This study aimed to establish sex-specific cutoff values for sarcopenia based on the muscle parameters skeletal muscle index (SMI) and psoas muscle thickness per height (PMTH) using CT scans in a presumably healthy Caucasian study cohort. In this retrospective, cross-sectional study, CT scans of 350 Caucasian patients (mean age, 32 years ± 8; mean BMI, 23 (women) and 24 kg/m2 (men)) with polytrauma, but otherwise young and presumably healthy, were evaluated. Sex-specific PMTH at the level of the umbilicus (mm/m) and the SMI (cm2/m2) at the level of the L3 vertebral body were calculated from cross-sectional images. Two standard deviations below the mean were considered the cutoff values for sarcopenia according to the recommendations of the European Working Group on Sarcopenia in Older People (EWGSOP). To exclude random outliers, only the 5th–95th percentiles were analyzed. The sex-specific cutoff values for PMTH were 15.7 mm/m for women and 20.2 mm/m for men, while those for SMI were 33.2 and 44.0 cm2/m2, respectively. The intra-rater and inter-rater variabilities were consistently low, indicating the high reliability of the measurement method. This study established sex-specific thresholds for sarcopenia based on two different muscle parameters in a presumably healthy Caucasian study cohort according to EWGSOP recommendations. Question Establishment of sarcopenia cutoff values according to the recommendations of the European Working Group on Sarcopenia in Older People (EWGSOP). Findings Cutoff values for psoas muscle thickness per height (mm/m) were 15.7 (women) and 20.2 (men); for skeletal muscle index (cm2/m2), 33.2 and 44.0, respectively. Clinical relevance These cutoff values for two different parameters that can be determined by CT allow patients with low muscle mass to be objectively identified, thereby revealing those at high risk of manifest sarcopenia.

BACKGROUND:Sarcopenia, characterized by loss of skeletal muscle mass and strength, is prevalent in patients undergoing treatment for colorectal cancer. Sarcopenia's prevalence in patients with cancer can reach up to 50% and is known to exacerbate postsurgical complications and affect long-term oncological outcomes. This study examined whether minimally invasive surgery (MIS) offers protective benefits against postoperative sarcopenia compared with open surgery in patients undergoing rectal cancer resection. METHODS:This retrospective analysis included 145 patients who underwent open or minimally invasive (laparoscopic or robot-assisted) rectal resections at the University Hospital Dresden between 2013 and 2021. Confounding variables were adjusted using propensity score matching. The skeletal muscle index (SMI) and psoas muscle thickness per height (PMTH) were analysed in preoperative and postoperative computed tomography scans to measure changes in skeletal muscle mass. Potential risk factors for muscle loss were evaluated, and oncological long-term outcome was analysed. RESULTS:The results indicate that oncological rectal resection did not result in pronounced postoperative muscle loss. No significant difference between the open and MIS groups in terms of postoperative muscle loss over 3 years postoperatively could be detected. Wound healing disorders were identified as the most significant independent risk factors for muscle loss (SMI loss > 10%). In contrast, neither the type of surgical technique nor the presence of a protective loop ileostomy significantly influenced the development of postoperative muscle loss. Patients who experienced a > 10% SMI loss within the first year had significantly poorer overall and disease-free survival. The 1-year survival rate was 93.3% in the group with high SMI loss compared with 100.0% in the group with low SMI loss (p = 0.435). The 3-year (66.7% vs. 95.6%, HR 8.75, 95% CI 1.855-41.286, p = 0.006) and 5-year (44.4% vs. 93.3%, HR 11.072, 95% CI 2.414-50.782, p = 0.002) survival rates were significantly lower in patients with high SMI loss. Patients with high SMI loss had an increased likelihood of recurrence and metastasis. CONCLUSIONS:Although MIS did not confer a protective advantage against postoperative muscle loss in patients with rectal cancer, the findings highlight the critical role of maintaining muscle mass in improving survival outcomes. Postoperative muscle loss appears to be a marker of aggressive tumour behaviour, and interventions aimed at minimizing muscle loss, such as enhanced nutritional support, may improve the long-term patient prognosis. Future studies should explore interventional strategies to mitigate sarcopenia in this population.

OBJECTIVE:Perianal fistulas in Crohn's disease (CD) are associated with a high burden of illness and their treatment is challenging. Recent data indicate promising short-term efficacy of bone marrow-derived mesenchymal stromal cell (bmMSC) therapy. The aim of this case series is to gather more information on the long-term effectiveness and safety. METHODS:Between 2013 and 2017, bmMSCs were administered under compassionate use to patients at a university hospital in Germany, as no stem cell therapy was approved at the time. Inclusion criteria were inactive CD (Harvey-Bradshaw Index <5) without proctitis, at least one treatment-refractory perianal fistula (with or without rectovaginal additional fistulas) and prior tumour necrosis factor-alpha inhibitor and/or surgical exposure. After curettage of the fistula tract, patients received repeated intrafistular injections with up to 300 million bmMSCs. We retrospectively analysed patient records to assess disease course, clinical fistula remission and radiological activity using the modified van Assche index. RESULTS:Six female patients with a total of 13 fistulas (9 trans-sphincteric, 2 extrasphincteric and 2 rectovaginal) underwent bmMSC application. Median radiological and clinical long-term follow-up was 80 months (range 44-98 months) after first local bmMSC injection. 8 of 13 fistulas (62%) exhibited complete closure. For rectovaginal fistulas, long-term remission (98 months) was 50% (1 of 2). Pelvic MRI showed a decrease in modified Van Assche index from baseline to long-term follow-up. No immediate adverse events related to bmMSC injections were observed. One patient was diagnosed with a local adenocarcinoma of the rectum 106 months after first bmMSC injection. MRI control 11 months prior showed complete fistula remission. The tumour exhibited a female karyotype, while bmMSC had been derived from a male volunteer. CONCLUSION:In this analysis, 62% of complex perianal and 50% of rectovaginal fistulas showed long-term remission up to 8 years post-bmMSC therapy. Further real-world data are needed.

Background: The aim of this study was to compare the technique of navigation-assisted biopsy based on fused PET and MRI datasets to CT-guided biopsies in terms of the duration of the procedure, radiation dose, complication rate, and accuracy of the biopsy, particularly in anatomically complex regions. Methods: Between 2019 and 2022, retrospectively collected data included all navigated biopsies and CT-guided biopsies of suspected primary bone tumors or solitary metastases. Navigation was based on preoperative CT, PET-CT/-MRI, and MRI datasets, and tumor biopsies were performed using intraoperative 3D imaging combined with a navigation system. Results: A total of 22 navigated (main group: m/f = 10/12, mean age: 56 yrs.) and 57 CT-guided biopsies (reference group: m/f = 36/21, mean age: 63 yrs.) were performed. Patients were grouped according to anatomic sites (pelvis, spine, extremities, thorax). The duration of the procedure in the reference group was significantly shorter than in the main group, particularly in the spine. The effective radiation dose was in the same range in both groups (main/reference group: 0.579 mSv and 0.687 mSv, respectively). In the reference group, a re-biopsy had to be performed in nine patients (diagnostic yield: 84%). A total of four major and three minor complications occurred in the reference group. Conclusions: Navigation-assisted percutaneous tumor biopsy resulted in correct, histologically useable diagnoses in all patients and reached a higher accuracy and first-time success rate (diagnostic yield: 100%) in comparison to CT-guided biopsies. The fusion of PET, CT, and MRI datasets enables us to combine anatomical with metabolic information. Consequently, target selection was improved, and the rate of false negative/low-grade sampling errors was decreased. Radiation exposure could be kept at a comparable level, and the durations of both procedures were comparable to conventional methods.

Abstract Background Perianal fistulising Crohn´s disease (CD) is associated with a high burden of disease and treatment of fistulas remains challenging. Promising data on short-term efficacy of bone marrow-derived mesenchymal stromal cell (bmMSC) treatment emerged in the recent past, but there is limited data regarding long-term efficacy and safety. Methods Between February 2013 and January 2016, patients with non-active CD (Harvey-Bradshaw Index < 5) and draining complex, treatment-refractory perianal or rectovaginal fistulas underwent local bmMSC therapy as compassionate use. After curettage of the fistula tract, patients received three local bmMSC injections biweekly with 20 million cells each. In case of incomplete clinical and radiological healing 3 to 12 months after the first treatment, up to six additional injections with 40 million cells each were administrated, resulting in a maximal cumulative dose of 300 million bmMSC (table 1). We retrospectively analysed patient records for disease course and documentation of adverse events. Clinical remission was defined by closure of external fistula openings without discharge at digital pressure. The modified Van Assche index was assessed before bmMSC treatment as well as in short- and long-term MRI follow-up. Results Six female patients (median age 35 years, range 19 – 46 years) with two or three complex fistulas each were included. In total, 13 fistulas (9 transsphincteric, 2 extrasphincteric and 2 rectovaginal) underwent local bmMSC application (table 1). Median radiological and clinical follow up was 80 months (range, 44 – 98 months) after first local bmMSC injection. 8 of 13 fistulas (62%) exhibited complete closure at last observation. For rectovaginal fistulas, long-term remission was 50 % (1 of 2). Excluding rectovaginal fistulas, 4 of 6 patients (67%) showed long-term closure of all other fistulas. Pelvic MRI showed a decrease in modified Van Assche index from baseline (median score 7.8, range 6.2-9.7) to long-term follow up (median score 2.1, range 1.5-11.7). No immediate adverse events related to bmMSC injections were observed. One patient (p1) was diagnosed with a local adenocarcinoma of the rectum (pT1, pN0, R0) 106 months after first bmMSC injection. MRI control 11 months prior showed complete fistula remission. The tumor exhibited a female karyotype, while bmMSC had been derived from a male volunteer. Conclusion More than 60% of all treatment-refractory CD perianal fistulas showed long-term remission up to 8 years after local allogenic bmMSC therapy.

BackgroundMicrovascular invasion is a major histopathological risk factor of postoperative recurrence in patients with hepatocellular carcinoma. This study aimed to develop and validate a digital biopsy model using imaging features to predict microvascular invasion before hepatectomy.MethodsA total of 217 consecutive patients who underwent hepatectomy for resectable hepatocellular carcinoma were enrolled at two tertiary-care reference centers. An imaging-based digital biopsy model was developed and internally validated using logistic regression analysis with adjustments for age, sex, etiology of disease, size and number of lesions.ResultsThree imaging features, i.e., non-smoothness of lesion margin (OR = 16.40), ill-defined pseudocapsula (OR = 4.93), and persistence of intratumoral internal artery (OR = 10.50), were independently associated with microvascular invasion and incorporated into a prediction model. A scoring system with 0 - 3 points was established for the prediction model. Internal validation confirmed an excellent calibration of the model. A cutoff of 2 points indicates a high risk of microvascular invasion (area under the curve 0.87). The overall survival and recurrence-free survival stratified by the risk model was significantly shorter in patients with high risk features of microvascular invasion compared to those patients with low risk of microvascular invasion (overall survival: median 35 vs. 75 months, P = 0.027; recurrence-free survival: median 17 vs. 38 months, P < 0.001)).ConclusionA preoperative assessment of microvascular invasion by digital biopsy is reliable, easily applicable, and might facilitate personalized treatment strategies.

Objectives Aortic intramural hematoma (IMH) is a rare disease. Thus far, only limited data is available and the indications for conservative and endovascular treatment are not well defined. The aim of this study was to investigate clinical presentation, course, CT imaging features and outcome of patients with type B aortic IMHs. Methods We included all patients with type B IMHs between 2012 and 2021 in this retrospective monocentric study. Clinical data, localization, thickness of IMHs and the presence of ulcer-like projections (ULPs) was evaluated before and after treatment. Results Thirty five patients (20 females; 70.3 y ± 11 y) were identified. Almost all IMHs (n = 34) were spontaneous and symptomatic with back pain (n = 34). At the time of diagnosis, TEVAR was deemed indicated in 9 patients, 26 patients were treated primarily conservatively. During the follow-up, in another 16 patients TEVAR was deemed indicated. Endovascularly and conservatively treated patients both showed decrease in thickness after treatment. Patients without ULPs showed more often complete resolution of the IMH than patients with ULPs (endovascularly treated 90.9% (10/11) vs 71.4% (5/7); conservatively treated 71.4% (10/14) vs 33.3% (1/3); P = .207). Complications after TEVAR occurred in 32% and more frequently in patients treated primarily conservatively (37.5% vs 22.2%). No in-hospital mortality was observed during follow-up. Conclusions Prognosis of IMH seems favourable in both surgically as well as conservatively treated patients. However, it is essential to identify patients at high risk for complications under conservative treatment, who therefore should be treated by TEVAR. In our study, ULPs seem to be an adverse factor for remodeling.

PURPOSE:To evaluate the effect of contrast timing, contrast volume, and contrast flow rate on the image quality of pulmonary arteries in computed tomography angiography (CTA) and to assess if bolus-tracking region of interest (ROI) positioning in the left atrium, which is used for triple-rule-out CTA, allows for sufficient depiction of the pulmonary arteries.METHODS:In this retrospective single-center study, data were collected for patients who underwent thoracic CTA during a specific period. Two groups of 121 patients each were created based on bolus-tracking ROI positioning in the main pulmonary artery or left atrium using propensity score matching. Image quality of the pulmonary arteries was evaluated using quantitative and qualitative scores. Subgroups were formed to examine the influence of contrast volume and flow rate. Two radiologists determined if pulmonary embolism was present, if pulmonary embolism could be excluded with certainty, and from which level pulmonary embolism could be excluded with certainty. Interrater reliability also was evaluated.RESULTS:ROI positioning in the main pulmonary artery scored significantly higher compared with the left atrium. There was no significant difference in subgroups of patients who were examined with 60 mL or more contrast volume and less than 4 mL/s flow rate; scores were similar or better than in the overall study population. Pulmonary embolism was not able to be excluded with certainty for each 1 patient in these subgroups compared with a high percentage in the overall study population.DISCUSSION:ROI positioning in the left atrium in combination with the 60 mL or more contrast volume and less than 4 mL/s flow rate does not adversely affect depiction of the pulmonary arteries compared with conventional ROI positioning in the main pulmonary artery.CONCLUSION:When using 60 mL or more contrast volume and less than 4 mL/s flow rate, ROI positioning in the left atrium, which is used in triple-rule-out CTA, is sufficient for the assessment of pulmonary arteries.

Importance Postpancreatectomy hemorrhage (PPH) due to postoperative pancreatic fistula (POPF) is a life-threatening complication after pancreatoduodenectomy. However, there is no prediction tool for early identification of patients at high risk of late PPH.Objective To develop and validate a prediction model for PPH.Design, Setting, and Participants This retrospective prognostic study included consecutive patients with clinically relevant POPF who underwent pancreatoduodenectomy from January 1, 2009, to May 20, 2023, at the University Hospital Mannheim (derivation cohort), and from January 1, 2012, to May 31, 2022, at the University Hospital Dresden (validation cohort). Data analysis was performed from May 30 to July 29, 2023.Exposure Clinical and radiologic features of PPH.Main Outcomes and MeasuresAccuracy of a predictive risk score of PPH. A multivariate prediction model-the hemorrhage risk score (HRS)-was established in the derivation cohort (n = 139) and validated in the validation cohort (n = 154).Results A total of 293 patients (187 [64%] men; median age, 69 [IQR, 60-76] years) were included. The HRS comprised 4 variables with associations: sentinel bleeding (odds ratio [OR], 35.10; 95% CI, 5.58-221.00; P < .001), drain fluid culture positive for Candida species (OR, 14.40; 95% CI, 2.24-92.20; P < .001), and radiologic proof of rim enhancement of (OR, 12.00; 95% CI, 2.08-69.50; P = .006) or gas within (OR, 12.10; 95% CI, 2.22-65.50; P = .004) a peripancreatic fluid collection. Two risk categories were identified with patients at low risk (0-1 points) and high risk (>= 2 points) to develop PPH. Patients with PPH were predicted accurately in the derivation cohort (C index, 0.97) and validation cohort (C index 0.83). The need for more invasive PPH management (74% vs 34%; P < .001) and severe complications (49% vs 23%; P < .001) were more frequent in high-risk patients compared with low-risk patients.Conclusions and Relevance In this retrospective prognostic study, a robust prediction model for PPH was developed and validated. This tool may facilitate early identification of patients at high risk for PPH.

PDF file - 170K, Cumulative incidence curves of acute GvHD grade 2 to 4 with respect to LIC, transfusion burden and ferritin

Background The prognosis of pancreatic ductal adenocarcinoma (PDAC) is one of the most dismal of all cancers and the median survival of PDAC patients is only 6–8 months after diagnosis. While decades of research effort have been focused on early diagnosis and understanding of molecular mechanisms, few clinically useful markers have been universally applied. To improve the treatment and management of PDAC, it is equally relevant to identify prognostic factors for optimal therapeutic decision-making and patient survival. Compelling evidence have suggested the potential use of extracellular vesicles (EVs) as non-invasive biomarkers for PDAC. The aim of this study was thus to identify non-invasive plasma-based EV biomarkers for the prediction of PDAC patient survival after surgery. Methods Plasma EVs were isolated from a total of 258 PDAC patients divided into three independent cohorts (discovery, training and validation). RNA sequencing was first employed to identify differentially-expressed EV mRNA candidates from the discovery cohort ( n = 65) by DESeq2 tool. The candidates were tested in a training cohort ( n = 91) by digital droplet polymerase chain reaction (ddPCR). Cox regression models and Kaplan–Meier analyses were used to build an EV signature which was subsequently validated on a multicenter cohort ( n = 83) by ddPCR. Results Transcriptomic profiling of plasma EVs revealed differentially-expressed mRNAs between long-term and short-term PDAC survivors, which led to 10 of the top-ranked candidate EV mRNAs being tested on an independent training cohort with ddPCR. The results of ddPCR enabled an establishment of a novel prognostic EV mRNA signature consisting of PPP1R12A , SCN7A and SGCD for risk stratification of PDAC patients. Based on the EV mRNA signature, PDAC patients with high risk displayed reduced overall survival (OS) rates compared to those with low risk in the training cohort ( p = 0.014), which was successfully validated on another independent cohort ( p = 0.024). Interestingly, the combination of our signature and tumour stage yielded a superior prognostic performance ( p = 0.008) over the signature ( p = 0.022) or tumour stage ( p = 0.016) alone. It is noteworthy that the EV mRNA signature was demonstrated to be an independent unfavourable predictor for PDAC prognosis. Conclusion This study provides a novel and non-invasive prognostic EV mRNA signature for risk stratification and survival prediction of PDAC patients.

BackgroundChest drain management has a significant influence on postoperative recovery after robot-assisted minimally invasive esophagectomy (RAMIE). The use of chest drains increases postoperative pain by irritating intercostal nerves and hinders patients from early postoperative mobilization and recovery. To our knowledge, no study has investigated the use of two vs. one intercostal chest drains after RAMIE.MethodsThis retrospective cohort study evaluated patients undergoing elective RAMIE with gastric conduit pull-up and intrathoracic anastomosis. Patients were divided into two groups according to placement of one (11/2020–08/2022) or two (08/2018–11/2020) chest drains. Propensity score matching was performed in a 1:1 ratio, and the incidences of overall and pulmonary complications, drainage-associated re-interventions, radiological diagnostics, analgesic use, and length of hospital stay were compared between single drain and double drain groups.ResultsDuring the study period, 194 patients underwent RAMIE. Twenty-two patients were included after propensity score matching in the single and double chest drain group, respectively. Time until removal of the last chest drain [postoperative day (POD) 6.7 ± 4.4 vs. POD 9.4 ± 2.7, p = 0.004] and intensive care unit stay (4.2 ± 5.1 days vs. 5.3 ± 3.5 days, p = 0.01) were significantly shorter in the single drain group. Overall and pulmonary complications, drainage-associated events, re-interventions, number of diagnostic imaging, analgesic use, and length of hospital stay were comparable between both groups.ConclusionThis study is the first to demonstrate the safety of single intercostal chest drain use and, at least, non-inferiority to double chest drains in terms of perioperative complications after RAMIE.

PDF file - 98K, Graph depicting sensitivity, specificity and accuracy of different LIC thresholds for the prediction of Overall Survival

Introduction: Sarcopenia is a known risk factor for adverse outcomes after esophageal cancer (EC) surgery. Robot -assisted minimally invasive esophagectomy (RAMIE) of-fers numerous advantages, including reduced morbidity and mortality. However, no evidence exists to date comparing the development of sarcopenia after RAMIE and open esophagectomy (OE). The objective was to evaluate whether the development of sarcopenia within the first post-operative year after esophagectomy is associated with the surgical approach: RAMIE versus OE.Methods: A total of 168 patients with EC were analyzed who either underwent total robotic or fully open Ivor Lewis esophagectomy in a propensity score-matched analysis. Sar-copenia was assessed using the skeletal muscle index (cm2/ m2) and psoas muscle thickness per height (mm/m) on axial computed tomography scans during the first postoperative year; in total 540 computed tomography scans were evaluated.Results: After 1-to-1 propensity score matching for con-founders, 67 patients were allocated to RAMIE and OE groups, respectively. Skeletal muscle index in the OE group was significantly lower compared with the RAMIE group at the third (43.2 +/- 7.6 cm2/m2 versus 49.1 +/- 6.9 cm2/m2, p = 0.001), sixth (42.7 +/- 7.8 cm2/m2 versus 51.5 +/- 8.2 cm2/m2, p < 0.001) and ninth (43.0 +/- 7.0 cm2/m2 versus 49.9 +/- 6.6 cm2/m2, p = 0.015) postoperative month. Similar results were recorded for psoas muscle thickness per height.Conclusions: To our knowledge, this study is the first to suggest a substantial benefit of RAMIE compared with open esophagectomy in terms of postoperative sarcopenia. These results add further evidence to support the implementation of the robotic approach in multimodal therapy of EC. (c) 2022 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

PDF file - 137K, Receiver-Operator-Characteristics of Transfusion Burden and Ferritin for the prediction of an LIC ≥ 125 mol/g

BACKGROUND:The aim of this study was to assess the usefulness of adding thoracic CT to abdominal CT in intensive care unit (ICU) patients with signs of infection after abdominopelvic surgery. METHODS:143 thoracoabdominal CTs of ICU patients with signs of infection after abdominopelvic surgery were retrospectively reviewed for thoracic pathologies. It was determined if pathologic findings were visible only on thoracic CT above the diaphragmatic dome or also on abdominal CT up to the diaphragmatic dome. All thoracic pathologies visible only above the diaphragmatic dome were retrospectively analyzed by an ICU physician in terms of clinical relevance. Diagnostic and therapeutic efficacy of thoracic CT were assessed with regard to an infectious focus and to other pathologic findings. RESULTS:297 pathologic thoracic findings were recorded. 26 of the 297 findings could only be detected on images obtained above the diaphragmatic dome (in 23 of 143 CTs). A change in patient management was initiated due to only one of the 26 supradiaphragmatic findings. Diagnostic efficacy of thoracic CT in addition to abdominal CT to identify an infectious focus was 3.5% (95%-CI: 0.5-6.5%) and therapeutic efficacy was 0.7% (95%-CI: 0-2.1%). With regard to all pathologic thoracic findings, diagnostic efficacy was 16.1% (95%-CI: 10.1-22.1%) and therapeutic efficacy remained at 0.7%. CONCLUSIONS:Additional thoracic CT to detect an infectious focus in ICU patients after abdominopelvic surgery leads to identification of the focus in only 3.5% and to changes in patient management in only 0.7%. Other relevant findings are more common (16.1%), but very rarely affect patient management.

PDF file - 103K, Contains supplementary tables S1 - S6 and legends for supplementary figures Supplementary table S1. Impact of pre-transplant variables on the cumulative incidence of relapse one year after transplantation. The cumulative incidences are given with 95% confidence intervals. Supplementary table S2. Causes of Non-replapse mortality. Absolute numbers and percentages in the respective LIC group are given. GvHD - Graft-versus-Host-Disease. Supplementary table S3. Multivariate competing risk regression analysis assessing serum ferritin in the context of other risk factors for NRM. Supplementary table S4. Multivariate competing risk regression analysis assessing transfusion burden in the context of other risk factors for NRM. Supplementary table S5. Multivariate Cox-regression analysis of overall survival including serum ferritin instead of LIC. Supplementary table S6. Multivariate Cox-regression analysis of overall survival including transfusion burden instead of LIC.

Due to its excellent intrinsic soft tissue contrast, magnetic resonance imaging allows excellent visualization and anatomical separation of therapy-relevant risk structures such as the mesorectal fascia, local lymph nodes, and vascular structures in patients with rectal carcinoma. This makes magnetic resonance imaging (MRI) a valuable evaluation method for further therapeutic stratification. In particular, MRI is indispensable for the decision to refrain from neoadjuvant therapy and to choose a primary surgical approach. In addition to the oncologically generally relevant T-, N-, and M-criteria, two further parameters are included: the extramural vascular infiltration and the circumferential resection margin. Due to the significant impact of MRI on further therapeutic decision-making, standardized MR image quality is considered essential. Key Points: Magnetic resonance imaging is a valuable evaluation method for further therapeutic stratification. Critical anatomic landmarks for evaluation are circumferential resection margins.

Purpose To compare the diagnostic performance of 18 F-fluorodeoxyglucose-PET/MRI and MRI in the diagnosis of pelvic recurrence of rectal cancer. Methods All PET/MRIs of patients in the follow-up of rectal cancer performed between 2011 and 2018 at our institution were retrospectively reviewed. Recurrence was confirmed/excluded either by histopathology or imaging follow-up (> 4 months). Four groups of readers (groups 1/2: one radiologist each, groups 3/4: one radiologist/one nuclear medicine physician) independently interpreted MRI and PET/MRI. The likelihood of recurrence was scored on a 5-point-scale. Inter-reader agreement, sensitivity, specificity, PPV/NPV and accuracy were assessed. ROC curve analyses were performed. Results Fourty-one PET/MRIs of 40 patients (mean 61 years ± 10.9; 11 women, 29 men) were included. Sensitivity of PET/MRI in detecting recurrence was 94%, specificity 88%, PPV/NPV 97% and 78%, accuracy 93%. Sensitivity of MRI was 88%, specificity 75%, PPV/NPV 94% and 60%, accuracy 85%. ROC curve analyses showed an AUC of 0.97 for PET/MRI and 0.92 for MRI, but the difference was not statistically significant ( p = 0.116). On MRI more cases were scored as equivocal (12% versus 5%). Inter-reader agreement was substantial for PET/MRI and MRI (0.723 and 0.656, respectively). Conclusion 18 F-FDG-PET/MRI and MRI are accurate in the diagnosis of locally recurrent rectal cancer. Sensitivity, specificity, PPV, NPV and accuracy are comparable for both modalities, but PET/MRI increases readers’ confidence levels and reduces the number of equivocal cases. Graphic abstract