Large retrorectal spindle cell sarcoma: A case report and brief review of the literature.

Large retrorectal tumors are rare and often a diagnostic and surgical challenge due to their anatomical location. We report the case of a 55-year-old patient with weight loss and changed bowel habits, where digital rectal examination revealed a retrorectal mass raising suspicion of a tumor. Magnetic resonance imaging (MRI) and computed tomography (CT) showed a large retrorectal tumor and histopathology after surgical resection showed undifferentiated spindle cell sarcoma. This tumor type has not been previously reported as the etiology of large retrorectal tumors. We discuss the implications of diagnostic imaging, especially MRI, in the approach to diagnosis and surgical treatment of retrorectal tumors with reference to the scientific literature and previously reported cases of retrorectal tumors.

Rate of Unexpected Malignancy in Patients Undergoing Percutaneous Vertebroplasty after Implementing a New Scanning Protocol.

STUDY DESIGN: Retrospective quality improvement study. OBJECTIVE: To investigate if the rate of unsuspected malignancy in biopsies in patients with VCF who underwent PVP at the same orthopedic department has changed after implementation of a new MRI scanning protocol. SUMMARY OF BACKGROUND DATA: Discrimination between benign and malign vertebral compression fracture (VCF) can be difficult. However, early diagnosis of malignant VCF is crucial to further treatment and prognosis. An earlier study at an orthopedic department reported a rate of unsuspected malignancy of 4.9% in patients with VCF who underwent percutaneous vertebroplasty (PVP) when biopsies were obtained during the procedure. MRI scanning protocol was changed in this period. METHODS: Retrospective on 427 patients with vertebral compression fracture undergoing PVP from 28th of April 2017 to 28th of April 2022, identifying operated patients from the Danish national DaneSpine registry. Subsequently, individual clinical information was collected in journal records. RESULTS: The rate of unsuspected malignancy was 0.9% (4/427) and the overestimation of malignant VCF was 50% (16/32). CONCLUSION: During the last 5 years, the rate of unsuspected malignancy in patients with VCF undergoing PVP has improved considerably from 4.9% to 0.9%. Furthermore, MRI is over-diagnosing malignancies. Thus, the new scanning procedure is effective in differentiating between benign and malign VCFs. LEVEL OF EVIDENCE: 3.

ctDNA-guided adjuvant treatment after radical-intent treatment of metastatic spread from colorectal cancer-the first interim results from the OPTIMISE study.

BACKGROUND: Patients with detectable ctDNA after radical-intent treatment of metastatic spread from colorectal cancer (mCRC) have a very high risk of recurrence, which may be prevented with intensified adjuvant chemotherapy (aCTh). In the OPTIMISE study, we investigate ctDNA-guided aCTh after radical-intent treatment of mCRC. Here we present results from the preplanned interim analysis. MATERIAL AND METHODS: The study is an open-label 1:1 randomized clinical trial comparing ctDNA-guided aCTh against standard of care (SOC), with a run-in phase investigating feasibility measures. Key inclusion criteria; radical-intent treatment for mCRC and clinically eligible for triple-agent chemotherapy. Patients underwent a PET-CT scan before randomization. ctDNA analyses of plasma samples were done by ddPCR, detecting CRC-specific mutations and methylation of the NPY gene. In the ctDNA-guided arm, ctDNA positivity led to an escalation strategy with triple-agent chemotherapy, and conversely ctDNA negativity led to a de-escalation strategy by shared-decision making. Patients randomized to the standard arm were treated according to SOC. Feasibility measures for the run-in phase were; the inclusion of 30 patients over 12 months in two Danish hospitals, compliance with randomization >80%, rate of PET-CT-positive findings <20%, and eligibility for triple-agent chemotherapy >80%. RESULTS: Thirty-two patients were included. The rate of PET-CT-positive cases was 22% (n = 7/32). Ninety-seven percent of the patients were randomized. Fourteen patients were randomly assigned to SOC and sixteen to ctDNA-guided adjuvant treatment and follow-up. All analyses of baseline plasma samples in the ctDNA-guided arm passed the quality control, and 19% were ctDNA positive. The median time to result was three working days. All ctDNA-positive patients were eligible for triple-agent chemotherapy. CONCLUSION: The study was proven to be feasible and continues in the planned large-scale phase II trial. Results from the OPTIMISE study will potentially optimize the adjuvant treatment of patients undergoing radical-intent treatment of mCRC, thereby improving survival and reducing chemotherapy-related toxicity.

Delta tocotrienol as a supplement to FOLFOXIRI in first-line treatment of metastatic colorectal cancer. A randomized, double-blind, placebo-controlled phase II study.

PURPOSE: Triplet chemotherapy might be more effective than doublet chemotherapy in metastatic colorectal cancer (mCRC), but it may also be marked by increased toxicity. To investigate whether δ-tocotrienol, a vitamin E analogue, with possible neuroprotective and anti-inflammatory effects, reduces the toxicity of triplet chemotherapy, we conducted a randomized, double-blind, placebo-controlled trial in mCRC patients receiving first-line 5-fluorouracil, oxaliplatin and irinotecan (FOLFOXIRI). MATERIAL AND METHODS: Seventy patients with mCRC were randomly assigned (1:1) to receive FOLFOXIRI plus either δ-tocotrienol or placebo at the Department of Oncology, Vejle Hospital, Denmark. Eligibility criteria were adenocarcinoma in the colon or rectum, age 18-75 years and ECOG performance status 0-1. FOLFOXIRI was given in eight cycles followed by four cycles of 5-fluorouracil. δ-tocotrienol 300 mg or placebo × 3 daily was added during chemotherapy and for a maximum of two years. The primary endpoint was time to hospitalization or death during treatment with chemotherapy. RESULTS: Median time to first hospitalization or death was 3.7 months in the placebo group (95% CI 1.93-not reached (NR)), and was NR in the δ-tocotrienol group (95% CI 1.87-NR) with a hazard ratio of 0.70 (95% CI 0.36-1.36). Grade 3-4 toxicities were uncommon in both groups, except for neutropenia, which occurred in 19 patients (58%) in the placebo group and 17 patients (50%) in the δ-tocotrienol group. There were no grade 3 or 4 peripheral sensory neuropathy. In the placebo group, 24 patients (71%) had oxaliplatin dose reductions compared to 17 patients (47%) in the δ-tocotrienol group (p = 0.047). CONCLUSION: The addition of δ-tocotrienol to FOLFOXIRI did not statistically significant prolong the time to first hospitalization or death compared to FOLFOXIRI plus placebo. Toxicity was manageable and not statistically different. There was a statistically significant difference in dose reductions of oxaliplatin pointing to a possible neuroprotective effect of δ-tocotrienol.

Intestinal ultrasound in patients with suspected Crohn's disease - results of a prospective evaluation by trainees.

BACKGROUND AND AIMS: Intestinal ultrasound (IUS) performed by experts is a valuable tool for the diagnostic work-up and monitoring of Crohn's disease (CD). However, concern about insufficient training and perceived high inter-observer variability limit the adoption of IUS in CD. We examined the diagnostic accuracy of trainee-performed IUS in patients with suspected CD. METHOD: Patients recruited to a prospective trial investigating the diagnostic accuracy of magnetic resonance enterocolonography (MREC) in patients with clinically suspected CD underwent IUS performed by trainees. The primary end-point was IUS per-patient sensitivity and specificity for ileocolonic CD determined by ileocolonoscopy. RESULTS: 129 patients with clinically suspected CD and a complete IC and IUS were included in the analysis. IUS detected signs of CD in 49 cases (small bowel 31, colon 15, small bowel, and colon 3). The sensitivity and specificity for detection of ileocolonic CD by trainee performed IUS improved during the first to the second half of the study period from 57.1% (CI 34.0-78.2) to 73.1% (CI 52.2-88.4) and 76.5% (CI 58.8-89.3) to 89.7% (CI 72.6-97.8). The overall sensitivity and specificity of diagnosing CD with IUS were 65.4% (CI 50.9-78.0) and 80.5% (CI 69.9-88.7). There was no difference in diagnostic performance between IUS and MREC for the detection of CD. CONCLUSION: Trainees improved during the study, and IUS performance in disease detection corresponded to expert-evaluated MREC.Registered at ClinicalTrials.gov (NCT03134586).

Calcium electroporation in cutaneous metastases - A non-randomised phase II multicentre clinical trial.

BACKGROUND: Cutaneous metastases can cause distressing symptoms and be challenging to treat. Local therapies are essential in management. Calcium electroporation uses calcium and electrical pulses to selectively kill cancer cells. This multicentre study aimed to define response in cutaneous metastases across different cancer types. METHODS: Patients with tumours ≤3 cm of any histology were included (stable or progressing on current therapy ≥2 months), at three centres. Tumours were treated with 220 mM calcium chloride injection and manual application of eight 0.1 ms pulses with 1 kV/cm and 1Hz with a handheld electrode, in local or general anaesthesia. Clinical response was evaluated after 1, 2, 3, 4, 5, 6, and 12 months. Primary endpoint was response at two months. The overall response rate (ORR) was partial- and complete responses of treated tumours. MR-imaging and qualitative interviews were performed in respective subsets. RESULTS: Nineteen patients with disseminated cancer (breast n = 4, lung n = 5, pancreatic n = 1, colorectal n = 2, gastric n = 1, and endometrial cancer n = 1) were enrolled, and 58 metastases were treated (50 once, 8 retreated). The ORR was 36% (95% CI 22-53) after two months. Best ORR was 51% (CR 42%; PR 9%). Previous irradiation improved outcomes (p = 0.0004). Adverse events were minimal. Median pain score was reduced after two months (p = 0.017). Treatment may relieve symptoms according to qualitative interviews. MRI showed restriction in treated tissue. CONCLUSION: The majority of tumours were treated only once with calcium electroporation, achieving an ORR of 36% after two months and best ORR of 51%. Efficacy, symptom-relief and safety support calcium electroporation as a palliative treatment option for cutaneous metastases.

Precision medicine applied to metastatic colorectal cancer using tumor-derived organoids and in-vitro sensitivity testing: a phase 2, single-center, open-label, and non-comparative study.

BACKGROUND: Patients with colorectal metastatic disease have a poor prognosis, limited therapeutic options, and frequent development of resistance. Strategies based on tumor-derived organoids are a powerful tool to assess drug sensitivity at an individual level and to suggest new treatment options or re-challenge. Here, we evaluated the method's feasibility and clinical outcome as applied to patients with no satisfactory treatment options. METHODS: In this phase 2, single-center, open-label, non-comparative study (ClinicalTrials.gov, register NCT03251612), we enrolled 90 patients with metastatic colorectal cancer following progression on or after standard therapy. Participants were 18 years or older with an Eastern Cooperative Oncology Group performance status of 0-2, adequate organ function, and metastasis available for biopsy. Biopsies from the metastatic site were cultured using organoids model. Sensitivity testing was performed with a panel of drugs with proven activity in phase II or III trials. At the discretion of the investigator considering toxicity, the drug with the highest relative activity was offered. The primary endpoint was the proportion of patients alive without disease progression at two months per local assessment. RESULTS: Biopsies available from 82 to 90 patients were processed for cell culture, of which 44 successfully generated organoids with at least one treatment suggested. The precision cohort of 34 patients started treatment and the primary endpoint, progression-free survival (PFS) at two months was met in 17 patients (50%, 95% CI 32-68), exceeding the pre-defined level (14 of 45; 31%). The median PFS was 67 days (95% CI 51-108), and the median overall survival was 189 days (95% CI 103-277). CONCLUSIONS: Patient-derived organoids and in-vitro sensitivity testing were feasible in a cohort of metastatic colorectal cancer. The primary endpoint was met, as half of the patients were without progression at two months. Cancer patients may benefit from functional testing using tumor-derived organoids. TRIAL REGISTRATION: ClinicalTrials.gov, register NCT03251612.

Using structured templates or free text style in reporting CT staging on colon cancer: a national survey.

BACKGROUND: Computed tomography (CT) is a widely used method for the staging of colon cancer. Accurate reports could lead to a better preoperative evaluation and planning of the treatment of colon cancer. PURPOSE: To evaluate the use of CT free-text reports and structured report templates when it comes to staging CT imaging of colon cancer. MATERIAL AND METHODS: A multiple choice questionnaire survey was conducted over four weeks. Online questionnaire software was used, and a link was shared to medical doctors with help from the Danish Colorectal Cancer Group (DCCG) and from a social media radiologist group. RESULTS: Clinicians preferred the template style (95%), whereas the level of support was lower among the radiologists (76%). All female responders preferred the template style, in contrast to only 84% of the male responders. Furthermore, the survey showed a slightly deficient level of the national CT reporting quality; only 7/13 questions and sub-questions, concerning CT report quality, achieved an approval rate >85%. The colorectal cancer multidisciplinary team consultants who always or usually work with template style reporting of CT scans of colon cancer tend to be more satisfied with the quality and content of the reports, compared to those who rarely use or read template reports. CONCLUSION: The following indicators were insufficiently reported: tumor invasion growth; number of hepatic metastases; segment location of hepatic metastasis; and retroperitoneal lymph node involvement. In the template reports group, nearly all participants found relevant information easily accessible.

Diffusion-Weighted MRI as a Quantitative Imaging Biomarker in Colon Tumors.

PURPOSE: To assess the use of quantitative diffusion-weighted MRI (DW-MRI) as a diagnostic imaging biomarker in differentiating between benign colon adenoma, early, and advanced cancer of the colon, as well as predicting lymph node involvement, and finally comparing mucinous-producing colon cancer with adenomas and non-mucinous colon cancer. METHOD: Patients with a confirmed tumor on colonoscopy were eligible for inclusion in this study. Using a 3.0 Tesla MRI machine, the main tumor mean apparent diffusion coefficient (mADC) was obtained. Surgically resected tumor specimens served as an endpoint, except in mucinous colon cancers, which were classified based on T2 images. RESULTS: A total of 152 patients were included in the study population. The mean age was 71 years. A statistically significant mADC mean difference of -282 × 10-6 mm2/s [-419--144 95% CI, p < 0.001] was found between colon adenomas and early colon cancer, with an AUC of 0.80 [0.68-0.93 95% CI] and an optimal cut off value of 1018 × 10-6 mm2/s. Only a small statistically significant difference (p = 0.039) in mADC was found between benign tumors and mucinous colon cancer. We found no statistical difference in mADC mean values between early and advanced colon cancer, and between colon cancer with and without lymph node involvement. CONCLUSION: Quantitative DW-MRI is potentially useful for determining whether a colonic tumor is benign or malignant. Mucinous colon cancer shows less diffusion restriction when compared to non-mucinous colon cancer, a potential pitfall.

Endorectal Ultrasound Shear-Wave Elastography of Complex Rectal Adenoma and Early Rectal Cancer.

Purpose: To investigate the diagnostic performance of endorectal ultrasound (ERUS), shear-wave elastography (SWE), and magnetic resonance imaging (MRI) in patients with a complex rectal adenoma or an early rectal cancer, i.e., T1 or T2 adenocarcinoma in a clinical setting, and to evaluate the association between SWE and stromal fraction (SF) and apparent diffusion coefficient (ADC) and SF. Method: This prospective study included patients undergoing ERUS and SWE for a rectal tumor subsequently confirmed by histopathology to be an adenoma or a T1 or T2 adenocarcinoma. The accuracy of the imaging methods was assessed by comparing the T category as determined by ERUS and MRI with histopathology, which served as the gold standard. SF was assessed on surgical specimens. Results: A total of 86 patients were included. Of these, 62 patients had adenomas and 24 patients had carcinomas, of which 11 were T1 tumors and 13 were T2 tumors. ERUS and MRI yielded sensitivity, specificity, and accuracy of 0.79 and 0.73, 0.95 and 0.90, and 0.86 and 0.78, respectively, for discrimination between benign and malignant lesions. The area under the receiver operating characteristics curve for SWE was 0.88, and with a cut-off value of 40 kPa the sensitivity, specificity, and accuracy were 0.79, 0.89, and 0.86, respectively. There was a positive correlation between SF and SWE with a p-value of <0.001 and a negative correlation between SF and ADC with a p-value of 0.011. Conclusion: Both ERUS and MRI classified T categories with a high accuracy; however, ERUS classified more adenomas correctly than MRI. In this small population, SWE could differentiate an adenoma from early carcinoma. SF was correlated with both SWE and ADC, as increasing SF tended to yield higher SWE and lower ADC values.

Diagnostic accuracy of pan-enteric capsule endoscopy and magnetic resonance enterocolonography in suspected Crohn's disease.

BACKGROUND AND AIMS: Magnetic resonance enterocolonography (MREC) and pan-enteric capsule endoscopy (CE) offers visualization of the entire gastrointestinal tract in a single examination. We examined the diagnostic accuracy of MREC and CE in patients with suspected Crohn's disease (CD). METHOD: In a prospective, blinded, multicenter study, we included patients with clinically suspected CD. Patients were examined with MREC, CE, and ileocolonoscopy (IC) within 2 weeks. The primary outcome was per patient sensitivity, specificity, and diagnostic accuracy for ileocolonic CD. IC served as reference standard. RESULTS: 153 patients were included in the study and IC, MREC, and CE was performed in 152, 151, 133 patients, respectively. CD was diagnosed with IC in 59 (39%) patients (terminal ileum (TI) 22, colon 20, TI and colon 17). The sensitivity and specificity for diagnosing ileocolonic CD with MREC was 67.9% (CI 53.7-80.1) and 76.3% (CI 65.2-85.3) (TI 76.9% and 85.6%; colon 27% and 93%) compared to 87.5% (CI 73.2-95.8) and 87.8% (CI 78.2-94.3) with CE (TI 96.6% and 87.5%; colon 75.0% and 93.0%). The sensitivity of CE was superior to that of MREC (p = 0.02). The patient experienced discomfort was equal with CE and MREC and significantly less than with IC. CONCLUSION: In patients with suspected CD, CE has a high sensitivity for diagnosing CD in the TI and colon, which is superior to that of MREC. The sensitivity of MREC for diagnosing CD in the colon is poor. CE could be a patient-friendly alternative to IC in selected patients with suspected CD. Registered at ClinicalTrials.gov: NCT03134586.

Intra- and Interobserver Variability of Shear Wave Elastography in Rectal Cancer.

BACKGROUND: Endorectal ultrasound (ERUS) is an important tool when evaluating complex rectal adenomas and rectal cancer, and the accuracy is improved by adding elastography measurements. A high interobserver agreement is imperative in clinical practice. Therefore, the aim of this study was to evaluate interobserver agreement assessed on real-time images. Additionally, we investigated the intra- and interobserver agreement between experienced and inexperienced observers. MATERIALS AND METHODS: We prospectively included patients referred to an ERUS at the Department of Radiology with a complex rectal polyp or suspected rectal malignancy. Two operators independently scanned each patient in turn. Furthermore, four observers assessed previously obtained images using three different methods for placing the region of interest (ROI). Three months later, the four observers reassessed the images to assess intraobserver variability. RESULTS: A total of 19 patients were included for live assessment. Agreement of tumor classification was substantial for T stage (kappa: 0.86) and fair for N stage (kappa: 0.73), with an absolute agreement for T and N stages of 84% and 89%, respectively. Agreement of SWE was good for Emean (ICC 0.94, 95% CI 0.86-0.98) and fair for Emax (ICC 0.85, 95% CI 0.66-0.94). Intra- and interobserver agreement between inexperienced and experienced observers showed good to excellent agreement with all ROI methods. CONCLUSION: Interobserver agreement is high in SWE when performed in a clinical setting. We found the best agreement using the mean value of several ROIs. Intra- and interobserver agreement was high regardless of operator experience.

Interobserver Reliability and the Sigmoid Takeoff-An Interobserver Study.

Background: Colorectal cancer is the second most common cancer worldwide. The sigmoid takeoff is the landmark where the colon sigmoid curves toward the sacrum viewed from sagittal magnetic resonance imaging (MRI). The purpose of this study was to assess interobserver variability in the assessment of the anal verge and anorectal junction in patients diagnosed with rectal cancer on magnetic resonance imaging (MRI). Materials and Methods: The rectal MRI examinations were performed using a 1.5- or 3.0-tesla unit using an anterior coil and a standard scan protocol. Two senior radiologists assessed MRI scans from patients under investigation for rectal cancer. The two observers assessed the anal verge and takeoff in cm independently. Difference in agreement between the observers were evaluated using intraclass correlation (ICC) and graphically by Bland-Altman plots. Results: The study population (n = 122) included 68 (55.7%) female and 54 (44.3%) male subjects. The overall median age was 69.5 years (range 39-95 years). There was perfect agreement between the two observers when defining rectal tumor above or below the takeoff landmark. The reliability of measuring the distance from the anal verge to the sigmoid takeoff was 0.712. Conclusion: Overall, the study found a moderate reliability in assessing the location of the sigmoid takeoff, with a low difference in the distance measuring, as well as a good consensus concerning the determination of tumors in relation to the sigmoid takeoff. Routine implementation of this information within the report seems reasonable.

CT and 3 Tesla MRI in the TN Staging of Colon Cancer: A Prospective, Blind Study.

(1) Background: Computer tomography (CT) scanning is currently the standard method for staging of colon cancer; however, the CT based preoperative local staging is far from optimal. The purpose of this study was to investigate the sensitivity and specificity of magnetic resonance imaging (MRI) compared to CT in the T- and N-staging of colon cancer. (2) Methods: Patients underwent a standard contrast-enhanced CT examination. For the abdominal MRI scan, a 3 Tesla unit was used, including diffusion weighted imaging (DWI). Experienced radiologists reported the CT and MRI scans blinded to each other and the endpoint of the pathological report. (3) Results: From 2018 to 2021, 134 patients received CT and MRI scans. CT identified 118 of the 134 tumors, whereas MRI identified all tumors. For discriminating between stage T3ab and T3cd, the sensitivity of CT was 51.1% and of MRI 80.0% (p = 0.02). CT and MRI showed a sensitivity of 21.4% and 46.4% in detecting pT4 tumors and a specificity of 79.0% and 85.0%, respectively. (4) Conclusion: Compared to CT, the sensitivity of MRI was statistically significantly higher in staging advanced T3cd and T4 tumors. MRI has the potential to be used in the treatment planning of colon cancer.

MRI interobserver reliability in rectal tumor angulation.

BACKGROUND: When rectal tumors are examined using magnetic resonance imaging (MRI) the perpendicular angulation of the axial T2-weighted image to the tumor axis is essential for a correct measure of the shortest distance between tumor and mesorectal facia. PURPOSE: The purpose of this study was to determine the interobserver variability in rectal tumor angulation between a radiologist and a radiographer. MATERIAL AND METHODS: Two observers performed the angulation independently. All MRI examinations were performed using an MRI 1.5 Tesla unit. A Bland-Altman plot was used to assess the interobserver variance and Intraclass correlation coefficient (ICC) statistic was used to assess the interobserver reliability. RESULTS: MRI was performed in 55 patients with rectal cancer during a one-year period (25 (45.5%) women and 30 (54.5%) men). The median age was 71 years (range 46-87 years). The rectal tumor mean length was 3.9 cm. The interobserver reliability was good (ICC = 0.83, 95% confidence interval 0.72-0.90). CONCLUSION: Radiographers receiving training will be able to perform MRI rectal tumor angulation.

ECCO-ESGAR Topical Review on Optimizing Reporting for Cross-Sectional Imaging in Inflammatory Bowel Disease.

BACKGROUND AND AIMS: The diagnosis and follow up of patients with inflammatory bowel disease [IBD] requires cross-sectional imaging modalities, such as intestinal ultrasound [IUS], magnetic resonance imaging [MRI] and computed tomography [CT]. The quality and homogeneity of medical reporting are crucial to ensure effective communication between specialists and to improve patient care. The current topical review addresses optimized reporting requirements for cross-sectional imaging in IBD. METHODS: An expert consensus panel consisting of gastroenterologists, radiologists and surgeons convened by the ECCO in collaboration with ESGAR performed a systematic literature review covering the reporting aspects of MRI, CT, IUS, endoanal ultrasonography and transperineal ultrasonography in IBD. Practice position statements were developed utilizing a Delphi methodology incorporating two consecutive rounds. Current practice positions were set when ≥80% of the participants agreed on a recommendation. RESULTS: Twenty-five practice positions were developed, establishing standard terminology for optimal reporting in cross-sectional imaging. Assessment of inflammation, complications and imaging of perianal CD are outlined. The minimum requirements of a standardized report, including a list of essential reporting items, have been defined. CONCLUSIONS: This topical review offers practice recommendations to optimize and homogenize reporting in cross-sectional imaging in IBD.

Management and follow-up of gallbladder polyps: updated joint guidelines between the ESGAR, EAES, EFISDS and ESGE.

MAIN RECOMMENDATIONS: 1. Primary investigation of polypoid lesions of the gallbladder should be with abdominal ultrasound. Routine use of other imaging modalities is not recommended presently, but further research is needed. In centres with appropriate expertise and resources, alternative imaging modalities (such as contrast-enhanced and endoscopic ultrasound) may be useful to aid decision-making in difficult cases. Strong recommendation, low-moderate quality evidence. 2. Cholecystectomy is recommended in patients with polypoid lesions of the gallbladder measuring 10 mm or more, providing the patient is fit for, and accepts, surgery. Multidisciplinary discussion may be employed to assess perceived individual risk of malignancy. Strong recommendation, low-quality evidence. 3. Cholecystectomy is suggested for patients with a polypoid lesion and symptoms potentially attributable to the gallbladder if no alternative cause for the patient's symptoms is demonstrated and the patient is fit for, and accepts, surgery. The patient should be counselled regarding the benefit of cholecystectomy versus the risk of persistent symptoms. Strong recommendation, low-quality evidence. 4. If the patient has a 6-9 mm polypoid lesion of the gallbladder and one or more risk factors for malignancy, cholecystectomy is recommended if the patient is fit for, and accepts, surgery. These risk factors are as follows: age more than 60 years, history of primary sclerosing cholangitis (PSC), Asian ethnicity, sessile polypoid lesion (including focal gallbladder wall thickening > 4 mm). Strong recommendation, low-moderate quality evidence. 5. If the patient has either no risk factors for malignancy and a gallbladder polypoid lesion of 6-9 mm, or risk factors for malignancy and a gallbladder polypoid lesion 5 mm or less, follow-up ultrasound of the gallbladder is recommended at 6 months, 1 year and 2 years. Follow-up should be discontinued after 2 years in the absence of growth. Moderate strength recommendation, moderate-quality evidence. 6. If the patient has no risk factors for malignancy, and a gallbladder polypoid lesion of 5 mm or less, follow-up is not required. Strong recommendation, moderate-quality evidence. 7. If during follow-up the gallbladder polypoid lesion grows to 10 mm, then cholecystectomy is advised. If the polypoid lesion grows by 2 mm or more within the 2-year follow-up period, then the current size of the polypoid lesion should be considered along with patient risk factors. Multidisciplinary discussion may be employed to decide whether continuation of monitoring, or cholecystectomy, is necessary. Moderate strength recommendation, moderate-quality evidence. 8. If during follow-up the gallbladder polypoid lesion disappears, then monitoring can be discontinued. Strong recommendation, moderate-quality evidence. SOURCE AND SCOPE: These guidelines are an update of the 2017 recommendations developed between the European Society of Gastrointestinal and Abdominal Radiology (ESGAR), European Association for Endoscopic Surgery and other Interventional Techniques (EAES), International Society of Digestive Surgery-European Federation (EFISDS) and European Society of Gastrointestinal Endoscopy (ESGE). A targeted literature search was performed to discover recent evidence concerning the management and follow-up of gallbladder polyps. The changes within these updated guidelines were formulated after consideration of the latest evidence by a group of international experts. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was adopted to define the strength of recommendations and the quality of evidence. KEY POINT: • These recommendations update the 2017 European guidelines regarding the management and follow-up of gallbladder polyps.