Detection of bladder cancer with feature fusion, transfer learning and CapsNets.

This paper confronts two approaches to classify bladder lesions shown in white light cystoscopy images when using small datasets: the classical one, where handcrafted-based features feed pattern recognition systems and the modern deep learning-based (DL) approach. In between, there are alternative DL models that had not received wide attention from the scientific community, even though they can be more appropriate for small datasets such as the human brain motivated capsule neural networks (CapsNets). However, CapsNets have not yet matured hence presenting lower performances than the most classic DL models. These models require higher computational resources, more computational skills from the physician and are more prone to overfitting, making them sometimes prohibitive in the routine of clinical practice. This paper shows that carefully handcrafted features used with more robust models can reach similar performances to the conventional DL-based models and deep CapsNets, making them more useful for clinical applications. Concerning feature extraction, it is proposed a new feature fusion approach for Ta and T1 bladder tumor detection by using decision fusion from multiple classifiers in a scheme known as stacking of classifiers. Three Neural Networks perform classification on three different feature sets, namely: Covariance of Color Histogram of Oriented Gradients, proposed in the ambit of this paper; Local Binary Patterns and Wavelet Coefficients taken from lower scales. Data diversity is ensured by a fourth Neural Network, which is used for decision fusion by combining the outputs of the ensemble elements to produce the classifier output. Both Feed Forward Neural Networks and Radial Basis Functions are used in the experiments. Contrarily, DL-based models extract automatically the best features at the cost of requiring huge amounts of training data, which in turn can be alleviated by using the Transfer Learning (TL) strategy. In this paper VGG16 and ResNet-34 pretrained in ImageNet were used for TL, slightly outperforming the proposed ensemble. CapsNets may overcome CNNs given their ability to deal with objects rotational invariance and spatial relationships. Therefore, they can be trained from scratch in applications using small amounts of data, which was beneficial for the current case, improving accuracy from 94.6% to 96.9%.

Resistance of different guidewires to laser injury: an in-vitro experiment.

BACKGROUND: In urology, lasers are used in a variety of endoscopic procedures such as ureteroscopy and retrograde renal surgery for stone fragmentation of urinary calculi and ablation of urothelial tumors. To perform these procedures, guidewires are used as a preliminary safe-mainstay for referencing the urinary tract. This study aims to determine the effect of two different lasers: holmium:YAG (Ho:YAG) and thulium:YAG (Tm:YAG) lasers on metal guidewires with PTFE coating (PTFE), nitinol guidewires with hydrophilic coating (Hydrophilic) and nitinol guidewires with hydrophilic listed coating (Zebra). METHODS: Different combinations of frequency (5, 10 and 12 Hz) and energy per pulse (0.5, 1.5, and 2.6 J) of Ho:YAG laser were applied on the three kinds of guidewires in two experiments (50 J vs. 100 J of total energy). For the Tm:YAG laser three power levels (5, 35, and 70 W) with a total energy of 100 J were applied to the guidewires. The degree of damage (0 to 5) of the guidewire was assessed after each laser application. RESULTS: A higher degree of injury of guidewires was related to higher values of total energy used for the Ho:YAG laser (P=0.036), and to higher values of power applied with the Tm:YAG (P=0.051). The most resistant guidewire to Ho:YAG laser energy was Zebra, followed by PTFE and Hydrophilic (P<0.001). With the Tm:YAG laser, PTFE guidewire appears to be the most resistant and the Hydrophilic the most fragile, although without reaching the statistical significance (P=0.223). CONCLUSIONS: Both lasers revealed a harmful effect on the three tested guidewires. There was an association between the degree of injury and the amount of Ho:YAG laser energy and Tm:YAG laser power. The guidewire Zebra proved to be the safest when using Ho:YAG laser and the PTFE guidewire the most resistant to laser Tm:YAG. Further studies are necessary to confirm these results.

Abscess originating from osteomyelitis as a cause of lower urinary tract symptoms (LUTS) and acute urinary retention.

Lower urinary tract symptoms (LUTS) are a common complaint in the general population with great impact on the quality of life. Besides the classical pathologies, there are less common causes that must be considered in the treatment approach for patients with LUTS. We present the case of a 30-year-old patient with multiple emergency department episodes with dysuria, urinary frequency, suprapubic pain and an episode of acute urinary retention. The blood and urine tests only revealed increased systemic inflammatory parameters. The ultrasound examination showed thickening of the bladder wall, and the CT scan revealed a retropubic abscess originating from a pubic symphysis osteomyelitis. A percutaneous drainage was performed and, after empirical antibiotic therapy, there was complete resolution of the clinical picture.

[Smoking Cessation after Bladder Cancer Diagnosis]. / Cessação Tabágica após o Diagnóstico de Cancro da Bexiga.

INTRODUCTION: Smoking is an important risk factor for the development, recurrence and progression of bladder cancer. Our aim was to analyze smoking habits after diagnosis in bladder cancer patients. Additionally, we evaluated patient knowledge about smoking as a risk factor and the urologist role in promoting abstinence. MATERIAL AND METHODS: A cross-sectional, observational and descriptive study was performed in bladder cancer patients, diagnosed between January 2013 and September 2015 (n = 160) in Braga Hospital, in Portugal. RESULTS: Smoking history was present in 71.9% of the sample, with 21.9% current smokers, (40.7% of abstinence after diagnosis). Smoking was acknowledged as a risk factor by 74.4% of the sample, with only 51.3% of ever smokers and 24.4% of non-smokers recognizing smoking as the leading risk factor (p = 0.008). The presence of other household smokers were significantly higher in patients who continued smoking (40%) than in ex-smokers after diagnosis (4.2%) (p = 0.005). The majority of smokers at diagnosis (83.1%) were advised to quit by their urologist, but only one smoker (1.7%) was offered any specific intervention to aid in cessation. DISCUSSION: Smoking is not recognized as the leading risk factor for bladder cancer. This limited awareness, associated with the known difficulties in quitting smoking and the observed lack of smoking cessation interventions, may account for the high current smoking prevalence, albeit in line with other studies. CONCLUSION: This study highlights the need for efficient smoking cessation programs directed to bladder cancer patients.

Introdução: O tabagismo é um importante fator de risco para o desenvolvimento, recorrência e progressão do cancro da bexiga. Este estudo pretendia analisar os hábitos tabágicos após o diagnóstico em doentes com cancro da bexiga. Adicionalmente, foi avaliado o reconhecimento do tabagismo como fator de risco e a atuação médica na promoção da cessação tabágica. Material e Métodos: Estudo transversal, observacional e descritivo realizado em doentes com cancro da bexiga, diagnosticados entre janeiro de 2013 e setembro de 2015 (n = 160) no Hospital de Braga. Resultados: História tabágica estava presente em 71,9% da amostra, com 21,9% de tabagismo atual (40,7% de abstinência após o diagnóstico). O tabagismo foi reconhecido como fator de risco por 74,4% dos doentes, mas apenas 51,3% dos doentes com história tabágica e 24,4% dos não fumadores referem o tabagismo como a principal causa etiológica (p = 0,008). A presença de outros fumadores em casa foi significativamente maior em doentes que mantiveram tabagismo (40%) do que em ex-fumadores após o diagnóstico (4,2%) (p = 0,005). A maioria dos fumadores (83,1%) refere ter sido aconselhada a deixar de fumar, mas apenas um (1,7%) recebeu apoio específico para a cessação. Discussão: O tabagismo não é adequadamente reconhecido como a principal etiologia de cancro da bexiga. Este desconhecimento, aliado à reconhecida dificuldade na abstinência tabágica e ao défice de estratégias promotoras de cessação tabágica observados, poderá justificar a elevada prevalência de fumadores atuais, todavia, em linha com outros estudos. Conclusão: Este estudo evidencia a necessidade de programas de cessação tabágica eficientes dirigidos a pacientes com cancro da bexiga.

Ileal intussusception due to a parasite egg: a case report.

Ileal intussusception is the invagination of the small intestine within itself and accounts for 1% of cases of acute obstruction. However, physicians do not initially consider intussusception as a possible diagnosis of obstruction due to its rarity in adults. Herein, we report the case of a 22-year-old male who was admitted to the Emergency Department with continuous abdominal pain. Ultrasonography and computed tomography revealed an ileal intussusception. The patient underwent surgical removal of the segment of the small bowel. Unexpectedly, pathology revealed that the invagination occurred due to a parasite egg, with features suggestive of Schistosoma species. Schistosomiasis, although considered a parasitic disease in tropical countries, is not absent from Europe and though it is highly improbable, it may be responsible for cases of intussusception in adults.