Measures of performance and proficiency in robotic assisted surgery: a systematic review.

Robotic assisted surgery (RAS) has seen a global rise in adoption. Despite this, there is not a standardised training curricula nor a standardised measure of performance. We performed a systematic review across the surgical specialties in RAS and evaluated tools used to assess surgeons' technical performance. Using the PRISMA 2020 guidelines, Pubmed, Embase and the Cochrane Library were searched systematically for full texts published on or after January 2020-January 2022. Observational studies and RCTs were included; review articles and systematic reviews were excluded. The papers' quality and bias score were assessed using the Newcastle Ottawa Score for the observational studies and Cochrane Risk Tool for the RCTs. The initial search yielded 1189 papers of which 72 fit the eligibility criteria. 27 unique performance metrics were identified. Global assessments were the most common tool of assessment (n = 13); the most used was GEARS (Global Evaluative Assessment of Robotic Skills). 11 metrics (42%) were objective tools of performance. Automated performance metrics (APMs) were the most widely used objective metrics whilst the remaining (n = 15, 58%) were subjective. The results demonstrate variation in tools used to assess technical performance in RAS. A large proportion of the metrics are subjective measures which increases the risk of bias amongst users. A standardised objective metric which measures all domains of technical performance from global to cognitive is required. The metric should be applicable to all RAS procedures and easily implementable. Automated performance metrics (APMs) have demonstrated promise in their wide use of accurate measures.

STAR-TREC: An International Three-arm Multicentre, Partially Randomised Controlled Trial Incorporating an External Pilot.

AIM: Organ saving treatment for early-stage rectal cancer can reduce patient reported side effects compared to standard total mesorectal excision (TME) and preserve quality of life (QOL). An optimal strategy for achieving organ preservation and longer-term oncological outcomes are unknown, thus there is a need for high quality trials. METHOD: Can we Save the rectum by watchful waiting or TransAnal surgery following (chemo)Radiotherapy versus Total mesorectal excision for early REctal Cancer (STAR-TREC) is an international 3-arm multi-centre, partially randomised controlled trial incorporating an external pilot. In phase III, patients with cT1-3b N0 tumours, ≤40mm in diameter, who prefer organ preservation are randomised 1:1 between mesorectal long course chemoradiation versus mesorectal short course radiotherapy, with selective transanal microsurgery. Patients preferring radical surgery receive TME. STAR-TREC aims to recruit 380 patients to organ preservation and 120 to TME surgery. The primary outcome is the rate of organ preservation at 30 months. Secondary clinician reported outcomes include acute treatment-related toxicity, rate of non-operative management, non-regrowth pelvic tumour control at 36 months, non-regrowth disease free survival at 36 months, and overall survival at 60 months and patient reported toxicity, health related QOL at baseline, 12 and 24 months. Exploratory biomarker research uses circulating tumour DNA to predict response and relapse. DISCUSSION: STAR-TREC will prospectively evaluate contrasting therapeutic strategies and implement new measures including a smaller mesorectal target volume, 2-step response assessment and non-operative management for complete response. The trial will yield important information to guide routine management of patients with early-stage rectal cancer.

Detection of non-metastatic non-small-cell lung cancer in urine by methylation-specific PCR analysis: A feasibility study.

BACKGROUND: Lung cancer has the highest cancer-related mortality worldwide and earlier detection could improve outcomes. Urine circulating tumor DNA (ctDNA) represents a true non-invasive means for ambulant sample collection. In this prospective study, the potential of urine for perioperative detection of non-metastatic non-small cell lung cancer (NSCLC) using ctDNA methylation analysis is evaluated. METHODS: Preoperative urine samples of 46 surgical NSCLC patients and 50 sex and age-matched controls were analyzed for DNA methylation of NSCLC-associated methylation markers CDO1, SOX17, and TAC1, using quantitative methylation-specific PCR (qMSP). The accuracy for NSCLC detection was determined by univariable and multivariable logistic regression analysis, followed by leave-one-out cross-validation. Fourteen additional urine samples were collected postoperatively to evaluate whether DNA methylation levels alter after surgery with curative intent. RESULTS: Methylation levels of CDO1 and SOX17 were significantly elevated in patients compared to controls (P =.016 and P <.001, respectively). This marker combination yielded an area under the receiver operating curve (AUC) value of 0.71 upon leave-one-out cross-validation for non-metastatic NSCLC detection in urine. Stage I patients tended to have higher methylation levels of SOX17 as compared to stage III patients. Similar methylation levels were found across the different histological subtypes of NSCLC. In some patients with preoperative elevated methylation levels, reduced methylation levels were found in post-operative urine samples. CONCLUSIONS: Urine CDO1 and SOX17 showed increased methylation levels in NSCLC patients as compared to sex- and age-matched controls. This demonstrates that urine ctDNA methylation analysis may provide an interesting non-invasive means to detect non-metastatic NSCLC. Further studies are needed to validate the clinical usefulness of this approach and to assess the potential of post-operative monitoring.

Hypothalamic Pilomyxoid Astrocytoma in a Child with Lipodystrophy.

Pilomyxoid astrocytoma is a rare form of pediatric CNS malignancy first classified in 2007 by the World Health Organization. The tumors are similar to pilocytic astrocytomas, sharing both some imaging and histologic traits. However, pilomyxoid astrocytomas portend a more ominous prognosis, with more aggressive local tendencies and a greater proclivity for leptomeningeal spread. Although tissue sampling is ultimately required to differentiate pilocytic astrocytomas and pilomyxoid astrocytomas, some imaging features can be used to suggest a pilomyxoid astrocytoma, including homogeneous enhancement, leptomeningeal seeding, and lack of intratumoral cysts. In this article, a case of a hypothalamic pilomyxoid astrocytoma is described, in which the presenting disorder was profound generalized lipodystrophy. The aforementioned imaging characteristics of pilomyxoid astrocytomas are reviewed, as are the pathologic features of such tumors, including their angiocentric cellular arrangement and myxoid background.

Detection of colorectal cancer in urine using DNA methylation analysis.

Colorectal cancer (CRC) is the second leading cause for cancer-related death globally. Clinically, there is an urgent need for non-invasive CRC detection. This study assessed the feasibility of CRC detection by analysis of tumor-derived methylated DNA fragments in urine. Urine samples, including both unfractioned and supernatant urine fractions, of 92 CRC patients and 63 healthy volunteers were analyzed for DNA methylation levels of 6 CRC-associated markers (SEPT9, TMEFF2, SDC2, NDRG4, VIM and ALX4). Optimal marker panels were determined by two statistical approaches. Methylation levels of SEPT9 were significantly increased in urine supernatant of CRC patients compared to controls (p < 0.0001). Methylation analysis in unfractioned urine appeared inaccurate. Following multivariate logistic regression and classification and regression tree analysis, a marker panel consisting of SEPT9 and SDC2 was able to detect up to 70% of CRC cases in urine supernatant at 86% specificity. First evidence is provided for CRC detection in urine by SEPT9 methylation analysis, which combined with SDC2 allows for an optimal differentiation between CRC patients and controls. Urine therefore provides a promising liquid biopsy for non-invasive CRC detection.

Research quality and transparency, outcome measurement and evidence for safety and effectiveness in robot-assisted surgery: systematic review.

BACKGROUND: Robot-assisted surgery (RAS) has potential panspecialty surgical benefits. High-quality evidence for widespread implementation is lacking. This systematic review aimed to assess the RAS evidence base for the quality of randomized evidence on safety and effectiveness, specialty 'clustering', and outcomes for RAS research. METHODS: A systematic review was undertaken according to PRISMA guidelines. All pathologies and procedures utilizing RAS were included. Studies were limited to RCTs, the English language and publication within the last decade. The main outcomes selected for the review design were safety and efficacy, and study purpose. Secondary outcomes were study characteristics, funding and governance. RESULTS: Searches identified 7142 titles, from which 183 RCTs were identified for data extraction. The commonest specialty was urology (35·0 per cent). There were just 76 unique study populations, indicating significant overlap of publications; 103 principal studies were assessed further. Only 64·1 per cent of studies reported a primary outcome measure, with 29·1 per cent matching their registration/protocol. Safety was assessed in 68·9 per cent of trials; operative complications were the commonest measure. Forty-eight per cent of trials reported no significant difference in safety between RAS and comparator, and 11 per cent reported RAS to be superior. Efficacy or effectiveness was assessed in 80·6 per cent of trials; 43 per cent of trials showed no difference between RAS and comparator, and 24 per cent reported that RAS was superior. Funding was declared in 47·6 per cent of trials. CONCLUSION: The evidence base for RAS is of limited quality and variable transparency in reporting. No patterns of harm to patients were identified. RAS has potential to be beneficial, but requires continued high-quality evaluation.

Investigation of the genotoxic effects of fluoride on a bone tissue model.

Fluorides are thought to be a major cause of osteocarcinogenesis, due to their widespread industrial use, ability to accumulate in bone tissue, and genotoxic and probable carcinogenic properties. In vitro experiments investigating the genotoxic potential of fluorides in bone tissue models can provide valuable indirect information on their involvement in osteocarcinogenesis. Here, we investigated whether sodium fluoride (NaF) has the ability to induce DNA damage and chromosomal abnormalities in human osteosarcoma cells after 48 and 72 h of exposure. The cell cultures were treated with NaF in concentrations of 0, 20, 100 and 200 µg/ml. The level of DNA damage was assessed by the comet assay, and the frequency of chromosomal abnormalities by a micronucleus test. A significant increase in DNA damage indicators was noted in the samples treated with fluoride concentrations of 100 and 200 µg/ml, after 48 and 72 h of exposure. The micronucleus test revealed a dose-dependent increase in cells with micronuclei, nucleoplasmic bridges and nuclear protrusions. Increasing the concentration of NaF led to an increase in the prevalence of cytogenetic indicators after both treatment durations. This demonstrated ability of fluorine to exert genotoxic effects on bone cells indirectly indicates the possible importance of fluoride in the aetiology of osteosarcoma.

Hartmann's procedure versus intersphincteric abdominoperineal excision (HiP Study): a multicentre prospective cohort study.

AIM: In patients with low rectal cancer it is occasionally necessary to avoid a low coloanal anastomosis due to patient frailty or poor function. In such situations there are two alternative approaches: Hartmann's procedure (HP) or intersphincteric abdominoperineal excision (IAPE). There are few data to guide surgeons as to which of these two procedures is the safest. The aim of this study was to determine the surgical complication rates associated with each procedure. METHOD: This was a multicentre, nonrandomized prospective cohort study of patients undergoing either HP or IAPE. The primary objective was to determine surgical complication rates. Secondary objectives included length of stay, time to adjuvant therapy and quality of life at 90 days. RESULTS: One hundred and seventy nine patients were recruited between April 2016 and June 2019; approximately two thirds of patients underwent HP and one third IAPE. The overall complication rate was high in both groups (54% for the HP group and 52% for the IAPE group). Surgery-specific complication rates were also high, but not significantly different: 43% for HP and 48% for IAPE. The pelvic abscess rate in HP was 11% and was significantly higher in patients with a palpable staple line (15% vs 2%). There was a higher incidence of serious medical complications following IAPE (16% vs 5%), along with a reduction in 90-day quality of life scores. CONCLUSION: This is the largest prospective study to compare HP and IAPE in patients undergoing rectal cancer surgery where primary anastomosis is not deemed appropriate. With similar complication rates, these data support the ongoing use of either HP or IAPE in this patient group.

National prospective cohort study of the burden of acute small bowel obstruction.

Background: Small bowel obstruction is a common surgical emergency, and is associated with high levels of morbidity and mortality across the world. The literature provides little information on the conservatively managed group. The aim of this study was to describe the burden of small bowel obstruction in the UK. Methods: This prospective cohort study was conducted in 131 acute hospitals in the UK between January and April 2017, delivered by trainee research collaboratives. Adult patients with a diagnosis of mechanical small bowel obstruction were included. The primary outcome was in-hospital mortality. Secondary outcomes included complications, unplanned intensive care admission and readmission within 30 days of discharge. Practice measures, including use of radiological investigations, water soluble contrast, operative and nutritional interventions, were collected. Results: Of 2341 patients identified, 693 (29·6 per cent) underwent immediate surgery (within 24 h of admission), 500 (21·4 per cent) had delayed surgery after initial conservative management, and 1148 (49·0 per cent) were managed non-operatively. The mortality rate was 6·6 per cent (6·4 per cent for non-operative management, 6·8 per cent for immediate surgery, 6·8 per cent for delayed surgery; P = 0·911). The major complication rate was 14·4 per cent overall, affecting 19·0 per cent in the immediate surgery, 23·6 per cent in the delayed surgery and 7·7 per cent in the non-operative management groups (P < 0·001). Cox regression found hernia or malignant aetiology and malnutrition to be associated with higher rates of death. Malignant aetiology, operative intervention, acute kidney injury and malnutrition were associated with increased risk of major complication. Conclusion: Small bowel obstruction represents a significant healthcare burden. Patient-level factors such as timing of surgery, acute kidney injury and nutritional status are factors that might be modified to improve outcomes.

A protocol for urine collection and storage prior to DNA methylation analysis.

BACKGROUND: Urine poses an attractive non-invasive means for obtaining liquid biopsies for oncological diagnostics. Especially molecular analysis on urinary DNA is a rapid growing field. However, optimal and practical storage conditions that result in preservation of urinary DNA, and in particular hypermethylated DNA (hmDNA), are yet to be determined. AIM: To determine the most optimal and practical conditions for urine storage that result in adequate preservation of DNA for hmDNA analysis. METHODS: DNA yield for use in methylation analysis was determined by quantitative methylation specific PCR (qMSP) targeting the ACTB and RASSF1A genes on bisulfite modified DNA. First, DNA yield (ACTB qMSP) was determined in a pilot study on urine samples of healthy volunteers using two preservatives (Ethylenediaminetetraacetic acid (EDTA) and Urine Conditioning Buffer, Zymo Research) at four different temperatures (room temperature (RT), 4°C, -20°C, -80°C) for four time periods (1, 2, 7, 28 days). Next, hmDNA levels (RASSF1A qMSP) in stored urine samples of patients suffering from bladder cancer (n = 10) or non-small cell lung cancer (NSCLC; n = 10) were measured at day 0 and 7 upon storage with and without the addition of 40mM EDTA and/or 20 µl/ml Penicillin Streptomycin (PenStrep) at RT and 4°C. RESULTS: In the pilot study, DNA for methylation analysis was only maintained at RT upon addition of preserving agents. In urine stored at 4°C for a period of 7 days or more, the addition of either preserving agent yielded a slightly better preservation of DNA. When urine was stored at -20 °C or -80 °C for up to 28 days, DNA was retained irrespective of the addition of preserving agents. In bladder cancer and NSCLC samples stored at RT loss of DNA was significantly less if EDTA was added compared to no preserving agents (p<0.001). Addition of PenStrep did not affect DNA preservation (p>0.99). Upon storage at 4°C, no difference in DNA preservation was found after the addition of preserving agents (p = 0.18). The preservation of methylated DNA (RASSF1A) was strongly correlated to that of unmethylated DNA (ACTB) in most cases, except when PCR values became inaccurate. CONCLUSIONS: Addition of EDTA offers an inexpensive preserving agent for urine storage at RT up to seven days allowing for reliable hmDNA analysis. To avoid bacterial overgrowth PenStrep can be added without negatively affecting DNA preservation.

Recommendations for Randomised Trials in Surgical Oncology.

Trials of surgical procedures in the treatment of malignant disease face a unique set of challenges. This review aimed to describe recommendations for the design, delivery and reporting of randomised trials in surgical oncology. A literature search was carried out without date limits to identify articles related to trial methodology research in surgery and surgical oncology. A narrative review was framed around two open National Institute of Health Research portfolio trials in colon and rectal cancer: the STAR-TREC trial (ISRCTN14240288) and the ROCCS trial (ISRCTN46330337). Twelve specific challenges were highlighted: standardisation of technique; pilot and feasibility studies; balancing treatments; the recruitment pathway; outcome measures; patient and public representation; trainee-led networks; randomisation; novel techniques and training; learning curves; blinding; follow-up. Evidence-based recommendations were made for the future design and conduct of surgical oncology trials. Better understanding of the challenges facing trials in the surgical treatment of cancer will accelerate high-quality evaluation and rapid adoption of innovation for the benefit of patient care.

6E11, a highly selective inhibitor of Receptor-Interacting Protein Kinase 1, protects cells against cold hypoxia-reoxygenation injury.

Necroptosis is a programmed cell death pathway that has been shown to be of central pathophysiological relevance in multiple disorders (hepatitis, brain and cardiac ischemia, pancreatitis, viral infection and inflammatory diseases). Necroptosis is driven by two serine threonine kinases, RIPK1 (Receptor Interacting Protein Kinase 1) and RIPK3, and a pseudo-kinase MLKL (Mixed Lineage Kinase domain-Like) associated in a multi-protein complex called necrosome. In order to find new inhibitors for use in human therapy, a chemical library containing highly diverse chemical structures was screened using a cell-based assay. The compound 6E11, a natural product derivative, was characterized as a positive hit. Interestingly, this flavanone compound: inhibits necroptosis induced by death receptors ligands TNF-α (Tumor Necrosis Factor) or TRAIL (TNF-Related Apoptosis-Inducing Ligand); is an extremely selective inhibitor, among kinases, of human RIPK1 enzymatic activity with a nM Kd; has a non-ATP competitive mode of action and a novel putative binding site; is weakly cytotoxic towards human primary blood leukocytes or retinal pigment epithelial cells at effective concentrations; protects human aortic endothelial cells (HAEC) from cold hypoxia/reoxygenation injury more effectively than necrostatin-1 (Nec-1) and Nec-1s. Altogether, these data demonstrate that 6E11 is a novel potent small molecular inhibitor of RIPK1-driven necroptosis.

Vertical zonation and functional diversity of fish assemblages revealed by ROV videos at oil platforms in The Gulf.

An assessment of vertical distribution, diel migration, taxonomic and functional diversity of fishes was carried out at offshore platforms in The (Arabian-Iranian-Persian) Gulf. Video footage was recorded at the Al Shaheen oil field between 2007 and 2014 using a remotely operated vehicle (ROV). A total of 12 822 individual fishes, from 83 taxonomic groups were recorded around the platforms. All the species identified are considered native to The Gulf, although Cyclichthys orbicularis and Lutjanus indicus were recorded for the first time in Qatari waters. Several trends were uncovered in the vertical distribution of the fish community; most species were observed between 20 and 50 m depth and fish abundance decreased towards the bottom, with the highest abundances recorded in the upper layers, i.e. down to 40 m depth. Vertical variation in fish diversity, however, was generally not accompanied by differences in vertical movements. Carnivores and invertivores were the dominant trophic groups, being found at each depth range from surface to seabed. The functional indices showed no significant differences between water depths or diel cycles. The study demonstrates that oil platforms represent a hotspot of fish diversity and interesting sites for studying fish communities, abundance and behaviour.

[Specific folic-acid targeted photosensitizer. The first step toward intraperitoneal photodynamic therapy for epithelial ovarian cancer]. / Photosensibilisateur spécifique pour la thérapie photodynamique ciblée des métastases péritonéales des cancers ovariens.

OBJECTIVE: Epithelial ovarian cancer (EOC) management remains association of debulking surgery in combination with platinum-based chemotherapy. Sixty percent of women with EOC considered in remission will develop recurrent disease. An option to improve the completion of cytoreductive surgery may be the use of photodynamic therapy to induce necrosis of peritoneal metastases. A limit of this technique was the toxicity induced by the lack of specificity of old-generation photosensitizer (PS) for tumor tissue if the light could not be specifically applied. To solve this problem, a solution is the design of selective PS. Folate receptor is a promising target for EOC targeted therapy. We present preclinical results concerning properties of a folic-acid targeted photosensitizer. METHOD: Preclinical studies have been performed in vitro on murine and human cell lines of EOC and in vivo with a preclinical model of peritoneal carcinomatosis (Fisher F344 rat/NuTu-19 cell line). They aimed to precise the ability of PS to target specifically tumor tissue, to emit specific fluorescence, and to obtain cell death. RESULTS: Tissue quantification of the PS showed specific incorporation of the folate-targeted PS within tumor tissue. Specificity for ovarian cancer metastases is better than previously reported with others photosensitizers (tumor-to-normal tissue ratio 9.6). We could detect specific fluorescence in vitro and in vivo on peritoneal metastases. Folic-acid targeted PDT allows to obtain human EOC cells death. CONCLUSION: Specific PS may allow the development of efficient and safe intraperitoneal PDT procedure, which could play a role in the prevention of EOC peritoneal recurrences.

A national patient and public colorectal research agenda: integration of consumer perspectives in bowel disease through early consultation.

AIM: There is a recognized need to include the views of patients and the public in prioritizing health research. This study aimed: (i) to explore patients' views on colorectal research; and (ii) to prioritize research topics with patients and the public. METHOD: In phase 1, 12 charitable organizations and patient groups with an interest in bowel disease were invited to attend a consultation exercise. Participants were briefed on 25 colorectal research topics prioritized by members of the Association of Coloproctology of Great Britain and Ireland. Focus groups were conducted and discussions were recorded with field notes. Analysis was conducted using principles of thematic analysis. In phase 2, a free public consultation was undertaken. Participants were recruited from newspaper advertisements, were briefed on the same research topics and were asked to rate the importance of each on a five-point Likert scale. Descriptive statistics were used to rank the topics. Univariable linear regression compared recorded demographic details with mean topic scores. RESULTS: Focus groups were attended by 12 patients who highlighted the importance of patient-centred information for trial recruitment and when selecting outcome measures. Some 360 people attended the public consultation, of whom 277 (77%) were recruited. Participants rated 'What is the best way to treat early cancer in the back passage?' highest, with 227 (85%) scoring it 4 or 5. There was no correlation between participant demographics and mean topic scores. CONCLUSION: The present study prioritized a colorectal research agenda with the input of patients and the public. Further research is required to translate this agenda into real improvements in patient care.

Multicentre study of short-course radiotherapy and transanal endoscopic microsurgery for early rectal cancer.

BACKGROUND: Organ-preserving treatment for early-stage rectal cancer may avoid the substantial perioperative morbidity and functional sequelae associated with total mesorectal excision (TME). The initial results of an organ-preserving approach using preoperative short-course radiotherapy (SCRT) and transanal endoscopic microsurgery (TEMS) are presented. METHODS: Patients with cT1-2N0 rectal cancers staged using high-quality MRI and endorectal ultrasonography received SCRT, with TEMS 8-10 weeks later, at four regional referral centres between 2007 and 2013. Patients were generally considered high risk for TME surgery (a small number refused TME). RESULTS: Following SCRT and TEMS, 60 (97 per cent) of 62 patients had an R0 resection. Histopathological staging identified 20 ypT0 tumours, 23 ypT1, 18 ypT2 and one ypT3. Preoperative uT category was significantly associated with a complete pathological response, which was achieved in 13 of 27 patients with uT0/uT1 disease and in five of 29 with uT2 (P = 0·010). Acute complications affected 19 patients, the majority following TEMS. No fistulas occurred and no stomas were formed. Surveillance detected four intraluminal local recurrences at a median follow-up of 13 months, all in patients with tumours staged as ypT2. Salvage TME achieved R0 resection in three patients and a stent was placed in one patient owing to co-morbidities. CONCLUSION: SCRT with TEMS was effective in the majority of patients considered high risk for (or who refused) TME surgery.

Combined endorectal ultrasonography and strain elastography for the staging of early rectal cancer.

AIM: Strain elastography is a novel approach to rectal tumour evaluation. The primary aim of this study was to correlate elastography to pT stages of rectal tumours and to assess the ability of the method to differentiate rectal adenomas (pT0) from early rectal cancer (pT1-2). Secondary aims were to compare elastography with endorectal ultrasonography (ERUS) and to propose a combined strain elastography and ERUS staging algorithm. METHOD: In all, 120 consecutive patients with a suspected rectal tumour were examined in this staging study. Patients receiving surgery without neoadjuvant radiotherapy were included (n = 59). All patients were examined with ERUS and elastography. Treatment decisions were made by multidisciplinary team (MDT) assessment, without considering the strain elastography examination. RESULTS: Histopathology identified 21 adenomas, 13 pT1, 9 pT2, 15 pT3 and one pT4. Mean elastography strain ratios were predictive of T stage (P = 0.01). Differentiation of adenomas from early rectal cancer (pT1-2) had sensitivity, specificity and accuracy of 0.82, 0.86 and 0.84 for elastography and 0.82, 0.62 and 0.72 for ERUS. A combined staging algorithm was developed to identify tumours eligible for local resection. Based on MDT evaluation 32% of tumours later identified as pT0 or pT1 were treated with total mesorectal excision, even though a local excision might have sufficed. Combined ERUS and elastography evaluation would have significantly reduced this number to 9% (P = 0.008). CONCLUSION: Elastography may improve the staging of adenomas and early rectal cancer compared with ERUS alone. Combined ERUS and elastography assessment is likely to further improve the selection of patients for local resection.

Endorectal ultrasonography, strain elastography and MRI differentiation of rectal adenomas and adenocarcinomas.

AIM: Strain elastography is a method for recording tissue hardness. Strain in different areas may be compared using strain ratio (SR). The aims of this study were to validate a previously proposed SR cut-off value of 1.25 for differentiating adenocarcinomas from adenomas and to compare the performance of endorectal ultrasonography (ERUS), strain elastography and MRI in the same patients. METHOD: A prospective evaluation of 120 consecutive patients with rectal neoplasia, using a predetermined elastography strain ratio cut-off value, was performed to differentiate adenomas from adenocarcinomas. ERUS and MRI were performed according to standard routine at Haukeland University Hospital, defining T0 as adenomas and T1-T4 as adenocarcinomas. Subsequent histopathology was used as the reference standard. RESULTS: Histopathological evaluation revealed 21 adenomas and 99 adenocarcinomas. Sensitivity, specificity and accuracy (with 95% CI) were as follows: ERUS: 0.96 (0.90-0.99), 0.62 (0.40-0.80) and 0.90 (0.83-0.94); elastography SR: 0.96 (0.90-0.99), 0.86 (0.66-0.96) and 0.94 (0.88-0.97); and MRI: 0.99 (0.94-1.00), 0.07 (0.00-0.31) and 0.87 (0.80-0.93). CONCLUSION: This study confirms that the elastography SR assessment accurately differentiates sessile adenomas from adenocarcinomas. SR assessment has a superior ability to differentiate adenomas and adenocarcinomas when compared with ERUS and MRI. MRI examination seems unable to recognize adenomas and should be interpreted with care when early-stage rectal neoplasia is suspected.