Uncertainty Characterisation of Mobile Robot Localisation Techniques using Optical Surveying Grade Instruments.

Recent developments in localisation systems for autonomous robotic technology have been a driving factor in the deployment of robots in a wide variety of environments. Estimating sensor measurement noise is an essential factor when producing uncertainty models for state-of-the-art robotic positioning systems. In this paper, a surveying grade optical instrument in the form of a Trimble S7 Robotic Total Station is utilised to dynamically characterise the error of positioning sensors of a ground based unmanned robot. The error characteristics are used as inputs into the construction of a Localisation Extended Kalman Filter which fuses Pozyx Ultra-wideband range measurements with odometry to obtain an optimal position estimation, all whilst using the path generated from the remote tracking feature of the Robotic Total Station as a ground truth metric. Experiments show that the proposed method yields an improved positional estimation compared to the Pozyx systems' native firmware algorithm as well as producing a smoother trajectory.

From prostate-specific antigen (PSA) to precursor PSA (proPSA) isoforms: a review of the emerging role of proPSAs in the detection and management of early prostate cancer.

Despite the popularity of PSA blood testing for prostate cancer, there are a number of important limitations of this popular serum marker including the limited ability to accurately distinguish patients with and without prostate cancer and those who harbour an aggressive form of the disease. This is especially true when the total PSA is <10 ng/mL. Thus, significant efforts have been placed to find new serum markers that can help overcome these limitations. In this review article, we discuss the emerging role of the various precursor forms of PSA (proPSAs), with a special emphasis on [-2]proPSA in the detecion and management of early prostate cancer. The clinical utility of Prostate Health Index (phi) is also discussed. Despite the overall success of prostate-specific antigen (PSA) blood test, its use as a serum marker for prostate cancer has been limited due to the lack of specificity, especially in men presenting with a total PSA (tPSA) level of <10 ng/mL. PSA testing has also resulted in an increase in the number of patients being diagnosed with low-grade, potentially clinically insignificant prostate cancer. There is therefore an urgent need for new markers that can accurately detect as well as differentiate patients with aggressive vs unaggressive prostate cancer. In this review, we discuss the emerging role of precursor forms of PSA (proPSAs) and the Prostate Health Index (phi) measurement in the detection and management of early stage prostate cancer. A literature search was conducted using PubMed® to identify key studies. Studies to date suggest that [-2]proPSA, a truncated form of proPSA is the most cancer-specific form of all, being preferentially expressed in cancerous prostatic epithelium and being significantly elevated in serum of men with prostate cancer. There is evidence to suggest that %[-2]proPSA measurement ([-2]proPSA/free PSA [fPSA] × 100) improves the specificity of both tPSA and fPSA in detecting prostate cancer. phi incorporating [-2]proPSA, fPSA and tPSA measurements has also yielded promising results and appears superior to tPSA and fPSA in predicting those patients with prostate cancer. Increased phi levels also seem to preferentially detect patients harbouring more aggressive disease. Further studies in the form of large, multicentre, prospective trials with detailed health economic analyses are required to evaluate the true clinical applicability of these novel markers.

Can a trained non-physician provider perform transrectal ultrasound-guided prostatic biopsies as effectively as an experienced urologist?

UNLABELLED: WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: PSA testing has resulted in a large number of patients being referred to urologists for investigation of potential prostate cancer. Despite limited evidence, non-physician providers now perform a number of routine urological procedures such as transrectal ultrasound-guided prostatic biopsies (TRUSP) in a bid to help relieve this increasing workload. In the largest series to date, we provide evidence that an adequately trained non-physician provider is able to perform TRUSP as effectively as an experienced urologist after an initial learning curve. OBJECTIVE: To evaluate differences in cancer detection rates between a trained non-physician provider (NPP) and an experienced urologist performing transrectal ultrasound-guided prostatic biopsies (TRUSP) at a single UK institution. PATIENTS AND METHODS: We retrospectively analysed a prospectively accrued database of patients (n = 440) referred for investigation of an abnormal digital rectal examination and/or a raised age-specific prostate-specific antigen (PSA) value undergoing first-time outpatient prostatic biopsies who were sequentially allocated to either an NPP or a physician-led TRUSP clinic. Differences in overall and risk-stratified prostate cancer detection rates were evaluated according to TRUSP operator. Continuous variables were analysed using Mann-Whitney U test whereas categorical variables were analysed using Pearson's chi-squared test. A multivariate binary logistic regression model was fitted for predictors of a positive biopsy. RESULTS: In all, 57.3% (126/220) of patients who underwent physician-led TRUSP were diagnosed with prostate cancer compared with 52.7% (116/220) in the NPP-led clinic (P = 0.338). Sub-group analysis revealed a lower cancer detection rate in men presenting with a low PSA level (<9.9 ng/mL) during the first 50 independent TRUSP procedures performed by the NPP (P = 0.014). This initial difference was lost with increasing case volume, suggesting the presence of a learning curve. Multivariate logistic regression analysis revealed age (odds ratio (OR) 1.054, 95% confidence interval (95% CI) 1.025-1.084, P ≤ 0.001), presenting PSA level (OR 1.05, 95% CI 1.02-1.081, P = 0.001), prostatic volume (OR 0.969, 95% CI 0.958-0.981, P ≤ 0.001) and clinical stage (OR 1.538, 95% CI 1.046-2.261, P = 0.029) to be predictors of a positive prostatic biopsy outcome. The choice of TRUSP operator was not predictive of a positive prostatic biopsy (OR 0.729, 95% CI 0.464-1.146, P = 0.171). CONCLUSION: An adequately trained NPP is able to perform TRUSP as effectively as an experienced urologist after an initial learning curve of 50 cases.

Future demand for primary hip and knee arthroplasty in Scotland.

INTRODUCTION: The rising prevalence of osteoarthritis, associated with an ageing population, is expected to deliver increasing demand for arthroplasty services in the future. Understanding the scale of potential change is essential to ensure adequate provision of services and prevent prolonged waiting times that can cause patient harm. METHODS: We set out to provide projections of future primary knee and hip arthroplasty out to 2038 utilising historical trend data (2008-2018) from the Scottish Arthroplasty Project. All analyses were performed using the Holt's exponential smoothing projection method with the forecast package in R statistics. Results were adjusted for projected future population estimates provided by National Records of Scotland. Independent age group predictions were also performed. RESULTS: The predicted rise of primary hip arthroplasty for all ages is from 120/100k/year in 2018 to 152/100k/year in 2038, a 28% increase. The predicted rise of primary knee arthroplasty for all ages is from 164/100k/year in 2018 to 220/100k/year in 2038, a 34% increase. Based on a static 3-day length of stay average this would see 4280 and 7392 additional patient bed days required for primary hip and knee arthroplasty patients respectively per annum. The associated additional cost is anticipated to be approximately £26 million. CONCLUSIONS: Anticipated future demand for arthroplasty will require significant additional resource and funding to prevent deterioration in quality of care and an increase in patient wait times, additional to that already required to clear the COVID-19 backlog. Understanding presented projections of changes to arthroplasty demand is key to future service delivery.

Prostate cancer and diet: food for thought?

• There is now increasing evidence that diet plays a major role in prostate cancer biology and tumorigenesis. • In a health conscious society, it is becoming increasingly common for Urologists to be asked about the impact of diet on prostate cancer. • In the present review, we explore the current evidence for the role of different dietary components and its' effect on prostate cancer prevention and progression. • A literature search was conducted using PubMed® to identify key studies. • There was some evidence to suggest that green tea, isoflavones, lycopenes, cruciferous vegetables and omega 3 polyunsaturated fatty acid intake to be beneficial in the prevention and/or progression of prostate cancer. • There was also evidence to suggest that a high total fat, meat (especially well cooked) and multivitamin intake may be associated with an increased risk of developing prostate cancer. • To date publications have been highly heterogeneous and variable in quality and design. More robust, high quality research trials are needed to help us understand the complex relationship between diet and prostate cancer.

First 500 cases of robotic-assisted laparoscopic radical prostatectomy from a single UK centre: learning curves of two surgeons.

OBJECTIVE: • To study the outcomes and learning curve of robotic-assisted laparoscopic radical prostatectomy (RALP) in a single centre by two surgeons. PATIENTS AND METHODS: • In total, 500 consecutive patients underwent RALP between 2005 and 2009 carried out by two surgeons. Using an ethically-approved database, prospective data collection of demographic, surgical, oncological and functional outcomes (patient reported) was performed, with up to 4 years of follow-up. • The learning curves of both surgeons were analyzed and, in addition, the first 100 and last 100 patients were compared to determine the effect of surgeon experience. RESULTS: • The mean age of the patients was 61.5 years and mean preoperative prostate-specific antigen was 7.0 µg/L. Clinical stages were T1 in 63.2%, T2 in 33.8% and T3 in 3.0% of patients. Median (range) operating time was 170 (63-420) min and median (range) blood loss was 200 (20-3000) mL, with significant improvements for both surgeons with increasing experience (P < 0.001 and P= 0.029, respectively). • Pathological stages were pT2 in 53.4%, pT3a in 41.6%, pT3b in 4.0% and pT4 in 0.6% of patients. Overall, the positive margin rate (PMR) was 24.0% and stage-specific rates were 16.1%, 30.4%, 55.0% and 100.0% for pT2, pT3a, pT3b and pT4 disease, respectively. In the last 50 cases performed by each surgeon, the PMRs for pT2 and pT3a disease were 8.0% and 19.1% (surgeon 1) and 12.9% and 23.5% (surgeon 2). • At 12 months of follow-up, 91.3% of patients were continent and, by 48 months of follow-up, 75% of men with preoperative potency who underwent bilateral nerve-sparing RALP were potent. CONCLUSION: • This is the first report of two surgeons' learning curves in a single centre and shows that key learning curve outcomes continued to improve during the series, suggesting that the learning curve for RALP may be longer than has been previously suggested.

Changing antibiotic prophylaxis for transrectal ultrasound-guided prostate biopsies: are we putting our patients at risk?

OBJECTIVE: To evaluate whether changing antibiotic prophylaxis from quinolone to penicillin antibiotics has affected infectious complication rates in those men undergoing transrectal ultrasound-guided prostate biopsy (TRUSgpb). PATIENTS AND METHODS: This interventional study was designed to determine whether changing antibiotic prophylaxis had any bearing on developing serious infectious complications after taking TRUSgpb. As a secondary aim, we also investigated Clostridium difficile (C. difficile) rates in the same groups of men undergoing TRUSgpb. Men historically received ciprofloxacin 500 mg orally 1 h before their procedure followed by a 3-day course of 500 mg given twice daily (group A). Due to increasing local patterns of antimicrobial resistance to quinolones and concerns regarding potential antibiotic induced C. difficile infection, antibiotic prophylaxis was changed to a penicillin-based regimen comprising of co-amoxiclav 625 mg given orally 1 h before TRUSgpb followed by a three times daily course for 3 days (group B). Excluded from the study were those men given an alternative antibiotic prophylaxis than those given within the two distinct groups due to reasons of previous hypersensitivity reactions and/or clinical decision by the attending Urologist. Comparisons were made between the groups using two-tailed Fisher's exact tests. RESULTS: In all, 119 and 110 men were identified in groups A and B, respectively. Two men in group A (1.68%) developed sepsis after TRUSgpb requiring hospital admission and intravenous antibiotic treatment. The sepsis rate in group B was significantly higher than that of group A (eight of 110, 7.27%; P = 0.036). Escherichia coli was the only organism isolated from our cohort of patients. There were no incidences of C. difficile infections in either antibiotic prophylaxis groups. CONCLUSION: Ciprofloxacin appears to provide superior prophylaxis than co-amoxiclav in men undergoing TRUSgpb and was not associated with an increased risk of quinolone induced C. difficile infections. Changing antibiotic prophylaxis from a quinolone-based regime may therefore be putting our patients at an increased risk of serious infectious complications after TRUSgpb.

Long-term outcome of epididymectomy for the management of chronic epididymal pain.

PURPOSE: We evaluated the long-term outcomes of patients who underwent epididymectomy for the treatment of chronic epididymal pain. MATERIALS AND METHODS: All 72 patients who underwent epididymectomy at our institution between 1994 and 2007 were invited to participate in the study. Patients were mailed questionnaires covering various aspects of the treatment. Questions regarding pain were rated on a scale between 0 and 10 (0--no pain, 10--severe pain). Patients who did not return the questionnaires were followed up by telephone and the medical case notes of all respondents were reviewed. Statistical analysis was performed using the Wilcoxon signed-rank and Fisher's exact tests with p <0.05 considered statistically significant. RESULTS: A total of 53 patients participated (74% response rate) and mean followup was 7.4 years. Of these patients 45 (84.9%) underwent epididymectomy for post-vasectomy pain and the remainder (8 of 53, 15.1%) had the procedure for various nonvasectomy reasons. There were significant improvements in pain score in the post-vasectomy (mean 7.3 preoperative to 2.4 postoperative, p <0.001) and nonvasectomy (mean 7 preoperative to 2.8 postoperative, p = 0.002) groups. Of the patients in the post-vasectomy group 93.3% (42 of 45) had less or no pain postoperatively compared to 75% (6 of 8) in the nonvasectomy group. The satisfaction rate with epididymectomy was also higher in the post-vasectomy (42 of 45, 93.3%) compared to the nonvasectomy (5 of 8, 62.5%) group (p = 0.038). CONCLUSIONS: With high patient satisfaction and a favorable long-term outcome epididymectomy appears to be an effective treatment option particularly for post-vasectomy chronic epididymal pain.

Development and validation of risk score for predicting positive repeat prostate biopsy in patients with a previous negative biopsy in a UK population.

BACKGROUND: Little evidence is available to determine which patients should undergo repeat biopsy after initial benign extended core biopsy (ECB). Attempts have been made to reduce the frequency of negative repeat biopsies using PSA kinetics, density, free-to-total ratios and Kattan's nomogram, to identify men more likely to harbour cancer but no single tool accurately predicts biopsy outcome. The objective of this study was to develop a predictive nomogram to identify men more likely to have a cancer diagnosed on repeat prostate biopsy. METHODS: Patients with previous benign ECB undergoing repeat biopsy were identified from a database. Association between age, volume, stage, previous histology, PSA kinetics and positive repeat biopsy was analysed. Variables were entered stepwise into logistic regression models. A risk score giving the probability of positive repeat biopsy was estimated. The performance of this score was assessed using receiver characteristic (ROC) analysis. RESULTS: 110 repeat biopsies were performed in this period. Cancer was detected in 31% of repeat biopsies at Hospital (1) and 30% at Hospital (2). The most accurate predictive model combined age, PSA, PSA velocity, free-to-total PSA ratio, prostate volume and digital rectal examination (DRE) findings. The risk model performed well in an independent sample, area under the curve (AUCROC) was 0.818 (95% CI 0.707 to 0.929) for the risk model and 0.696 (95% CI 0.472 to 0.921) for the validation model. It was calculated that using a threshold risk score of > 0.2 to identify high risk individuals would reduce repeat biopsies by 39% while identifying 90% of the men with prostate cancer. CONCLUSION: An accurate multi-variable predictive tool to determine the risk of positive repeat prostate biopsy is presented. This can be used by urologists in an outpatient setting to aid decision-making for men with prior benign histology for whom a repeat biopsy is being considered.

Mesothelioma subtypes of the tunica vaginalis: a rare case report and review of histological criteria.

Well-differentiated papillary mesothelioma (WDPM) is a rare histological subtype of mesothelioma arising from the tunica vaginalis. We present a case of a 23-year-old male with a palpable para-testicular lump of 3 years duration. Scrotal exploration revealed a grossly abnormal cystic appearance of his tunica vaginalis. An excision biopsy confirmed WDPM of the tunica vaginalis. The three subtypes of mesothelial tumours of the tunica vaginalis are described by their distinct histological features, tumour growth and reported prognosis. A summary of immunohistochemistry and the surgical management across the disease spectrum is provided. Recent clarification of the histological criteria of WDPM provides the opportunity for surgeons to offer a limited approach to managing this indolent tumour that mimics malignant mesothelioma. However, the lack of evidence on recurrence and progression rates in WDPM restricts most surgeons to performing a radical orchidectomy, as was performed in this case.

Erratum: Mesothelioma subtypes of the tunica vaginalis: a rare case report and review of histological criteria.

[This corrects the article DOI: 10.1093/jscr/rjz040.].

General practitioner perception of prostate-specific antigen testing has improved, but more awareness of prostate cancer risk in younger patients is still awaited.

BACKGROUND: In 2006, a county-wide survey of general practitioners (GPs) in the United Kingdom (UK) identified a reluctance to refer younger men with abnormal prostate specific antigen (PSA) levels. Younger men have the most to gain from early-detection of prostate cancer (PCa), which remains a national government priority in the UK and around the world. We sought to assess changes in perception of abnormal PSA-values amongst UK GPs over the past 10 years. MATERIALS AND METHODS: A total of 500 self-administered paper questionnaires were distributed to individually named GPs. One hundred and forty two responded (28.4%), representing a patient population of ∼600,000. A series of visual analogue questions assessed referral thresholds and understanding of risk factors related to the development of PCa. RESULTS: GPs with a median of 23-years experience responded. Although mean PSA threshold for referral to urology did fall between 2006 and 2016 in both the 45-year (5.42 ng/mL vs. 4.61 ng/mL P = 0.0003) and 55-year (5.81 ng/mL vs. 5.30 ng/mL P = 0.0164) age groups, the median referral values were unchanged. Significantly, referral thresholds quoted for younger men (<65 years) were considerably higher than recommended UK maximum PSA-levels. Using case-based scenarios, practitioners appeared more likely to refer older men with abnormal PSA values, with GPs reporting an average 56.2% likelihood of referring an asymptomatic 55-year-old with elevated age-adjusted PSA of 4.6 ng/mL. A total of 95.1% recognised a family history of PCa to be a potential risk factor but other at-risk categories were not so clearly understood. CONCLUSION: Awareness of abnormal PSA values in UK primary care is improving, but continues to lag behind the evidence. Strategies to disseminate knowledge of maximum PSA-values to GPs should focus especially on those for younger patients.

Acute upper airway obstruction secondary to late presentation of a massive oropharyngeal arteriovenous malformation.

The case of a 65 year-old man with a massive oropharyngeal arteriovenous malformation, with acute deterioration and airway compromise, is presented. Optimal airway management was deemed to be fiberoptic intubation without sedative drugs.