Delayed Surgery for Perforated Appendicitis is Feasible in Children Without Compromising the Outcome in Selected Cases.

BACKGROUND AND AIM: The relationship between time to surgery and risk of postoperative complications and re-intervention has not been conclusively investigated in pediatric perforated appendicitis (PA). The aim of this study was to determine whether time to appendectomy (TTA) is a risk factor for postoperative complications and re-intervention in a cohort of children undergoing appendectomy for PA. METHODS: A total of 254 children (age: 8.7 ± 3.7 years) undergoing appendectomy for PA were retrospectively evaluated and stratified into Group I-III according to the Clavien-Dindo classification for postoperative complications (Group I n = 218, 86%; Group II n = 7, 3%; Group III n = 29, 11%). RESULTS: The TTA was comparable between all groups (group I: 8.8 ± 9.2 h; group II: 7.8 ± 5.3 h; group III: 9.5 ± 9.6 h; overall: 8.8 ± 9.1 h; p = 0.885). A C-reactive protein (CRP) value at admission of ≥128.6 mg/l indicated a higher risk for developing Grade II complications with no need for re-intervention (OR: 3.963; 95% CI: 1.810-8.678; p = 0.001) and Grade III complications with the need for re-intervention (OR: 3.346; 95% CI: 1.456-7.690; p = 0.004). This risk was independent of the TTA (OR: 1.007; 95% CI: 0.980-1.035; p = 0.613). CONCLUSIONS: Appendectomy can be delayed by an average time delay of about 9 h in children with PA without increasing the risk of postoperative complications and re-intervention, also in patients at high risk defined by the initial CRP level ≥ 128.6 mg/l. This data may support the correct risk-adjusted scheduling of surgical interventions in times of limited capacity.

[Imaging of renal tumors in children]. / Bildgebung renaler Tumoren im Kindesalter.

CLINICAL/METHODOLOGICAL ISSUE: Renal tumors in children are treated according to the guidelines of the Renal Tumor Study Group of the International Society of Pediatric Oncology (SIOP-RTSG). Nephroblastoma is the most frequent renal tumor in children. STANDARD RADIOLOGICAL METHODS: After sonography, magnetic resonance imaging (MRI) is the preferred imaging modality. The task of imaging includes differential diagnosis with the help of morphological and epidemiological criteria. Thorax computed tomography (CT) is introduced for initial staging. METHODOLOGICAL INNOVATIONS: Current studies of diffusion-weighted imaging (DWI)-MRI with analysis of the apparent diffusion coefficient (ADC) histogram indicate the potential to differentiate blastemal or anaplastic high-risk histology nephroblatoma subtypes. Imaging criteria for nephron-sparing surgery are defined and allow an individual therapy option in unilateral and especially in bilateral renal nephroblastoma. PERFORMANCE: In addition to nephroblastoma, the differential diagnosis includes congenital mesoblastic nephroma, malignant rhabdoid tumor of the kidney, clear cell sarcoma and renal cell carcinoma. The diagnosis of nephrogenic rests and nephroblastomatosis is challenging. ACHIEVEMENTS: Diagnostic standardization improves diagnosis and therapy of renal childhood tumors, and new prognostic markers may be introduced in the near future.

Long-term outcome in displaced lateral humeral condyle fractures following internal screw fixation in children.

BACKGROUND: The aim of this study was to investigate the long-term clinical outcome following open reduction and internal screw fixation of displaced lateral condyle fractures (LCFs) of the distal humerus and compare the outcome of primary and secondary LCFs. METHODS: The clinical outcome in 31 children (mean age 5.8±2.4 years) operated for primary or secondary LCFs was retrospectively analyzed by standardized clinical examination and compared using the Mayo score, Morger score, and Patients Satisfaction score. RESULTS: The scores did not differ significantly between the primary and secondary displacement groups (Mayo score: 99.3±3.3 vs. 100±0, p=0.852; Morger score: 3.8±0.5 vs. 3.9±0.3, p=0.852; Patients Satisfaction score: 3.7±0.6 vs. 3.9±0.3, p=0.546). Deficits in range of motion and joint axis deviation were minor (< 10°) and no elbow instabilities were observed. CONCLUSIONS: Surgical treatment of a secondary displaced LCF with open reduction and internal screw fixation leads to a favorable long-term outcome. The long-term outcome is similar between primary and secondary displaced LCFs.

[Lung diseases in children]. / Lungenerkrankungen im Kindesalter.

BACKGROUND: Lung diseases belong to the most common acute and chronic childhood diseases. With specific diagnostics and therapy the outcome of many congenital and acquired pulmonary diseases in children and adults can be substantially improved. OBJECTIVE: The aim of this review is the presentation and evaluation of important lung diseases in children taking recent developments into consideration. MATERIAL AND METHODS: This article presents a review of the literature on selected acute and chronic lung diseases in children and adolescents. RESULTS: Acute pneumonia remains one of the most frequent causes of mortality in children worldwide. Antibiotic treatment has reduced the morbidity and mortality in Western industrialized countries; however, the treatment of complications, such as pleural empyema and lung abscesses remains challenging. With a prevalence of 10 %, asthma has evolved into the most common chronic disease in children and adolescents in Germany. Using anti-inflammatory inhalation therapy, effective control of asthma symptoms can be achieved in most patients. Cystic fibrosis (CF) remains the most common fatal inherited disease among Caucasians. More than 90 % of the mortality and morbidity of CF are caused by an early onset and progressive chronic obstructive lung disease. Approval of the first causal mutation-specific pharmacotherapy for a subgroup of patients with CF represents a milestone in individualized therapy of lung diseases. The pathogenesis of other rare chronic lung diseases including interstitial lung diseases (ILD) is still mostly unknown. CONCLUSION: Continuous improvement in the diagnostics and therapy is crucial to further improve the management and outcome of acute and chronic lung diseases in children. Pediatric pulmonology, as an interdisciplinary subspecialty at the interface of pediatrics, pulmonology and infectious diseases, plays a key role in the translation of scientific progress into clinical practice.

Pretreatment for bilateral nephroblastomatosis is an independent risk factor for progressive disease in patients with stage V nephroblastoma.

BACKGROUND: Treatment of stage V nephroblastoma is less established and more complex than in unilateral nephroblastoma. METHODS: Retrospective analysis of 121 consecutive patients with stage V nephroblastoma registered from January 1989 to May 2005. Registration, prospective data collection and treatment were carried out within the framework of 3 consecutive SIOP/GPOH-nephroblastoma-trials. RESULTS: 19 patients had metastasis and 29 syndromes at diagnosis. 13 patients had been pretreated for bilateral nephroblastomatosis. 1 patient was not treated and 17 patients had upfront surgery. Preoperative treatment duration ranged from 1-12 weeks (n=103). 1-3 preoperative treatment-cycles resulted in average tumor-volume-reduction of 45%. 1 patient underwent bilateral nephrectomy. 52% of the patients had 2 functioning kidneys after the end of treatment. 20 patients had died after mean follow-up of 8.6 years. 5y-Progression-Free (PFS) and Overall-Survival (OS) were excellent for patients having a localized disease without pretreatment for nephroblastomatosis (5yPFS/OS: 80±4%/93±3%). Metastasis at diagnosis (51±12%/56±12%; p=0.003) and pretreatment for nephroblastomatosis (37±14%/67±13%; p<0.001) were associated with significantly poorer outcome. Cox-regression analysis revealed an independent influence of pretreatment for nephroblastomatosis, metastasis and syndromes on PFS. The latter 2 as well as anaplasia and age (<2 years or >3 years) had an independent influence on OS. CONCLUSIONS: Pretreatment for nephroblastomatosis, metastasis and syndromes are independent risk factors. 1-3 preoperative treatment-cycles are sufficient to achieve save nephron-sparing-surgery in most patients.

Primary lung metastases in pediatric malignant non-Wilms renal tumors: data from SIOP 93-01/GPOH and SIOP 2001/GPOH.

Malignant non-Wilms renal tumors (NWRT) are a small but relevant subgroup of renal neoplasms in children. In this study we analyzed corresponding data from the trials SIOP 93-01/GPOH and SIOP 2001/GPOH of the Society of Pediatric Oncology and Hematology.Data of 22 patients with NWRT and primary lung metastases were retrospectively reviewed. Analyses included epidemiology, tumor characteristics, chemotherapy, local treatment, and outcome.The following diagnoses were registered: Malignant Rhabdoid tumor of the kidney (MRTK, n=15), Renal-cell carcinoma (RCC, n=3), Clear-cell sarcoma of the kidney (CCSK, n=3), and primitive neuro ectodermal tumor (PNET, n=1). Median age of patients at diagnosis was 14 months. Overall survival was 36.36% (8/22). Of the 15 children with MRTK 3 survived, 3/3 patients with RCC, 1/3 patients with CCSK, and 1/1 patient with PNET survived. Lung metastases disappeared in 6 patients after initial chemotherapy, 6/8 patients undergoing local treatment of lung metastases (surgery, irradiation, or both) achieved complete remission. Only patients with complete clearance of lung lesions, either through neoadjuvant chemotherapy or subsequent local treatment, survived. Mean Follow up was 31 months (1-137).Survival of patients with stage IV NWRT is dismal. Complete removal of lung metastases seems mandatory for survival. An aggressive diagnostic and therapeutic approach seems justified in affected children.

[Tumor predisposition syndromes and nephroblastoma : Early diagnosis with imaging]. / Tumorprädispositionssyndrome und Nephroblastom : Frühe Diagnose mit Bildgebung.

CLINICAL/METHODICAL ISSUE: The Beckwith-Wiedemann spectrum (BWSp) as well as the WT1-related syndromes, Denys-Drash syndrome (DDS) and WAGR spectrum (Wilms tumor, Aniridia, genitourinary anomalies and a range of developmental delays) are tumor predisposition syndromes (TPS) of Wilms tumor (WT). Patients with associated TPS are at higher risk of developing chronic kidney disease and bilateral and metachronous tumors as well as nephrogenic rests. STANDARD RADIOLOGICAL METHODS: Standard imaging diagnostics for WT include renal ultrasound and magnetic resonance imaging (MRI). In the current renal tumor studies Umbrella SIOP-RTSG 2016 and Randomet 2017, thoracic computed tomography (CT) is also recommended as standard. Positron emission tomography (PET)-CT and whole-body MRI, on the other hand, are not part of routine diagnostics. METHODOLOGICAL INNOVATIONS: In recent publications, renal ultrasound is recommended every 3 months until the age of 7 years in cases of clinical suspicion or molecularly proven TPS. PERFORMANCE: Patients with TPS and regular renal ultrasounds have smaller tumor volumes and lower tumor stages at WT diagnosis than patients without such a screening. This allows a reduction of therapy intensity and facilitates the performance of nephron sparing surgery, which is prognostically relevant especially in bilateral WT. ACHIEVEMENTS: Early diagnosis of WT in the context of TPS ensures the greatest possible preservation of healthy and functional renal tissue. Standardized screening by regular renal ultrasounds should therefore be firmly established in clinical practice. PRACTICAL RECOMMENDATIONS: The initial diagnosis of TPS is clinical and requires a skilled and attentive examiner in the presence of sometimes subtle clinical manifestations, especially in the case of BWSp. Clinical diagnosis should be followed by genetic testing, which should then be followed by sonographic screening.

Update on relapses in unilateral nephroblastoma registered in 3 consecutive SIOP/GPOH studies - a report from the GPOH-nephroblastoma study group.

INTRODUCTION: Treatment and stratification of progressive/relapsed unilateral nephroblastoma (PD) has significantly evolved over the last 20 years. Early PD (≤ 6 months), initial high risk histology, local stage III, multiple site PD and stage IV have been implemented as high risk classification factors and novel drugs have been introduced. PATIENTS AND METHODS: We analysed all 251 patients having had a unilateral nephroblastoma (Stage I-IV) and progressive disease who had been treated according to SIOP9/GPO (n = 77), SIOP93-1/GPOH (n = 93) and SIOP2001/GPOH (n = 81) initially. RESULTS: 3y-overall survival (OS) increased from 43% to 61% and 59% respectively (both p<0.01). 3y-OS for localized stage I-III rose from 43% to 65% and 68% respectively while only little improvement can be seen for initial stage IV patients with 43%, 53% and 44% respectively. Multivariate analysis confirmed high risk histology, local stage III, shorter time to PD, combined relapse as independent risk factors. 26 patients had received high-dose chemotherapy showing 64% 3y-OS compared to 54% for all non-transplanted (p=0.11). CONCLUSION: Structuring the treatment of progressive nephroblastoma as well as introducing new drugs have improved the outcome significantly. However improvement is depending on the specific risk profile. Very high risk tumours are often resistant to conventional treatment, hence an international uniform treatment concept is needed to achieve conclusive results in this small group.

[Shape analysis of retroperitoneal tumors in childhood in magnetic resonance imaging]. / Formanalyse in der Magnetresonanztomografie - Landmarken und Objektdifferenzierung bei retroperitonealen Tumoren im Kindesalter.

2D-shape analysis of biological objects is described first in 2007 with MRI-data (magnetic resonance imaging) of renal tumours of infancy. For shape analysis the evaluation of landmarks is necessary (n >2). In this study 24 landmarks are selected. Every object is described by these landmarks. The shape is the standardised and centred object. The procedure is applied on transversal as well as on frontal images. The results for frontal and transversal images are compared. Tumours of different origin, topography and size can be analysed. The differentiation of relevant landmarks is important for statistical and medical reason. In this study, evaluation of landmarks and their possibility for tumour differentiation is demonstrated.

DTI of commissural fibers in patients with Chiari II-malformation.

Chiari II-malformation is a complex congenital deformity of the brain which is frequently associated with hydrocephalus. Abnormalities of the corpus callosum are known to occur in the majority of patients. The objective of the present study was to study the microstructure of the corpus callosum (CC) and the anterior commissure (AC) to differentiate between different mechanisms of damage to these structures. We investigated 6 patients with Chiari II-malformation and 6 well-matched healthy volunteers employing T1-weighted 3D imaging and diffusion tensor imaging (DTI) to determine the fractional anisotropy (FA) and cross-sectional area of the CC and AC, as well as with neuropsychological testing. Four patients showed hydrocephalus, two patients had callosal dysplasia and four had a hypoplastic CC. The callosal FA in the patients was significantly reduced which was less pronounced for the genu alone. The area of CC was also reduced in Chiari II-patients. There was a strong correlation between the size and FA of the CC in the patients. In contrast, the thickness of the AC was significantly increased and was associated with higher FA in the patients. In psychological tests all patients showed reduced verbal memory; all but one patient showed reduced IQ as well as impaired visuo-spatial performance, indicating deficits in tasks requiring parieto-occipital integration. The existence of callosal dysplasia in two patients, the diminished FA reduction in the genu and the correlation of the cross-sectional area and FA in the patients point to a developmental white matter damage beside that exerted by hydrocephalus alone.

3D perfusion mapping and virtual surgical planning in the treatment of pediatric embryonal abdominal tumors.

INTRODUCTION: 3D imaging and surgical planning for the treatment of embryonal tumors using different techniques (CT versus MRI) are presently under discussion. Up to now, the main focus has been on visualizing the anatomy. Contrast medium dynamics have not been taken into consideration. The aim of the present study was to establish the technical means of integrating the 3D images from functional MRI data into the anatomical images and to determine clinical applications for this approach. MATERIAL AND METHODS: In 11 patients (mean age: 2.4 years) with solid tumors, 26 diagnostic MRI examinations were performed for primary diagnosis, treatment monitoring, or as part of the surgical planning. Seven children presented with neuroblastomas, three with Wilms' tumor, and one with advanced bilateral nephroblastomatosis. The MRI data were acquired using a 1.5-T system. For post-processing, we used volume rendering software, including an evaluation of perfusion. By using color-coded parametric images and integrating functional information, perfusion could be visualized and used for interactive surgical planning. Macroscopic and microscopic sections served as the gold standard for assessing tissue viability. RESULTS: We were able to integrate the dynamic data into the anatomical images for all patients. A good agreement was found between the results of surgical planning, including perfusion mapping, with the surgical site, subsequently produced macroscopic sections and the results of random microscopic examinations. CONCLUSIONS: Perfusion mapping using color-coded parametric images of pediatric abdominal tumors extends the diagnostic techniques currently available. We provide first proof of the possibility of integrating functional information into 3D MR images in children. Monitoring the treatment of nephroblastoma and surgical planning for pediatric embryonal tumors represent potential applications of this technique.

[Quality control of thoracic X-rays in children in diagnostic centers with and without pediatric-radiologic competence]. / Qualitätskontrolle von Röntgenthoraxaufnahmen bei Kindern in diagnostischen Zentren mit und ohne kinderradiologische Kompetenz.

PURPOSE: Radiation protection in pediatric radiology is very important because of the particular sensitivity of radiosensitive organs in younger patients. Optimized image quality supports radiation protection and should be targeted. In our study we examined the quality of pediatric chest X-rays at diagnostic centers (university hospitals and other large clinics). We then evaluated differences in image quality in departments without pediatric competence (R) and departments with pediatric competence (PR). MATERIALS AND METHODS: Our study was based on 313 conventional chest X-rays from 207 patients (192 p. a./a. p. and 121 lateral, 43 from R, 258 from PR and 12 neither from R nor KR) and 38 digital chest X-rays from 26 patients (25 p. a./a. p. and 13 lateral, 1 from R and 37 from PR). All patients (age 0 - 18 years) are from Nephroblastoma-Study SIOP-93/01-GPOH. We examined all initial chest X-rays, which were sent to us for evaluation upon request between 4/3/2002 and 6/14/2002. The examined parameters were: exposure, centering of the X-rays/patient positioning, collimation and sharpness. The X-rays were evaluated on a scale from 1 (best result) to 5 (worst result), resulting in an overall score of A = optimum, B = minor problems, C = major problems, or D = unusable. The optical density, the center of the image and the relative field size were also measured. Statistical tests (Mann-Whitney-U and log regression) were carried out on the conventional images. The study was performed retrospectively. The exposure, sharpness and optical density of the digital X-rays were not analyzed. RESULTS: In the case of all conventional X-rays, the quality of the centering of the X-rays/patient positioning and collimation was moderate (average scale value: 2.4 and 2.8), and the quality of the exposure and sharpness was good and very good (average scale value: 1.9 and 1.5). The quality of the chest X-rays in departments with additional pediatric radiological expertise was better mainly in the case of younger patients (younger than 5 years) than departments without additional pediatric radiological expertise (average scale value in age group 0 - 1 month: PR = 1.7; average scale value in age group 2 months - 2 years: R = 2.4 and PR = 1.8; average scale value in age group 3 - 5 years: R = 2.5 and PR = 1.8). CONCLUSION: Despite the good overall image quality, the quality of the centering of the X-rays/patient positioning and collimation was insufficient in both examiner groups (R and PR). For this reason, some radiation protection requirements could not be fulfilled. X-rays from PR were higher quality than X-rays from R in this special study group. Day-to-day quality checks are necessary for pediatric chest X-rays in order to achieve a high quality standard.

[Reference radiology in nephroblastoma: accuracy and relevance for preoperative chemotherapy]. / Referenzradiologie des Nephroblastoms: Diagnosegenauigkeit und Bedeutung für die präoperative Chemotherapie.

PURPOSE: A reference radiologic diagnosis was carried out for the purpose of quality control and in order to achieve high diagnostic accuracy in the ongoing trial and study SIOP 2001/GPOH for renal tumors during childhood. The aim of the present study is to evaluate the value of diagnostic imaging and the benefit of reference evaluation at a pediatric radiology center. MATERIALS AND METHODS: In 2004 the imaging studies of 97 patients suspected of having a renal tumor were presented at the beginning of therapy. Diagnostic imaging was compared to the primary imaging results and the histological findings and was analyzed in regard to the therapeutic consequence (primary chemotherapy without prior histology). 77 MRI, 35 CT and 67 ultrasound examinations of 47 girls and 50 boys (mean age 4 years; one day to 15.87 years old) were analyzed. In addition to the histological findings, the reference pathological results were submitted in 86 cases. Results from the primary imaging corresponding to the histology and results from the reference radiology corresponding to the histology were statistically compared in a binomial test. RESULTS: In 76 of the reference-diagnosed Wilms' tumors, 67 were confirmed histologically. In 72 cases preoperative chemotherapy was initiated. In 5 cases neither a Wilms' tumor nor a nephroblastomatosis was found. 16 of 21 cases (76 %) with reference-diagnosed non-Wilms' tumors were selected correctly. The results of the primary imaging corresponded to the histology in 71 cases, and those of the reference radiology in 82 cases. The statistical evaluation showed that the results of the reference radiology were significantly better (p = 0.03971). CONCLUSION: Reference radiological evaluation improved the diagnostic accuracy with therapeutic relevance. The differentiation of different renal tumors is not completely possible using imaging methods. The rate of patients with false preoperative chemotherapy for all renal neoplasms is currently 5.2 % and 1 % for benign renal tumors.

Predicting Postoperative Complications After Pediatric Perforated Appendicitis.

PURPOSE: Assessment of risk factors for postoperative complications following surgical treatment of pediatric perforated appendicitis (PA) is necessary to identify those patients in need of closer monitoring. In this study, we have investigated the impact of different risk factors on the occurrence of complications after an appendectomy in children with PA. MATERIAL AND METHODS: The study was a retrospective, single-centre analysis of all pediatric PA conducted over a 10-year period. Preoperative clinical and laboratory results, intraoperative findings, and postoperative complications were analyzed. Risk factors were defined and a risk score was determined for postoperative complications and reinterventions. RESULTS: Surgical treatment for appendicitis was performed in 840 pediatric patients during the observation period. 163 of the included patients were diagnosed with PA (mean age 8.9 ± 3.6 years). 19 (11.7%) patients developed postoperative complications, 17 (10.4%) of which required complication-related intervention. We identified five predictors of postoperative complications: the C-related protein value at admission, purulent peritonitis, open appendectomy (primary, secondary, or converted), placement of an abdominal drain, and administration of antibiotics not compliant to results from the subsequent antibiogram. The determined risk score was significantly higher in the complication group (p < .0001) and reintervention group (p < .001). CONCLUSIONS: Postoperative complications following pediatric PA can be predicted using specific preoperative, intraoperative, and postoperative risk factors. In the high-risk group, an active prevention, detection, and intervention of any occurring complication is necessary and we present a new specific pediatric risk score to define patients at risk for complications.

[MRI-morphology and staging of congenital mesoblastic nephroma: evaluation of a collection with 20 patients]. / MRT-Morphologie und Staging des kongenitalen mesoblastischen Nephroms: Auswertung einer Fallsammlung mit 20 Patienten.

PURPOSE: To differentiate classic and cellular type of congenital mesoblastic nephroma (CMN) in MRI and to evaluate MRI for staging according to the Societe Internationale de Oncologie Pediatrique (SIOP). MATERIAL AND METHODS: MRI examinations of 20 children with CMN (age 1st to 16th months, classic type n = 11, cellular type n = 7, mixed type n = 2) were analyzed retrospectively. Cysts, necrosis, hemmorhage in the tumor, signal intensity, tumor structure, thrombosis and dilatation of renal vein, crossing of the body midline, peripheral contrast-enhancement, tumor volume and existence of a tumor pseudocapsule in contrast to the residual kidney were described. The radiologic stage was compared with the histopathologic stage (infiltration of perirenal fat and infiltration of the renal sinus). RESULTS: Tumors of the classic type (mean volume 67.9 ml) had necrosis in 1 case, crossed the midline in 1 case, had no cysts or bleeding, and had a peripheral contrast-enhancement in 1 case, and were heterogeneous in 9 cases. The cellular type (mean volume 302.8 ml) had tumor necrosis in 6 cases, bleeding in 3 cases, cysts in 3 cases, crossed the midline in 4 cases, and peripheral contrast enhancement in 2 cases, and was predominantly heterogeneous. Mixed tumor types (7 ml and 202 ml) had tumor necrosis in 1 case and crossed the midline in 1 case, a peripheral contrast enhancement in 2 cases and a homogenous structure in 1 case. The signal intensity in T1 w and T2 w images was not specific. The renal vein was inconspicuous in all children. The evaluation of the infiltration in perirenal fatty tissue was true positive in 1 case, true negative in 10 cases, false negative in 4 cases and false positive in 5 cases. The infiltration of the renal hilus was true positive in 10 children, false positive in 8 cases and true negative in 2 cases. CONCLUSION: A typical finding of CMN in MRI is a heterogeneous tumor without demarcation from the rest of the kidney parenchyma by a pseudocapsule. The cellular type of CMN tends to have a higher tumor volume and shows more necrosis, bleeding and cysts than the classic type in MRI. A peripheral contrast-enhancement in MRI is not characteristic for any type of CMN. Local tumor staging is not possible with MRI.

[Radiologic differentiation of rhabdoid tumor from Wilms' tumor and mesoblastic nephroma]. / Bildgebende Differenzierung des Rhabdoidtumors vom Nephroblastom und mesoblastischen Nephrom.

Differentiation between rhabdoid tumor (RT) and mesoblastic nephroma (MN) and Wilms' tumor (WT) by imaging studies in babies and young children before histological confirmation is useful to start optimal treatment early. Typical radiologic criteria (crescent-shaped subcapsular liquid areas, tumor lobules, blurred tumor borders, metastasis in the lung, and regional lymph nodes) are described. The results of 26 MRI, 30 CT, and 22 ultrasound examinations of 49 patients (22 RT, 19 WT, and 8 MN, age 2-57 months) were analyzed. The above-mentioned radiologic criteria were classified with score values. The score value distribution was analyzed between the tumor entities and by two investigators.RT had significantly higher score values than the MN and WT. The difference between the two investigators was not significant. As a group RT differentiates from the group of WT and MN, but this is not possible in single cases with the radiologic criteria employed. Only if more signs are observed together in one case can a RT be presumed, which may indicate an early biopsy before chemotherapy.

[Multi-slice CT in the planning of nephron-sparing interventions for renal cell carcinoma: Prospective study correlated with histopathology]. / Multi-Slice-CT in der Planung der organerhaltenden Operation des Nierenzellkarzinoms: Prospektive histopathologisch korrelierte Studie.

OBJECTIVE: For nephron sparing surgery of renal cell carcinoma knowledge of the intrarenal extension of the tumor and infiltration of the renal pelvis, the intrarenal vessels and the perinephric fat is essential. This question is much more difficult to answer compared to the description of staging parameters. Aim of this study is to evaluate the value of multi-slice CT in planning of nephron sparing surgery. MATERIAL AND METHODS: In a prospective study 46 patients with suspected renal cell carcinoma underwent a triphasic multi-slice CT (unenhanced, delay 30 s and 120 s). A reconstructed slice thickness of 2 mm in the arterial and parenchymal phase was used to create volume rendered 3D-reconstructions. Based on the source data and multiplanar reconstructed images the extent of the renal cell carcinoma was assessed in terms of size, hilar infiltration, arterial and venous invasions, capsula infiltration and perirenal growth. The results of two blinded readers were correlated with histopathological staging and intraoperative findings. RESULTS: 36 carcinomas were evaluated histopathologically. 10 patients showed no renal cell carcinoma histopathologically. Multi-slice CT allowed us to diagnose the localization and size of all tumors correctly. Infiltration into perinephric fat was correctly excluded in 24/30 and 8/30 cases. Infiltration of the renal pelvis could be excluded in 17/24 and 12/24 cases. The state of venous infiltration could be correctly diagnosed in 29/30 and 27 /30 carcinomas. CONCLUSION: Despite of the high temporal and spatial resolution of multi-slice CT, which allows the delineation of intrarenal arteries as well as renal hilus and the veins, the evaluation of tumor infiltration into the renal hilus, the intrarenal vessels and the perinephric fat remains a diagnostic problem. For planning of nephron sparing surgery, a knowledge of the infiltration in these structures is essential.

[Organ-sparing surgery of renal cell carcinoma - operative technique and findings in radiological follow-up]. / Organerhaltende Chirurgie des Nierenzellkarzinoms - Operationstechniken und Befunde in der radiologischen Nachsorge.

Nephron-sparing surgery of renal cell carcinoma in the 1970's and 1980's in patients with bilateral renal tumors or reduced renal function (imperative indication) has shown a very low risk of recurrent cancer. Today, nephron-sparing surgery in renal cell carcinoma is considered in an increasing number of patients with expected sufficient renal function after nephrectomy (elective indication). Resection technique, the use of Tabotamp(R) to reduce bleeding, and pseudotumors do complicate the interpretation of the images. It has been not yet defined which diagnostic modality is best suited for follow-up after renal cell carcinoma resection. Follow-up protocols in different institutions show a wide variety. The follow-up of patients after nephron-sparing surgery is performed by annual sonography or MRI every three months. Up to now, CT and ultrasound are the standard methods. MRI with its multiplanar imaging and improved soft tissue contrast seems to have an equal diagnostic value. Additionally, MRI seems to be suited for patients with reduced renal function. The aim of this paper is to give guidelines for the radiologist to understand the different surgical procedures and to evaluate the postoperative findings. Different imaging modalities in the follow-up of patients and special radiological phenomena are discussed.