Treatment outcome with mTOR inhibitors for metastatic renal cell carcinoma with nonclear and sarcomatoid histologies.

BACKGROUND: The clinical trials that reported benefit of the rapalogs temsirolimus and everolimus in advanced renal cell carcinoma (RCC) were primarily conducted in patients with clear-cell histology (ccRCC). We assessed outcome with these mammalian target of rapamicin (mTOR) inhibitors in two subsets of kidney cancer: sarcomatoid variant ccRCC and nonclear-cell RCC. PATIENTS AND METHODS: Baseline clinical features, information on prior treatment, and histologic subtypes were collected for patients previously treated with rapalogs for metastatic RCC of either nonclear phenotype or ccRCC with sarcomatoid features. Outcome was assessed centrally by a dedicated research radiologist for determination of tumor response, progression-free survival (PFS), and overall survival (OS). RESULTS: Eighty-five patients received temsirolimus (n = 59) or everolimus (n = 26). Nonclear-cell phenotypes included papillary (n = 14), chromophobe (n = 9), collecting duct (n = 4), translocation-associated (n = 3), and unclassified (n = 32) RCC. Twenty-three patients had clear-cell histology with sarcomatoid features. The response rate in assessable patients (n = 82) was 7% (all partial responses); 49% of patients achieved stable disease, and 44% had progressive disease as their best response. Tumor shrinkage was observed in 26 patients (32%). Median PFS and OS were 2.9 and 8.7 months, respectively. Nine patients (11%) were treated for ≥1 year, including cases of papillary (n = 3), chromophobe (n = 2), unclassified (n = 3) RCC, and ccRCC with sarcomatoid features (n = 1). No tumor shrinkages were observed for patients with collecting duct or translocation-associated RCC. CONCLUSIONS: A subset of patients with nonclear-cell and sarcomatoid variant ccRCC subtypes benefit from mTOR inhibitors, but most have poor outcome. Histologic subtype does not appear to be helpful in selecting patients for rapalog therapy. Future efforts should include the identification of predictive tissue biomarkers.

Generic affiliations of Canthium species placed under Pyrostria group B sensu Bridson (Vanguerieae, Rubiaceae) inferred from morphology and molecular data.

BACKGROUND: Pyrostria sensu lato (s.l.) is regarded as one of the polyphyletic group within Vanguerieae formerly comprising of Pyrostria sensu stricto (s.s.), Pyrostria group A and Pyrostria group B delineated by the number of locules and geographical occurrence. Recent molecular phylogenetic studies within the genus have narrowed its circumscription that resulted in the merging of Pyrostria group A and Pyrostria s.s. Although some species of Pyrostria group B were already transferred to Pyrostria s.s. and Psydrax based on morphology, other representatives of the group remain unsettled. RESULTS: Bayesian and parsimony analysis of the combined ITS (nrDNA) and trnL-F (cpDNA) datasets showed a well-supported clade of the whole Vanguerieae containing four Philippine endemic representatives of Pyrostria group B. The placement of Canthium oligophlebium, Canthium obovatifolium and Canthium ramosii within Pyrostria s.s. (PP = 0.99; BS = 85%) is robustly supported likewise the affiliation of C. gynochthodes with Psydrax (PP = 0.94; BS = 85%). Morphological features shared by our species with Pyrostria s.s. and Psydrax further supports our molecular data. CONCLUSION: Our study supports the earlier hypothesis that Canthium oligophlebium, C. obovatifolium and C. ramosii should be placed under Pyrostria s.s. except for C. gynochthodes that grouped with Psydrax. Four new combinations are proposed in this study. The generic affiliations of other species of Pyrostria group B should be reinvestigated towards a more natural classfication in Vanguerieae.

Accuracy of linear intraoral measurements using cone beam CT and multidetector CT: a tale of two CTs.

OBJECTIVES: The aim was to compare the accuracy of linear bone measurements of cone beam CT (CBCT) with multidetector CT (MDCT) and validate intraoral soft-tissue measurements in CBCT. METHODS: Comparable views of CBCT and MDCT were obtained from eight intact cadaveric heads. The anatomical positions of the gingival margin and the buccal alveolar bone ridge were determined. Image measurements (CBCT/MDCT) were performed upon multiplanar reformatted data sets and compared with the anatomical measurements; the number of non-assessable sites (NASs) was evaluated. RESULTS: Radiological measurements were accurate with a mean difference from anatomical measurements of 0.14 mm (CBCT) and 0.23 mm (MDCT). These differences were statistically not significant, but the limits of agreement for bone measurements were broader in MDCT (-1.35 mm; 1.82 mm) than in CBCT (-0.93 mm; 1.21 mm). The limits of agreement for soft-tissue measurements in CBCT were smaller (-0.77 mm; 1.07 mm), indicating a slightly higher accuracy. More NASs occurred in MDCT (14.5%) than in CBCT (8.3%). CONCLUSIONS: CBCT is slightly more reliable for linear measurements than MDCT and less affected by metal artefacts. CBCT accuracy of linear intraoral soft-tissue measurements is similar to the accuracy of bone measurements.

[Cardiac low-dose computed tomography]. / Kardiale Niedrigdosis-Computertomographie.

Cardiac CT has evolved to a robust and accurate imaging modality in the cardiac diagnostic armamentarium. However, technical developments had been accompanied with an overall increase in radiation exposure. In the last years, several technical developments and algorithms aimed at the reduction of radiation exposure in cardiac CT. The most relevant dose reduction strategies will be highlighted in this article including appropriate indications for cardiac CT, different ECG synchronization techniques, reduction of tube voltage, and high-pitch CT studies.

MR/CT image fusion of the spine after spondylodesis: a feasibility study.

The objective of this study is to evaluate feasibility, accuracy and time requirements of MR/CT image fusion of the lumbar spine after spondylodesis. Sagittal MR and CT images derived from standard imaging protocols (sagittal T2-weighted MR/sagittal reformatted multi-planar-reformation of the CT) of the lumbar spine with correct (n = 5) and incorrect (n = 5) implant position were fused by two readers (R1, R2) using OsiriX in two sessions placing one (session 1) or two (session 2) reference point(s) on the dorsal tip(s) of the cranial and caudal endplates from the second lumbar to the first sacral vertebra. R1 was an experienced musculoskeletal radiologist; R2 a spine surgeon, both had received a short training on the software tool. Fusion times and fusion accuracy, defined as the largest deviation between MR and CT in the median sagittal plane on the ventral tip of the cranial end plate of the most cranial vertebra visible on the CT, were measured in both sessions. Correct or incorrect implant position was evaluated upon the fused images for all patients by an experienced senior staff musculoskeletal radiologist. Mean fusion time (session 1/session 2; in seconds) was 100.4/95 (R1) and 104.2/119.8 (R2). Mean fusion deviation (session 1/session 2; in mm) was 1.24/2.20 (R1) and 0.79/1.62 (R2). The correct/incorrect implant position was identified correctly in all cases. In conclusion, MR/CT image fusion of the spine with metallic implants is feasible, fast, accurate and easy to implement in daily routine work.

CT- and MRI-based volumetry of resected liver specimen: comparison to intraoperative volume and weight measurements and calculation of conversion factors.

OBJECTIVE: To compare virtual volume to intraoperative volume and weight measurements of resected liver specimen and calculate appropriate conversion factors to reach better correlation. METHODS: Preoperative (CT-group, n=30; MRI-group, n=30) and postoperative MRI (n=60) imaging was performed in 60 patients undergoing partial liver resection. Intraoperative volume and weight of the resected liver specimen was measured. Virtual volume measurements were performed by two readers (R1,R2) using dedicated software. Conversion factors were calculated. RESULTS: Mean intraoperative resection weight/volume: CT: 855 g/852 mL; MRI: 872 g/860 mL. Virtual resection volume: CT: 960 mL(R1), 982 mL(R2); MRI: 1112 mL(R1), 1115 mL(R2). Strong positive correlation for both readers between intraoperative and virtual measurements, mean of both readers: CT: R=0.88(volume), R=0.89(weight); MRI: R=0.95(volume), R=0.92(weight). Conversion factors: 0.85(CT), 0.78(MRI). CONCLUSION: CT- or MRI-based volumetry of resected liver specimen is accurate and recommended for preoperative planning. A conversion of the result is necessary to improve intraoperative and virtual measurement correlation. We found 0.85 for CT- and 0.78 for MRI-based volumetry the most appropriate conversion factors.

A simple method to approximate liver size on cross-sectional images using living liver models.

AIM: To assess whether a simple. diameter-based formula applicable to cross-sectional images can be used to calculate the total liver volume. MATERIALS AND METHODS: On 119 cross-sectional examinations (62 computed tomography and 57 magnetic resonance imaging) a simple, formula-based method to approximate the liver volume was evaluated. The total liver volume was approximated measuring the largest craniocaudal (cc), ventrodorsal (vd), and coronal (cor) diameters by two readers and implementing the equation: Vol(estimated)=cc x vd x cor x 0.31. Inter-rater reliability, agreement, and correlation between liver volume calculation and virtual liver volumetry were analysed. RESULTS: No significant disagreement between the two readers was found. The formula correlated significantly with the volumetric data (r>0.85, p<0.0001). In 81% of cases the error of the approximated volume was <10% and in 92% of cases <15% compared to the volumetric data. CONCLUSION: Total liver volume can be accurately estimated on cross-sectional images using a simple, diameter-based equation.