Single-fraction image-guided robotic radiosurgery efficiently controls local prostate cancer recurrence after radical prostatectomy.

Purpose: To assess the therapeutic potential of single-fraction robotic stereotactic ablative body radiotherapy (SABR) in patients with locally recurrent prostate cancer (PC) after radical prostatectomy (RP). Materials and methods: We included 35 patients with biochemical failure after RP with single-site local recurrence in the prostate bed diagnosed by PSMA PET/CT. About 20/35 pts had previously received post-surgical adjuvant radiation therapy.High-resolution multiparametric magnetic resonance imaging (mpMRI) for exact visualization of tumor tissue was performed at 1.5 (n = 23; Siemens Magnetom Aera) or 3 Tesla (n = 12; Siemens Magnetom VIDA, Siemens Healthineers, Erlangen, Germany). Using the MRI and PET/CT dataset for planning, SABR was carried out after ultrasound-guided placement of a single gold fiducial marker at the site of tumor recurrence using a CyberKnife M6 unit (Accuray Inc., Sunnyvale, USA). Due to the high diagnostic accuracy of PSMA PET/CT and mpMRI, pre-SABR biopsy of tumor tissue was not deemed necessary. PSMA PET/CT performed in median 88 days before SABR confirmed the absence of distant metastases. MpMRI was performed at a median of 22 days prior to the intervention. SABR was performed in a single fraction with a dose of 20 (5/35), 21 (27/35) or 22 (3/35) Gy. Follow-up serum PSA was measured every 3 months thereafter. Results: Median patient age was 72 years (57-80 years) and median time from RP to SABR was 96.8 months (IQR, 69.3-160.2). Median serum PSA before SABR was 1.38 ng/mL (IQR 0.75-2.72). At 3 months, median PSA had dropped significantly in 27/35 patients to a median of 0.35 ng/mL (IQR 0.25-0.68). At 6 months, 30/35 patients showed biochemical response to SABR, while five patients were progressing: three had systemic disease on PSMA PET/CT, while two patients had rising PSA values without a visible correlate on PET/CT. The median follow-up time was 16 months. Grade 1 genitourinary (GU) toxicity was reported in 3/35 patients (9%) and grade 1 gastrointestinal (GI) toxicity in 2/35 patients (6%), respectively. Conclusion: SABR is an efficient new treatment option in the management of single-site local recurrent PC without the evidence of systemic disease; due to its very low toxicity, it is an alternative to surgical re-treatment or other focal therapies. It can significantly delay the onset of androgen deprivation therapy (ADT) in biochemical failure after radical prostatectomy.

Dual energy CT allows for improved characterization of response to antiangiogenic treatment in patients with metastatic renal cell cancer.

OBJECTIVES: To evaluate the potential role of dual energy CT (DECT) to visualize antiangiogenic treatment effects in patients with metastatic renal cell cancer (mRCC) while treated with tyrosine-kinase inhibitors (TKI). METHODS: 26 patients with mRCC underwent baseline and follow-up single-phase abdominal contrast enhanced DECT scans. Scans were performed immediately before and 10 weeks after start of treatment with TKI. Virtual non-enhanced (VNE) and colour coded iodine images were generated. 44 metastases were measured at the two time points. Hounsfield unit (HU) values for VNE and iodine density (ID) as well as iodine content (IC) in mg/ml of tissue were derived. These values were compared to the venous phase DECT density (CTD) of the lesions. Values before and after treatment were compared using a paired Student's t test. RESULTS: Between baseline and follow up, mean CTD and DECT-derived ID both showed a significant reduction (p < 0.005). The relative reduction measured in percent was significantly greater for ID than for CTD (49.8 ± 36,3 % vs. 29.5 ± 20.8 %, p < 0.005). IC was also significantly reduced under antiangiogenic treatment (p < 0.0001). CONCLUSIONS: Dual energy CT-based quantification of iodine content of mRCC metastases allows for significantly more sensitive and reproducible detection of antiangiogenic treatment effects. KEY POINTS: • A sign of tumour response to antiangiogenic treatment is reduced tumour perfusion. • DECT allows visualizing iodine uptake, which serves as a marker for vascularization. • More sensitive detection of antiangiogenic treatment effects in mRCC is possible.

Rhinovirus inhibits IL-17A and the downstream immune responses in allergic asthma.

The proinflammatory cytokine interleukin-17A (IL-17A) is known to mediate antimicrobial activity, but its role during rhinovirus (RV) infections and in asthma needs further investigation. Therefore, we addressed the role of IL-17A during allergic asthma and antiviral immune response in human and murine immunocompetent cells. In this study we found that asthmatic children with a RV infection in their upper airways have upregulated mRNA levels of the antiviral cytokine interferon type I (IFN)-ß and the transcription factor T-box 21 (TBX21) and reduced levels of IL-17A protein in their peripheral blood mononuclear cells (PBMCs). We also found that IL-17A inhibited RV1b replication in infected human lung epithelial cells A549. Furthermore, by using gene array analysis we discovered that targeted deletion of Il17a in murine lung CD4(+) T cells impaired Oas1g mRNA downstream of Ifnß, independently from RV infection. Additionally, in PBMCs of children with a RV infection in their nasalpharyngeal fluid OAS1 gene expression was found downregulated. Finally RV1b inhibited IL-17A production in lung CD4(+) T cells in a setting of experimental asthma. These results indicate that the RV1b inhibits IL-17A in T helper type 17 cells and IL-17A clears RV1b infection in epithelial cells. In both cases IL-17A contributes to fend off RV1b infection by inducing genes downstream of interferon type I pathway.

Renal Pseudoaneurysms and Arteriovenous Fistulas as a Complication of Nephron-Sparing Partial Nephrectomy: Technical and Functional Outcomes of Patients Treated With Selective Microcoil Embolization During a Ten-Year Period.

PURPOSE: The aim of this study was to evaluate the clinical and functional outcomes in patients who underwent selective interventional embolization of renal pseudoaneurysms or arteriovenous fistulas at our center. MATERIALS AND METHODS: Our retrospective analysis included all consecutive patients who received selective transcatheter embolization of renal pseudoaneurysms or arteriovenous fistulas after partial nephrectomy in our department from January, 2003 to September, 2013. The technical and clinical success rate and functional outcome of every procedure was collected and analyzed. Furthermore, the change in renal parenchymal volume before and after embolization was determined in a subgroup. RESULTS: A total of 1425 patients underwent partial nephrectomy at our hospital. Of these, 39 (2.7 %) were identified with a pseudoaneurysm or an arteriovenous fistula after partial nephrectomy. The diagnosis of the vascular lesions was made by means of biphasic CT or CEUS. Technical success by means of selective microcoil embolization was achieved in all 39 patients (100 %). Clinical success, defined as no need for further operation or nephrectomy during follow-up, was achieved in 35 of 39 patients (85.7 %). Renal function, as measured by eGFR before and after the intervention, did not change significantly. However, a mean loss of parenchymal volume of 25.2 % was observed in a subgroup. No major or minor complications were attributable to the embolization procedure. CONCLUSION: Transcatheter embolization is a promising method for treating vascular complications which may occur after partial nephrectomy. We confirm the high success rate of this technique while discussing renal functional outcomes and potential safety aspects. KEY POINTS: Arterial pseudoaneurysms and arteriovenous fistulas are rare but severe complications after partial nephrectomy. Selective microcoil embolization is a safe and effective kidney-preserving procedure for treating these complications. Embolization leads to a significant loss of renal parenchymal volume but not to a loss of renal function.

Dual energy can accurately differentiate uric acid-containing urinary calculi from calcium stones.

PURPOSE: To retrospectively evaluate the accuracy of dual-energy CT (DECT) in the detection of the chemical composition of urinary calculi in correlation with infrared spectroscopic stone analysis. METHODS: We reviewed the CT scans of 255 patients who underwent DECT due to a clinical suspicion of urolithiasis. Out of this group, we included 64 patients with clinically symptomatic urolithiasis requiring stone removal. After surgical removal of the stone by ureterorenoscopy, chemical composition was analyzed with infrared spectroscopy. We correlated DECT stone characterization results with chemical stone composition based on dual-energy indices (DEI). A total of 213 renal and ureteral stones could be removed and chemically analyzed. RESULTS: A total of 213 calculi were evaluated. Thirty eight out of sixty four (59 %) patients had >1 stone. DECT was used to differentiate stones by using DEI. Stones harboring calcium (CA) were color-coded in blue, while stones containing uric acid (UA) were colored red. Median DEI in UA-containing stones were 0.001. Non-UA-containing stones had a DEI between 0.073 for pure CA stones and 0.077 containing CA and other substances (p = 0.001; p = 0.03, respectively). Sensitivity of DECT was 98.4 % for differentiation of UA from non-UA-containing calculi. Specificity was 98.1 %. Mean effective radiation dose of DECT was 4.18 mSv (0.44-14.27 mSv), thus comparable to conventional CT scans of the abdomen. Conventional measurement of Hounsfield units did not correlate with stone composition. CONCLUSION: DECT with image post-processing reliably discriminates UA-containing calculi from all other stones, but the study offered limitations. Discrimination within the non-UA stones cannot be reliably achieved but is clinically insignificant.

Right-sided diaphragmatic rupture after repair of a large Morgagni hernia.

We present a case of a combination of primary and secondary diaphragmatic hernia in a 63-year male patient. For progressive dyspnea and palpitations caused by a large and symptomatic Morgagni hernia resulting in a right-sided enterothorax, an open tension-free mesh repair was performed. The postoperative course was complicated by a secondary hepatothorax through a spontaneous rupture of the right diaphragm. Primary mesh repair of the Morgagni hernia, however, proved to be sufficient. This recurrent herniation might be a consequence of (1) preexisting atrophy of the right diaphragm caused by disposition and/or long-term diaphragmatic dysfunction due to the large hernia, combined with (2) further thinning out of the diaphragm by intraoperative hernia sac resection, and (3) postoperative increase of intra-abdominal pressure.

Comparison of manual and semi-automatic measuring techniques in MSCT scans of patients with lymphoma: a multicentre study.

OBJECTIVES: Multicentre evaluation of the precision of semi-automatic 2D/3D measurements in comparison to manual, linear measurements of lymph nodes regarding their inter-observer variability in multi-slice CT (MSCT) of patients with lymphoma. METHODS: MSCT data of 63 patients were interpreted before and after chemotherapy by one/two radiologists in five university hospitals. In 307 lymph nodes, short (SAD)/long (LAD) axis diameter and WHO area were determined manually and semi-automatically. Volume was solely calculated semi-automatically. To determine the precision of the individual parameters, a mean was calculated for every lymph node/parameter. Deviation of the measured parameters from this mean was evaluated separately. Statistical analysis entailed intraclass correlation coefficients (ICC) and Kruskal-Wallis tests. RESULTS: Median relative deviations of semi-automatic parameters were smaller than deviations of manually assessed parameters, e.g. semi-automatic SAD 5.3 vs. manual 6.5 %. Median variations among different study sites were smaller if the measurement was conducted semi-automatically, e. g. manual LAD 5.7/4.2 % vs. semi-automatic 3.4/3.4 %. Semi-automatic volumetry was superior to the other parameters (2.8 %). CONCLUSIONS: Semi-automatic determination of different lymph node parameters is (compared to manually assessed parameters) associated with a slightly greater precision and a marginally lower inter-observer variability. These results are with regard to the increasing mobility of patients among different medical centres and in relation to the quality management of multicentre trials of importance. KEY POINTS: • In a multicentre setting, semi-automatic measurements are more accurate than manual assessments. • Lymph node volumetry outperforms all other semi-automatically and manually performed measurements. • Use of semi-automatic lymph node analyses can reduce the inter-observer variability.

Can single-phase dual-energy CT reliably identify adrenal adenomas?

PURPOSE: To evaluate whether single-phase dual-energy-CT-based attenuation measurements can reliably differentiate lipid-rich adrenal adenomas from malignant adrenal lesions. MATERIALS AND METHODS: We retrospectively identified 51 patients with adrenal masses who had undergone contrast-enhanced dual-energy-CT (140/100 or 140/80 kVp). Virtual non-contrast and colour-coded iodine images were generated, allowing for measurement of pre- and post-contrast density on a single-phase acquisition. Adrenal adenoma was diagnosed if density on virtual non-contrast images was ≤10 HU. Clinical follow-up, true non-contrast CT, PET/CT, in- and opposed-phase MRI, and histopathology served as the standard of reference. RESULTS: Based on the standard of reference, 46/57 (80.7%) adrenal masses were characterised as adenomas or other benign lesions; 9 malignant lesions were detected. Based on a cutoff value of 10 HU, virtual non-contrast images allowed for correct identification of adrenal adenomas in 33 of 46 (71%), whereas 13/46 (28%) adrenal adenomas were lipid poor with a density ≥10 HU. Based on the threshold of 10 HU on the virtual non-contrast images, the sensitivity, specificity, and accuracy for detection of benign adrenal lesions was 73%, 100%, and 81% respectively. CONCLUSION: Virtual non-contrast images derived from dual-energy-CT allow for accurate characterisation of lipid-rich adrenal adenomas and can help to avoid additional follow-up imaging. KEY POINTS: • Adrenal adenomas are a common lesion of the adrenal glands. • Differentiation of benign adrenal adenomas from malignant adrenal lesions is important. • Dual-energy based virtual non-contrast images help to evaluate patients with adrenal adenomas.

Therapy response evaluation of malignant lymphoma in a multicenter study: comparison of manual and semiautomatic measurements in CT.

PURPOSE: Comparison of manual one-/bi-dimensional measurements versus semi-automatically derived one-/bi-dimensional and volumetric measurements for therapy response evaluation of malignant lymphoma during CT follow-up examinations in a multicenter setting. MATERIALS AND METHODS: MSCT data sets of patients with malignant lymphoma were evaluated before (baseline) and after two cycles of chemotherapy (follow-up) at radiological centers of five university hospitals. The long axis diameter (LAD), the short axis diameter (SAD) and the bi-dimensional WHO of 307 target lymph nodes were measured manually and semi-automatically using dedicated software. Lymph node volumetry was performed semi-automatically only. The therapeutic response was evaluated according to lymphoma-adapted RECIST. RESULTS: Based on a single lymph node, semi-automatically derived multidimensional parameters allowed for significantly more accurate therapy response classification than the manual or the semi-automatic unidimensional parameters. Incorrect classifications were reduced by up to 9.6%. Compared to the manual approach, the influence of the study center on correct therapy classification is significantly less relevant when using semi-automatic measurements. CONCLUSION: Semi-automatic volumetry and bi-dimensional WHO significantly reduce the number of incorrectly classified lymphoma patients by approximately 9.6% in the multicenter setting in comparison to linear parameters. Semi-automatic quantitative software tools may help to significantly reduce wrong classifications that are associated with the manual assessment approach. KEY POINTS: ► Semi-automatic volumetry and bi-dimensional WHO significantly reduce the number of incorrectly classified lymphoma patients ► Manual lymph node evaluation with uni-dimensional parameters is inferior to semi-automatic analysis in a multicenter setting ► Semi-automatic quantitative software tools should be introduced in clinical study evaluation.

[Radiological diagnostics in CUP syndrome]. / Radiologische Diagnostik des CUP-Syndroms.

CLINICAL/METHODICAL ISSUE: Imaging plays an essential role in the therapeutic management of cancer of unknown primary (CUP) patients for localizing the primary tumor, for the identification of tumor entities for which a dedicated therapy regimen is available and for the characterization of clinicopathological subentities that direct the subsequent diagnostic and therapeutic strategy. STANDARD RADIOLOGICAL METHODS: Modalities include conventional x-ray, computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound as well as positron emission tomography (PET)-CT and MRI-PET. PERFORMANCE: In whole body imaging CT has a high sensitivity for tumor entities which frequently present as a metastasized cancer illness. According to the current literature CT is diagnostic in 86% of patients with pancreatic carcinoma, in 36% of patients with colon carcinoma and in 74% of patients with lung carcinoma. Additionally a meta-analysis showed that for patients with squamous cell carcinoma and cervical lymph node metastases a positive diagnosis was possible in 22% of the cases using CT, in 36% using MRI and in 28-57% using 18F-fluorodeoxyglucose PET-CT ((18)F-FDG PET-CT). In addition, MRI plays an important role in the localization of primary occult tumors (e.g. breast and prostate) because of its high soft tissue contrast and options for functional imaging. ACHIEVEMENTS: At the beginning of the diagnostic algorithm stands the search for a possible primary tumor and CT of the neck, thorax and abdomen is most frequently used for whole body staging. Subsequent organ-specific imaging examinations follow, e.g. mammography in women with axillary lymphadenopathy. For histological and immunohistochemical characterization of tumor tissue, imaging is also applied to identify the most accessible and representative tumor manifestation for biopsy. Tumor biopsy may be guided by CT, MRI or ultrasound and MRI also plays a central role in the localization of primary occult tumors because of superior soft tissue contrast and options for functional imaging (perfusion, diffusion), e.g. investigation of breast carcinoma or prostate carcinoma. PRACTICAL RECOMMENDATIONS: Whole body staging stands at the beginning of the diagnostic algorithm in CUP syndrome to localize a potential primary tumor. Clinically, contrast-enhanced CT of the neck, thorax and abdomen is frequently applied; however, many studies have demonstrated augmented sensitivity of (18)F-FDG PET-CT for the detection of primary tumors and metastatic tumor manifestations.

Right-sided diaphragmatic rupture after repair of a large Morgagni hernia.

We present a case of a combination of primary and secondary diaphragmatic hernia in a 63-year male patient. For progressive dyspnea and palpitations caused by a large and symptomatic Morgagni hernia resulting in a right-sided enterothorax, an open tension-free mesh repair was performed. The postoperative course was complicated by a secondary hepatothorax through a spontaneous rupture of the right diaphragm. Primary mesh repair of the Morgagni hernia, however, proved to be sufficient. This recurrent herniation might be a consequence of (1) preexisting atrophy of the right diaphragm caused by disposition and/or long-term diaphragmatic dysfunction due to the large hernia, combined with (2) further thinning out of the diaphragm by intraoperative hernia sac resection, and (3) postoperative increase of intra-abdominal pressure.

[Early detection of colorectal cancer: role of endoscopy and imaging]. / Früherkennung des kolorektalen Karzinoms: rolle der Endoskopie und bildgebenden Verfahren.

Colorectal cancer is one of the leading causes of cancer-related morbidity and mortality. Colorectal cancer commonly develops slowly via adenomatous polyps, a process usually requiring ≥ 10 years. This allows for early detection. Endoscopic polypectomy and surgery of early disease can reduce the incidence and mortality of colorectal cancer. Both hemoccult testing and colonoscopy are the most widely used tests for colorectal cancer screening; however, colonoscopy has the highest sensitivity for colorectal neoplasia. Sigmoidoscopy is not commonly used for screening in Germany. Colon contrast enema is no longer recommended for screening. As colonoscopy serves as a diagnostic and therapeutic tool and is the reference method in hemoccult and sigmoidoscopy studies, it is viewed as the gold standard for the diagnosis of colonic disease. New methods including capsule colonoscopy and virtual colonoscopy have great potential but are currently not recommended for early detection of colonic neoplasia.

[Criteria for radiological assessment of therapy response: criteria-based appraisal]. / Kriterien für die radiologische Beurteilung des Therapieansprechens: Kriterienbasierte Befundung.

Oncologic imaging and reporting are an important part of clinical trials and have to be performed according to standardized criteria that clearly define how certain changes in the size and number of tumorous lesions have to be rated. Knowledge of these criteria is not only crucial when interpreting cases for a clinical trial but may also be used as guidelines for everyday clinical reporting as they aid decision making and can increase the validity of radiologic reporting.This article summarizes the most important and frequently used criteria: the response evaluation criteria in solid tumors (RECIST) criteria which are only used in solid malignancies, the Choi criteria that have been designed for the assessment of gastrointestinal stroma tumors (GIST), and the Cheson criteria that are applied to malignant lymphomas. The compilation of these criteria is designed to be used as a repetitorium for experts and can also serve as training guidelines for junior radiologists who want to become involved in clinical trial reporting.

[Modern imaging of kidney tumors]. / Moderne Bildgebung von Nierentumoren.

If a renal mass is suspected on clinical examination or ultrasound the finding has to be confirmed by cross-sectional imaging. Methods that are used include multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI). Also contrast-enhanced ultrasound has been successfully implemented in renal imaging and now plays a major role in the differentiation of benign from malignant renal masses. In expert hands it can be used to show very faint vascularization and subtle enhancement. The MDCT technique benefits from the recently introduced dual energy technology that allows superior characterization of renal masses in a single-phase examination, thereby greatly reducing radiation exposure. For young patients and persons allergic to iodine MRI should be used and it provides excellent soft tissue contrast and visualizes contrast enhancement kinetics in multiphase examinations.This article aims at giving a comprehensive overview of these different imaging modalities, their clinical indications and contraindications, as well as a description of imaging findings of various renal masses.

[Imaging diagnostics of advanced prostate cancer]. / Bildgebende Diagnostik des fortgeschrittenen Prostatakarzinoms.

The diagnostic approach to prostate cancer is still a big challenge for the treating physician. Regarding an individualized and risk-adapted evaluation of different therapeutic options, precise diagnostic tools are crucial to accurately distinguish between localized and advanced prostate cancer. Imaging of advanced prostate cancer is currently changing due to numerous technical innovations. While choline-based hybrid positron emission tomography-computed tomography (PET/CT) has been established as an important diagnostic tool in clinical imaging of advanced prostate cancer, well-investigated methods, such as magnetic resonance imaging (MRI) and bone scintigraphy are currently expanding the diagnostic potential due to technical improvements. The specific use of imaging for advanced prostate cancer may help to offer the patient a well-tailored oncologic therapy. Further research is needed to evaluate whether this individualized therapy can consistently improve the prognosis of patients suffering from advanced prostate cancer.

[Imaging for diagnostics of urolithiasis including dual-energy CT]. / Bildgebung zur Diagnostik der Urolithiasis einschließlich Dual-Energy-CT.

Patients with stone disease usually present to the urologist with acute colic pain. For the right choice of therapy the diagnosis needs to be confirmed using one of many imaging methods, including ultrasonography, abdominal radiography, intravenous urography, non-contrast-enhanced computed tomography (CT), CT and magnetic resonance imaging (MRI) urography and dual-energy CT. The techniques differ in the availability, diagnostic sensitivity and specificity and level of radiation exposure. Compared to the others dual-energy CT allows distinction between different stone compositions with high accuracy and can affect the choice of therapy. This article on imaging and diagnosis of urolithiasis discusses the different imaging methods and highlights dual-energy CT and its distinctive features.

Dose reduction in oncological staging multidetector CT: effect of iterative reconstruction.

OBJECTIVE: To compare radiation exposure and image quality of oncological staging multidetector CT (MDCT) examinations of the chest, abdomen and pelvis with and without iterative reconstruction (IR). METHODS: 40 patients with known malignancy underwent staging CT examinations at two time points. Both CT scans were performed on the same scanner (SOMATOM® Definition Flash, Siemens Healthcare, Forchheim, Germany). For the baseline scan, the tube current-time product was set to 250 mAs [image reconstruction: filtered back projection (FBP)] and for the follow-up scan to 150 mAs [reconstruction: iterative reconstruction (IR)]. Effective radiation doses were estimated based on dose-length products for both baseline and follow-up. Noise measurements in defined regions were compared for FBP and IR. Images were also subjectively evaluated for image quality by three radiologists with different levels of experience. RESULTS: Dose reduction was 44.4±8.2% for reduced-dose CT scans with IR compared with baseline with FBP. Image noise was not significantly different between images reconstructed with FBP and IR. The subjective quality of standard-dose FBP images and reduced-dose iteratively reconstructed CT images were identical. CONCLUSION: Our results show the dose-reducing potential of IR of CT image data in oncological patients. ADVANCES IN KNOWLEDGE: The algorithm tested in the present scientific study allows a >45% dose reduction at maintained image quality.