Pulmonary neuroendocrine tumours and somatostatin receptor status: an assessment of unlicensed use of somatostatin analogues in the clinical practice.

BACKGROUND: The use of somatostatin analogues (SSAs) has not been formally approved in pulmonary neuroendocrine tumours (NETs) in the absence of positive controlled trials, even though it is recommended as a potential therapeutic option in recent guidelines. PATIENTS AND METHODS: We have assessed the use of SSA in the general practice in Austria by retrospectively analysing patients with pulmonary NETs referred to our European Neuroendocrine Tumor Society centre in Vienna for second opinion or further therapy. In addition, we have analysed the somatostatin receptor (SSTR) expression of those patients by immunohistochemistry (IHC) and SSTR imaging, e.g. 68Ga-DOTANOC-positron emission tomography/computed tomography, and whether such analyses had been carried out before referral at our centre. RESULTS: Out of 34 patients (19 atypical and 15 typical carcinoids) with metastatic or advanced disease, 10/34 (29%) had been prescribed SSA before referral. No IHC for SSTR had been carried out, and only 9/34 (27%) had undergone SSTR imaging by nuclear medicine. Sufficient material for IHC was available in 29/34 (85%) patients and SSTR-IHC was rated negative in 13/29 (45%), weakly positive in 4/29 (14%), moderately positive in 5/29 (17%) and strongly positive in 7/29 (24%) patients. On SSTR imaging, 8/34 patients (24%) were positive, 13/34 (38%) negative and 13/34 patients (38%) showed a mix of positive and negative NET lesions. In 11/29 (38%) patients with both IHC and imaging available, discordance of SSTR expression on imaging and histological assessment was detected. CONCLUSIONS: These data show that uncritical use of SSA should be discouraged, and assessment of SSTR, preferably by imaging, is mandatory before prescription of SSA in pulmonary NETs.

KRAS mutation effects on the 2-[18F]FDG PET uptake of colorectal adenocarcinoma metastases in the liver.

BACKGROUND: Deriving individual tumor genomic characteristics from patient imaging analysis is desirable. We explore the predictive value of 2-[18F]FDG uptake with regard to the KRAS mutational status of colorectal adenocarcinoma liver metastases (CLM). METHODS: 2-[18F]FDG PET/CT images, surgical pathology and molecular diagnostic reports of 37 patients who underwent PET/CT-guided biopsy of CLM were reviewed under an IRB-approved retrospective research protocol. Sixty CLM in 39 interventional PET scans of the 37 patients were segmented using two different auto-segmentation tools implemented in different commercially available software packages. PET standard uptake values (SUV) were corrected for: (1) partial volume effect (PVE) using cold wall-corrected contrast recovery coefficients derived from phantom spheres with variable diameter and (2) variability of arterial tracer supply and variability of uptake time after injection until start of PET scan derived from the tumor-to-blood standard uptake ratio (SUR) approach. The correlations between the KRAS mutational status and the mean, peak and maximum SUV were investigated using Student's t test, Wilcoxon rank sum test with continuity correction, logistic regression and receiver operation characteristic (ROC) analysis. These correlation analyses were also performed for the ratios of the mean, peak and maximum tumor uptake to the mean blood activity concentration at the time of scan: SURMEAN, SURPEAK and SURMAX, respectively. RESULTS: Fifteen patients harbored KRAS missense mutations (KRAS+), while another 3 harbored KRAS gene amplification. For 31 lesions, the mutational status was derived from the PET/CT-guided biopsy. The Student's t test p values for separating KRAS mutant cases decreased after applying PVE correction to all uptake metrics of each lesion and when applying correction for uptake time variability to the SUR metrics. The observed correlations were strongest when both corrections were applied to SURMAX and when the patients harboring gene amplification were grouped with the wild type: p ≤ 0.001; ROC area under the curve = 0.77 and 0.75 for the two different segmentations, respectively, with a mean specificity of 0.69 and sensitivity of 0.85. CONCLUSION: The correlations observed after applying the described corrections show potential for assigning probabilities for the KRAS missense mutation status in CLM using 2-[18F]FDG PET images.

[Hemato-oncological imaging : Importance of hybrid procedures]. / Hämatoonkologische Bildgebung : Stellenwert der Hybridverfahren.

CLINICAL/METHODICAL ISSUE: Biomedical imaging procedures play a major role in hemato-oncological diseases with respect to pre-therapeutic staging and assessment of treatment response. STANDARD RADIOLOGICAL METHODS: Originally, the therapeutic management was the domain of computed tomography (CT) and whole-body magnetic resonance imaging (MRI). METHODICAL INNOVATIONS: Over the last decade these purely morphological techniques have gradually been replaced by hybrid imaging techniques, such as positron emission tomography-CT (PET/CT) and PET/MRI, which also provide metabolic and functional information. PERFORMANCE: For lymphomas, the PET tracer 18F-fluorodeoxyglucose (18 F-FDG) is meanwhile so well-established that its use is a cornerstone of the Lugano classification; however, for multiple myeloma the search for an optimal PET tracer that can also detect early disease stages is still ongoing. Functional MRI techniques, such as diffusion-weighted imaging (DWI), perfusion-weighted imaging and dynamic contrast-enhanced imaging have shown promising results for both lymphomas and multiple myelomas. ACHIEVEMENTS: The PET/MRI technique can combine the different types of information due to its truly multiparametric approach. PRACTICAL RECOMMENDATIONS: In the future PET/MRI could possibly become the hybrid imaging technique of choice for hemato-oncological diseases.

Texture-Based Analysis of 100 MR Examinations of Head and Neck Tumors - Is It Possible to Discriminate Between Benign and Malignant Masses in a Multicenter Trial?

AIM: To evaluate whether texture-based analysis of standard MRI sequences can help in the discrimination between benign and malignant head and neck tumors. MATERIALS AND METHODS: The MR images of 100 patients with a histologically clarified head or neck mass, from two different institutions, were analyzed. Texture-based analysis was performed using texture analysis software, with region of interest measurements for 2 D and 3 D evaluation independently for all axial sequences. COC, RUN, GRA, ARM, and WAV features were calculated for all ROIs. 10 texture feature subsets were used for a linear discriminant analysis, in combination with k-nearest-neighbor classification. Benign and malignant tumors were compared with regard to texture-based values. RESULTS: There were differences in the images from different field-strength scanners, as well as from different vendors. For the differentiation of benign and malignant tumors, we found differences on STIR and T2-weighted images for 2 D, and on contrast-enhanced T1-TSE with fat saturation for 3 D evaluation. In a separate analysis of the subgroups 1.5 and 3 Tesla, more discriminating features were found. CONCLUSION: Texture-based analysis is a useful tool in the discrimination of benign and malignant tumors when performed on one scanner with the same protocol. We cannot recommend this technique for the use of multicenter studies with clinical data. KEY POINTS: 2 D/3 D texture-based analysis can be performed in head and neck tumors. Texture-based analysis can differentiate between benign and malignant masses. Analyzed MR images should originate from one scanner with an identical protocol.

[Tumor boards: why they are necessary and which structure is needed]. / Tumorboards: Warum wir sie brauchen und welche Ausstattung nötig ist.

This review article gives a detailed overview regarding the growing importance of tumor boards in the daily clinical life. Improved diagnostic and therapeutic options for oncologic diseases lead to an increased complexity in patient management, which can only be handled optimally by a team of specialists. Within this process radiology as a specialty is of growing importance and constitutes the core in the diagnostic algorithm. Radiology is necessary for optimal tumor staging. In summary, there is a growing importance of tumor boards in the management of oncologic diseases and radiologists are a key factor in this process.

[Oncologic imaging: indications for and limitations of modern cross-sectional imaging techniques]. / Bildgebende Methoden in der onkologischen Diagnostik: Indikationen und Limitationen moderner Schnittbildverfahren.

Cross-sectional imaging techniques, such as computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) CT are an integral part of the modern oncological workup. They are used for tumor detection and staging as well as for treatment evaluation and monitoring. Due to pathophysiological and histological differences there is no universal imaging protocol for the assessment of different forms of cancer. For instance, CT is still the standard technique for the detection and staging of lung cancer supplemented by PET which aids the exclusion of nodal involvement and the detection of distant metastases. For hepatocellular carcinoma on the other hand, MRI is the preferred imaging technique, particularly when used in conjunction with liver-specific contrast media - PET/CT is only of limited value. Finally, for neuroendocrine tumors there is a focus on special radiotracers, which, in the context of PET/CT, enable a highly specific whole-body assessment. Thus, knowledge of the pathophysiological and imaging characteristics of different tumors is essential for a personalized, state-of-the art management of oncology patients.

Evaluation of native hyaline cartilage and repair tissue after two cartilage repair surgery techniques with 23Na MR imaging at 7 T: initial experience.

OBJECTIVE: To compare the sodium normalized mean signal intensity (NMSI) values between patients after bone marrow stimulation (BMS) and matrix-associated autologous chondrocyte transplantation (MACT) cartilage repair procedures. METHODS: Nine BMS and nine MACT patients were included. Each BMS patient was matched with one MACT patient according to age [BMS 36.7 ± 10.7 (mean ± standard deviation) years; MACT 36.9 ± 10.0 years], postoperative interval (BMS 33.5 ± 25.3 months; MACT 33.2 ± 25.7 months), and defect location. All magnetic resonance imaging (MRI) measurements were performed on a 7 T system. Proton images served for morphological evaluation of repair tissue using the magnetic resonance observation of cartilage repair tissue (MOCART) scoring system. Sodium NMSI values in the repair area and morphologically normal cartilage were calculated. Clinical outcome was assessed right after MRI. Analysis of covariance, t-tests, and Pearson correlation coefficients were evaluated. RESULTS: Sodium NMSI was significantly lower in BMS (P = 0.004) and MACT (P = 0.006) repair tissue, compared to reference cartilage. Sodium NMSI was not different between the reference cartilage in MACT and BMS patients (P = 0.664), however it was significantly higher in MACT than in BMS repair tissue (P = 0.028). Better clinical outcome was observed in BMS than in MACT patients. There was no difference between MOCART scores for MACT and BMS patients (P = 0.915). We did not observe any significant correlation between MOCART score and sodium repair tissue NMSI (r = -0.001; P = 0.996). CONCLUSIONS: Our results suggest higher glycosaminoglycan (GAG) content, and therefore, repair tissue of better quality in MACT than in BMS patients. Sodium imaging might be beneficial in non-invasive evaluation of cartilage repair surgery efficacy.

[Imaging of hip joint arthroplasty]. / Bildgebung bei Hüftgelenkendoprothesen.

The hip joint is the largest joint in the human body and consequently, its evaluation by diagnostic imaging is highly important. This includes imaging of hip joint arthroplasty, which is used to avoid joint immobility following a wide spectrum of diseases, such as end-stage degenerative disease, avascular necrosis of the femoral head or post-traumatic fractures. Conventional radiography is still the standard imaging modality for the evaluation of hip arthroplasty both directly following surgery and for periodical follow-up. In the majority of cases conventional radiography enables adequate assessment of early and late complications that can arise following hip arthroplasty, such as loosening, prosthetic or periprosthetic fracture, luxation, infection and soft tissue calcification. If the diagnosis cannot be established by means of radiography, advanced imaging methods such as computed tomography (CT) and magnetic resonance imaging (MRI), with or without injection of contrast media, may provide additional information. This is particularly true for the depiction of inflammatory processes. Regardless of the imaging modality used patients' clinical symptoms must also be taken into account in order to establish the correct diagnosis.

Short-term outcome of painful bone marrow oedema of the knee following oral treatment with iloprost or tramadol: results of an exploratory phase II study of 41 patients.

OBJECTIVES: To compare the therapeutic effects of oral iloprost and tramadol on the outcome of bone marrow oedema (BME) of the knee by MR imaging and clinical assessment. METHODS: Forty-one patients with painful ischemic or mechanical BME of the knee were enrolled in a double-blind, randomized controlled study. Patients were randomized either to iloprost (n = 21, group 1) or tramadol (n = 20, group 2). The treatment duration was 4 weeks. The Larson knee score was used to assess function before treatment and then 3 days, 1, 2, 3, 4 weeks and 3 months after the start of treatment. Short tau inversion recovery and T1-weighted MR images of the affected knees were obtained before and 3 months after the start of treatment. Bone marrow oedema was assessed visually and by computer-assisted quantification for baseline and follow-up MR examinations. RESULTS: Thirty-three patients completed the study as scheduled. The mean Larson score improved from 58.6 points to 81.8 points in group 1, and from 59.6 points to 86.8 points in group 2, after 3 months (no significant difference between the treatment groups). On MR images, complete BME regression in at least one bone was observed in nine patients (52.9%) in group 1, as opposed to three patients (18.7%) in group 2, after 3 months (P = 0.034). Correspondingly, the median BME volume decreased by 58.0% in group 1, and by 47.5% in group 2. CONCLUSIONS: The analgesic effect of iloprost and tramadol was similar. BME regression on MR images was more pronounced under iloprost treatment.

[Differential diagnosis of bone marrow edema of the knee joint]. / Differenzialdiagnosen des Knochenmarködems am Kniegelenk.

Bone marrow edema of the knee joint is a frequent clinical picture in MR diagnostics. It can be accompanied by symptoms and pain in the joint. Diseases that are associated with bone marrow edema can be classified into different groups. Group 1 includes vascular ischemic bone marrow edema with osteonecrosis (synonyms: SONK or Ahlbäck's disease), osteochondrosis dissecans, and bone marrow edema syndrome. Group 2 comprises traumatic or mechanical bone marrow edema. Group 3 encompasses reactive bone marrow edemas such as those occurring in gonarthrosis, postoperative bone marrow edemas, and reactive edemas in tumors or tumor-like diseases. Evidence for bone marrow edema is effectively provided by MRI, but purely morphological MR information is often unspecific so that anamnestic and clinical details are necessary in most cases for definitive disease classification.