A novel model of artificial intelligence based automated image analysis of CT urography to identify bladder cancer in patients investigated for macroscopic hematuria

OBJECTIVE

To evaluate whether artificial intelligence (AI) based automatic image analysis utilising convolutional neural networks (CNNs) can be used to evaluate computed tomography urography (CTU) for the presence of urinary bladder cancer (UBC) in patients with macroscopic hematuria.

METHODS

Our study included patients who had undergone evaluation for macroscopic hematuria. A CNN-based AI model was trained and validated on the CTUs included in the study on a dedicated research platform (Recomia.org). Sensitivity and specificity were calculated to assess the performance of the AI model. Cystoscopy findings were used as the reference method.

RESULTS

The training cohort comprised a total of 530 patients. Following the optimisation process, we developed the last version of our AI model. Subsequently, we utilised the model in the validation cohort which included an additional 400 patients (including 239 patients with UBC). The AI model had a sensitivity of 0.83 (95% confidence intervals [CI], 0.76-0.89), specificity of 0.76 (95% CI 0.67-0.84), and a negative predictive value (NPV) of 0.97 (95% CI 0.95-0.98). The majority of tumours in the false negative group (n = 24) were solitary (67%) and smaller than 1 cm (50%), with the majority of patients having cTaG1-2 (71%).

CONCLUSIONS

We developed and tested an AI model for automatic image analysis of CTUs to detect UBC in patients with macroscopic hematuria. This model showed promising results with a high detection rate and excessive NPV. Further developments could lead to a decreased need for invasive investigations and prioritising patients with serious tumours.

Diagnostic value of repeated comprehensive investigation with CT urography and cystoscopy for recurrent macroscopic haematuria

Objectives

To perform a descriptive analysis of a series of patients with recurrent macroscopic haematuria after a primary standard evaluation including computed tomography urography (CTU) and cystoscopy negative for urinary bladder cancer (UBC) and upper tract urothelial cancer (UTUC) and to identify potential factors associated with occurrence of recurrent macroscopic haematuria.

Methods

All patients older than 50 years who underwent urological investigation for macroscopic haematuria with both cystoscopy and CTU 2015-2017 were retrospectively reviewed. A descriptive analysis of the primary and later investigations for recurrent macroscopic haematuria was performed. To investigate the association between explanatory variables and the occurrence of recurrent macroscopic haematuria, a Poisson regression analysis was performed.

Results

A total of 1395 eligible individuals with primary standard investigation negative for UBC and UTUC were included. During a median follow-up of 6.2 (IQR 5.3-7) years, 248 (18%) patients had recurrent macroscopic haematuria, of whom six patients were diagnosed with UBC, two with prostate cancer, one with renal cell carcinoma and one had a suspected UTUC at the repeated investigation. Within 3 years, 148 patients (11%) experienced recurrent macroscopic haematuria, of whom two patients were diagnosed with low-grade UBC (TaG1-2), one with T2G3 UBC and one with low-risk prostate cancer. The presence of an indwelling catheter, use of antithrombotic medication, pathological findings at CTU or cystoscopy or history of pelvic radiotherapy were all statistically significant independent predictors for increased risk for recurrent macroscopic haematuria.

Conclusion

In the case of recurrent macroscopic haematuria within 3 years of primary standard evaluation for urinary tract cancer, there was a low risk of later urological malignancies in patients initially negative for UBC and UTUC. Therefore, waiting 3 years before conducting another complete investigation in cases of recurrent macroscopic haematuria might be appropriate.

Shortened time to diagnosis for patients suspected of urinary bladder cancer managed in a standardized care pathway was associated with an improvement in tumour characteristics

Objectives

To evaluate whether the implementation of standardized care pathway (SCP) for patients with suspected urinary bladder cancer (UBC) was associated with changes in tumour characteristics. Additionally, the study aims to explore whether there was a shift in the selection of patients prioritized for immediate evaluation regarding suspicion of UBC.

Materials and Methods

The study included all patients diagnosed with UBC in the NU Hospital Group between 2010 and 2019. To evaluate changes associated with SCP, patients were divided into two diagnostic time periods, either before (2010-2015) or during (2016-2019) the implementation of the SCP. To evaluate which patients were prioritized for prompt evaluation within 13 days, logistic regression analysis was performed on all patients before and during SCP.

Results

Median time to transurethral resection of the tumour in urinary bladder (TURBT) decreased from 29 days (interquartile range [IQR] 16-48) before SCP to 12 days (IQR 8-19) during SCP (p < 0.001) with a clear break from 2016. The proportion of cT2 + tumours decreased during SCP from 26% to 20% (p = 0.035). In addition, tumours detected during SCP were smaller (p = 0.023), but with more multiple lesions (p = 0.055) and G3 tumours (p = 0.007). During SCP, there was no statistically significant difference between the groups of patients with TURBT within or after 13 days. In contrast, before SCP, a majority of the patients treated within 13 days had advanced tumours and were admitted from the emergency ward.

Conclusions

The implementation of an SCP for suspected UBC was associated with improved tumour characteristics. Interestingly, during SCP, there were no substantial differences in patients' or tumours' characteristics among those who underwent TURBT within or after 13 days. This indicates that the 13-day timeframe for TURBT might be prolonged, especially in less urgent cases in order to facilitate a prioritization of more severe cases with treatable disease.

Artificial Intelligence-Based Organ Delineation for Radiation Treatment Planning of Prostate Cancer on Computed Tomography

Purpose

Meticulous manual delineations of the prostate and the surrounding organs at risk are necessary for prostate cancer radiation therapy to avoid side effects to the latter. This process is time consuming and hampered by inter- and intraobserver variability, all of which could be alleviated by artificial intelligence (AI). This study aimed to evaluate the performance of AI compared with manual organ delineations on computed tomography (CT) scans for radiation treatment planning.

Methods and Materials

Manual delineations of the prostate, urinary bladder, and rectum of 1530 patients with prostate cancer who received curative radiation therapy from 2006 to 2018 were included. Approximately 50% of those CT scans were used as a training set, 25% as a validation set, and 25% as a test set. Patients with hip prostheses were excluded because of metal artifacts. After training and fine-tuning with the validation set, automated delineations of the prostate and organs at risk were obtained for the test set. Sørensen-Dice similarity coefficient, mean surface distance, and Hausdorff distance were used to evaluate the agreement between the manual and automated delineations.

Results

The median Sørensen-Dice similarity coefficient between the manual and AI delineations was 0.82, 0.95, and 0.88 for the prostate, urinary bladder, and rectum, respectively. The median mean surface distance and Hausdorff distance were 1.7 and 9.2 mm for the prostate, 0.7 and 6.7 mm for the urinary bladder, and 1.1 and 13.5 mm for the rectum, respectively.

Conclusions

Automated CT-based organ delineation for prostate cancer radiation treatment planning is feasible and shows good agreement with manually performed contouring.

A randomised study of TURP after intraprostatic injection of mepicacaine/adrenaline versus regular TURP in patients with LUTS/BPO

INTRODUCTION

During transurethral resection of the prostate (TURP), the most established surgical treatment of lower urinary tract symptoms (LUTS) due to benign prostatic obstruction (BPO), the prostate can bleed profusely, bringing about anaemia and compromised oxygen delivery to the entire body.

OBJECTIVE

The primary objective of this study was to assess the efficacy of mepivacaine and adrenaline (MA) injected into the prostate on bleeding. The primary endpoint was to measure blood loss per resected weight of prostate tissue.

MATERIAL AND METHODS

This randomised controlled trial evaluated 81 patients with LUTS/BPO. Patients were randomly allocated to regular TURP or TURP with intraprostatic injections of MA.

RESULTS

On univariable analyses there was a significant difference in resection weight in favour of the experimental group, not reflected by a statistically significant difference in the other studied outcome parameters. Nevertheless, in multivariable analyses, blood loss per resection weight, which was the primary outcome, showed a significant decrease in favour of the experimental group. Clavien-Dindo complication classification showed three men with a grade I complication and two men with grade II.

CONCLUSIONS

The results obtained in this study showed that it is beneficial to apply intraprostatic injections of MA in immediate conjunction with TURP, in terms of blood loss per resected gram. The study is, however, small and corroboration of our results in more extensive prospective studies may therefore be warranted before embarking upon this technique.

Clinical Value of a Routine Urine Culture Prior to Transrectal Prostate Biopsy

Background

Infectious complications after a transrectal prostate biopsy may be severe. In Sweden, a routine culture prior to all prostate biopsies was introduced to enable targeted antimicrobial prophylaxis and reduce postbiopsy infections.

Objective

To investigate whether a clinical routine with a urine culture prior to a prostate biopsy and targeted prophylactic antibiotic therapy reduces postbiopsy infections.

Design setting and participants

In 2015, a site-specific antimicrobial stewardship programme with a urine culture prior to a prostate biopsy was initiated in Region Kronoberg. To evaluate this routine, we designed a population-based register study including all men who had an outpatient prostate biopsy in 2015-2019 and a control period including all men who had a biopsy in 2010-2014, when a urinary culture was obtained only on clinical suspicion.

Outcome measurements and statistical analysis

The primary outcome was infectious complications within 10 d and the secondary outcome was a change in antibiotic prophylactic treatment. An infectious complication was defined as prescription of antibiotics for urinary tract infections or admission to hospital for urinary tract infections or sepsis after a biopsy.

Results and limitations

The urine culture period included 2971 prostate biopsy procedures, of which 2684 (90%) were preceded by a urine culture. The control period included 2818 procedures, of which 135 (4.8%) were preceded by a urine culture. Infectious complications were slightly more common during the urine culture period (5.0%) than during the control period (4.3%, p = 0.17), as was inpatient care for infections (3.5% vs 2.2%, p = 0.002). The routine identified 5.4% men with asymptomatic bacteriuria. Despite targeted antibiotic treatment (1.5% received a nonfluoroquinolone treatment), the rate of infectious complications (6.3%) was similar to that in the control period.

Conclusions

Prebiopsy urine culture did not lead to fewer postbiopsy infections. Other measures are needed to reduce infectious complications after a prostate biopsy.

Patient summary

In this report, we evaluated a routine with urine culture prior to a transrectal prostate biopsy and found that it did not lead to fewer infectious complications.

Detection of lymph node metastases in patients with prostate cancer: Comparing conventional and digital [18 F]-fluorocholine PET-CT using histopathology as a reference

BACKGROUND

Positron emission tomography-computed tomography (PET-CT) with [¹⁸ F]-fluorocholine (FCH) is used to detect and stage metastatic lymph nodes in patients with prostate cancer. Improvements to hardware and software have recently been made. We compared the capability of detecting regional lymph node metastases using conventional and digital silicon photomultiplier (SiPM)-based PET-CT technology for FCH. Extended pelvic lymph node dissection (ePLND) histopathology was used as a reference method.

METHODS

The study retrospectively examined 177 patients with intermediate or high-risk prostate cancer who had undergone staging with FCH PET-CT before ePLND. Images were obtained with either the conventional Philips Gemini PET-CT (n = 93) or the digital SiPM-based GE Discovery MI PET-CT (n = 84) and compared.

RESULTS

Images that were obtained using the Philips Gemini PET-CT system showed 19 patients (20%) with suspected lymph node metastases, whereas the GE Discovery MI PET-CT revealed 36 such patients (43%). The sensitivity, specificity, and positive and negative predictive values were 0.3, 0.84, 0.47, and 0.72 for the Philips Gemini, while they were 0.58, 0.62, 0.31, and 0.83 for the GE Discovery MI, respectively. The areas under the curves in a receiver operating characteristic curve analysis were similar between the two PET-CT systems (0.57 for Philips Gemini and 0.58 for GE Discovery MI, p = 0.89).

CONCLUSIONS

Marked differences in sensitivity and specificity were found for the different PET-CT systems, although the overall diagnostic performance was similar. These differences are probably due to differences in both hardware and software, including reconstruction algorithms, and should be considered when new technology is introduced.

The transferability of laparoscopic and open surgical skills to robotic surgery

BACKGROUND

Within the last decades, robotic surgery has gained popularity. Most robotic surgeons have changed their main surgical activity from open or laparoscopic without prior formal robotic training. With the current practice, it is of great interest to know whether there is a transfer of surgical skills. In visualization, motion scaling, and freedom of motion, robotic surgery resembles open surgery far more than laparoscopic surgery. Therefore, our hypothesis is that open-trained surgeons have more transfer of surgical skills to robotic surgery, compared to surgeons trained in laparoscopy.

METHODS

Thirty-six surgically inexperienced medical students were randomized into three groups for intensive simulation training in an assigned modality: open surgery, laparoscopy, or robot-assisted laparoscopy. The training period was, for all study subjects, followed by performing a robot-assisted bowel anastomosis in a pig model. As surrogate markers of surgical quality, the anastomoses were tested for resistance to pressure, and video recordings of the procedure were evaluated by two blinded expert robotic surgeons, using a global rating scale of robotic operative performance (Global Evaluative Assessment of Robotic Skills (GEARS)).

RESULTS

The mean leak pressure of bowel anastomosis was 36.25 (7.62-64.89) mmHg in the laparoscopic training group and 69.01 (28.02-109.99) mmHg in the open surgery group, and the mean leak pressure for the robotic training group was 108.45 (74.96-141.94) mmHg. The same pattern was found with GEARS as surrogate markers of surgical quality. GEARS score was 15.71 (12.37-19.04) in the laparoscopic training group, 18.14 (14.70-21.58) in the open surgery group, and 22.04 (19.29-24.79) in the robotic training group. In comparison with the laparoscopic training group, the robotic training group had a statistically higher leak pressure (p = 0.0015) and GEARS score (p = 0.0023). No significant difference, for neither leak pressure nor GEARS, between the open and the robotic training group.

CONCLUSION

In our study, training in open surgery was superior to training in laparoscopy when transitioning to robotic surgery in a simulation setting performed by surgically naive study subjects.

Treatment with CoreTherm in 570 patients with prostate volumes of 80-366 ml: an evaluation of short- and long-term retreatment risk

INTRODUCTION

CoreTherm (ProstaLund AB, Lund, Sweden) is an outpatient treatment option in men with lower urinary tract symptoms and catheter-dependent men with chronic urinary retention caused by benign prostatic obstruction (BPO). CoreTherm is high-energy transurethral microwave thermotherapy with feedback technique. Modern treatment with CoreTherm includes transurethral intraprostatic injections of mepivacaine and adrenaline via the Schelin Catheter (ProstaLund AB, Lund, Sweden) and is often referred to as the CoreTherm Concept.

OBJECTIVES

The aim of this study was to evaluate the short- and long-term retreatment risk in men with large prostates and BPO or chronic urinary retention, all primarily treated with CoreTherm.

MATERIAL AND METHODS

All men from the same geographical area with prostate volumes ≥ 80 ml treated 1999-2015 with CoreTherm and having BPO or were catheter-dependent due to chronic urinary retention, were included. End of study period was defined as December 31, 2019.

RESULTS

We identified and evaluated 570 men treated with CoreTherm, where 12% (71 patients) were surgically retreated during the follow-up. Mean follow-up was 11 years, and maximum follow-up was 20 years. The long-term retreatment rate in our study was 23%. A majority of these could be retreated with CoreTherm or TURP, with only 3% requiring open surgery.

CONCLUSION

We conclude that CoreTherm is a suitable outpatient treatment option in patients with profoundly enlarged prostates, regardless of age, prostate size, and reason for treatment.

Computed tomography urography with corticomedullary phase can exclude urinary bladder cancer with high accuracy

BACKGROUND

To evaluate the diagnostic accuracy of computed tomography-urography (CTU) to rule out urinary bladder cancer (UBC) and whether patients thereby could omit cystoscopy.

METHODS

All patients evaluated for macroscopic hematuria with CTU with cortico-medullary phase (CMP) and cystoscopy at our institute between 1^st November 2016 and 31^st December 2019 were included. From this study cohort a study group consisting of all UBC patients and a control group of 113 patients randomly selected from all patients in the study cohort without UBC. Two radiologists blinded to all clinical data reviewed the CTUs independently. CTUs were categorized as positive, negative or indeterminate. Diagnostic accuracy and proportion of potential omittable cystoscopies were calculated for the study cohort by generalizing the results from the study group.

RESULTS

The study cohort consisted of 2195 patients, 297 of which were in the study group (UBC group, n = 207 and control group, n = 90). Inter-rater reliability was high (κ 0.84). Evaluation of CTUs showed that 174 patients were assesessed as positive (showing UBC), 46 patients as indeterminate (not showing UBC but with limited quality of CTU), and 77 patients as negative (not showing UBC with good quality of CTU). False negative rate was 0.07 (95%, CI 0.04-0.12), false positive rate was 0.01 (95% CI 0.0-0.07) and negative predictive value was 0.99 (95% CI 0.92-1.0). The area under the curve was 0.93 (95% CI 0.90-0.96). Only 2.9% (3/102) with high-risk tumors and 11% (12/105) with low- or intermediate-risk tumors had a false negative CTU. Cystoscopy could potentially have been omitted in 57% (1260/2195) of all evaluations.

CONCLUSIONS

CTU with CMP can exclude UBC with high accuracy. In case of negative CTU, it might be reasonable to omit cystoscopy, but future confirmative studies with possibly refined technique are needed.

Standardized care pathways for patients with suspected urinary bladder cancer: the Swedish experience

OBJECTIVES

To compare time intervals to diagnosis and treatment, tumor characteristics, and management in patients with primary urinary bladder cancer, diagnosed before and after the implementation of a standardized care pathway (SCP) in Sweden.

MATERIALS AND METHODS

Data from the Swedish National Register of Urinary Bladder Cancer was studied before (2011-2015) and after (2016-2019) SCP. Data about time from referral to transurethral resection of bladder tumor (TURBT), patients and tumor characteristics, and management were analyzed. Subgroup analyses were performed for cT1 and cT2-4 tumors.

RESULTS

Out of 26,795 patients, median time to TURBT decreased from 37 to 27 days after the implementation of SCP. While the proportion of cT2-T4 tumors decreased slightly (22-21%, p < 0.001), this change was not stable over time and the proportions cN + and cM1 remained unchanged. In the subgroups with cT1 and cT2-4 tumors, the median time to TURBT decreased and the proportions of patients discussed at a multidisciplinary team conference (MDTC) increased after SCP. In neither of these subgroups was a change in the proportions of cN + and cM1 observed, while treatment according to guidelines increased after SCP in the cT1 group.

CONCLUSION

After the implementation of SCP, time from referral to TURBT decreased and the proportion of patients discussed at MDTC increased, although not at the levels recommended by guidelines. Thus, our findings point to the need for measures to increase adherence to SCP recommendations and to guidelines.

Automated artificial intelligence-based analysis of skeletal muscle volume predicts overall survival after cystectomy for urinary bladder cancer

BACKGROUND

Radical cystectomy for urinary bladder cancer is a procedure associated with a high risk of complications, and poor overall survival (OS) due to both patient and tumour factors. Sarcopenia is one such patient factor. We have developed a fully automated artificial intelligence (AI)-based image analysis tool for segmenting skeletal muscle of the torso and calculating the muscle volume.

METHODS

All patients who have undergone radical cystectomy for urinary bladder cancer 2011-2019 at Sahlgrenska University Hospital, and who had a pre-operative computed tomography of the abdomen within 90 days of surgery were included in the study. All patients CT studies were analysed with the automated AI-based image analysis tool. Clinical data for the patients were retrieved from the Swedish National Register for Urinary Bladder Cancer. Muscle volumes dichotomised by the median for each sex were analysed with Cox regression for OS and logistic regression for 90-day high-grade complications. The study was approved by the Swedish Ethical Review Authority (2020-03985).

RESULTS

Out of 445 patients who underwent surgery, 299 (67%) had CT studies available for analysis. The automated AI-based tool failed to segment the muscle volume in seven (2%) patients. Cox regression analysis showed an independent significant association with OS (HR 1.62; 95% CI 1.07-2.44; p = 0.022). Logistic regression did not show any association with high-grade complications.

CONCLUSION

The fully automated AI-based CT image analysis provides a low-cost and meaningful clinical measure that is an independent biomarker for OS following radical cystectomy.

Artificial intelligence-based measurements of PET/CT imaging biomarkers are associated with disease-specific survival of high-risk prostate cancer patients

OBJECTIVE

Artificial intelligence (AI) offers new opportunities for objective quantitative measurements of imaging biomarkers from positron-emission tomography/computed tomography (PET/CT). Clinical image reporting relies predominantly on observer-dependent visual assessment and easily accessible measures like SUV_max, representing lesion uptake in a relatively small amount of tissue. Our hypothesis is that measurements of total volume and lesion uptake of the entire tumour would better reflect the disease`s activity with prognostic significance, compared with conventional measurements.

METHODS

An AI-based algorithm was trained to automatically measure the prostate and its tumour content in PET/CT of 145 patients. The algorithm was then tested retrospectively on 285 high-risk patients, who were examined using ¹⁸F-choline PET/CT for primary staging between April 2008 and July 2015. Prostate tumour volume, tumour fraction of the prostate gland, lesion uptake of the entire tumour, and SUV_max were obtained automatically. Associations between these measurements, age, PSA, Gleason score and prostate cancer-specific survival were studied, using a Cox proportional-hazards regression model.

RESULTS

Twenty-three patients died of prostate cancer during follow-up (median survival 3.8 years). Total tumour volume of the prostate (p = 0.008), tumour fraction of the gland (p = 0.005), total lesion uptake of the prostate (p = 0.02), and age (p = 0.01) were significantly associated with disease-specific survival, whereas SUV_max (p = 0.2), PSA (p = 0.2), and Gleason score (p = 0.8) were not.

CONCLUSION

AI-based assessments of total tumour volume and lesion uptake were significantly associated with disease-specific survival in this patient cohort, whereas SUV_max and Gleason scores were not. The AI-based approach appears well-suited for clinically relevant patient stratification and monitoring of individual therapy.

Cumulative incidence of ureteroenteric strictures after radical cystectomy in a population-based Swedish cohort

OBJECTIVE

The incidence of benign ureteroenteric strictures following radical cystectomy (RC) for urinary bladder cancer (UBC) is investigated mainly in single-centre studies from high-volume centres. The aim of this study was to evaluate the cumulative incidence of strictures and risk factors in a population-based cohort.

PATIENTS AND METHODS

Data was collected from Bladder Cancer Data Base Sweden (BladderBaSe). The primary endpoint was stricture with intervention. Secondary endpoint included hydronephrosis both with/without intervention.

RESULTS

In total, 5,816 patients were registered as having had RC due to UBC between 1997 and 2014. After a median follow-up of 23.5 months (IQR = 9.0-63.1 months; range = 0.0-214.0 months), we found that 515 (8.9%) patients underwent intervention for stricture. Seven hundred and sixty-one (13.1%) patients were diagnosed with hydronephrosis without intervention. The cumulative incidence of strictures with intervention was 19.7% (95% CI = 16.7-23.1%) during the 17 years of follow-up. In the first year, the cumulative incidence of strictures was 5.6% (95% CI = 5.0-6.2%), and in the first 2 years 8.4% (95% CI = 7.6-9.3%). For the secondary endpoint, the cumulative incidence was 30.4% (95% CI = 26.7-33.1%) after 17 years. Only the year of RC was associated with stricture incidence in Cox regression analysis, whereas hospital cystectomy volume, patient age and patient sex were not.

CONCLUSION

Ureteroenteric strictures requiring intervention may be more common than previously reported, affecting nearly one fifth of patients who have undergone RC for UBC. The annual incidence was highest in the first 2 years after surgery but the cumulative incidence increased continuously during 17 years of follow-up.

Detection of any-stage cancer using plasma and urine glycosaminoglycans

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Background: Non-invasive liquid biopsies promise to enable early cancer detection and improve patient outcomes. However, virtually all liquid biopsies rely on genomic biomarkers, with limited sensitivity to early-stage tumors and poor detection of cancers shedding little cell-free DNA, like genitourinary or brain tumors. Here, we explored the use of plasma and urine glycosaminoglycan (GAGs) profiles, or GAGomes, as biomarkers reflective of tumor metabolism to serve as an alternative pan-cancer liquid biopsy. Methods: In this case-control study, we enrolled retrospective and prospective cohorts from Sweden and Italy. Included cases were treatment-naïve early-stage/low-grade cancers or metastatic/high-grade cancers across 14 histological types. Included controls were healthy 22-78 y/o adults with no history of cancer. We measured GAGomes – encompassing 17 chondroitin sulfate (CS), heparan sulfate (HS), and hyaluronate (HA) disaccharides - using a standardized UHPLC-MS/MS-based kit in a central blind laboratory. We tested the top GAGome features different in cancer using Bayesian estimation. These were used to design one plasma and one urine GAG score for the binary classification of cancer vs. control in a discovery set. We computed the area-under-the-curve (AUC), and sensitivity at 98% specificity of each GAG score in the validation set. A subset analysis was performed in early-stage/low-grade cancers only. In the subset of cases with survival records, we used multivariable Cox regression to estimate the hazard ratio (HR) for overall survival (OS) on each GAG score adjusted for cancer type, age, and gender. Results: GAGomes were measured in 753 plasma samples (460 cancers across 14 types, median age = 66 y/o, 51% female vs. 293 healthy adults, median age = 58 y/o, 57% female) and 559 urine samples (219 cancers across 5 types, median age = 69 y/o, 23% female vs. 340 healthy adults, median age = 56 y/o, 60% female). In the discovery set, the urine GAG score had an AUC = 0.80 (95% CI: 0.74-0.85, 124 cancers across 5 types vs. 184 controls) while the plasma GAG score had an AUC = 0.82 (95% CI: 0.78-0.86, 153 cancers across 14 types vs. 282 controls). In the validation set, the urine GAG score had an AUC = 0.78 (95% CI: 0.71-0.84, 95 cancers across 5 types vs. 156 controls) with 35% sensitivity at 98% specificity. The plasma GAG score had an AUC = 0.84 (95% CI: 0.79-0.88, 178 cancers across 14 types vs. 140 controls) with 41% sensitivity at 98% specificity. In the subset of early-stage/low-grade cancers, the AUC was 0.78 and 0.72 in plasma and urine, respectively. The plasma and urine GAG scores were independent predictors of OS regardless of cancer type (HR = 1.39, p = 0.005 in plasma [ N = 283, 11 types, 67 deaths, median follow-up 17 months] and HR = 1.53, p = 0.016 in urine [ N = 161, 4 types, 32 deaths, median follow-up 15 months]). Conclusions: GAGomes were sensitive non-invasive metabolic biomarkers for any-stage cancer, including genitourinary and brain tumors.

A retrospective study assessing the accuracy of [18F]-fluorocholine PET/CT for primary staging of lymph node metastases in intermediate and high-risk prostate cancer patients undergoing robotic-assisted laparoscopic prostatectomy with extended lymph node dissection

BACKGROUND

Previous studies have investigated [18F]-fluorocholine (FCH) positron emission tomography with computed tomography (PET/CT) in primary staging of men with intermediate or high-risk prostate cancer and have generally shown high specificity and poor sensitivity. FCH PET/CT is not recommended for the primary staging of metastases in the European guidelines for prostate cancer. However, it has been an option in the Swedish recommendations. Our aim was to assess PET/CT for primary staging of lymph node metastases before robotic-assisted laparoscopic prostatectomy (RALP) with extended pelvic lymph node dissection (ePLND) in patients with intermediate or high-risk prostate cancer.

METHOD

We identified all men with prostate cancer undergoing FCH PET/CT for initial staging followed by RALP and ePLND at Skåne University Hospital between 2015 and 2018. The result from PET/CT scan was compared with pathology report as the reference method for calculation of sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV).

RESULTS

In total, 252 patients were included in the final analysis. Among 85 patients with a suspicion of regional lymph node metastases on FCH PET/CT only 31 had pathology-proven metastases. The sensitivity was 43% (95% CI 0.32-0.55) and the specificity 70% (95% CI 0.63-0.76) for PET/CT to predict lymph node metastases. PPV was 36% and NPV was 75%. Risk group analyses showed similar results.

CONCLUSION

Our study emphasizes the poor performance of FCH PET/CT to predict lymph node metastasis in intermediate and high-risk prostate cancer. The method should be replaced with newer radiopharmaceuticals, such as prostate-specific membrane antigen ligands.

Artificial intelligence-based detection of lymph node metastases by PET/CT predicts prostate cancer-specific survival

INTRODUCTION

Lymph node metastases are a key prognostic factor in prostate cancer (PCa), but detecting lymph node lesions from PET/CT images is a subjective process resulting in inter-reader variability. Artificial intelligence (AI)-based methods can provide an objective image analysis. We aimed at developing and validating an AI-based tool for detection of lymph node lesions.

METHODS

A group of 399 patients with biopsy-proven PCa who had undergone ¹⁸ F-choline PET/CT for staging prior to treatment were used to train (n = 319) and test (n = 80) the AI-based tool. The tool consisted of convolutional neural networks using complete PET/CT scans as inputs. In the test set, the AI-based lymph node detections were compared to those of two independent readers. The association with PCa-specific survival was investigated.

RESULTS

The AI-based tool detected more lymph node lesions than Reader B (98 vs. 87/117; p = .045) using Reader A as reference. AI-based tool and Reader A showed similar performance (90 vs. 87/111; p = .63) using Reader B as reference. The number of lymph node lesions detected by the AI-based tool, PSA, and curative treatment was significantly associated with PCa-specific survival.

CONCLUSION

This study shows the feasibility of using an AI-based tool for automated and objective interpretation of PET/CT images that can provide assessments of lymph node lesions comparable with that of experienced readers and prognostic information in PCa patients.

Prostate volume and age are predictors of energy delivery using the CoreTherm Concept in patients with LUTS/BPO: a study on thermal dose

Objective: The primary aim of this study was to evaluate the scientific evidence supporting the use of thermal dose as a secondary (or an alternative) endpoint when using the CoreTherm Concept.Material and methods: Baseline and treatment data from 283 consecutive treatments were evaluated. All patients had lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH). After evaluation, benign prostatic enlargement (BPE) with benign prostatic obstruction (BPO) was evident. As treatment, the CoreTherm Concept was used in all patients with LUTS/BPO. Data parameters were retrospectively extracted and included patient age, prostate volume, energy delivery, treatment time and calculated cell kill. In addition, assessment of temperature curves and calculated intraprostatic blood flow was made to define an optimal treatment. In total, 199 treatments assessed as optimal were included in the study.Results: There was a significant correlation between pretreatment prostate volume and energy delivery (p < .001). Age also influenced energy consumption significantly (p = .01).Conclusion: The solid correlation between pretreatment prostate volume and age versus total energy deposition implies the recommendation that a pretreatment calculation of an appropriate energy deposition should be used in all treatments as an alternative treatment endpoint.

Development and validation of a prediction model for identifying men with intermediate- or high-risk prostate cancer for whom bone imaging is unnecessary: a nation-wide population-based study

Objective: To develop and validate a nomogram that identifies men for whom bone scan is unnecessary.Material and methods: The study datasets were derived from the National Prostate Cancer Register (NPCR) of Sweden. All men in the NPCR ≤80 years of age who were diagnosed with intermediate- or high-risk prostate cancer and who had pretreatment bone imaging (^99mTc MDP scintigraphy, plain x-ray, computed tomography, magnetic resonance imaging, and/or positron emission tomography fused with computed tomography) were included. Men diagnosed from 2015-2016 formed a development dataset and men diagnosed in 2017 formed a validation dataset. Outcome was metastasis on bone imaging as registered in NPCR. Multivariable logistic regression was used to develop a nomogram.Results: In the development dataset 482/5084 men (10%) had bone metastasis, the corresponding percentage in the validation dataset was 282/2554 (11%). Gleason grade group, clinical T stage, and prostate-specific antigen were included in the final model. Discrimination and calibration were satisfactory in both the development (AUC 0.80, 95% CI 0.78-0.82) and validation dataset (AUC 0.80, 95% CI, 0.77-0.82). Compared with using the EAU guidelines' recommendation for selecting men for imaging, using the nomogram with a cut-off at 4% chance of bone metastasis, would have avoided imaging in 519/2068 men (25%) and miss bone metastasis in 10/519 (2%) men in the validation dataset.Conclusion: By use of our nomogram, bone scans of men with prostate cancer can be avoided in a large proportion of men.

A randomised trial comparing two protocols for transrectal prostate repeat biopsy: six lateral posterior plus six anterior cores versus a standard posterior 12-core biopsy

Objective: To test the hypothesis that a combination of 6 posterior and 6 anterior cores detects more cancer than 12 posterior cores at a repeat transrectal prostate biopsy in men who have had one previous benign systematic biopsy.Patients and methods: Three hundred and forty men with persistently raised serum PSA were randomly allocated 1:1 to either a standard 12-core biopsy (12 cores from the lateral peripheral zone through a side-fire biopsy canal) or an experimental 12-core biopsy protocol with 6 anterior cores through an end-fire biopsy canal and 6 cores from the lateral peripheral zone through a side-fire biopsy canal. All biopsies were obtained transrectally with ultrasound guidance. The primary endpoint was cancer detection. Secondary endpoints were detection of ISUP Grade Groups/Gleason Grade Group ≥2 cancer, total biopsy cancer length and complications leading to medical intervention.Results: Prostate cancer was detected in 42/168 men (25%) in the experimental biopsy group and in 36/172 (21%) in the standard biopsy group (p = 0.44). The corresponding proportions for Gleason score ≥7 were 12% and 7% (p = 0.14). Median total cancer length was 4 (inter quartile range [IQR] = 1.5 - 6) mm in the end-fire group and 3 (IQR = 1.3 - 7) mm in the side-fire group. Ten men in the end-fire group and three in the side-fire group had a medical intervention for biopsy-related complications (p = 0.05).Conclusion: The biopsy protocol that included six end-fire anterior cores did not detect more cancer and was associated with more complications.Trial registration: ClinicalTrials.gov identifier: NCT02761135.

Pre-treatment 18F-choline PET/CT is prognostic for biochemical recurrence, development of bone metastasis, and cancer specific mortality following radical local therapy of high-risk prostate cancer

Background

The aim of this study was to determine whether lymph node metastasis on pre-treatment ¹⁸F-choline PET/CT is an independent prognostic factor for biochemical recurrence (BCR), skeletal metastasis, and cancer specific mortality (CSM), after radical local treatment (radical prostatectomy and/or radiotherapy) in men with high-risk prostate cancer. Medical records were reviewed for men with newly diagnosed high-risk prostate cancer who had pre-treatment ¹⁸F-choline positron emission tomography fused with computed tomography (PET/CT) scan for primary metastasis staging.

Results

Of 174 eligible men, 124 met the criteria for inclusion. The PET/CT scan was negative for metastasis in 97 (78%) men, inconclusive in 15 (12%), and positive in 12 (10%). The men with a positive PET/CT scan had significantly shorter time to BCR (p = 0.02), time to skeletal metastasis (p = 0.002), and time to prostate cancer specific death (p < 0.001). On multivariable Cox regression analysis, including also tumour stage, Gleason score, and PSA, a non-negative PET/CT scan was the only significant covariate for time to BCR (HR 2.6, 95% CI 1.3–5.5) and time to skeletal metastasis (HR 2.7, 95% CI 1.3–5.9).

Conclusions

In men with a newly diagnosed high-risk prostate cancer and a negative or inconclusive bone scan, ¹⁸F-choline uptake on PET/CT suggestive metastasis was associated with recurrence, progression to distant metastasis, and prostate cancer death. This strongly indicates that the choline uptakes represented metastasis and not false positive findings.

Use of a virtual reality, real-time, simulation model for the training of urologists in transurethral resection of the prostate

OBJECTIVE

There is a growing need to develop surgical skills outside the operating theatre. In this study we describe the development of a virtual reality training system for practising transurethral resection of the prostate (TURP).

MATERIAL AND METHODS

A face validity study was performed using a questionnaire sent to 28 experienced urologists to find out the ideal characteristics of a simulated TURP. Based on the comments a simulator was constructed and a content validity study was then performed in which nine experienced urologists tested the simulator and answered a second questionnaire. After corrections to the simulator, a basic construct validity test was performed.

RESULTS

We have developed a computer-based simulator based on the requirements listed by 17 urologists. It consists of a modified resectoscope connected to a haptic device and supported by a frame. The software provides a virtual view of the prostatic lumen and resectoscope tip, a haptic rendering that generates force feedback and a simulation module that computes the information from the haptic device, resectoscope fluid tap and handle and the foot pedals. The software also simulates bleeding, absorption of irrigation fluid and pressure gradients. Variables are measured and presented in a result file after each "operation". Nine experienced urologists performed a content validity study and changes were made accordingly. A basic construct validity test performed by seven inexperienced students showed a significant improvement in performance after they each performed six simulated procedures.

CONCLUSION

We have developed a simulator that may be used to practise TURP and which meets most of the demands raised in a face validity study. A basic construct validity test showed improved performance after repeated practice in the simulated environment.