Multiparametric MRI for assessment of early response to neoadjuvant sunitinib in renal cell carcinoma

Purpose To detect early response to sunitinib treatment in metastatic clear cell renal cancer (mRCC) using multiparametric MRI. Method Participants with mRCC undergoing pre-surgical sunitinib therapy in the prospective NeoSun clinical trial (EudraCtNo: 2005-004502-82) were imaged before starting treatment, and after 12 days of sunitinib therapy using morphological MRI sequences, advanced diffusion-weighted imaging, measurements of R2* (related to hypoxia) and dynamic contrast-enhanced imaging. Following nephrectomy, participants continued treatment and were followed-up with contrast-enhanced CT. Changes in imaging parameters before and after sunitinib were assessed with the non-parametric Wilcoxon signed-rank test and the log-rank test was used to assess effects on survival. Results 12 participants fulfilled the inclusion criteria. After 12 days, the solid and necrotic tumor volumes decreased by 28% and 17%, respectively (p = 0.04). However, tumor-volume reduction did not correlate with progression-free or overall survival (PFS/OS). Sunitinib therapy resulted in a reduction in median solid tumor diffusivity D from 1298x10-6 to 1200x10-6mm2/ s (p = 0.03); a larger decrease was associated with a better RECIST response (p = 0.02) and longer PFS (p = 0.03) on the log-rank test. An increase in R2* from 19 to 28s-1 (p = 0.001) was observed, paralleled by a decrease in Ktrans from 0.415 to 0.305min-1 (p = 0.01) and a decrease in perfusion fraction from 0.34 to 0.19 (p<0.001). Conclusions Physiological imaging confirmed efficacy of the anti-angiogenic agent 12 days after initiating therapy and demonstrated response to treatment. The change in diffusivity shortly after starting pre-surgical sunitinib correlated to PFS in mRCC undergoing nephrectomy, however, no parameter predicted OS

Correlating Radiomic Features of Heterogeneity on CT with Circulating Tumor DNA in Metastatic Melanoma

Clinical imaging methods, such as computed tomography (CT), are used for routine tumor response monitoring. Imaging can also reveal intratumoral, intermetastatic, and interpatient heterogeneity, which can be quantified using radiomics. Circulating tumor DNA (ctDNA) in the plasma is a sensitive and specific biomarker for response monitoring. Here we evaluated the interrelationship between circulating tumor DNA mutant allele fraction (ctDNAmaf), obtained by targeted amplicon sequencing and shallow whole genome sequencing, and radiomic measurements of CT heterogeneity in patients with stage IV melanoma. ctDNAmaf and radiomic observations were obtained from 15 patients with a total of 70 CT examinations acquired as part of a prospective trial. 26 of 39 radiomic features showed a significant relationship with log(ctDNAmaf). Principal component analysis was used to define a radiomics signature that predicted ctDNAmaf independent of lesion volume. This radiomics signature and serum lactate dehydrogenase were independent predictors of ctDNAmaf. Together, these results suggest that radiomic features and ctDNAmaf may serve as complementary clinical tools for treatment monitoring

Imaging techniques in ALS

Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease characterized by degeneration of both upper and lower motor neuron located in the spinal cord and brainstem. Diagnosis of ALS is predominantly clinical, nevertheless, electromyography and Magnetic Resonance Imaging (MRI) may provide support. Several advanced MRI techniques have been proven useful for ALS diagnosis and, indeed, the combination of different MRI techniques demonstrated an improvement in sensitivity and specificity as far as 90%. This review focus on the imaging techniques currently used in the diagnosis and management of ALS with brief considerations on future applications

Ossification of the pterygoalar and pterygospinous ligaments: a computed tomography analysis of infratemporal fossa anatomical variants relevant to percutaneous trigeminal rhizotomy.

OBJECTIVE: Ossification of pterygoalar and pterygospinous ligaments traversing the superior aspect of the infratemporal fossa results in formation of osseous bars that can obstruct percutaneous needle access to the trigeminal ganglion through the foramen ovale (FO), interfere with lateral mandibular nerve block, and impede transzygomatic surgical approaches. Presence of these ligaments has been studied on dry skulls, but description of their radiological anatomy is scarce, in particular on cross-sectional imaging. The aim of this study was to describe visualization of pterygoalar and pterygospinous bars on computed tomography (CT) and to review their prevalence and clinical significance. METHODS: The authors retrospectively reviewed 200 helical sinonasal CT scans by analyzing 0.75- to 1.0-mm axial images, maximum intensity projection (MIP) reconstructions, and volume rendered (VR) images, including views along the anticipated axis of the needle in percutaneous Hartel and submandibular approaches to the FO. RESULTS: Ossified pterygoalar and pterygospinous ligaments were readily identifiable on CT scans. An ossified pterygoalar ligament was demonstrated in 10 patients, including 1 individual with bilateral complete ossification (0.5%), 4 patients with unilateral complete ossification (2.0%), and 5 with incomplete unilateral ossification (2.5%). Nearly all patients with pterygoalar bars were male (90%, p < 0.01). An ossified pterygospinous ligament was seen in 35 patients, including 2 individuals with bilateral complete (1.0%), 8 with unilateral complete (4%), 8 with bilateral incomplete (4.0%), 12 with bilateral incomplete (6.0%) ossification, and 5 (2.5%) with mixed ossification (complete on one side and incomplete on the contralateral side). All pterygoalar bars interfered with a hypothetical needle access to the FO using the Hartel approach but not the submandibular approach. In contrast, 54% of complete and 24% of incomplete pterygospinous bars impeded the submandibular approach to the FO, without affecting the Hartel approach. CONCLUSIONS: This study provides the first detailed description of cross-sectional radiological and applied surgical anatomy of pterygoalar and pterygospinous bars. Our data are clinically useful during skull base imaging to predict potential obstacles to percutaneous cannulation of the FO and assist in the choice of approach, as these two variants differentially impede the Hartel and submandibular access routes. Our results can also be useful in planning surgical approaches to the skull base through the infratemporal fossa