"Feed-and-wrap" technique versus deep sedation for neonatal magnetic resonance imaging: a retrospective comparative study.

OBJECTIVES: Neonatal MRI is usually performed under deep sedation, which is challenging-especially in low-weight premature patients. In addition, long-term side effects, such as neurotoxicity, are of concern. An alternative to sedation is to induce natural sleep by feeding and immobilising the child, the "feed-and-wrap" technique (FWT). The objective of this study was to evaluate differences in image quality between neonates examined under sedation and by using the FWT during the first four months of life. MATERIALS AND METHODS: We retrospectively assessed image quality (based on a 4-point semiquantitative scale) of all MRI examinations in neonates performed at our institution between July 2009 and August 2022. Differences in image quality between examinations under sedation versus FWT were evaluated. RESULTS: We included 432 consecutive patients, 243 (56%) using sedation and 189 (44%) using the FWT. Corrected age and body weight (mean ± SD: 3.7 ± 1.1 versus 4.5 ± 1.3 kg, p < 0.001) were significantly lower in the FWT group. The overall success rate in the FWT group was 95%. Image quality was slightly lower when using the FWT (mean ± SD: 3.7 ± 0.43 versus 3.96 ± 0.11, p < 0.001). Multivariate analysis showed a higher risk of acquiring sequences with diagnostic limitations in the FWT group (p < 0.001), increasing with corrected age (p = 0.048). CONCLUSION: The FWT is a highly successful method to perform MRI scans in term and preterm neonates. Overall image quality is only slightly lower than under sedation. Especially in immature low-weight preterm patients, the FWT is a reliable option to perform MRI studies without exposing the child to risks associated with sedation. CLINICAL RELEVANCE STATEMENT: The "feed-and-wrap" technique enables high-quality MRI examinations in neonates, including low-weight premature patients. Deep sedation for diagnostic MRI procedures in this age group, which has the risk of short- and long-term complications, can often be avoided. KEY POINTS: Deeply sedating neonates for MR examinations comes with risks. Image quality is only slightly lower when using the "feed-and-wrap" technique. The "feed-and-wrap" technique is feasible even in low-weight premature infants.

Biventricular strain assessment indicates progressive impairment of myocardial contractility in phenotypically negative patients with Fabry's disease.

PURPOSE: The accumulation of sphingolipids in Fabry's disease (FD) leads to left ventricular (LV) hypertrophy and shortened T1 in cardiac magnetic resonance (CMR). Early detection of myocardial involvement is essential for the timely initiation and efficacy of enzyme replacement therapy. However, there is a diagnostic gap between the onset of accumulation and detectable myocardial changes. This study aimed to evaluate the diagnostic value of biventricular strain assessment in early FD. METHODS: Genetically proven FD patients (n = 58) and healthy volunteers (HV, n = 62) who had undergone 3 T CMR were retrospectively identified and stratified into 3 groups according to disease severity. Biventricular volumetry, global longitudinal strains (GLS), indexed biventricular masses (RVMi/LVMi), and T1 were evaluated. Group comparisons were performed by ANOVA and diagnostic accuracy was evaluated by ROC-analysis. RESULTS: The study population included 19 group I, 20 group II and 19 group III patients. LV volumetry and T1 showed no significant difference between early FD patients and HV (all p > 0.760). However, RVMi was increased, while RV-GLS and LV-GLS were significantly impaired (p = 0.024 and < 0.001, respectively). Biventricular strains accurately discriminated early FD patients and HV with RV-GLS being non-inferior to LV-GLS (AUC for both 0.83, p > 0.05). Adding strains to the established approach using T1 and LVMi further increased diagnostic accuracy (AUC 0.99, p < 0.05). CONCLUSIONS: Biventricular strains may help detect altered myocardial deformation patterns in phenotypically negative FD patients. These findings may lead to an earlier initiation of therapy, which in turn may slow hypertrophy and the associated long-term risks.

[Pheochromocytoma and paraganglioma during childhood and adolescence]. / Phäochromozytom und Paragangliom im Kindes- und Jugendalter.

BACKGROUND: Pheochromocytoma and paraganglioma belong to the group of rare catecholamine-producing tumours during childhood and adolescence. They occur most frequently in patients with tumour predisposition syndromes. Imaging is essential to assess tumour stage and to plan therapy initiation. OBJECTIVE: The aim of this review is a summary of the most important characteristics of the aforementioned tumour entities with a special focus on imaging. In particular, magnetic resonance imaging (MRI) as well as nuclear medicine techniques are presented. MATERIALS AND METHODS: Diagnostic methods in patients with pheochromocytoma and paraganglioma are presented based on the literature and own case reports. RESULTS: The radiologic modality of choice for the staging of catecholamine-producing tumours during childhood and adolescence is MRI, due to the lack of ionizing radiation and high soft tissue contrast. In addition, 123-I-meta-iodo-benzyl-guanidine (MIBG) scintigraphy and positron emission tomography/computer tomography (PET/CT) are performed. Whole-body MRI is particularly important as a screening tool in patients with a tumour predisposition syndrome. CONCLUSIONS: Radiologic imaging and nuclear medicine techniques are important for the assessment of disease stage and therapy planning in patients with catecholamine-producing tumours. Detection of metastatic disease is essential, as there are no known histopathologic markers, which can predict the metastatic potential of the tumours.

Diffusion-weighted MRI and histogram analysis: assessment of response to neoadjuvant chemotherapy in nephroblastoma.

PURPOSE: To assess the value of diffusion-weighted MRI (DW-MRI) in the non-invasive prediction of blastemal remnant after neoadjuvant chemotherapy in nephroblastoma. METHODS: This IRB-approved study included 32 pediatric patients with 35 tumors who underwent DW-MRI prior and after completion of neoadjuvant chemotherapy and subsequent surgical resection. Two blinded radiologists volumetrically assessed each tumor on pre- and post-neoadjuvant images and the parameters mean ADC, median ADC, 12.5th/25th/75th ADC percentile, skewness, and kurtosis were calculated. Blastemal remnant was determined per the pathology report. Associations between imaging features and blastemal remnant quartiles were examined using the Kruskal-Wallis test and adjusted for false discovery rate. RESULTS: Inter-reader agreement was high for mean ADC, skewness, kurtosis, and volume (ICC: 0.76-0.998). Pre-therapeutic histogram parameters skewness and kurtosis were found to be higher in patients with a higher amount of blastemal remnant for reader 1 (overall p = 0.035) and for kurtosis in reader 2 (overall p = 0.032) with skewness not reaching the level of statistical significance (overall p = 0.055). Higher tumor volume on pre-treatment imaging was associated with a higher amount of blastemal remnant after therapy (overall p = 0.032 for both readers). CONCLUSIONS: Pre-treatment skewness and kurtosis of ADC histogram analysis were significantly associated with a larger fraction of a blastemal remnant after neoadjuvant chemotherapy. These findings could be incorporated into a more personalized chemotherapeutic regime in these patients and offer prognostic information at the time of initial diagnosis.

Exploiting Gangliosides for the Therapy of Ewing's Sarcoma and H3K27M-Mutant Diffuse Midline Glioma.

The ganglioside GD2 is an important target in childhood cancer. Nevertheless, the only therapy targeting GD2 that is approved to date is the monoclonal antibody dinutuximab, which is used in the therapy of neuroblastoma. The relevance of GD2 as a target in other tumor entities remains to be elucidated. Here, we analyzed the expression of GD2 in different pediatric tumor entities by flow cytometry and tested two approaches for targeting GD2. H3K27M-mutant diffuse midline glioma (H3K27M-mutant DMG) samples showed the highest expression of GD2 with all cells strongly positive for the antigen. Ewing's sarcoma (ES) samples also showed high expression, but displayed intra- and intertumor heterogeneity. Osteosarcoma had low to intermediate expression with a high percentage of GD2-negative cells. Dinutuximab beta in combination with irinotecan and temozolomide was used to treat a five-year-old girl with refractory ES. Disease control lasted over 12 months until a single partially GD2-negative intracranial metastasis was detected. In order to target GD2 in H3K27M-mutant DMG, we blocked ganglioside synthesis via eliglustat, since dinutuximab cannot cross the blood-brain barrier. Eliglustat is an inhibitor of glucosylceramide synthase, and it is used for treating children with Gaucher's disease. Eliglustat completely inhibited the proliferation of primary H3K27M-mutant DMG cells in vitro. In summary, our data provide evidence that dinutuximab might be effective in tumors with high GD2 expression. Moreover, disrupting the ganglioside metabolism in H3K27M-mutant DMG could open up a new therapeutic option for this highly fatal cancer.

Acoustic radiation force impulse point shear wave elastography of the liver and spleen in patients with Gaucher disease type 1: Correlations with clinical data and markers of disease severity.

PURPOSE: To evaluate the feasibility of acoustic radiation force impulse point shear wave elastography (ARFI-pSWE) of the liver and spleen in patients with Gaucher disease type 1 (GD1), and to assess correlations between organ stiffness and clinico-radiologic data, particularly the GD1 Severity Scoring System (GD-DS3). MATERIALS AND METHODS: We retrospectively evaluated the results of ARFI-pSWE as measures of liver and spleen stiffness in 57 patients with GD1. The feasibility of the method was assessed. Correlations between elastography data and clinical data related to the metabolic syndrome, laboratory tests, and GD1-related clinico-radiologic data (bone marrow burden score, GD-DS3) were assessed. RESULTS: ARFI-pSWE provided reliable results (i.e. standard deviation <30% of the mean value between the measurements) in 50/57 patients. Significant liver fibrosis was present in 35/50 patients (70%). Liver stiffness significantly correlated with GD-DS3 score (p = .03), and number of fulfilled criteria of metabolic syndrome (p = .03). Spleen stiffness significantly correlated with age (p = .021), body mass index (p = .002), number of fulfilled criteria of metabolic syndrome (p = .02), and several laboratory parameters (alanine aminotransferase, gamma glutamyltranspeptidase, triglycerides, cholesterol), and nearly significantly with GD-DS3 score (p = .059). CONCLUSION: ARFI-pSWE is a useful tool for a more detailed assessment of disease severity in patients with GD1, which adds relevant information to the standard clinical scores. Thus, elastography might allow for extended therapy monitoring, especially in patients with significant liver fibrosis. Spleen elastography showed promising results; thus, its role should be further investigated.

Diffusion-weighted MRI in the assessment of nephroblastoma: results of a multi-center trial.

PURPOSE: To assess the value of diffusion-weighted MRI in the pre-therapeutic evaluation of pediatric renal cortical tumors. METHODS: This IRB-approved, retrospective multi-center study included 122 pediatric patients with 130 renal tumors, who underwent MRI including DWI before neoadjuvant chemotherapy and nephrectomy. Two radiologists independently assessed each tumor volumetrically, and apparent diffusion coefficient (ADC) values were calculated on a voxel-wise basis, including parameters derived from histogram and texture analysis. RESULTS: Inter-reader agreement was excellent (ICC 0.717-0.975). For both readers, patients with locally aggressive tumor growth (SIOP 3 stage) or with metastases (M1) had significantly lower 12.5th-percentile ADC values (p ≤ 0.028) compared to those with lower-stage tumors, and the parameter energy differed significantly between patients with M1 and those with M0 status (p ≤ 0.028). Contrast and homogeneity differed significantly between benign nephroblastomatosis and malignant nephroblastoma (p ≤ 0.045, both readers). As compared to all other subtypes, the blastemal subtype demonstrated significantly higher skewness (p ≤ 0.022, both readers) and the diffuse anaplastic subtype demonstrated significantly higher 75th-percentile ADC values (p ≤ 0.042, both readers). CONCLUSIONS: Diffusion-weighted MRI may be of value in identifying benign nephroblastomatosis and assessing nephroblastoma subtypes. Therefore, further research is warranted to assess its value in risk stratification for pediatric patients with renal tumors in the future.

Benchmarking Wilms' tumor in multisequence MRI data: why does current clinical practice fail? Which popular segmentation algorithms perform well?

Wilms' tumor is one of the most frequent malignant solid tumors in childhood. Accurate segmentation of tumor tissue is a key step during therapy and treatment planning. Since it is difficult to obtain a comprehensive set of tumor data of children, there is no benchmark so far allowing evaluation of the quality of human or computer-based segmentations. The contributions in our paper are threefold: (i) we present the first heterogeneous Wilms' tumor benchmark data set. It contains multisequence MRI data sets before and after chemotherapy, along with ground truth annotation, approximated based on the consensus of five human experts. (ii) We analyze human expert annotations and interrater variability, finding that the current clinical practice of determining tumor volume is inaccurate and that manual annotations after chemotherapy may differ substantially. (iii) We evaluate six computer-based segmentation methods, ranging from classical approaches to recent deep-learning techniques. We show that the best ones offer a quality comparable to human expert annotations.

The Link Between Local Recurrence and Distant Metastases in Patients With Rectal Cancer.

BACKGROUND/AIM: The relationships between local recurrence (LR), the development of distant metastases (DM) and prognosis in patients with rectal cancer remain unclear. PATIENTS AND METHODS: In 606 patients who underwent curative resection, the role of LR was assessed retrospectively by time-dependent multivariate Cox models with inverse probability of treatment weighting taking into account competing risks. RESULTS: Patients with LR had more DM than patients without LR (49/79, 62% vs. 86/524, 16.4%; p<0.001); 37% of LR-associated DM developed before or at LR, 63% after diagnosis of LR. Fifty-five percent of patients without DM at diagnosis of LR later developed DM. In these patients, the incidence of DM significantly exceeded the incidence in patients without LR. DM risk was most strongly associated with preceding LR and stage UICC III and II. CONCLUSION: There is a causal link between LR and DM in patients with rectal cancer.

[From Xrays to PET/MR, and then? - Future imaging in pediatric radiology]. / Vom Röntgen zum PET/MRT, und dann? ­ Zukunftsweisende Bildgebung in der Kinderradiologie.

Significant changes can be expected in modern pediatric radiology. New imaging techniques are progressively added to basic modalities like Xrays and ultrasound. This essay summarizes recent advances and technical innovations in pediatric radiology, which are supposed to gain further importance in the future. Thus, CT dose reduction techniques including artificial intelligence as well as advances in the fields of magnetic resonance and molecular imaging are presented. KEY POINTS: · Technical innovations will lead to significant changes in pediatric radiology.. · CT dose reduction is crucial for pediatric patient collectives.. · New MR-techniques will lower the need for sedation and contrast media application.. · Functional MR-imaging might gain further importance in patients with chronic lung disease.. · Molecular imaging enables detection, characterization and quantification of molecular processes in tumors.. CITATION FORMAT: · Staatz G, Daldrup-Link HE, Herrmann J et al. From Xrays to PET/MR, and then? - Future imaging in pediatric radiology. Fortschr Röntgenstr 2019; 191: 357 - 366.

Retrospective Analysis of Whole-Body Magnetic Resonance Imaging of Bone Manifestations in Long-Term Treated Patients with Gaucher Disease Type 1.

PURPOSE: We retrospectively assessed bone and visceral manifestations in patients with Gaucher disease type 1 (GD1) with whole-body magnetic resonance imaging (WB-MRI) to determine the effects of different timing in initiating long-term enzyme replacement therapy. MATERIALS AND METHODS: In 17 patients with GD1, we performed 2 WB-MRI examinations at a median interval of 13 months. Patients had received enzyme replacement therapy with alglucerase/imiglucerase for a median of 13 years prior to the first examination. MRI results were retrospectively stratified based on treatment initiation into 2 groups: "early" (age ≤12 years, median 5 years) and "late" (during adulthood, median 32 years). We evaluated occurrence of irreversible avascular necroses (AVN) and applied several semi-quantitative scores, including the Bone-Marrow-Burden (BMB) score, the Düsseldorf-Gaucher score (DGS), the Vertebra-Disc-Ratio (VDR), and the Gaucher disease type 1 Severity Scoring System (GD-DS3). RESULTS: MRI assessments showed no AVN in the "early" group. AVN were observed in 2 patients of the "late" group; one also had a splenic Gaucheroma. The follow-up examinations showed slight improvements in the BMB-score, DGS, and VDR, with similar tendencies in both treatment groups. The GD-DS3 score only improved in "late" group. CONCLUSION: This retrospective study supported the ongoing clinical value of enzyme replacement therapy with alglucerase/imiglucerase, as WB-MRI-based scores stayed constant or slightly improved even after long-term treatment. Secondary complications were only observed in the late treatment group. Our results suggest that "early initiation" of enzyme replacement therapy may protect the bone.

Quantification of intramuscular fat in patients with late-onset Pompe disease by conventional magnetic resonance imaging for the long-term follow-up of enzyme replacement therapy.

OBJECTIVE: The objective of this study was to evaluate a quantitative method based on conventional T1-weighted magnetic resonance (MR) imaging to assess fatty muscular degeneration in patients with late-onset Pompe disease and to compare it with semi-quantitative visual evaluation (the Mercuri score). In addition, a long-term retrospective data analysis was performed to evaluate treatment response to enzyme replacement therapy with alglucosidase alfa. METHODS: MR images of the lumbar spine were acquired in 41 patients diagnosed with late-onset Pompe disease from 2006 through 2015. Two independent readers retrospectively evaluated fatty degeneration of the psoas and paraspinal muscles by applying the Mercuri score. Quantitative semi-automated muscle and fat tissue separation was performed, and inter-observer agreement and correlations with clinical parameters were assessed. Follow-up examinations were performed in 13 patients treated with alglucosidase alfa after a median of 39 months; in 7/13 patients, an additional follow-up examination was completed after a median of 63 months. RESULTS: Inter-observer agreement was high. Measurements derived from the quantitative method correlated well with Medical Research Council scores of muscle strength, with moderate correlations found for the 6-minute walk test, the 4-step stair climb test, and spirometry in the supine position. A significant increase in the MR-derived fat fraction of the psoas muscle was found between baseline and follow-up 1 (P = 0.016), as was a significant decrease in the performance on the 6-minute walk test (P = 0.006) and 4-step stair climb test (P = 0.034), as well as plasma creatine kinase (P = 0.016). No statistically significant difference in clinical or MR-derived parameters was found between follow-up 1 and follow-up 2. CONCLUSIONS: Quantification of fatty muscle degeneration using the semi-automated method can provide a more detailed overview of disease progression than semi-quantitative Mercuri scoring. MR-derived data correlated with clinical symptoms and patient exercise capacity. After an initial worsening, the fat fraction of the psoas muscle and performance on the 6-minute walk test stayed constant during long-term follow-up under enzyme replacement therapy.

Impact of Pectus Excavatum on Cardiopulmonary Function.

BACKGROUND: Pectus excavatum is classified using the Haller Index (HI) or the Correction Index. However, no correlation between the HI and CI and cardiopulmonary impairment has been described in detail. METHODS: This prospective cohort study included 99 otherwise healthy patients with pectus excavatum who underwent cardiopulmonary exercise testing and magnetic resonance imaging at inspiration and expiration to correlate cardiopulmonary function with the grade of thoracic dysmorphia. RESULTS: Probands with an HI exceeding 3.25 had first an increase in heart rate at anaerobic threshold (from 148.0 ± 16.0 beats/min to 155.9 ± 15.0 beats/min, p = 0.036), with an HI of more than 3.6 a reduction in oxygen pulse at anaerobic threshold (from 10.7 ± 2.6 mL/beat to 9.3 ± 2.9 mL/beat, p = 0.017), with an HI exceeding 3.8 a reduction of maximum oxygen pulse (from 13.9 ± 3.4 mL/beat to 11.9 ± 3.7 mL/beat, p = 0.010), and with an HI of exceeding 4.0 a decline in maximum oxygen uptake (from 43.7 ± 6.5 mL · kg-1 · min-1 to 40.4 ± 7.4 mL · kg-1 · min-1, p = 0.025). The CI of more 27% reflects cardiopulmonary changes earlier than the corresponding HI exceeding 3.25 (p = 0.01 for maximum oxygen pulse; p = 0.017 for oxygen pulse at anaerobic threshold; p = 0.015 for heart rate at anaerobic threshold). CONCLUSIONS: The inspiratory HI and CI reflect the effect of pectus excavatum on cardiopulmonary function. The cardiopulmonary system reacts first with an increase in heart rate at anaerobic threshold, followed by a decrease in stroke volume at anaerobic threshold and maximum stroke volume. Increased severity of the deformity then leads to a decrease in cardiac output.

Differences in myocardial strain between pectus excavatum patients and healthy subjects assessed by cardiac MRI: a pilot study.

OBJECTIVES: To evaluate differences in myocardial strain between pectus excavatum (PE) patients and healthy subjects (HS) assessed by cardiac MRI using the feature-tracking algorithm. METHODS: Cardiac MRI was performed in 14 PE patients and 14 HS (9:5 male to female in each group; age 11-30 years) using a 3T scanner. Post-examination analysis included manual biventricular contouring with volumetry and ejection fraction measurement by two independent radiologists. Dedicated software was used for automated strain assessment. RESULTS: In five of the PE patients, the right ventricular ejection fraction was slightly impaired (40-44 %). PE patients had a significantly higher left ventricular longitudinal strain (P=0.004), mid (P=0.035) and apical (P=0.001) circumferential strain as well as apical circumferential strain rate (P=0.001), mid right ventricular circumferential strain (P=0.008) and strain rate (P=0.035), and apical right ventricular circumferential strain (P=0.012) and strain rate (P=0.044) than HS. The right ventricular longitudinal strain and strain rate did not differ significantly between PE patients and HS. CONCLUSIONS: Myocardial strain differs significantly between PE patients and HS. Higher myocardial strain in the mid and apical ventricles of PE patients indicates a compensation mechanism to enhance ventricular output against basal sternal compression. KEY POINTS: • The right ventricle is frequently affected by the pectus excavatum deformity. • Cardiac MRI revealed differences in myocardial strain in pectus excavatum patients. • Pectus excavatum patients exhibited higher strain in the mid/apical ventricles. • A compensation mechanism to enhance ventricular output against sternal compression is possible.

Influence of Local Recurrence and Distant Metastasis on Prognosis After Local Excision of Rectal Carcinoma.

BACKGROUND: Influence of local recurrence (LR) on prognosis after a local excision (LE) for rectal cancer is unclear. PATIENTS AND METHODS: A total of 152 patients were retrospectively assigned to one of three groups: Groups 1 and 2: complete and incomplete resection respectively, for low-risk carcinoma; group 3: high-risk carcinoma. We evaluated LR, distant metastasis (DM), overall survival, and cancer-specific survival (CSS). RESULTS: LR rates were 10.4%, 43% and 29% for groups 1-3, respectively (p=0.002). In all three groups, DM incidence was low in patients without LR, but high in patients with LR (p<0.0001). Prior LR was an important risk factor for DM (hazard ratio: 14.1, 95% confidence interval=4.3-45.8, p<0.0001). DM significantly reduced CSS. CONCLUSION: There is a strong association between LR and DM independently in the cause of LR. Avoiding LE for high-risk carcinoma and complete LE of low-risk carcinoma are essential to reduce LR and DM.

Ultrasound Evaluation of Thyroid Gland Pathologies After Radiation Therapy and Chemotherapy to Treat Malignancy During Childhood.

PURPOSE: The purpose of this study was to evaluate correlations between treatment of malignancy by radiation therapy during childhood and the occurrence of thyroid gland pathologies detected by ultrasonography in follow-up examinations. METHODS AND MATERIALS: Reductions of thyroid gland volume below 2 standard deviations of the weight-specific mean value, occurrence of ultrasonographically detectable thyroid gland pathologies, and hypothyroidism were retrospectively assessed in 103 children and adolescents 7 months to 20 years of age (median: 7 years of age) at baseline (1997-2013) treated with chemoradiation therapy (with the thyroid gland dose assessable) or with chemotherapy alone and followed by ultrasonography and laboratory examinations through 2014 (median follow-up time: 48 months). RESULTS: A relevant reduction of thyroid gland volume was significantly correlated with thyroid gland dose in univariate (P<.001) and multivariate analyses for doses above 2 Gy. Odds ratios were 3.1 (95% confidence interval: 1.02-9.2; P=.046) for medium doses (2-25 Gy) and 14.8 (95% confidence interval: 1.4-160; P=.027) for high doses (>25 Gy). Thyroid gland dose was significantly higher in patients with thyroid gland pathologies during follow-up (P=.03). Univariate analysis revealed significant correlations between hypothyroidism and thyroid gland dose (P<.001). CONCLUSIONS: Ultrasonographically detectable changes, that is, volume reductions, pathologies, and hypothyroidism, after malignancy treatment during childhood are associated with thyroid gland dose. Both ultrasonography and laboratory follow-up examinations should be performed regularly after tumor therapy during childhood, especially if the treatment included radiation therapy.

Rectal cancer: dynamic contrast-enhanced MRI correlates with lymph node status and epidermal growth factor receptor expression.

PURPOSE: To evaluate correlations between dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and clinicopathologic data as well as immunostaining of the markers of angiogenesis epidermal growth factor receptor (EGFR) and CXC-motif chemokine receptor 4 (CXCR4) in patients with rectal cancer. MATERIALS AND METHODS: Presurgical DCE-MRI was performed in 41 patients according to a standardized protocol. Two quantitative parameters (k21 , A) were derived from a pharmacokinetic two-compartment model, and one semiquantitative parameter (TTP) was assessed. Standardized surgery and histopathologic examinations were performed in all patients. Immunostaining for EGFR and CXCR4 was performed and evaluated with a standardized scoring system. RESULTS: DCE-MRI parameter A correlated significantly with the N category (P = 0.048) and k21 with the occurrence of synchronous and metachronous distant metastases (P = 0.029). A trend was shown toward a correlation between k21 and EGFR expression (P = 0.107). A significant correlation was found between DCE-MRI parameter TTP and the expression of EGFR (P = 0.044). DCE-MRI data did not correlate with CXCR4 expression. CONCLUSION: DCE-MRI is a noninvasive method which can characterize microcirculation in rectal cancer and correlates with EGFR expression. Given the relationship between the dynamic parameters and the clinicopathologic data, DCE-MRI data may constitute a prognostic indicator for lymph node and distant metastases in patients with rectal cancer.

Rectal cancer: assessment of response to neoadjuvant chemoradiation by dynamic contrast-enhanced MRI.

PURPOSE: To assess pretreatment functional and morphological tumor characteristics with magnetic resonance imaging (MRI) in advanced rectal carcinoma and to identify factors predicting response to neoadjuvant chemoradiation. MATERIALS AND METHODS: In a prospective study, 95 patients with rectal carcinoma underwent dynamic contrast-enhanced MRI before and after chemoradiation. Quantitative parameters were derived from a pharmacokinetic two-compartment model. Tumors were also characterized with regard to mucinous status at pretreatment high-resolution MRI as nonmucinous or mucinous. Response to treatment was defined as a downshift in the local tumor stage. RESULTS: The parameter k21 (contrast medium exchange rate) was higher at pretreatment MRI in nonmucinous compared with mucinous carcinomas (P < 0.001). The effect of chemoradiation on dynamic MR parameters was higher in nonmucinous carcinomas than in the mucinous subtype (P < 0.001). A higher rate of response to treatment was linked with nonmucinous morphology (P < 0.001). Multivariate analysis revealed an association between mucinous tumor morphology and poor response (odds ratio [95% confidence interval]: 0.113 [0.032-0.395], P < 0.001) as well as an association between a high 75th percentile of k21 and a higher response rate (odds ratio: 1.043 [1.001-1.086], P = 0.019). CONCLUSION: Functional and morphological parameters of pretreatment MRI can assess tumor characteristics associated with the effectiveness of chemoradiation before treatment initiation.