Multivariable prognostic modelling to improve prediction of colorectal cancer recurrence: the PROSPeCT trial.

OBJECTIVE: Improving prognostication to direct personalised therapy remains an unmet need. This study prospectively investigated promising CT, genetic, and immunohistochemical markers to improve the prediction of colorectal cancer recurrence. MATERIAL AND METHODS: This multicentre trial (ISRCTN 95037515) recruited patients with primary colorectal cancer undergoing CT staging from 13 hospitals. Follow-up identified cancer recurrence and death. A baseline model for cancer recurrence at 3 years was developed from pre-specified clinicopathological variables (age, sex, tumour-node stage, tumour size, location, extramural venous invasion, and treatment). Then, CT perfusion (blood flow, blood volume, transit time and permeability), genetic (RAS, RAF, and DNA mismatch repair), and immunohistochemical markers of angiogenesis and hypoxia (CD105, vascular endothelial growth factor, glucose transporter protein, and hypoxia-inducible factor) were added to assess whether prediction improved over tumour-node staging alone as the main outcome measure. RESULTS: Three hundred twenty-six of 448 participants formed the final cohort (226 male; mean 66 ± 10 years. 227 (70%) had ≥ T3 stage cancers; 151 (46%) were node-positive; 81 (25%) developed subsequent recurrence. The sensitivity and specificity of staging alone for recurrence were 0.56 [95% CI: 0.44, 0.67] and 0.58 [0.51, 0.64], respectively. The baseline clinicopathologic model improved specificity (0.74 [0.68, 0.79], with equivalent sensitivity of 0.57 [0.45, 0.68] for high vs medium/low-risk participants. The addition of prespecified CT perfusion, genetic, and immunohistochemical markers did not improve prediction over and above the clinicopathologic model (sensitivity, 0.58-0.68; specificity, 0.75-0.76). CONCLUSION: A multivariable clinicopathological model outperformed staging in identifying patients at high risk of recurrence. Promising CT, genetic, and immunohistochemical markers investigated did not further improve prognostication in rigorous prospective evaluation. CLINICAL RELEVANCE STATEMENT: A prognostic model based on clinicopathological variables including age, sex, tumour-node stage, size, location, and extramural venous invasion better identifies colorectal cancer patients at high risk of recurrence for neoadjuvant/adjuvant therapy than stage alone. KEY POINTS: Identification of colorectal cancer patients at high risk of recurrence is an unmet need for treatment personalisation. This model for recurrence, incorporating many patient variables, had higher specificity than staging alone. Continued optimisation of risk stratification schema will help individualise treatment plans and follow-up schedules.

Pelvic floor imaging in asymptomatic subjects.

AIM: The aim of this work was to determine the range of normal imaging features during total pelvic floor ultrasound (TPFUS) (transperineal, transvaginal, endovaginal and endoanal) and defaecation MRI (dMRI). METHOD: Twenty asymptomatic female volunteers (mean age 36.5 years) were prospectively investigated with dMRI and TPFUS. Subjects were screened with symptom questionnaires (ICIQ-B, St Mark's faecal incontinence score, obstructed defaecation syndrome score, ICIQ-V, BSAQ). dMRI and TPFUS were performed and interpreted by blinded clinicians according to previously published methods. RESULTS: The subjects comprised six parous and 14 nulliparous women, of whom three were postmenopausal. There were three with a rectocoele on both modalities and one with a rectocoele on dMRI only. There was one with intussusception on TPFUS. Two had an enterocoele on both modalities and one on TPFUS only. There were six with a cystocoele on both modalities, one on dMRI only and one on TPFUS only. On dMRI, there were 12 with functional features. Four also displayed functional features on TPFUS. Two displayed functional features on TPFUS only. CONCLUSION: This study demonstrates the presence of abnormal findings on dMRI and TPFUS without symptoms. There was a high rate of functional features on dMRI. This series is not large enough to redefine normal parameters but is helpful for appreciating the wide range of findings seen in health.

Positioning intestinal ultrasound in a UK tertiary centre: significant estimated clinical role and cost savings.

Objective: Intestinal ultrasound (IUS) is an inexpensive, non-invasive method of diagnosing and monitoring inflammatory bowel disease (IBD). We aimed to establish the proportion of lower gastrointestinal endoscopies (LGIEs) and magnetic resonance enterographies (MREs) that could have been performed as IUS, the potential pathology miss-rates if IUS was used and the associated cost savings. Methods: All MREs and LGIEs performed for either assessment of IBD activity or investigation of possible IBD, performed at a single UK tertiary centre in January 2018, were retrospectively reviewed against predetermined criteria for IUS suitability. Case outcomes were recorded and cost of investigation if IUS was performed instead was calculated. Results: 73 of 260 LGIEs (28.1%) and 58 of 105 MREs (55.2%) met the criteria for IUS suitability. Among potential IUS-suitable endoscopy patients, one case each of a <5 mm adenoma and sessile serrated lesion were found; no other significant pathology that would be expected to be missed with IUS was encountered. Among IUS-suitable MRE patients, no cases of isolated upper gastrointestinal inflammation likely to be missed by IUS were found, and extraintestinal findings not expected to be seen on IUS were of limited clinical significance. The predicted cost saving over 1 month if IUS was used instead was £8642, £25 866 and £5437 for MRE, colonoscopy and flexible sigmoidoscopy patients, respectively. Conclusion: There is a significant role for IUS, with annual projected cost savings of up to almost £500 000 at our centre. Non-inflammatory or non-gastrointestinal pathology predicted to be missed in this cohort was of limited clinical significance.

A retrospective cohort study: pre-operative oral enteral nutritional optimisation for Crohn's disease in a UK tertiary IBD centre.

BACKGROUND: Low-quality evidence suggests that pre-operative exclusive enteral nutrition (E/EN) can improve postoperative outcomes in patients with Crohn's disease (CD). It is not standard practice in most centres. AIMS: To test the hypothesis that pre-operative EN in patients undergoing ileal/ileocolonic surgery for CD is associated with improved postoperative outcome. METHODS: We performed a single centre retrospective observational study comparing surgical outcomes in patients receiving pre-operative EN (≥600 kcal/day for ≥2 weeks) with those who received no nutritional optimisation. Consecutive adult patients undergoing ileal/ileocolonic resection from 2008 to 2020 were included. The primary outcome was postoperative complications <30 days. Secondary outcomes included EN tolerance, specific surgical complications, unplanned stoma formation, length of stay, length of bowel resected, readmission and biochemical/anthropometric changes. RESULTS: 300 surgeries were included comprising 96 without nutritional optimisation and 204 optimised cases: oral EN n = 173, additional PN n = 31 (4 of whom had received nasogastric/nasojejunal EN). 142/204 (69.6%) tolerated EN. 125/204 (61.3%) initiated EN in clinic. Patients in the optimised cohort were younger at operation and diagnosis, with an increased frequency of penetrating disease and exposure to antibiotics or biologics, and were more likely to undergo laparoscopic surgery. The optimised cohort had favourable outcomes on multivariate analysis: all complications [OR 0.29; 0.15-0.57, p < 0.001], surgical complications [OR 0.41; 95% CI 0.20-0.87, p = 0.02], non-surgical complications [OR 0.24 95% CI 0.11-0.52, p < 0.001], infective complications [OR 0.32; 95% CI 0.16-0.66, p = 0.001]. CONCLUSIONS: Oral EN was reasonably well tolerated and associated with a reduction in 30-day postoperative complications. Randomised controlled trials are required to confirm these findings.

Predicting response to neoadjuvant chemotherapy in patients with oesophageal adenocarcinoma.

BACKGROUND: Neoadjuvant chemotherapy is often used prior to surgical resection for oesophageal adenocarcinoma but remains ineffective in a high proportion of patients. The histological Mandard tumour regression grade is used to determine chemoresponse but is not available at the time of treatment decision-making. The aim of this cohort study was to identify factors that predict chemotherapy response prior to surgery. METHODS: A prospectively collected database of patients undergoing surgical resection for oesophageal adenocarcinoma from a high-volume UK institution was used. Patients were subcategorised using pathological tumour response into 'responders' (Mandard grade 1-3) and 'non-responders' (Mandard grade 4 and 5). Multivariable logistic regression analysis was performed to calculate crude and adjusted odds ratios (OR) with 95% confidence intervals (CI) for responder status adjusting for a variety of parameters. Receiver operating characteristic (ROC) curves were calculated. RESULTS: Among 315 patients included, 102 (32%) were responders and 213 (68%) non-responders. A decrease in radiological tumour volume (OR 1.92 95%CI 1.02-3.62; p = 0.05), a 'partial response' RECIST score (OR 7.16 95%CI 1.49-34.36; p = 0.01), a clinically improved dysphagia score (OR 2.79 95%CI 1.05-7.04; p = 0.04) and lymphovascular invasion (OR 0.06 95%CI 0.02-0.13; p = 0.000) influenced responder status. ROC curve analysis for responder status utilising all available parameters had an area under the curve (AUC) of 0.86. CONCLUSION: This study has highlighted the potential for using pre-defined factors to identify those patients who have responded to neoadjuvant chemotherapy, prior to surgical resection, potentially facilitating a more individualised therapeutic approach.

Does a high Mandard score really define a poor response to chemotherapy in oesophageal adenocarcinoma?

BACKGROUND: A high Mandard score implies a non-response to chemotherapy in oesophageal adenocarcinoma. However, some patients exhibit tumour volume reduction and a nodal response despite a high score. This study examines survival and recurrence patterns in these patients. METHODS: Clinicopathological factors were analysed using multivariable Cox regression assessing time to death and recurrence. Computed tomography-estimated tumour volume change was examined in a subgroup of consecutive patients. RESULTS: Five hundred and fifty-five patients were included. Median survival was 55 months (Mandard 1-3) and 21 months (Mandard 4 and 5). In the Mandard 4 and 5 group (332 patients), comparison between complete nodal responders and persistent nodal disease showed improved survival (90 vs 18 months), recurrence rates (locoregional 14.75 vs 28.74%, systemic 24.59 vs 48.42%) and circumferential resection margin positivity (22.95 vs 68.11%). Complete nodal response independently predicted improved survival (hazard ratio 0.34 (0.16-0.74). Post-chemotherapy tumour volume reduction was greater in patients with a complete nodal response (-16.3 vs -7.7 cm3, p = 0.033) with no significant difference between Mandard groups. CONCLUSION: Patients with a complete nodal response to chemotherapy have significantly improved outcomes despite a poor Mandard score. High Mandard score does not correspond with a non-response to chemotherapy in all cases and patients with nodal downstaging may still benefit from adjuvant chemotherapy.

The Prognostic Role of Pre-operative Positron Emission Tomography-Computed Tomography and Endoscopic Ultrasound Parameters in Oesophageal Adenocarcinoma.

Background: To evaluate the prognostic role of Positron Emission Tomography/Computed Tomography (PET/CT) and Endoscopic Ultrasound (EUS) performed before neoadjuvant chemotherapy (NAC) and surgery for oesophageal adenocarcinoma (OAC) patients, focusing on lymph node (LN) assessment. Methods: OAC patients treated in a single tertiary center during January 2008 until December 2014 were retrospectively studied. All patients had PET/CT and EUS before NAC and oesophagectomy. PET-FDG-avid local LNs and maximum standardized uptake value (SUVmax) of the primary tumour, EUS positive LNs and EUS tumour length were recorded. Univariate, multivariate and survival analyses were performed. Results: Following exclusions 151consecutive patients met the inclusion criteria, (median age 62 years). PET/CT and EUS sensitivity for local LNs metastasis was 39.2% and 88.6%, with specificities of 83.33% and 19.15% respectively. No overall survival (OS) difference was found between patients with PET/CT FDG-avid LNs and those with negative LNs (p=0.347). SUVmax uptake was divided into high and low (median cut-off value: 10) with no significant difference in OS between groups (p=0.141). EUS tumour length was not prognostic (OS, p=0.455). Conclusions: Initial LN staging in OA is inaccurate. Although PET/CT and EUS assessments may be complimentary, none independently predicted survival.

Abdominal manifestations of IgG4-related disease: a pictorial review.

In the last decade, autoimmune pancreatitis has become recognised as part of a wider spectrum of IgG4-related disease, typically associated with elevated serum IgG4 levels and demonstrating a response to corticosteroid therapy. Radiologically, there is imaging overlap with other benign and neoplastic conditions. This pictorial review discusses the intra-abdominal manifestations of this disease on cross-sectional imaging before and after steroid treatment and the main radiological features which help to distinguish it from other key differentials. TEACHING POINTS: • Autoimmune pancreatitis is part of a spectrum of IgG4-related disease. • Diagnosis is based on raised serum IgG4, clinical, radiological and histopathological findings. • Cross-sectional imaging can demonstrate the typical findings of abdominal IgG4-related disease. • Cross-sectional imaging can be used to monitor response to corticosteroid treatment.

Patient optimization for surgery relating to Crohn's disease.

The majority of patients with Crohn's disease require abdominal surgery during their lifetime, some of whom will require multiple operations. Postoperative complications are seen more frequently in patients requiring abdominal surgery for Crohn's disease than in patients requiring abdominal surgery for other conditions. In this article, we review the evidence supporting preoperative optimization, discussing strategies that potentially improve surgical outcomes and reduce perioperative morbidity and mortality. We discuss the roles of adequate cross-sectional imaging, nutritional optimization, appropriate adjustments of medical therapy, management of preoperative abscesses and phlegmons, smoking cessation and thromboembolic prophylaxis. We also review operation-related factors, and discuss their potential implications with respect to postoperative complications. Overall, the literature suggests that preoperative management has a major effect on postoperative outcomes.

Magnetic Resonance Enterography in Crohn׳s Disease.

Over the past decade, magnetic resonance (MR) enterography has become established as the first-line imaging test for patients with Crohn׳s disease. This article reviews the role of MR enterography in assessing the extent and activity of Crohn׳s disease at baseline and on treatment follow-up. It discusses the role of diffusion-weighted imaging, and the recent introduction of MR scoring systems to facilitate noninvasive objective assessment of disease activity and cumulative bowel damage.

A Role for Tumor Volume Assessment in Resectable Esophageal Cancer.

BACKGROUND: Esophageal cancer has a poor prognosis, and many patients undergoing surgery have a low chance of cure. Imaging studies suggest that tumor volume is prognostic. The study aimed to evaluate pathological tumor volume (PTV) as a prognostic variable in esophageal cancer. METHODS: This single-center cohort study included 283 patients who underwent esophageal cancer resections between 2000 and 2012. PTVs were obtained from pathological measurements using a validated volume formula. The prognostic value of PTV was analyzed using multivariable regression models, adjusting for age, tumor grade, tumor (T) stage, nodal stage, lymphovascular invasion, resection margin, resection type, and chemotherapy response, which provided hazard ratios (HRs) with 95 % confidence intervals (CIs). Primary outcomes were time to death and time to recurrence. Secondary outcomes were margin involvement and lymph node positivity. Correlation analysis was performed between imaging and PTVs. RESULTS: On unadjusted analysis, increasing PTV was associated with worse overall mortality (HR 2.30, 95 % CI 1.41-3.73) and disease recurrence (HR 1.87, 95 % CI 1.14-3.07). Adjusted analysis demonstrated worse overall mortality with increasing PTV but reached significance in only one subgroup (HR 1.70, 95 % CI 1.09-2.38). PTV was an independent predictor of margin involvement (OR 2.28, 95 % CI 1.02-5.13) and lymph node-positive status (OR 2.77, 95 % CI 1.23-6.28). Correlation analyses demonstrated significant positive correlation between computed tomography (CT) software and formula tumor volumes (r = 0.927, p < 0.0001), CT and positron emission tomography tumor volumes (r = 0.547, p < 0.0001), and CT and PTVs (r = 0.310, p < 0.001). CONCLUSIONS: Tumor volume may predict survival, margin status, and lymph node positivity after surgery for esophageal cancer.

Prevalence and Risk Factors for Functional Vitamin B12 Deficiency in Patients with Crohn's Disease.

BACKGROUND: Crohn's disease (CD) is a risk factor for vitamin B12 deficiency due to frequent involvement of the terminal ileum. Conventional screening for B12 deficiency with serum B12 is relatively insensitive and measures total B12 concentration, of which a minority is present in a biologically active form. Holotranscobalamin (holoTC) combined with methylmalonic acid (MMA) is believed to be more accurate in identifying impaired B12 status. We evaluated the prevalence and risk factors for B12 deficiency using holoTC supported by MMA among patients with CD. METHODS: We performed a single-center service evaluation of 381 patients with CD who underwent B12 assessment (holoTC/MMA) and compared them with 141 patients with ulcerative colitis. Eighty-nine patients with CD underwent paired serum B12 and holoTC. Among patients with CD, risk factors including terminal ileal resection length, ileal inflammation on endoscopy, and disease characteristics on magnetic resonance imaging were recorded. RESULTS: Prevalence of B12 deficiency among patients with CD was 33% compared with 16% in ulcerative colitis (P < 0.0001). In 89 patients who underwent paired tests, conventional testing identified B12 deficiency in 5% of patients with CD, which increased to 32% using holoTC/MMA. Independent risk factors for B12 deficiency were ileal resection length ≤20 cm (odds ratio: 3.0, 95% confidence interval, 1.5-6.0, P = 0.002) and >20 cm (odds ratio: 6.7, 95% confidence interval, 3.0-14.7, P < 0.0001) and ileal inflammation (odds ratio: 3.9, 95% confidence interval, 2.2-6.9, P < 0.0001). On magnetic resonance imaging, active terminal ileal inflammation (P = 0.02) and an increased disease burden (≥1 skip lesion, P = 0.01 and prestenotic dilatation >3 cm, P = 0.01) were associated with B12 deficiency. CONCLUSIONS: Vitamin B12 deficiency is common in patients with CD. holoTC supported by MMA identifies patients with B12 deficiency considered replete on conventional testing.

Assessment of sarcopenia and changes in body composition after neoadjuvant chemotherapy and associations with clinical outcomes in oesophageal cancer.

OBJECTIVES: Sarcopenia and changes in body composition following neoadjuvant chemotherapy (NAC) may affect clinical outcome. We assessed the associations between CT body composition changes following NAC and outcomes in oesophageal cancer. METHODS: A total of 35 patients who received NAC followed by oesophagectomy, and underwent CT assessment pre- and post-NAC were included. Fat mass (FM), fat-free mass (FFM), subcutaneous fat to muscle ratio (FMR) and visceral to subcutaneous adipose tissue ratio (VA/SA) were derived from CT. Changes in FM, FFM, FMR, VA/SA and sarcopenia were correlated to chemotherapy dose reductions, postoperative complications, length of hospital stay (LOS), circumferential resection margin (CRM), pathological chemotherapy response, disease-free survival (DFS) and overall survival (OS). RESULTS: Nine (26 %) patients were sarcopenic before NAC and this increased to 15 (43 %) after NAC. Average weight loss was 3.7 % ± 6.4 (SD) in comparison to FM index (-1.2 ± 4.2), FFM index (-4.6 ± 6.8), FMR (-1.2 ± 24.3) and VA/SA (-62.3 ± 12.7). Changes in FM index (p = 0.022), FMR (p = 0.028), VA/SA (p = 0.024) and weight (p = 0.007) were significant univariable factors for CRM status. There was no significant association between changes in body composition and survival. CONCLUSIONS: Loss of FM, differential loss of VA/SA and skeletal muscle were associated with risk of CRM positivity. KEY POINTS: • Changes in CT body composition occur after neoadjuvant chemotherapy in oesophageal cancer. • Sarcopenia was more prevalent after neoadjuvant chemotherapy. • Fat mass, fat-free mass and weight decreased after neoadjuvant chemotherapy. • Changes in body composition were associated with CRM positivity. • Changes in body composition did not affect perioperative complications and survival.

Functional imaging of the bowel.

Functional imaging techniques enable physiological information to be derived, which, combined with high-resolution anatomical imaging, has the potential to improve the management of patients with intestinal disease. Two of the common pathologies where imaging has a substantial role in depicting disease extent, in staging disease, and assessing therapeutic response and/or disease relapse are cancer and inflammatory bowel disease. In these scenarios, functional imaging may augment assessment of disease activity, therapeutic response/non-response, as well as disease relapse by indicating physiological changes as a result of tumor, inflammation, or fibrosis.

The role of hepatocyte-specific contrast agents in hepatobiliary magnetic resonance imaging.

Hepatocyte-specific contrast agents have been made available in the last 15 years for magnetic resonance imaging of the liver. These agents are differentially taken up by functioning hepatocytes and excreted in the biliary system. They can help distinguish focal liver lesions of hepatocellular origin from lesions of nonhepatocellular origin, and can also be used in the evaluation of the biliary tree. The purpose of this review is to summarize the different types of hepatocyte-specific contrast agents presently available, their use in the characterization of focal liver lesions, their role in the evaluation of biliary pathology, and their potential future applications.

Magnetic resonance elastography in the diagnosis of hepatic fibrosis.

Liver fibrosis is a common feature of many chronic liver diseases, and can ultimately progress to cirrhosis. Conventional imaging is insensitive to liver fibrosis, necessitating a liver biopsy for diagnosis and monitoring of progression. However, liver biopsy risks complications, and is an imperfect gold standard in view of sampling error and intraobserver or interobserver variation. Magnetic resonance elastography (MRE) is a noninvasive method for assessing the mechanical properties of tissues and is gaining credence as a method of assessment for hepatic fibrosis. The aim of this review is to describe how MRE is performed, to review the present literature on the subject, to compare MRE with other noninvasive techniques used to assess for liver fibrosis, and to highlight areas of future research.

A comparison of MR elastography and 31P MR spectroscopy with histological staging of liver fibrosis.

OBJECTIVES: Conventional imaging techniques are insensitive to liver fibrosis. This study assesses the diagnostic accuracy of MR elastography (MRE) stiffness values and the ratio of phosphomonoesters (PME)/phosphodiesters (PDE) measured using (31)P spectroscopy against histological fibrosis staging. METHODS: The local research ethics committee approved this prospective, blinded study. A total of 77 consecutive patients (55 male, aged 49 ± 11.5 years) with a clinical suspicion of liver fibrosis underwent an MR examination with a liver biopsy later the same day. Patients underwent MRE and (31)P spectroscopy on a 1.5 T whole body system. The liver biopsies were staged using an Ishak score for chronic hepatitis or a modified NAS fibrosis score for fatty liver disease. RESULTS: MRE increased with and was positively associated with fibrosis stage (Spearman's rank = 0.622, P < 0.001). PME/PDE was not associated with fibrosis stage (Spearman's rank = -0.041, p = 0.741). Area under receiver operating curves for MRE stiffness values were high (range 0.75-0.97). The diagnostic utility of PME/PDE was no better than chance (range 0.44-0.58). CONCLUSIONS: MRE-estimated liver stiffness increases with fibrosis stage and is able to dichotomise fibrosis stage groupings. We did not find a relationship between (31)P MR spectroscopy and fibrosis stage. KEY POINTS: Magnetic resonance elastography (MRE) and MR spectroscopy can both assess the liver. MRE is superior to ( 31 ) P MR spectroscopy in staging hepatic fibrosis. MRE is able to dichotomise liver fibrosis stage groupings. Gradient-echo MRE may be problematic in genetic haemochromatosis.

The value of postoperative/preadjuvant chemotherapy computed tomography in the management of patients with ovarian cancer.

OBJECTIVE: The objectives of the study were to compare the operative assessment of residual disease with the postoperative computed tomography (CT) findings in patients with ovarian cancer who underwent primary surgical cytoreduction or interval debulking surgery to residual disease 1 cm or less and to assess the effect of potential prognostic factors on patient survival. METHODS: Patients scheduled for surgery and with an available postoperative CT were eligible for the study. Images were retrospectively analyzed in consensus by 2 radiologists.A 5-point qualitative scoring system was used to evaluate the CT findings (1 = tumor definitely absent, 2 = tumor probably absent, 3 = tumor possibly present, 4 = tumor probably present, 5 = tumor definitely present). RESULTS: Between September 2005 and December 2008, 206 consecutive patients were enrolled; 51 were eligible. In 30 cases (59%), the postoperative CT findings correlated with the surgeon's assessment of residual disease. For the univariate analyses, the only significant prognostic factors associated with overall survival were no residual disease versus residual disease of less than 1 cm as assessed by the surgeon (hazard ratio [HR], 3.06; 95%confidence interval [CI], 1.29--7.27; P = 0.011) and no residual disease versus residual disease greater than 1 cm on CT (HR, 2.57; 95% CI, 1.02--6.48; P = 0.045). The interaction of surgical residual disease and stage 3 was significant (HR, 3.40; 95% CI, 1.42--8.16;P = 0.006) in the multivariate Cox model. CONCLUSIONS: There was only 59% correlation between the surgical assessment and post operative CT findings of residual disease in patients reported to have undergone optimal surgery. Stage and residual disease as assessed by the surgeon were significant prognostic factors for overall survival. The value for postoperative CT may lie in those cases with small-volume residual disease (visible but reported as G1 cm) at surgery.

Anal carcinomas: the role of endoanal ultrasound and magnetic resonance imaging in staging, response evaluation and follow-up.

Anal carcinoma is an important but rare condition, managed in specialist centres. Both endoanal ultrasound and magnetic resonance imaging (MRI) can be used in the locoregional staging and follow-up of patients with anal cancer, and both may assist in treatment planning and prognosis. Recent guidelines published by the European Society for Medical Oncology have recommended MRI as the technique of choice for assessment of locoregional disease. This paper describes the techniques for both endoanal ultrasound and MRI, and compares the relative merits and disadvantages of each in the local assessment of anal carcinoma.