scores between the two sequences in both readers (all p > 0.05). The lesion contrast (p = 0.013) was significantly higher in SMS-RESOLVE, and the CNR was similar in the two DWIs. The scores of distinctions of anatomical structures in SMS-RESOLVE were lower (all p < 0.05) in both readers. The SNR of SMS-RESOLVE was lower than that of RESOLVE (p = 0.004), and the tSNR of SMS-RESOLVE was significantly higher (p < 0.001). The ADC value of the tumor was lower in SMS-RESOLVE (p = 0.001), but the ADC values of the normal rectal wall showed no difference between the two DWIs. CONCLUSION: SMS-RESOLVE allowed a substantial reduction in acquisition time while maintaining overall image quality and lesion conspicuity in rectal cancer. It also had a higher contrast of the lesion and a higher temporal SNR.

Predictive role of diffusion-weighted MRI in the assessment of response to total neoadjuvant therapy in locally advanced rectal cancer.

OBJECTIVE: To investigate the predictive role of diffusion-weighted magnetic resonance imaging (DW-MRI) in the assessment of response to total neoadjuvant therapy (TNT) in patients with locally advanced rectal cancer (LARC). METHODS: In this single-center retrospective study, patients with LARC who underwent staging MRI and TNT were enrolled. MRI-based staging, tumor volume, and DWI-ADC values were analyzed. Patients were classified as complete responders (pCR) and non-complete responders (non-pCR), according to post-surgical outcome. Pre-treatment ADC values were compared to pathological outcome, post-treatment downstaging, and reduction of tumor volume. The diagnostic accuracy of DWI-ADC in differentiating between pCR and non-pCR groups was calculated with receiver operating characteristic (ROC) analysis. RESULTS: A total of 36 patients were evaluated (pCR, n = 20; non-pCR, n = 16). Pre-treatment ADC values were significantly different between the two groups (p = 0.034), while no association was found between pre-TNT tumor volume and pathological response. ADC values showed significant correlations with loco-regional downstaging after therapy (r = -0.537, p = 0.022), and with the reduction of tumor volume (r = -0.480, p = 0.044). ADC values were able to differentiate pCR from non-pCR patients with a sensitivity of 75% and specificity of 70%. CONCLUSIONS: ADC values on pre-treatment MRI were strongly associated with the outcome in patients with LARC, both in terms of pathological response and in loco-regional downstaging after TNT, suggesting the use of DW-MRI as a potential predictive tool of response to therapy. KEY POINTS: • ADC values of pre-TNT MRI examinations of patients with LARC were significantly associated with a pathological complete response (pCR) and with post-treatment regression of TNM staging. • An ADC value of 1.042 ×10-3 mm2/s was found to be the optimal cutoff value for discriminating between pCR and non-pCR patients, with a sensitivity of 75% and specificity of 70%. • DW-MRI proved to have a potential predictive role in the assessment of response to therapy in patients with LARC, throughout the analysis of ADC map values.

Value of texture analysis based on dynamic contrast-enhanced magnetic resonance imaging in preoperative assessment of extramural venous invasion in rectal cancer.

OBJECTIVE: Accurate preoperative assessment of extramural vascular invasion (EMVI) is critical for the treatment and prognosis of rectal cancer. The aim of our research was to develop an assessment model by texture analysis for preoperative prediction of EMVI. MATERIALS AND METHODS: This study enrolled 44 rectal patients as train cohort, 7 patients as validation cohort and 18 patients as test cohort. A total of 236 texture features from DCE MR imaging quantitative parameters were extracted for each patient (59 features of Ktrans, Kep, Ve and Vp), and key features were selected by least absolute shrinkage and selection operator regression (LASSO). Finally, clinical independent risk factors, conventional MRI assessment, and T-score were incorporated to construct an assessment model using multivariable logistic regression. RESULTS: The T-score calculated using the 4 selected key features were significantly correlated with EMVI (p < 0.010). The area under the receiver operating characteristic curve (AUC) was 0.797 for discriminating between EMVI-positive and EMVI-negative patients with a sensitivity of 88.2% and specificity of 70.4%. The conventional MRI assessment of EMVI had a sensitivity of 23.53% and a specificity of 96.30%. The assessment model showed a greatly improved performance with an AUC of 0.954 (sensitivity, 88.2%; specificity, 92.6%) in train cohort, 0.833 (sensitivity, 66.7%; specificity, 100%) in validation cohort and 0.877 in test cohort, respectively. CONCLUSIONS: The assessment model showed an excellent performance in preoperative assessment of EMVI. It demonstrates strong potential for improving the accuracy of EMVI assessment and provide a reliable basis for individualized treatment decisions.

Cost analysis of total neoadjuvant therapy with 5 × 5 Gy radiation therapy versus conventional chemoradiotherapy for locally advanced rectal cancer among Peruvians.

Background and Objectives: Conventional long-course radiotherapy (LCRT) and a new paradigm of short-course radiotherapy with total neoadjuvant therapy (SCRT-TNT) are used in locally advanced rectal cancer (RC). There are few economic assessment reports available on TNT that focus on cost analysis in a country with limited funding for healthcare systems. The objective of this study was to perform a cost analysis comparing SCRT-TNT versus LCRT. Materials and Methods: In 2020-2021, a prospective registry was created to document RC patients who received neoadjuvant therapy and the costs of cancer treatments, transportation and the time patients and family members spent in the hospital. This registry outlined the direct and indirect costs of LCRT versus SCRT-TNT. Results: LCRT and SCRT-TNT regimens have direct costs that range from S/.5,993.30 to S/.27,928.36 and from S/.3,409.81 to S/.18,159.42, respectively. FOLFOX regimens are the most expensive. Administering radiotherapy in 28 3D sessions and 5 sessions of intensity-modulated radiation therapy (IMRT) or volumetric-modulated arc therapy (VMAT) sessions costs S/.2,603.88, S/.1,277.19 and S/.1,027.77, respectively. The indirect cost of FOLFOX regimens is twice that of the similar modality that combines irradiation and Oxaliplatin IV and Capecitabine VO (CAPOX). SCRT-TNT regimens with CAPOX reduce costs by at least 50%, while SCRT-TNT regimens with FOLFOX reduce costs by 32%. Conclusion: Despite using IMRT/VMAT, SCRT-TNT is a less expensive approach for patients with RC when compared to LCRT. The costs to patients using SCRT-TNT are much lower, but it is also a better option because it saves hospital resources.

Relationship between diverting stoma and adjuvant chemotherapy in patients with rectal cancer: a nationwide study using the National Database of Health Insurance Claims and Specific Health Checkups of Japan.

BACKGROUND: Patients at risk of recurrence after curative surgery for rectal cancer usually receive adjuvant chemotherapy. Postoperative recovery after low anterior resection (LAR) for rectal cancer can be improved by placement of a diverting stoma to reduce anastomotic leakage. However, it remains unclear how a diverting stoma affects administration of adjuvant chemotherapy in these patients. METHODS: We identified Japanese patients with rectal cancer who underwent LAR in 2014 and received adjuvant chemotherapy within 12 months of surgery in the National Database of Health Insurance Claims and Specific Health Checkups of Japan. Doses of five types of chemotherapy administered (tegafur/uracil, tegafur/gimeracil/oteracil potassium, capecitabine, 5-fluorouracil, and oxaliplatin) were assessed according to the presence or absence of diverting stoma and the timing of stoma closure. RESULTS: There was no significant difference in the cumulative doses of chemotherapy administered in the 12 months after LAR between patients with and without diverting stoma, but more doses were administered in the early postoperative period (0-2 months after LAR) in patients without diverting stoma. Also, more doses of chemotherapy, regardless of type, were administered in the late closure group (7-12 months after LAR) than in the early closure (≤ 6 months) and no closure groups. CONCLUSION: Presence of a diverting stoma did not influence the dose of adjuvant chemotherapy administered within 12 months after LAR but could have delayed the start of adjuvant chemotherapy. Patients with late closure of a diverting stoma received more doses of adjuvant chemotherapy administered over 12 months.

Value of intravoxel incoherent motion for assessment of lymph node status and tumor response after chemoradiation therapy in locally advanced rectal cancer.

OBJECTIVE: To assess the role of region of interest (ROI) selection of intravoxel incoherent motion (IVIM) for predicting lymph node metastases (LNM) and tumor response after chemoradiation therapy (CRT) in locally advanced rectal cancer. MATERIALS AND METHODS: Seventy-nine patients with biopsy-proven rectal adenocarcinoma who underwent pre- and post-CRT MRI and surgery were prospectively enrolled. The exclusion criteria included nonresectable and/or metastatic disease and loss of follow-up. Pathological stage was determined using ypTNM stage and tumor regression grade. Slow diffusion coefficient (D), fast diffusion coefficient (D*), perfusion-related diffusion fraction (f), apparent diffusion coefficient (ADC) and their percentage changes (Δ%) were evaluated by two readers using whole-volume, single-slice and small samples ROI methods. Risk factors including carcinoembryonic antigen, post-CRT T-staging, extramural venous invasion and IVIM parameters were evaluated through multivariate analyses. Areas under the receiver operating characteristic curves (AUCs) were calculated to evaluate diagnostic performance. Duration of follow-up was two-year. Recurrence-free survival of patients with LNM and tumor response was estimated using Kaplan-Meier analysis. RESULTS: Interobserver agreement were good for pre- and post-CRT three ROI methods (intraclass correlation coefficient [ICC], 0.581-0.953). Whole-volume ROI-derived Δ%D was an independent risk factor for LNM, non-pathological complete response (non-pCR) and poor response (odds ratio, 0.940, 0.952, 0.805, respectively; all p < 0.001). Whole-volume ROI-derived Δ%D showed best AUC of 0.810, 0.851 and 0.903 for LNM, non-pCR and poor response (cutoff value, 31.8%, 54.5%, 52.8%, respectively). Patients with post-CRT LNM showed reduction in 2-year recurrence-free survival (hazard ratio, 3.253). CONCLUSIONS: Whole-volume ROI-derived Δ%D provided high diagnostic performance for evaluating post-CRT LNM and tumor response. Patients with post-CRT LNM showed earlier recurrence.

Variation in outcomes across surgeons meeting the Leapfrog volume standard for complex oncologic surgery.

BACKGROUND: A large body of evidence supports regionalization of complex oncologic surgery to high-volume surgeons at high-volume hospitals. However, whether there is heterogeneity of outcomes among high-volume surgeons at high-volume hospitals remains unknown. METHODS: Patients who underwent esophagectomy, lung resection, pancreatectomy, or proctectomy for primary cancer were identified within the Medicare 100% Standard Analytic File (2013-2017). Mixed-effects analyses assessed the association between Leapfrog annual volume standards for surgeons (esophagectomy ≥7, lung resection ≥15, pancreatectomy ≥10, proctectomy ≥6) and hospitals (esophagectomy ≥20, lung resection ≥40, pancreatectomy ≥20, proctectomy ≥16) relative to postoperative complications and 90-day mortality. Additional analyses using New York's all-payer Statewide Planning and Research Cooperative System (2004-2015) were performed. RESULTS: Among 112,154 Medicare beneficiaries, high-volume surgeons at high-volume hospitals were associated with lower adjusted odds of complications (esophagectomy: odds ratio [OR], 0.73 [95% CI, 0.61-0.86]; lung resection: OR, 0.88 [95% CI, 0.82-0.94]; pancreatectomy: OR, 0.73 [95% CI, 0.66-0.80]; proctectomy: OR, 0.92 [95% CI, 0.85-0.99]) and 90-day mortality (esophagectomy: OR, 0.60 [95% CI, 0.44-0.76]; lung resection: OR, 0.82 [95% CI, 0.73-0.93]; pancreatectomy: OR, 0.66 [95% CI, 0.56-0.76]; proctectomy: OR, 0.74 [95% CI, 0.65-0.85]). For the average patient at the average high-volume hospital, there was a 2-fold difference in the adjusted complication rate between the best-performing and worst-performing high-volume surgeon for all operations (esophagectomy, 28%-55%; lung resection, 7%-21%; pancreatectomy, 16%-35%; proctectomy, 16%-28%). Wide variation was also present in adjusted 90-day mortality for esophagectomy (3.5%-9.3%). Results from New York's all-payer database were similar. CONCLUSIONS: Even among high-volume surgeons meeting the Leapfrog volume standards, wide variation in postoperative outcomes exists. These findings suggest that volume alone should not be used as a quality indicator, and quality metrics should be continuously evaluated across all surgeons and hospital systems. LAY SUMMARY: Previous studies have demonstrated a surgical volume-outcome relationship for high-risk operations-that is high-volume surgeons and hospitals that perform a specific surgical procedure more frequently have better outcomes for that operation. Although most high-volume surgeons had better outcomes, this study demonstrated that some high-volume surgeons did not have better outcomes. Therefore, volume is an important factor but should not be the only factor considered when assessing the quality of a surgeon and a hospital for cancer surgery.

The assessment of risk factors for long-term survival outcome in ypN0 patients with rectal cancer after neoadjuvant therapy and radical anterior resection.

BACKGROUND: The main negative prognostic factors in patients with rectal cancer after radical treatment include regional lymph node involvement, lymphovascular invasion, and perineural invasion. However, some patients still develop cancer recurrence despite the absence of the above risk factors. The aim of the study was to assess clinicopathological factors influencing long-term oncologic outcomes in ypN0M0 rectal cancer patients after neoadjuvant therapy and radical anterior resection. METHODS: A retrospective survival analysis was performed on a group of 195 patients. We assessed clinicopathological factors which included tumor regression grade, number of lymph nodes in the specimen, Charlson comorbidity index (CCI), and colorectal anastomotic leakage (AL). RESULTS: In the univariate analysis, AL and CCI > 3 had a significant negative impact on disease-free survival (DFS), disease-specific survival (DSS), and overall survival (OS). After the division of ALs into early and late ALs, it was found that only patients with late ALs had a significantly worse survival. The multivariate Cox regression analysis showed that CCI > 3 was a significant adverse risk factor for DFS (HR 5.78, 95% CI 2.15-15.51, p < 0.001), DSS (HR 7.25, 95% CI 2.25-23.39, p < 0.001), and OS (HR 3.9, 95% CI 1.72-8.85, p = 0.001). Similarly, late ALs had a significant negative impact on the risk of DFS (HR 5.05, 95% CI 1.97-12.93, p < 0.001), DSS (HR 10.84, 95% CI 3.44-34.18, p < 0.001), and OS (HR 4.3, 95% CI 1.94-9.53, p < 0.001). CONCLUSIONS: Late AL and CCI > 3 are the factors that may have an impact on long-term oncologic outcomes. The impact of lymph node yield on understaging was not demonstrated.

[Assessment of setup errors of IGRT combined with a six degrees of freedom bed for patients with primary rectal cancer].

Objective: To investigate the effect of six degree of freedom (6-DOF) bed combined with cone beam computed tomography (CBCT) in the on-line correction of setup errors in patients with primary rectal cancer. Methods: The clinicopathological data of 17 patients with primary rectal cancer in Department of Radiotherapy, Third Hospital of Peking University from July 2013 to January 2014 were collected. There were 14 males and 3 females, a median age of 65 years. The difference of CBCT and 6-DOF bed combined with CBCT online correction of patients with positioning error were retrospectively analyzed. Results: Before position correction, the first CBCT verification of setup errors in the three translation directions including X (left and right), Y (in and out) and Z (up and down) directions were (0.06±0.25) cm, (0.13±0.40) cm and (-0.28±0.31) cm, respectively. The setup errors of RX (rotation pitch), RY(rolling) and RZ (left and right rotation) directions were (0.62±1.15)°, (-0.19±0.99)°, and (-0.34 ± 0.84)°, respectively . After correction of IGRT combined with six freedom of bed, the setup errors of translation X, Y and Z were (0.01±0.09) cm, (-0.01±0.05) cm and (-0.03±0.08) cm, respectively, and the setup errors of rotation RX, RY and RZ directions were (-0.16±0.40)°, (0.36±0.31)°and (-0.01±0.25)°, respectively. There were significant differences in translation direction (X, Y and Z direction) and rotation direction (Rx, RY and RZ) before and after 6-DOF bed combined with CBCT correction (all P<0.05). In the translation direction, the higher frequency range of Z-direction error value was 0.20-0.79 cm. In the rotation direction, the frequency range of error in Rx direction was 0.20°-2.99°. There was no significant difference between bone mode and gray scale model registration (P>0.05). With the progress of radiotherapy, the setup errors of X, Z, Rx, RY and RZ directions increased except Y direction. Conclusions: In radiotherapy, six freedom bed combined with CBCT is helpful to correct the setup errors of patients with primary rectal cancer. Six freedom bed may be used to correct the setup errors of patients with primary rectal cancer online. Image-guided radiation therapy (IGRT) is recommended for bone pattern registration in patients with rectal cancer.

The value of intravoxel incoherent motion and diffusion kurtosis imaging in the assessment of tumor regression grade and T stages after neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer.

PURPOSE: To evaluate the role of IVIM and diffusion kurtosis imaging (DKI) in identifying pathologic complete response (pCR) and T stages after neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer (LARC). METHOD: Forty-two patients with biopsy-proven rectal adenocarcinoma, who underwent both pre-and post-CRT MRI with IVIM and DKI sequences on a 3 T scanner, were enrolled prospectively. According to the pathologic ypTNM stages and tumor regression grade (TRG), patients were grouped into pCR (TRG0) and non-pCR (TRG1-3) groups and low T stage (ypT0-2) and high T stage (ypT3-4) groups. IVIM parameters (the slow diffusion coefficient [D], fast diffusion coefficient [D*], perfusion fraction [f]), DKI parameters (mean diffusivity [MD] and mean kurtosis [MK]), and mono-exponential ADC were calculated and analyzed between groups. RESULTS: The pCR group had significantly higher post-CRT ADC, D*, f, and MD values than non-pCR group, and higher percent changes in the ADC, f, and MD values (all P < 0.05). The post-CRT MD values yielded the highest AUC (0.788) with higher sensitivity than post-ADC values (82.9 % vs. 77.1 %, respectively). Post-CRT ADC and MD values and the percent changes in the ADC and MD values were also negatively correlated with TRG (all P < 0.05). Besides, negative correlations were found among the pre-CRT MD, post-CRT ADC, D, f, and MD values and the ypT stages (all P < 0.05). CONCLUSIONS: Both IVIM and DKI parameters could provide more information when evaluating pCR and T stages after nCRT. In particular, the diagnostic performance of the MD values was more valuable than ADC values in being able to determine pCR.

Comparison of 18F-FDG PET/CT and DW-MRI in assessment of neoadjuvant radiochemotherapy response in locally advanced rectal cancer patients. / Comparación de la PET/TC 18F-FDG y la DW-MRI en la evaluación de la respuesta a la radioquimioterapia neoadyuvante en pacientes con cáncer rectal localmente avanzado.

OBJECTIVE: Our aim is to evaluate if different metabolic parameters obtained by 18F-FDG PET/CT and diffusion weighted magnetic resonance imaging (DW-MRI) can aid in neoadjuvant radiochemotherapy (RCT) response assessment in locally advanced rectal cancer (LARC) patients. METHODS: Out of 20 LARC patients, who were planned to receive neoadjuvant RCT, 19 were included in this prospective study. Patients had 18F-FDG PET/CT and DW-MRI at initial staging, interim (2 weeks after onset of RCT) and after completion of RCT (post-therapy). Standardized uptake value (SUV) parameters (SUVmax, SUVmean, SUVpeak, SULpeak), metabolic tumor volume (MTV) and tumor lesion glycolysis (TLG) detected on PET images and apparent diffusion coefficient (ADC) values (for b=400 and b=1000s/mm2) obtained from DW-MRI were recorded. Postoperative tumor regression grade (TRG) was used as gold-standard, except for 2 patients who were under complete remission with non-operative management 19 months post-therapy and scored as responders. RESULTS: On interim PET/CT, no significant difference was found among PET parameters between responders and non-responders, whereas post-therapy SUVmax, SUVpeak, MTV, SULpeak, TLG (P=0.02, P=0.014, P=0.025, P=0.007, P=0.02, respectively) and initial MTV (P=0.034) were significantly lower in responders. ADC response index (RI) was higher in responders (interim P=0.026; post-therapy: P=0.018) and ROC analysis revealed that a threshold of ADC RI>41.6% for interim MRI and >44.6% for post-therapy MRI had sensitivity and specificity of 75.0% and 90.9%, respectively. CONCLUSIONS: While interim 18F-FDG PET/CT failed to predict therapy response during RCT, post-therapy PET could accurately differentiate responders. DW-MRI was found to be more promising in interim detection of RCT response.

Assessment of intraoperative use of indocyanine green fluorescence imaging on the incidence of anastomotic leakage after rectal cancer surgery: a PRISMA-compliant systematic review and meta-analysis.

BACKGROUND: The current data on the intraoperative use of indocyanine green (ICG) fluorescence imaging to reduce the anastomotic leak (AL) rate in rectal cancer surgery remain controversial. The aim of this systematic review and meta-analysis was to evaluate the efficacy of ICG fluorescence imaging in decreasing the AL rate after rectal cancer surgery. METHODS: Studies comparing ICG fluorescence imaging with standard care in patients with rectal cancer were systematically searched from PubMed, Embase, Web of Science and Cochrane Library through January 2020. The current meta-analysis was performed according to the preferred reporting items for systematic review and meta-analysis guidelines. A pooled analysis was performed for the available data regarding the baseline features, AL rate and other surgical outcomes. RevMan version 5.3 software was used for the present meta-analysis. RESULTS: Nine studies with a total of 2088 patients with rectal cancer (926 in the ICG group and 1162 in the control group) were included in the present study. In the pooled analysis, the available patient and tumour-related baseline data were all comparable and without significant heterogeneity. In the present pooled analysis, the AL rate in the ICG group was significantly lower (OR 0.34; 95% CI 0.22-0.52; p < 0.0001) than that in the control group. Additionally, intraoperative use of ICG was associated with a decreased overall complication rate (OR 0.57; 95% CI 0.42-0.78; p = 0.0003) and reduced reoperation rate (OR 0.26; 95% CI 0.08-0.86; p = 0.03) in patients who had rectal cancer surgery. CONCLUSIONS: The present study demonstrated the superiority of the intraoperative use of ICG in reducing the AL rate. However, considering the limitations of the included studies, more high-quality prospective studies and randomized controlled trials are needed.

[Epidemiological research status and surgical treatment strategy of presacral recurrent rectal cancer].

Presacral recurrence, a special recurrence type in rectal cancer after surgical treatment, refers to recurrent cancer invading the presacral soft tissue or the bony structure of sacrum. It is also a major constituent of recurrent rectal cancer (15.63% to 41.67%). Reports show that presacral recurrence rate is about 2.8% to 4.8%, and it is associated with clinic staging, pathological type, surgical approach, (neo) adjuvant radiochemotherapy, tumor distance from the anus, positive circumferential margin, lymph node metastasis, and unilateral lateral lymph node dissection. CT and MRI are important for the detection of presacral recurrence. Presacral recurrence is always combined with local recurrence in other parts and distant organ metastasis. Therefore, we divide that into the following 3 types: 1) presacral recurrence with distant metastasis; 2) presacral recurrence with pelvic wall or lateral lymph node metastasis, or with recurrence of pelvic organs or anastomosis; and 3) simple presacral relapse. According to MDT evaluation. We adopt corresponding treatment scheme and surgical approach depending on the types mentioned above. When tumor recurred in the sacrum and located lower than S2/3 articular surface, then resection of recurrent tumor combined with sacrococcygeal should be the treatment of choice. For presacral recurrence with anterior invasion, combined total pelvic exenteration were available. For presacral recurrence with lateral pelvic wall invasion, internal iliac arteriovenous resection and lateral lymph node dissection and para-aortic lymph node dissection should be carried out. R0 resection may improve the 5-year overall survival rate of these patients.

[Imaging modalities in the assessment of presacral recurrent rectal cancer].

Imaging plays a key role in the diagnosis and decision-making process including pre-treatment planning, surgical strategy, and follow-up. The critical point in diagnosis of presacral recurrent rectal cancer by imaging modalities is to distinguish the recurrent tumor from nonmalignant tissues induced by operation or radiotherapy. The practice guideline recommends CT as surveillance imaging modality for recurrent rectal cancer. MRI shows higher accuracy, sensitivity, and specificity in diagnosis of presacral recurrent rectal cancer compared with CT. If CT or MRI can not make final diagnosis in challenging cases, 18-fluorodeoxyglucose positron emission tomography ((18)FDG PET) is recommended to aid diagnosis with high sensitivity and specificity, though false-positivity and negativity should be considered. If new or enlarging soft tissue are shown in the follow-up examination, tumor recurrence should be suspected. In addition, tumor-related high risk factors, treatment protocol, surgery, quality of specimen and pathological stages should also be considered when presacral recurrent rectal cancer is to be diagnosed.

[Technological innovation and patent transformation in rectal cancer surgery].

Surgery for rectal cancer has obtained quick improvement in techniques and concepts in recent years but still has challenging areas. Colorectal surgeons always seek to make operations clearer and easier, so that surgery can be safer and less time-consuming while guaranteeing surgical goals. With this purpose, our team have explored to make innovations in operations for rectal cancer and translate relevant patents from 2009. We summarize our achievements in this article as follows: (1) Reverse Miles operation (perineal operation first then laparoscopic abdominal operation) with two relevant patents-specialized instruments bag for laparoscopic operations (patent number ZL201520442331.0) and accessory spotlight for ultrasound scalpel (patent number ZL20102 0137689.X). (2) Laparoscopic sphincter-saving surgery for low rectal cancer through marker meeting approach with two patents-vacuum rectal drainage tube with functions of irrigation and ventilation (patent number ZL201520374385.8) and sterile sleeve cover of ultrasound scalpel handle (patent number ZL201920648102.2). (3) Laparoscopic radical resection of colorectal cancer and natural orifice specimen extraction. Different methods were designed according to the location of the tumor that classified as 20-40 cm, 10-20 cm and 5-10 cm to anus. Two relevant patents were specialized instruments for natural orifice specimen extraction (patent application number ZL2017101480141) and plastic film sleeve for natural orifice specimen extraction (patent application number ZL 201921169857.0). Reformation of surgical technique and innovation of surgical instruments should be conducted by surgeons with innovative thinking who always seek the way to translate ideas to patents and then real products to promote surgical treatment.