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What ' s known on the subject? and What does the study add?Stone density on non-contrast computed tomography (NCCT) is reported to be a prognosis factor for extracorporeal shockwave lithotripsy (ESWL). In this prospective study, we determined that a 970 HU threshold of stone density is a very specifi c and sensitive threshold beyond which the likelihood to be rendered stone free is poor. Thus, NCCT evaluation of stone density before ESWL may useful to identify which patients should be offered alternative treatment to optimise their outcome. OBJECTIVE• To evaluate the usefulness of measuring urinary calculi attenuation values by non-contrast computed tomography (NCCT) for predicting the outcome of treatment by extracorporeal shockwave lithotripsy (ESWL). PATIENTS AND METHODS• We prospectively evaluated 50 patients with urinary calculi of 5 -22 mm undergoing ESWL.• All patients had NCCT at 120 kV and 100 mA on a spiral CT scanner. Patient age, sex, body mass index, stone laterality, stone size, stone attenuation values (Hounsfi eld units [ HU ] ), stone location, and presence of JJ stent were studied as potential predictors.• The outcome was evaluated 4 weeks after the ESWL session by NCCT.• ESWL success was defi ned as patients being stone-free (SF) or with remaining stone fragments of < 4 mm, which were considered as clinically insignifi cant residual fragments (CIRF). RESULTS• Our survey concluded that 26 patients (52%) were SF, 12 (24%) had CIRF and 12 (24%) had residual fragment on NCCT after a one ESWL treatment.• Stones of patients who became SF or had CIRF had a lower density compared with stones in patients with residual fragments [ mean ( SD ) 715 (260) vs 1196 (171) HU, P < 0.001 ] .• The Youden Index showed that a stone density of 970 HU represented the most sensitive (100%) and specifi c (81%) point on the receiver-operating characteristic curve.• The stone-free rate for stones of < 970 HU was 96% vs 38% for stones of ≥ 970 HU ( P < 0.001). A linear relationship between the calculus density and the success rate of ESWL was identifi ed. CONCLUSION• The use of NCCT to determine the attenuation values of urinary calculi before ESWL helps to predict treatment outcome, and, consequently, could be helpful in planning alternative treatment for patients with a likelihood of a poor outcome from ESWL. KEYWORDSshockwave lithotripsy , non-contrast computed tomography , urolithiasis Study Type -Therapy (prospective cohort) Level of Evidence 2b

SummaryUp to 30% of patients complain about urine leakage after radical prostatectomy, but persistent stress incontinence ( beyond 1 year) affects <5% of them. This complication is mainly caused by sphincter dysfunction. Some preventive measures have been described to decrease the risk of incontinence after radical prostatectomy, but with conflicting results. The effectiveness of preoperative and early postoperative physiotherapy is controversial. Moreover, while meticulous apical dissection of the prostate significantly improves postoperative continence, the benefit of other surgical techniques, e.g. preserving the bladder neck and the neurovascular bundles, is under debate. The treatment of persistent stress urinary incontinence is mainly based on surgery, as this type of incontinence usually does not respond to physiotherapy and anticholinergic medication. While injection therapy is safe and well tolerated, its effect on postoperative continence is limited and decreases with time. The best results are achieved by implanting an artificial urinary sphincter, but with significant complication and revision rates.

Renal cell cancer (RCC) represents the fifth most common cancer in men, with a rising incidence. Radical cancer surgery remains the only curative treatment in localized and advanced RCC. Therefore, preoperative imaging is most important for the planning of the surgical approach and strategy. The aim of any preoperative imaging in RCC is to differentiate benign from malignant lesions, to adequately assess tumor size, localization and organ confinement, to identify lymph node and/or visceral metastases, and to reliably predict the presence and extent of any thrombus of the vena cava. It is our aim to review the current status of preoperative imaging modalities in RCC. Computed tomography (CT) remains the most appropriate imaging modality to differentiate benign from malignant lesions. Although RCC can appear as iso-, hyper- or hypodense lesions on native CT scans, it usually demonstrates a significant contrast enhancement of about 115 HU and intratumoral areas of necrosis following the intravenous application of contrast medium. Benign masses such as renal oncocytoma are most often homogenous lesions exhibiting hypodensity compared to the normal renal parenchyma following the i.v. application of contrast dye. CT accurately predicts the tumor size with only a 0.5 cm difference as compared to the pathological size of the lesion. The identification of lymph node metastases still remains a problem since the limiting size is 4 mm and CT will result in a false negative rate of about 10%, especially in the presence of micrometastases; the false positive rate of 3-43% is mainly due to reactive hyperplasia. New technologies, such as the multidetector CT with thin collimation and multiplanar reformatting, might result in a diagnostic improvement. The involvement of the adrenal gland can be accurately predicted by CT scans or MRI, allowing an adrenal sparing approach in the case of unsuspicious findings. The detection of visceral metastases appears to be crucial since it has been shown that even patients with metastatic disease might benefit from radical nephrectomy followed by systemic immunotherapy in the case of a good performance status, and the presence of lymph node and pulmonary metastases only. Involvement of the renal vein and the vena cava with tumor thrombus formation will change the surgical strategy. Preoperatively, the presence and the cranial extent of the thrombus need to be known in order to plan the surgical approach. With regard to the extent of renal vein thrombi, a three phase helical CT scan is most appropriate; for vena caval thrombi only a MRI examination is able to accurately identify any infra- or suprahepatic as well as intracardial extension of the thrombus. The identification of multifocal lesions remains another unsolved problem in preoperative imaging techniques for RCC. Compared to the pathohistological analysis of nephrectomy specimens, neither ultrasonography, color duplex sonography nor regular CT scans are able to identify multifocal lesions with acceptable sensitivity and specificity. The ...

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: A low TmPi is more frequently encountered in stone formers with a normal PTH concentration than in control subjects and is associated with a high urinary Ca excretion. The hypophosphatemia induced by a renal phosphate leak may predispose the subject to calcium stone formation by increasing the serum calcitriol level, calcium excretion, and urinary saturation.

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