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Clinical/methodical Issue: Gastroenteropancreatic neuroendocrine tumors (GEP-NET) are a rare, heterogeneous group of neoplasms. Only 2% of gastrointestinal tumors belong to the group of neuroendocrine neoplasms., Standard Radiological Methods: A wide spectrum of diagnostic imaging modalities is available: apart from ultrasound not only computed tomography (CT) but also magnetic resonance imaging (MRI) and positron emission tomography CT (PET-CT) play an important role in detection and staging of GEP-NETs., Methodical Innovations: The PET-CT technique with somatostatin analogues is used for staging as well as for evaluation and monitoring of treatment with peptide radionuclide radiation therapy., Performance: According to the literature NETs of the small bowel with a size over 3 cm can be detected with a sensitivity of 84.7% and a specificity of 96.6% using CT enteroclysis and MR enteroclysis provides the detection of NETs of the small bowel in 93.3% of cases. 'The sensitivity of MRI in detection of pancreatic NETs is between 74% and 100% and is, therefore, higher than CT. Detection of small primary tumors is carried out using PET-CT and seems to be the most sensitive imaging modality to identify the exact location. On the other hand MRI has to be regarded as the best imaging modality for detection of liver metastases compared to CT and PET-CT., Achievements: The role of diagnostic imaging is to identify the exact location of the primary tumor and possible metastases, to define an appropriate therapy and to monitor treatment effects; however, the choice of the most appropriate diagnostic imaging modality varies depending on the location and type of the primary tumor., Practical Recommendations: The GEP-NETs are predominantly well-vascularized; therefore, dual-phase CT/MR imaging with the arterial and venous phases after contrast media injection is mandatory for detection and localization of primary tumors and metastases. For whole body staging CT and PET-CT should be performed.

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.

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.

Soft tissue sarcomas are rare malignant neoplasms accounting for only 1% of malignant tumors in adults. Complete surgical resection of tumors is the key to therapeutic success. Indications for adjuvant radiation therapy vary according to the lesion grade. Comprehensive diagnostic imaging significantly contributes to successful preoperative planning procedures. Besides morphological imaging, functional imaging strategies will have an increasing impact on individual risk assessment and contribute to optimized, non-invasive treatment response monitoring.

Clinical/methodical Issue: Modern radiotherapy benefits from precise and targeted diagnostic and pretherapeutic imaging., Standard Radiological Methods: Standard imaging modalities, such as computed tomography (CT) offer high morphological detail but only limited functional information on tumors., Methodical Innovations: Novel functional and molecular imaging modalities provide biological information about tumors in addition to detailed morphological information., Performance: Perfusion magnetic resonance imaging (MRI) CT or ultrasound-based perfusion imaging as well as hybrid modalities, such as positron emission tomography (PET) CT or MRI-PET have the potential to identify and precisely delineate viable and/or perfused tumor areas, enabling optimization of targeted radiotherapy. Functional information on tissue microcirculation and/or glucose metabolism allow a more precise definition and treatment of tumors while reducing the radiation dose and sparing the surrounding healthy tissue., Achievements: In the development of new imaging methods for planning individualized radiotherapy, preclinical imaging and research plays a pivotal role, as the value of multimodality imaging can only be assessed, tested and adequately developed in a preclinical setting, i.e. in animal tumor models., Practical Recommendations: New functional imaging modalities will play an increasing role for the surveillance of early treatment response during radiation therapy and in the assessment of the potential value of new combination therapies (e.g. combining anti-angiogenic drugs with radiotherapy).

Obesity is an increasing problem faced by the healthcare system. In managing obesity, bariatric surgery is becoming more important with evidence showing a reduction in long-term morbidity and mortality. There are special challenges faced by the radiology department in providing an imaging service for this population of patients, from technical requirements through to the interpretation of post-surgical images. This article provides an overview of the most frequently performed procedures, normal postoperative imaging findings and the appearance of common complications.

Acute intestinal inflammation is common. In most cases the medical history, clinical investigations and laboratory parameters alone are not sufficient for a conclusive diagnosis because of the wide variety of differential diagnoses and the striking similarity of symptoms. Modern imaging methods can help to clarify the diagnosis and multi-slice CT (MSCT) is highly useful in this diagnostic dilemma. It is widely available, employs standardized protocols, is cost-effective and can be performed within an acceptable examination time. MSCT enables the location and extension of the underlying pathology to be assessed and detection of complications which require immediate therapeutic intervention.

Soft tissue sarcomas are rare malignant neoplasms accounting for only 1% of malignant tumors in adults. Complete surgical resection of the tumor is key for therapeutic success. Comprehensive diagnostic imaging significantly contributes to adequate preoperative planning. With effective targeted molecular pharmacotherapies entering the clinical scenario, functional imaging strategies will have a significant effect on individual risk assessment and will contribute to optimized, noninvasive treatment response monitoring.

Selective internal radiation therapy (SIRT) is used for the treatment of patients with liver tumors, especially for those with hepatocellular carcinoma (HCC) or liver metastases from various primary tumors. Currently this innovative treatment concept is recommended when established state-of-the-art treatment regimes have failed and tumor progression is noted or if the treatment has to be abandoned because of intolerable toxic effects. For SIRT small biocompatible microspheres (SIR-Spheres(R)) are labelled with the radioactive isotope 90Yttrium, a pure beta emitter, and are superselectively infused into the hepatic arteries. The microspheres are collected in the precapillary vessels in and surrounding the tumor. The beta radiation of 90Yttrium has an average penetration in tissue of approximately 2.5 mm and results in very high doses of radiation being selectively targeted to metastases providing protection to the surrounding healthy liver tissue. In this paper we review the results of SIRT in patients with hepatic metastases from colorectal cancer, breast cancer, neuroendocrine tumors and primary liver cancer (HCC).

Only 1-2 % of all pediatric tumors occur in the liver. Two thirds of these tumors are malignant and almost all of the tumors cause clinical symptoms due to their mass effects. Besides the poor prognosis in most of the malignant tumors, for further treatment the origin and nature of the neoplasm has to be known. Due to the mostly unimpeded growth into the peritoneal cavity, the origin of the tumors is primarily often unclear and can non-invasively only be determined by advanced imaging techniques. The display of the macro- and microhistological key features of primary pediatric liver neoplasms, including hepatoblastoma (HB), infantile hemangioendothelioma (IHE), mesenchymal hamartoma (MH), undifferentiated (embryonal) sarcoma (UES), and hepatocellular carcinoma (HCC), together with their imaging representation by ultrasound, computed tomography, and magnetic resonance imaging, may deepen the understanding of the underlying pathology and its imaging appearance. Furthermore, in many cases sufficient information may be provided not only to differentiate benign from malignant tumors, but also to guide for adequate treatment.

Purpose: To evaluate the different ultrasound techniques for quantification of contrast enhanced ultrasound (CEUS) in an experimental rat prostate carcinoma model. Method and materials: Prostate carcinoma (MLLB-2) cells were subcutaneously injected into the right flank of male rat (Charles River, Sulzfeld, Germany, 180 to 220 g body weight). Following 18 days of subcutaneous tumor growth 9 rats underwent CEUS examination. Real time CEUS was performed after a bolus injection of SonoVue (0.2 ml, Bracco, Italy) via the lateral tail vein using a high end ultrasound system (Siemens Sequoia 512®/Acuson, Mountain View) with an 15 Mhz probe. Two different CEUS techniques, pure contrast (pc) and contrast with background (cbg) examination, were analyzed (CPS-software). Exported signal intensity (SI)-time curves and the normalized area under the curve (AUC) for the active tumor tissue, whole tumor and necrosis were compared. Results: The mean normalized AUC for the active tumor tissue and the whole tumor was 0.84 and 0.5 in the pure contrast examination group and 0.49 and 0.3 for the contrast examination with background signal. Therefore the signal intensity of the pc group was in every examination significant higher than of the cbg group (p < 0.02). The advantage of using the additional background information is to detect the anatomic landmarks in the solid tumor model in comparison to the pure contrast enhanced ultrasound examination. Conclusion: The complete extension of the tumor is much easier to detect with the cbg technique due to orientation of the anatomic landmarks. As the signal intensity of the pc group is always significant higher we recommend this technique for quantification of contrast enhanced ultrasound, especially for the follow up of tumor microcirculation. [ABSTRACT FROM AUTHOR]

The purpose of the study was to evaluate observer performance in the detection of pneumothorax with cesium iodide and amorphous silicon flat-panel detector radiography (CsI/a-Si FDR) presented as 1K and 3K soft-copy images. Forty patients with and 40 patients without pneumothorax diagnosed on previous and subsequent digital storage phosphor radiography (SPR, gold standard) had follow-up chest radiographs with CsI/a-Si FDR. Four observers confirmed or excluded the diagnosis of pneumothorax according to a five-point scale first on the 1K soft-copy image and then with help of 3K zoom function (1K monitor). Receiver operating characteristic (ROC) analysis was performed for each modality (1K and 3K). The area under the curve (AUC) values for each observer were 0.7815, 0.7779, 0.7946 and 0.7066 with 1K-matrix soft copies and 0.8123, 0.7997, 0.8078 and 0.7522 with 3K zoom. Overall detection of pneumothorax was better with 3K zoom. Differences between the two display methods were not statistically significant in 3 of 4 observers (p-values between 0.13 and 0.44; observer 4: p = 0.02). The detection of pneumothorax with 3K zoom is better than with 1K soft copy but not at a statistically significant level. Differences between both display methods may be subtle. Still, our results indicate that 3K zoom should be employed in clinical practice. [ABSTRACT FROM AUTHOR]