Preoperative smoking and robot-assisted radical cystectomy outcomes & complications in multicenter KORARC database.

To investigate the influence of preoperative smoking history on the survival outcomes and complications in a cohort from a large multicenter database. Many patients who undergo radical cystectomy (RC) have a history of smoking; however, the direct association between preoperative smoking history and survival outcomes and complications in patients with muscle-invasive bladder cancer (MIBC) who undergo robot-assisted radical cystectomy (RARC) remains unexplored. We conducted a retrospective analysis using data from 749 patients in the Korean Robot-Assisted Radical Cystectomy Study Group (KORARC) database, with an average follow-up duration of 30.8 months. The cohort was divided into two groups: smokers (n = 351) and non-smokers (n = 398). Propensity score matching was employed to address differences in sample size and baseline demographics between the two groups (n = 274, each). Comparative analyses included assessments of oncological outcomes and complications. After matching, smoking did not significantly affect the overall complication rate (p = 0.121). Preoperative smoking did not significantly increase the occurrence of complications based on complication type (p = 0.322), nor did it increase the readmission rate (p = 0.076). There were no perioperative death in either group. Furthermore, preoperative smoking history showed no significant impact on overall survival (OS) [hazard ratio (HR) = 0.87, interquartile range (IQR): 0.54-1.42; p = 0.589] and recurrence-free survival (RFS) (HR = 1.12, IQR: 0.83-1.53; p = 0.458) following RARC for MIBC. The extent of preoperative smoking (≤ 10, 10-30, and ≥ 30 pack-years) had no significant influence on OS and RFS in any of the categories (all p > 0.05). Preoperative smoking history did not significantly affect OS, RFS, or complications in patients with MIBC undergoing RARC.

Successful robotic kidney transplantation for surgeons with no experience in minimally invasive surgery: a single institution experience.

BACKGROUND: Robotic kidney transplantation (RKT) is a novel and welcomed innovation yielding good surgical outcomes. However, data on the feasibility and safety of performing RKT by surgeons with a lack of prior minimally invasive surgery (MIS) experience are limited. The authors aimed to evaluate the surgical and functional results of RKT and present the learning curves (LC) of RKT by a single surgeon with no prior experience in MIS. MATERIALS AND METHODS: This was a retrospective study of all RKT performed between November 2019 and April 2023 at Severance Hospital in Seoul, South Korea. The authors analyzed surgical and functional outcomes, as well as complication rates of RKT in comparison to open kidney transplantation (OKT). The authors evaluated LCs using the cumulative summation method to describe the number of cases associated with the competency of a single surgeon. RESULTS: A total of 50 patients who underwent RKT and 104 patients who underwent OKT were included in this study. In RKT group, the median surgical console time was 193 min (interquartile range, 172-222) and the median vascular anastomoses time was 38 min (35-44). Total operation time was 323 min (290-371) and rewarming time was 62.5 min (56.0-70.0) in RKT group compared to 210 min (190-239) and 25 min (21-30), respectively, in OKT group. Despite extended surgical durations with a robotic technique, both groups had comparable intraoperative and postoperative outcomes, as well as renal function. Estimated blood loss and post-transplant hospital stays were significantly lower in RKT group than in OKT group. LC analysis of RKT by the single surgeon revealed that surgical competence was achieved after 15 cases. CONCLUSION: Even if surgeons do not have prior experience with MIS, they can rapidly overcome the LC and safely perform RKT with adequate preparation and acquisition of basic robotic surgical techniques.

Superiority of magnetic resonance imaging in small renal mass diagnosis where image reports mismatches between computed tomography and magnetic resonance imaging.

PURPOSE: To analyze malignancy of computed tomography (CT) and magnetic resonance imaging (MRI) results in the same renal mass. MATERIALS AND METHODS: We retrospectively reviewed 1,216 patients who underwent partial nephrectomy from January 2017 to December 2021 in our institute. Patients who had both CT and MRI reports prior to surgery were included. We compared the diagnostic accuracy between the CT and the MRI. The patients were divided into two groups according to the consistency of reports: the 'Consistent group' and the 'Inconsistent group'. The Inconsistent group was further divided into two subgroups. Group 1 is the case that showed benign findings on CT but malignancy on MRI. Group 2 is the cases of malignancy on CT but benign on MRI. RESULTS: 410 patients were identified. Benign lesion was identified in 68 cases (16.6%). The sensitivity, specificity and diagnostic accuracy of MRI was 91.2%, 36.8%, and 82.2% respectively, whereas that of CT was 84.8%, 41.2%, and 77.6% respectively. Consistent group were 335 cases (81.7%) and inconsistent group were 75 cases (18.3%). The mean mass size was significantly smaller in the inconsistent group compared to the consistent group (consistent group vs. inconsistent group: 2.31±0.84 cm vs.1.84±0.75 cm, p<0.001). Also, the Group 1 had higher odds of malignancy compared to Group 2 in the renal mass size 2-4 cm (odds ratio, 5.62 [1.02-30.90]). CONCLUSIONS: Smaller mass size affects the discrepancy of CT and MRI reports. In addition, MRI showed better diagnostic performance in mismatch cases in the small renal masses.

Robotic ureter reconstruction using the native ureter to treat long-segment ureteral stricture of the transplant kidney utilizing Indocyanine green: The first Korean experience.

PURPOSE: Ureteral strictures are a common complication after kidney transplantation. Open reconstruction is preferred for long-segment ureteral strictures that cannot be resolved endoscopically; however, it is known to have the potential to fail. We report 2 successful cases of robotic reconstruction surgery of a transplant ureter using the native ureter with the aid of intraoperative Indocyanine green (ICG). MATERIALS AND METHODS: Patients were placed in semi-lateral position. Using Da Vinci Xi, the transplant ureter was dissected, and the stricture site was identified. End-to-side anastomosis of the native ureter to the transplant ureter was performed. ICG was utilized to identify the course of the transplant ureter and confirm the vascularity of the native ureter. RESULTS: Case 1: A 55-year-old female underwent renal transplantation at another hospital. She had recurrent febrile urinary tract infections (UTIs) and a ureteral stricture requiring percutaneous nephrostomy (PCN). The PCN and ureteral stent were removed successfully after surgery. The patient had only 1 febrile UTI episode after surgery. Case 2: A 56-year-old female underwent renal transplantation at another hospital. She had acute pyelonephritis 1-month post-transplantation, and a long-segment ureteral stricture was identified. She developed a UTI with anastomosis site leakage in the early postoperative period, which resolved with conservative treatment. The PCN and ureteral stent were removed 6 weeks after surgery. CONCLUSIONS: Robotic surgery for managing long-segment ureteral stricture after kidney transplantation is safe and feasible. The use of ICG during surgery to identify the ureter course and its viability can improve the success.

Ultra-soft and highly stretchable tissue-adhesive hydrogel based multifunctional implantable sensor for monitoring of overactive bladder.

A highly stretchable and tissue-adhesive multifunctional sensor based on structurally engineered islets embedded in ultra-soft hydrogel is reported for monitoring of bladder activity in overactive bladder (OAB) induced rat and anesthetized pig. The use of hydrogel yielded a much lower sensor modulus (1 kPa) compared to that of the bladder (300 kPa), while the strong adhesiveness of the hydrogel (adhesive strength: 260.86 N/m) allowed firm attachment onto the bladder. The change in resistance of printed liquid metal particle thin-film lines under strain were used to detect bladder inflation and deflation; due to the high stretchability and reliability of the lines, surface strains of 200% could be measured repeatedly. Au electrodes coated with Platinum black were used to detect electromyography (EMG). These electrodes were placed on structurally engineered rigid islets so that no interfacial fracture occurs under high strains associated with bladder expansion. On the OAB induced rat, stronger signals (change in resistance and EMG root-mean-square) were detected near intra-bladder pressure maxima, thus showing correlation to bladder activity. Moreover, using robot-assisted laparoscopic surgery, the sensor was placed onto the bladder of an anesthetized pig. Under voiding and filling, bladder strain and EMG were once again monitored. These results confirm that our proposed sensor is a highly feasible, clinically relevant implantable device for continuous monitoring OAB for diagnosis and treatment.

Synergic Effect of Metformin and Everolimus on Mitochondrial Dynamics of Renal Cell Carcinoma.

Renal cell carcinoma (RCC) frequently recurs or metastasizes after surgical resection. Everolimus, an mTOR inhibitor, is used as a second-line treatment, but the response of RCC to everolimus is insufficient. Metformin is an antidiabetic drug; recent reports have indicated its anti-cancer effects in various cancers, and it is known to have synergistic effects with other drugs. We investigated the possibility of coadministering everolimus and metformin as an effective treatment for RCC. RCC cells treated with a combination of the two drugs showed significantly inhibited cell viability, cell migration, and invasion, and increased apoptosis compared to those treated with each drug alone. An anti-cancer synergistic effect was also confirmed in the xenograft model. Transcriptome analysis for identifying the underlying mechanism of the combined treatment showed the downregulation of mitochondrial fusion genes and upregulation of mitochondrial fission genes by the combination treatment. Changes in mitochondrial dynamics following the combination treatment were observed using LysoTracker, LysoSensor, and JC-1 staining. In conclusion, the combination of everolimus and metformin inhibited RCC growth by disrupting mitochondrial dynamics. Therefore, we suggest that a treatment combining metformin and everolimus disrupts mitochondrial dynamics in RCC, and may be a novel strategy for RCC treatment.

Mitochondrial metabolic reprogramming by SIRT3 regulation ameliorates drug resistance in renal cell carcinoma.

Clear cell renal cell carcinoma (ccRCC) alters metabolic signals frequently, leading to mitochondrial dysfunction, such as increase of glycolysis and accumulation of lipid. Sirtuin3 (SIRT3) is a key factor for the regulation of both mitochondrial integrity and function. SIRT3 is downregulated and contributes in both cancer development and progression in ccRCC. The aim of this study is to investigate SIRT3-regulated mitochondrial biogenesis in ccRCC. SIRT3 overexpression alone reduced glucose uptake rate and enhanced membrane potential in mitochondria. ccRCC with overexpressed SIRT3 further improved the lethal effects when combined with anticancer drugs (Resveratrol, Everolimus and Temsirolimus). Cell viability was markedly decreased in a dose-dependent manner when treated with resveratrol or mTOR inhibitors in SIRT3 overexpressing ccRCC. In conclusion, SIRT3 improved mitochondrial functions in ccRCC through metabolic reprogramming. Mitochondrial reprogramming by SIRT3 regulation improves the sensitivity to anticancer drugs. The combination of SIRT3 and resveratrol functioned synergistically lethal effect in ccRCC.

Clinical Implications for da Vinci SP Partial Nephrectomy in High-Complexity Tumors: Propensity Score-Matching Analysis.

Purpose: To compare surgical outcomes between robot-assisted laparoendoscopic single-site (R-LESS) surgery using the da Vinci Si or Xi system and the da Vinci SP system for partial nephrectomy. Materials and Methods: From 2008 to 2020, 66 partial nephrectomies were performed using a single-site robotic approach: 44 used the da Vinci Xi or Si system (R-LESS group) and 22 used the da Vinci SP system (SP group). After 1:1 propensity score matching, surgical outcomes were compared between groups. Results: Median patient age was 51.5 years. Median tumor size was 2.1 cm and was not significantly different between groups. Median operation time was longer in the R-LESS group (R-LESS vs SP: 180 vs 155 minutes, p = 0.034), but median warm ischemic time was comparable between groups. Estimated blood loss was higher in the R-LESS group (R-LESS vs SP: 215 vs 20 mL, p < 0.001). Median operation time was significantly shorter in the SP group in patients with moderate- to high-complexity tumors (R-LESS vs SP: 200 vs 172 minutes, p = 0.035). Rates of trifecta achievement were similar between groups (63.6% in both groups, p = 1.00). Conclusions: R-LESS and da Vinci SP methods are both feasible approaches for single-site incision robotic partial nephrectomy. The da Vinci SP platform allows "true" single-site surgery without additional ports and provides a wider working space. It was associated with better performance than R-LESS partial nephrectomy. In complex tumors, operation time was shorter with SP partial nephrectomy than with R-LESS partial nephrectomy, suggesting that the SP method is especially advantageous for managing complex renal tumors.

The first robotic kidney transplantation in Korea: a case report.

Minimally invasive surgery reduces perioperative pain and morbidity, facilitating rapid recovery. However, the field of kidney transplantation has lagged in this regard, its customary open surgical techniques going nearly unchanged until recently. Robotic kidney transplantation (RKT) is a novel and welcomed innovation yielding good surgical outcomes. In Korea, the first RKT performed (November 2019) involved a 30-year-old man (body mass index, 22 kg/m2) with end-stage hypertensive nephrosclerosis. A left donor kidney from his 28-year-old sister was successfully transplanted using the daVinci Robotic Surgical System. Transperitoneal regional hypothermia (Vattikuti Urology Institute-Medanta technique) was also implemented across the main periumbilical incision (up to 6 cm). Total operative time was 260 minutes (cold ischemia, 34 minutes; rewarming, 54 minutes), with 50 mL of blood loss. There was immediate graft function, unencumbered by surgical complications (e.g., postoperative bleeding, leakage, or lymphocele). The patient was discharged on postoperative day 8, with serum creatinine at 1.27 mg/dL. RKT with regional hypothermia may be a viable, minimally invasive intervention that is safe and effective in select patients, showing good surgical results.

Diagnostic accuracy of prostate-specific antigen below 4 ng/mL as a cutoff for diagnosing prostate cancer in a hospital setting: A systematic review and meta-analysis.

PURPOSE: A prostate-specific antigen (PSA) cutoff of 4 ng/mL has been widely used for prostate cancer screening in population-based settings. However, the accuracy of PSA below 4 ng/mL as a cutoff for diagnosing prostate cancer in a hospital setting is inconclusive. We systematically reviewed the accuracy of PSA below 4 ng/mL cutoff in a hospital setting. MATERIALS AND METHODS: We systematically reviewed the literature by searching major databases until March 2020, and a meta-analysis and quality assessment were performed. RESULTS: A total of 11 studies were included at the completion of the screening process. The meta-analysis showed a sensitivity of 0.92 and a specificity of 0.16 for a PSA cutoff below 4 ng/mL. The area under the hierarchical summary receiver operating characteristic curve was 0.87, the positive likelihood ratio was 1.23, the negative likelihood ratio was 0.46, and the diagnostic odds ratio was 2.64. PSA sensitivities and specificities varied according to the cutoff range: 0.94 and 0.17 for 2 to 2.99 ng/mL, and 0.92 and 0.16 for 3 to 3.99 ng/mL, respectively. No significant differences in the sensitivity and specificity of PSA cutoffs in the range of 2 to 2.99 ng/mL and 3 to 3.99 ng/mL were found. CONCLUSIONS: Although a PSA cutoff <3 ng/mL is relatively more sensitive and specific than PSA ≥3 ng/mL, no significant differences in sensitivity and specificity were found in the diagnosis of prostate cancer. Therefore, clinicians should choose an appropriate PSA cutoff on the basis of clinical circumstances and patients' characteristics.

Pure single-port retzius-sparing robot-assisted radical prostatectomy with the da Vinci SP: Initial experience and technique description.

Objective: To assess the feasibility and safety of pure single-port (SP) retzius-sparing robot-assisted radical prostatectomy (RARP) using the da Vinci SP and describe the technique. Materials and Methods: From August 2020 to November 2020, data of 10 consecutive patients with localized prostate cancer, who underwent SP retzius-sparing RARP, were prospectively collected. Patients demographics, intraoperative variables, postoperative complications, early oncological, and functional outcomes were assessed. Results: The patients were aged 46-73 years with a body mass index between 20.3 and 27.4 kg/m2. Prostate volumes ranged from 15 to 47.2 ml, with a median (interquartile range, IQR) PSA level of 7.4 (6.2-9.1) ng/ml. All surgeries were successfully completed without conversion. The median (IQR) operative and console time were 106 (101-109) min and 65 (63-68) min, respectively. The median (IQR) blood loss was 125 (50-150) ml, and one Clavien-Dindo grade I complication occurred. At 3 months, nine patients had undetectable PSA levels and all patients were continent. Conclusions: Pure SP retzius-sparing RARP could be safely performed using the da Vinci SP system, with acceptable surgical times and minimal complications. Future research will evaluate the advantages of this technique over the standard multiport robotic surgery.

Predicting factor analysis of postoperative complications after robot-assisted radical cystectomy: Multicenter KORARC database study.

OBJECTIVES: To evaluate postoperative complications following robot-assisted radical cystectomy in patients diagnosed with bladder cancer and reveal if there are predictors for postoperative complications. METHODS: Prospectively collected medical records of 730 robot-assisted radical cystectomy patients between 2007/04 and 2019/05 in 13 tertiary referral centers were reviewed. Perioperative outcomes were compared between two groups by postoperative complications (complication vs non-complication). We assessed recurrence-free survival, cancer-specific survival, and overall survival between groups. Regression analyses were implemented to identify factors associated with postoperative complications. RESULTS: Any total and high-grade complication (Clavien-Dindo grade ≥3) rates were 57.8% and 21.1%, respectively. Patients in complication group had significantly higher proportion of diabetes mellitus (P = 0.048), chronic kidney disease (P = 0.011), dyslipidemia (P < 0.001), longer operation time (P = 0.001), more estimated blood loss (P = 0.001), and larger intraoperative fluid volume (P < 0.001). There was a significant difference in cancer-specific survival (log-rank P = 0.038, median cancer-specific survival: both groups not reached). Dyslipidemia (odds ratio 2.59, P = 0.002) and intraoperative fluid volume (odds ratio 1.0002, P = 0.040) were significantly associated with high-grade postoperative complications. Diabetes mellitus (odds ratio 1.97, P = 0.028), chronic kidney disease (odds ratio 1.89, P = 0.046), dyslipidemia (odds ratio 5.94, P = 0.007), and intraoperative fluid volume (odds ratio 1.0002, P = 0.009) were significantly associated with any postoperative complications. CONCLUSIONS: Patients with diabetes mellitus, chronic kidney disease, dyslipidemia, or a relatively large intraoperatively infused fluid volume are more likely to develop postoperative complications. Patients with postoperative complications might have a possibility of lower cancer-specific survival rate.

Gender-related outcomes in robot-assisted radical cystectomy: A multi-institutional study.

PURPOSE: Robot-assisted radical cystectomy (RARC) optimizes patient recovery and has outcomes comparable with those of open surgery. This study aimed to compare the perioperative and oncologic outcomes of RARC in female and male patients. MATERIALS AND METHODS: A retrospective cohort study of the Korean Robot-Assisted Radical Cystectomy Study Group database from 2007 to 2019 identified 749 patients (111 females and 638 males). Female were matched 1:1 to male by propensity score matching using a logistic regression. We compared perioperative outcomes, oncologic outcomes, and complications between the two groups. RESULTS: The female group had comparable perioperative outcomes to the male group in terms of operation time, lymph node yield, positive surgical margin, blood transfusion rate, and hospitalization days. Complication rate and grade were not significantly different between the two groups. The most common complication was infection in female and gastrointestinal complications in male. We compared the 5-year overall, disease-specific, and recurrence-free survival of female and male: 58.2% vs. 68.0% (p=0.495), 75.7% vs. 79.3% (p=0.645), and 40.8% vs. 53.5% (p=0.913), respectively. On multivariable analysis, T stage (>T2), postoperative complications, and positive surgical margin were prognostic factors of poor outcome. Sex was not an independent predictor of the three survivals. CONCLUSIONS: The current study suggests that RARC in female has comparable perioperative and oncologic outcomes to those in male. The complication rate of RARC in female was comparable to that in male, but the type of complications differed by sex.

Evaluation of the Surgical Margin Threshold for Avoiding Recurrence after Partial Nephrectomy in Patients with Renal Cell Carcinoma.

PURPOSE: An adequate minimal surgical margin for partial nephrectomy (PN) has not yet been conclusively established. Therefore, we aimed to compare PN recurrence rates according to surgical margin status and to establish an adequate minimal surgical margin. MATERIALS AND METHODS: We retrospectively studied patients with clinically localized renal cell carcinoma who underwent PN between 2005 and 2014. Surgical margin width (SMW) was assessed for all surgical tissues and divided into three groups: SMW <1 mm, SMW ≥1 mm, and positive surgical margin (PSM). The data were analyzed using the Kaplan-Meier method with log-rank tests and multivariate Cox regression models. RESULTS: Of 748 patients (median age, 55 years; interquartile range, 46-64 years; 220 female), 704 (94.2%) and 44 (5.8%) patients had negative and PSMs, respectively. Recurrence-free survival was significantly lower in patients with PSMs (p<0.001) and was not significantly different between SMW ≥1 mm and <1 mm groups (p=0.604). PSM was a significant predictor of recurrence (hazard ratio: 8.03, 95% confidence interval: 2.74-23.56, p<0.001), in contrast to SMW <1 mm (p=0.680). CONCLUSION: A PSM after PN significantly increases the risk of recurrence. We discovered that even a submillimeter safety surgical margin may be enough to prevent recurrence. To maximize normal renal parenchyma preservation and to avoid cancer recurrence in renal parenchymal tumor patients, PN may be a safe treatment, except for those with a PSM in the final pathology.

Comparing Revo-i and da Vinci in Retzius-Sparing Robot-Assisted Radical Prostatectomy: A Preliminary Propensity Score Analysis of Outcomes.

Purpose: This study aims to compare perioperative and oncologic outcomes between matched cohorts of localized prostate cancer (PCa) operated on by the same surgeon using the da Vinci Si robot and the Revo-i robot. Materials and Methods: Nonmetastatic PCa patients undergoing Retzius-sparing robot-assisted laparoscopic radical prostatectomy (RS-RARP) from January 2016 to December 2020 were matched one-to-one (33:33) to da Vinci Si controls using propensity score matching according to the following covariates: age, American Society of Anesthesiology (ASA) score, body mass index, previous abdominal and endoscopic surgery, preoperative prostate specific antigen, prostate volume, Gleason grade group, tumor stage, and need for pelvic lymphadenectomy. Outcomes of interest were estimated blood loss, length of stay, complication rate, operative times, positive surgical margins, and biochemical recurrence at 6 months. Results: Both cohorts were similar in estimated blood loss, rate of margin positivity, and rate of complications. Length of stay was significantly shorter with the Revo-i cohort. The da Vinci robot showed faster console, suture, and total operation times. Positive margin rate and biochemical recurrence at 6 months were similar in both groups. Conclusion: Despite the longer suture, console, and operative time those in the da Vinci robot in the authors' institution, the Revo-i robot-assisted radical prostatectomy had equivalent short-term oncologic outcomes with the da Vinci standard.

Future Platforms of Robotic Surgery.

Among the various robotic devices that exist for urologic surgery, the most common are synergistic telemanipulator systems. Several have achieved clinical feasibility and have been licensed for use in humans: the standard da Vinci, Avatera, Hinotori, Revo-i, Senhance, Versius, and Surgenius. Handheld and hands-on synergistic systems are also clinically relevant for use in urologic surgeries, including minimally invasive and endoscopic approaches. Future trends of robotic innovation include an exploration of more robust haptic systems that offer kinesthetic and tactile feedback; miniaturization and microrobotics; enhanced visual feedback with greater magnification and higher fidelity detail; and autonomous robots.

Computed Tomography-Derived Skeletal Muscle Radiodensity Is an Early, Sensitive Marker of Age-Related Musculoskeletal Changes in Healthy Adults.

BACKGROUND: A decrease in computed tomography (CT)-derived skeletal muscle radiodensity (SMD) reflects age-related ectopic fat infiltration of muscle, compromising muscle function and metabolism. We investigated the age-related trajectory of SMD and its association with vertebral trabecular bone density in healthy adults. METHODS: In a cohort of healthy adult kidney donors aged 19 to 69 years (n=583), skeletal muscle index (SMI, skeletal muscle area/height2), SMD, and visceral-to-subcutaneous fat (V/S) ratio were analyzed at the level of L3 from preoperative CT scans. Low bone mass was defined as an L1 trabecular Hounsfield unit (HU) <160 HU. RESULTS: L3SMD showed constant decline from the second decade (annual change -0.38% and -0.43% in men and women), whereas the decline of L3SMI became evident only after the fourth decade of life (-0.37% and -0.18% in men and women). One HU decline in L3SMD was associated with elevated odds of low bone mass (adjusted odds ratio, 1.07; 95% confidence interval, 1.02 to 1.13; P=0.003), independent of L3SMI, age, sex, and V/S ratio, with better discriminatory ability compared to L3SMI (area under the receiver-operating characteristics curve 0.68 vs. 0.53, P<0.001). L3SMD improved the identification of low bone mass when added to age, sex, V/S ratio, and L3SMI (category-free net reclassification improvement 0.349, P<0.001; integrated discrimination improvement 0.015, P=0.0165). CONCLUSION: L3SMD can be an early marker for age-related musculoskeletal changes showing linear decline throughout life from the second decade in healthy adults, with potential diagnostic value for individuals with low bone mass.

Development of prediction models of spontaneous ureteral stone passage through machine learning: Comparison with conventional statistical analysis.

OBJECTIVES: To develop a prediction model of spontaneous ureteral stone passage (SSP) using machine learning and logistic regression and compare the performance of the two models. Indications for management of ureteral stones are unclear, and the clinician determines whether to wait for SSP or perform active treatment, especially in well-controlled patients, to avoid unwanted complications. Therefore, suggesting the possibility of SSP would help make a clinical decision regarding ureteral stones. METHODS: Patients diagnosed with unilateral ureteral stones at our emergency department between August 2014 and September 2018 were included and underwent non-contrast-enhanced computed tomography 4 weeks from the first stone episode. Predictors of SSP were applied to build and validate the prediction model using multilayer perceptron (MLP) with the Keras framework. RESULTS: Of 833 patients, SSP was observed in 606 (72.7%). SSP rates were 68.2% and 75.6% for stone sizes 5-10 mm and <5 mm, respectively. Stone opacity, location, and whether it was the first ureteral stone episode were significant predictors of SSP. Areas under the curve (AUCs) for receiver operating characteristic (ROC) curves for MLP, and logistic regression were 0.859 and 0.847, respectively, for stones <5 mm, and 0.881 and 0.817, respectively, for 5-10 mm stones. CONCLUSION: SSP prediction models were developed in patients with well-controlled unilateral ureteral stones; the performance of the models was good, especially in identifying SSP for 5-10-mm ureteral stones without definite treatment guidelines. To further improve the performance of these models, future studies should focus on using machine learning techniques in image analysis.

Metabolic tumour volume on 18F-FDG PET/CT predicts extended pathological T stages in patients with renal cell carcinoma at staging.

We evaluated the predictive value of 18F-fluorodeoxyglucose (FDG) uptake on positron emission tomography/CT (PET/CT) for extended pathological T (pT) stages (≥ pT3a) in Renal cell carcinoma (RCC) patients at staging. Thirty-eight RCC patients who underwent 18F-FDG PET/CT at staging, followed by radical nephrectomy between September 2016 and September 2018, were included in this prospective study. Patients were classified into two groups (limited pT stage: stage T1/2, n = 17; extended pT stage: T3/4, n = 21). Univariate and multivariate logistic regression analyses were performed to identify clinicopathological and metabolic variables to predict extended pT stages. 18F-FDG metabolic parameters were compared in relation to International Society of Urological Pathology (ISUP) grade and lymphovascular invasion (LVI). In univariate analysis, maximum standardised uptake value, metabolic tumour volume (MTV), and ISUP grade were significant. In multivariate analysis, MTV was the only significant factor of extended pT stages. With a cut-off MTV of 21.2, an area under the curve was 0.944, which was higher than 0.824 for clinical T stages (p = 0.037). In addition, high MTV, but not tumour size, was significantly correlated with aggressive pathologic features (ISUP grade and LVI). High glycolytic tumour volume on 18F-FDG PET/CT in RCC patients at staging is predictive of extended pT stages which could aid decision-making regarding the best type of surgery.

Glycolysis on F-18 FDG PET/CT Is Superior to Amino Acid Metabolism on C-11 Methionine PET/CT in Identifying Advanced Renal Cell Carcinoma at Staging.

We evaluated the value of F-18 fluorodeoxyglucose (FDG) and C-11 methionine positron emission tomography/computed tomography (PET/CT) to predict high-Fuhrman grade and advanced-stage tumours in patients with renal cell carcinoma (RCC). Forty patients with RCC underwent F-18 FDG and C-11 methionine PET/CT between September 2016 and September 2018. They were classified into limited (stages I and II, n = 15) or advanced stages (stages III and IV, n = 25) according to pathological staging. Logistic regressions were used to predict the advanced stage using various parameters, including maximum standardised uptake value (SUVmax) and metabolic tumour volume (MTV). Receiver operating characteristic analyses were performed to predict high-grade tumours (Fuhrman 3 and 4). On univariate analysis, tumour size, SUVmax and MTV of F-18 FDG and C-11 methionine, and Fuhrman grades were significant predictors for the advanced stage. On multivariate analysis, F-18 FDG MTV > 21.3 cm3 was the most significant predictor (p < 0.001). The area under the curve for predicting high-grade tumours was 0.830 for F-18 FDG (p < 0.001) and 0.726 for C-11 methionine PET/CT (p = 0.014). In conclusion, glycolysis on F-18 FDG PET/CT and amino acid metabolism on C-11 methionine PET/CT were variable but increased in high-grade RCCs. Increased MTV on F-18 FDG PET/CT is a powerful predictor of advanced-stage tumours.