Advanced hepatocellular carcinoma and sorafenib: Diagnosis, indications, clinical and radiological follow-up.

Advanced stage hepatocellular carcinoma (HCC) is a category of disease defined by radiological, clinical and hepatic function parameters, comprehending a wide range of patients with different general conditions. The main therapeutic option is represented by sorafenib treatment, a multi-kinase inhibitor with anti-proliferative and anti-angiogenic effect. Trans-arterial Radio Embolization also represents a promising new approach to intermediate/advanced HCC. Post-marketing clinical studies showed that only a portion of patients actually benefits from sorafenib treatment, and an even smaller percentage of patients treated shows partial/complete response on follow-up examinations, up against relevant costs and an incidence of drug related adverse effects. Although the treatment with sorafenib has shown a significant increase in mean overall survival in different studies, only a part of patients actually shows real benefits, while the incidence of drug related significant adverse effects and the economic costs are relatively high. Moreover, only a small percentage of patients also shows a response in terms of lesion dimensions reduction. Being able to properly differentiate patients who are responding to the therapy from non-responders as early as possible is then still difficult and could be a pivotal challenge for the future; in fact it could spare several patients a therapy often difficult to bear, directing them to other second line treatments (many of which are at the moment still under investigation). For this reason, some supplemental criteria to be added to the standard modified Response Evaluation Criteria in Solid Tumors evaluation are being searched for. In particular, finding some parameters (cellular density, perfusion grade and enhancement rate) able to predict the sensitivity of the lesions to anti-angiogenic agents could help in stratifying patients in terms of treatment responsiveness before the beginning of the therapy itself, or in the first weeks of sorafenib treatment. This would bring a strongly desirable help in clinical managements of these patients.

Assessment of Liver Perfusion by IntraVoxel Incoherent Motion (IVIM) Magnetic Resonance-Diffusion-Weighted Imaging: Correlation With Phase-Contrast Portal Venous Flow Measurements.

OBJECTIVES: To prospectively verify, in vivo, Le Bihan's model of signal decay in magnetic resonance/diffusion-weighted imaging (intravoxel incoherent motion) in healthy liver parenchyma. METHODS: Informed consent and institutional board approval were obtained. To measure both underfasting and postprandial conditions, apparent, slow, and fast diffusion (D*) coefficients and perfusion fraction of liver parenchyma, 40 healthy volunteers (19 women and 21 men) underwent a 3.0-T magnetic resonance imaging examination, including portal venous flow measurements by a 2-dimensional phase-contrast sequence, and multi-b diffusion-weighted imaging acquired before and 30 minutes after a 600-Kcal meal. Parameters were measured by fitting procedure with regions of interest drawn on the right liver lobe. Paired-sample t test was performed to search for any statistically significant difference between preprandial and postprandial values of each parameter and of portal flow. Pearson correlation coefficients were calculated to evaluate the relationship between portal flow increase and diffusion-weighted imaging parameter changes in postprandial conditions. Interobserver agreement for measurement of the intravoxel incoherent motion parameters was determined, both for preprandial and postprandial values. RESULTS: Mean increase in postprandial portal flow was 98% (P < 0.0009). The t test did not show any statistically significant difference between the preprandial and postprandial values for apparent, slow diffusion coefficients and perfusion fraction (P ≥ 0.05), whereas a statistically significant postprandial increase (P < 0.01) of D* was detected. Correlation with portal venous flow increase at Pearson test was statistically significant for D* (P = 0.04) and nonsignificant for the other parameters. All the parameters showed wide variability, with a higher percent coefficient of variation for D*. Interobserver agreement was always greater than 0.70. CONCLUSIONS: This study verifies Le Bihan's theory, confirming that in the liver, D* is influenced by perfusional changes related to portal venous flow.

Metal and motion artifacts by cone beam computed tomography (CBCT) in dental and maxillofacial study.

OBJECTIVES: This study aimed at evaluating incidence/degree of metal/motion artifacts and CT-dose-index in oral/maxillofacial examinations using Cone-Beam-CT. METHODS: Interferences caused by metal and motion artifacts were evaluated in 500 patients aged from 6 to 81 years, in dental arches, maxillofacial and splanchocranium Cone-Beam-CT exams. The interferences was divided into four progressive degrees (G0-G3) related to the possibility to answer the clinical query. The parameters considered were field-of-view, scan time, patient's age, and anatomical area. Furthermore volumetric CT-dose-index was measured. RESULTS: In the presence of metal artifacts the clinical query was always answered (G3 = 0). No artifacts (G0) were found in all cases when metal was beyond 5 cm from interest site and in 18.4% when metal was inside this distance. Beam hardening and photon starvation due to implants, restoration and orthodontic therapies achieved 56.2% G1 and 25.4% G2. Motion artifacts were more frequent in under ten (31.5%) and over sixty (82.2%), and in mandible analysis (inferior arch 59.5%, both arches 47.3%). Moreover, their incidence and intensity were influenced by scan time (49.1% at 36 s) but not by field-of-view. Mean volumetric CT-dose-index of all patients was mGy 9.11 (mGy 3.62, 5.78, 8.89, and 13.07 at 18, 24, 26, and 36 s, respectively). CONCLUSIONS: In our series Cone-Beam-CT diagnostic evaluation was never inhibited by metal artifacts and only in 1.9% of the cases by motion artifacts, always with a very low CT-dose-index.

Focal liver lesion classification and characterization in noncirrhotic liver: a prospective comparison of diffusion-weighted magnetic resonance-related parameters.

PURPOSE: The objective of this study was to prospectively verify if diffusion-weighted magnetic resonance (DwMR)-related parameters such as perfusion fraction (f) and slow diffusion coefficient (D), according to Le Bihan theory, are more effective than apparent diffusion coefficient (ADC) for classification and characterization of the more frequent focal liver lesions (FLLs) in noncirrhotic liver. METHODS: Sixty-seven patients underwent standard liver magnetic resonance imaging (MRI) and free-breath multi-b DwMR study. Two regions of interest were defined by 2 observers, including 1 FLL for each patient (21 hemangiomas, 21 focal nodular hyperplasias, 25 metastases) and part of surrounding parenchyma, respectively. For every FLL, D, f, and ADC were estimated both as absolute value and as ratio between FLL and surrounding parenchyma by fitting the reduced equation of the bicompartmental model to experimental data; t test, analysis of variance, and receiver operating characteristic analysis were performed. RESULTS: t Test showed significant differences in ADClesion, f lesion, D lesion, ADCratio, and D ratio values between benign and malignant FLLs, more pronounced for ADClesion (P < 0.0009) and ADCratio (P = 0.001). Applying cutoff values of 1.55 × 10 mm/s (ADClesion) and 0.89 (ADCratio), the DwMR study presented sensitivities and specificities, respectively, of 84% and 80% (for ADClesion), 72% and 80% (ADCratio). CONCLUSIONS: Apparent diffusion coefficient (by fitting procedures) better performs than do D and f in FLL classification, especially when its values are less than 1.30 or greater than 2.00 × 10 mm/s.