Role of MR texture analysis in histological subtyping and grading of renal cell carcinoma: a preliminary study

Purpose

The study evaluated the usefulness of magnetic resonance imaging (MRI) texture parameters in differentiating clear cell renal carcinoma (CC-RCC) from non-clear cell carcinoma (NC-RCC) and in the histological grading of CC-RCC.

Materials and methods

After institutional ethical approval, this retrospective study analyzed 33 patients with 34 RCC masses (29 CC-RCC and five NC-RCC; 19 low-grade and 10 high-grade CC-RCC), who underwent MRI between January 2011 and December 2012 on a 1.5-T scanner (Avanto, Siemens, Erlangen, Germany). The MRI protocol included T2-weighted imaging (T2WI), diffusion-weighted imaging [DWI; at b 0, 500 and 1000 s/mm² with apparent diffusion coefficient (ADC) maps] and T1-weighted pre and postcontrast [corticomedullary (CM) and nephrographic (NG) phase] acquisition. MR texture analysis (MRTA) was performed using the TexRAD research software (Feedback Medical Ltd., Cambridge, UK) by a single reader who placed free-hand polygonal region of interest (ROI) on the slice showing the maximum viable tumor. Filtration histogram-based texture analysis was used to generate six first-order statistical parameters [mean intensity, standard deviation (SD), mean of positive pixels (MPP), entropy, skewness and kurtosis] at five spatial scaling factors (SSF) as well as on the unfiltered image. Mann–Whitney test was used to compare the texture parameters of CC-RCC versus NC-RCC, and high-grade versus low-grade CC-RCC. P value < 0.05 was considered significant. A 3-step feature selection was used to obtain the best texture metrics for each MRI sequence and included the receiver-operating characteristic (ROC) curve analysis and Pearson’s correlation test.

Results

The best performing texture parameters in differentiating CC-RCC from NC-RCC for each sequence included (area under the curve in parentheses): entropy at SSF 4 (0.807) on T2WI, SD at SSF 4 (0.814) on DWI b500, SD at SSF 6 (0.879) on DWI b1000, mean at SSF 0 (0.848) on ADC, skewness at SSF 2 (0.854) on T1WI and skewness at SSF 3 (0.908) on CM phase. In differentiating high from low-grade CC-RCC, the best parameters were: entropy at SSF 6 (0.823) on DWI b1000, mean at SSF 3 (0.889) on CM phase and MPP at SSF 5 (0.870) on NG phase.

Conclusion

Several MR texture parameters showed excellent diagnostic performance (AUC > 0.8) in differentiating CC-RCC from NC-RCC, and high-grade from low-grade CC-RCC. MRTA could serve as a useful non-invasive tool for this purpose.

     

Manual versus rotary instrumentation for primary molar pulpectomies- A 24 months randomized clinical trial

Objective

The study compared manual and rotary canal instrumentation differences in primary molars receiving pulpectomy and their effect on clinical success after two years.

An unusual large abdominal malakoplakia following trauma: Diagnosed on FNAC

Malakoplakia is a rare chronic granulomatous inflammatory disease, related to immune deficiency and impaired bactericidal macrophage activity. Common sites of involvement include urinary bladder and kidney followed by gastrointestinal tract. We present an unusual case of abdominal malakoplakia diagnosed preoperatively on ultrasound‐guided fine‐needle aspiration cytology (FNAC). It presented as a large locally aggressive mass with extensive involvement of multiple bowel loops in an 18‐year‐old boy following blunt trauma to the abdomen. The demonstration of calcified laminated intracytoplasmic Michaelis–Gutman bodies in histiocytes is a reliable diagnostic feature of malakoplakia on FNAC smears, which can guide an appropriate medical management. Diagn. Cytopathol. 2015;43:490–494. © 2015 Wiley Periodicals, Inc.     

Comparative evaluation of reproducibility of peripheral tissues produced by different border molding materials in edentulous patients: An in vivo study

Aim:

The aim of the study is to analyze the effect of different materials and techniques in current use on peripheral shaping of complete denture impression.

Methods:

The present study was conducted to compare and evaluate the maxillary border morphology produced using tissue conditioner as control and low fusing impression compound, Polyether, Pattern resin and periphery wax as border molding materials. The study was carried out on 15 denture wearer patients with well formed, rounded edentulous maxillary arch with adequate width and height. On each patient, border moldings were done, with tissue conditioner which was loaded on the borders of previous maxillary denture of the patient (control group), low fusing impression compound (Group 1), polyether (Group 2), Pattern resin (Group 3) and Peripheral wax (Group 4), respectively on special tray made for the patient. Sulcus width height and area was then measured for each group using stereomicroscope.

Results and Conclusions:

Based on the study it is concluded that the polyether was the best material for border molding which will give most accurate borders to a denture.     

Exposure-Response Analyses for Tafenoquine after Administration to Patients with Plasmodium vivax Malaria

Tafenoquine (TQ), a new 8-aminoquinoline with activity against all stages of the Plasmodium vivax life cycle, is being developed for the radical cure of acute P. vivax malaria in combination with chloroquine. The efficacy and exposure data from a pivotal phase 2b dose-ranging study were used to conduct exposure-response analyses for TQ after administration to subjects with P. vivax malaria. TQ exposure (i.e., area under the concentration-time curve [AUC]) and region (Thailand compared to Peru and Brazil) were found to be statistically significant predictors of clinical response based on multivariate logistic regression analyses. After accounting for region/country, the odds of being relapse free at 6 months increased by approximately 51% (95% confidence intervals [CI], 25%, 82%) for each 25-U increase in AUC above the median value of 54.5 μg · h/ml. TQ exposure was also a significant predictor of the time to relapse of the infection. The final parametric, time-to-event model for the time to relapse, included a Weibull distribution hazard function, AUC, and country as covariates. Based on the model, the risk of relapse decreased by 30% (95% CI, 17% to 42%) for every 25-U increase in AUC. Monte Carlo simulations indicated that the 300-mg dose of TQ would provide an AUC greater than the clinically relevant breakpoint obtained in a classification and regression tree (CART) analysis (56.4 μg · h/ml) in more than 90% of subjects and consequently result in a high probability of being relapse free at 6 months. This model-based approach was critical in selecting an appropriate phase 3 dose. (This study has been registered at ClinicalTrials.gov under registration no. {"type":"clinical-trial","attrs":{"text":"NCT01376167","term_id":"NCT01376167"}}NCT01376167.)     

Blocking the Adhesion Cascade at the Premetastatic Niche for Prevention of Breast Cancer Metastasis

Shear-resistant adhesion and extravasation of disseminated cancer cells at the target organ is a crucial step in hematogenous metastasis. We found that the vascular adhesion molecule E-selectin preferentially promoted the shear-resistant adhesion and transendothelial migration of the estrogen receptor (ER)^–/CD44⁺ hormone-independent breast cancer cells, but not of the ER⁺/CD44^-/low hormone-dependent breast cancer cells. Coincidentally, CD44⁺ breast cancer cells were abundant in metastatic lung and brain lesions in ER^– breast cancer, suggesting that E-selectin supports hematogenous metastasis of ER^–/CD44⁺ breast cancer. In an attempt to prevent hematogenous metastasis through the inhibition of a shear-resistant adhesion of CD44⁺ cancer cells to E-selectin-expressing blood vessels on the premetastatic niche, an E-selectin targeted aptamer (ESTA) was developed. We demonstrated that a single intravenous injection of ESTA reduced metastases to a baseline level in both syngeneic and xenogeneic forced breast cancer metastasis models without relocating the site of metastasis. The effect of ESTA was absent in E-selectin knockout mice, suggesting that E-selectin is a molecular target of ESTA. Our data highlight the potential application of an E-selectin antagonist for the prevention of hematogenous metastasis of ER^–/CD44⁺ breast cancer.     

Role of FNAC in the diagnosis of intraosseous jaw lesions

Background

FNAC of intraosseous jaw lesions has not been widely utilized for diagnosis due to rarity and diversity of these lesions, limited experience and lack of well established cytological features. Aim of the study was to determine the role of FNAC in the diagnosis of intraosseous jaw swellings.

Material and Methods

42 patients underwent FNAC over a period of 7 years (2007-2013), of which 37 (88.1%) aspirates were diagnostic. Histopathology correlation was available in 33 cases and diagnostic accuracy of FNAC was calculated.

Results

Lesions were categorized into inflammatory 3, cysts/hamartomas 15 and neoplasms 19. Mandibular and maxillary involvement was seen in 21 and 16 patients respectively. Of these, benign cysts and malignant lesions were commonest, accounting for 27% lesions (10 cases) each. One case of cystic ameloblastoma was misdiagnosed as odontogenic cyst on cytology. Overall, sensitivity and specificity of FNAC were 94.7% and 100% respectively with a diagnostic accuracy of 97.3%. Definitive categorization of giant cell lesions, fibro-osseous lesions, odontogenic tumors and cystic lesions was not feasible on FNAC.

Conclusions

FNAC is a simple, safe and minimally invasive first line investigation which can render an accurate preoperative diagnosis of intraosseous jaw lesions, especially the malignant ones in the light of clinic-radiological correlation. Key words: Jaw swellings, intraosseous, FNAC.     

Ophthalmic artery occlusion immediately following placement of a flow diverter without clinical sequelae

Branch vessel occlusion is a potential consequence following flow diverter placement for intracranial aneurysms, but the frequency and clinical impact has not been completely elucidated. In this case of a 45-year-old woman with a large left internal carotid artery aneurysm, the ophthalmic artery was covered by two flow diverters and was acutely occluded along with the aneurysm. Common carotid injections failed to demonstrate collateral flow to the ophthalmic artery via the external carotid artery. Nonetheless, the patient woke from anesthesia with objectively stable and subjectively improved vision. This case demonstrates that an acute occlusion of the ophthalmic artery without external carotid artery collaterals can be tolerated clinically.