Prediction models of incontinence and sexual function one year after radical prostatectomy based on data from 20 164 prostate cancer patients.

BACKGROUND: Incontinence and sexual dysfunction are long-lasting side effects after surgical treatment (radical prostatectomy, RP) of prostate cancer (PC). For an informed treatment decision, physicians and patients should discuss expected impairments. Therefore, this paper firstly aims to develop and validate prognostic models that predict incontinence and sexual function of PC patients one year after RP and secondly to provide an online decision making tool. METHODS: Observational cohorts of PC patients treated between July 2016 and March 2021 in Germany were used. Models to predict functional outcomes one year after RP measured by the EPIC-26 questionnaire were developed using lasso regression, 80-20 splitting of the data set and 10-fold cross validation. To assess performance, R2, RMSE, analysis of residuals and calibration-in-the-large were applied. Final models were externally temporally validated. Additionally, percentages of functional impairment (pad use for incontinence and firmness of erection for sexual score) per score decile were calculated to be used together with the prediction models. RESULTS: For model development and internal as well as external validation, samples of 11 355 and 8 809 patients were analysed. Results from the internal validation (incontinence: R2 = 0.12, RMSE = 25.40, sexual function: R2 = 0.23, RMSE = 21.44) were comparable with those of the external validation. Residual analysis and calibration-in-the-large showed good results. The prediction tool is freely accessible: https://nora-tabea.shinyapps.io/EPIC-26-Prediction/. CONCLUSION: The final models showed appropriate predictive properties and can be used together with the calculated risks for specific functional impairments. Main strengths are the large study sample (> 20 000) and the inclusion of an external validation. The models incorporate meaningful and clinically available predictors ensuring an easy implementation. All predictions are displayed together with risks of frequent impairments such as pad use or erectile dysfunction such that the developed online tool provides a detailed and informative overview for clinicians as well as patients.

Cluster-based stability evaluation in time series data sets.

In modern data analysis, time is often considered just another feature. Yet time has a special role that is regularly overlooked. Procedures are usually only designed for time-independent data and are therefore often unsuitable for the temporal aspect of the data. This is especially the case for clustering algorithms. Although there are a few evolutionary approaches for time-dependent data, the evaluation of these and therefore the selection is difficult for the user. In this paper, we present a general evaluation measure that examines clusterings with respect to their temporal stability and thus provides information about the achieved quality. For this purpose, we examine the temporal stability of time series with respect to their cluster neighbors, the temporal stability of clusters with respect to their composition, and finally conclude on the temporal stability of the entire clustering. We summarise these components in a parameter-free toolkit that we call Cluster Over-Time Stability Evaluation (CLOSE). In addition to that we present a fuzzy variant which we call FCSETS (Fuzzy Clustering Stability Evaluation of Time Series). These toolkits enable a number of advanced applications. One of these is parameter selection for any type of clustering algorithm. We demonstrate parameter selection as an example and evaluate results of classical clustering algorithms against a well-known evolutionary clustering algorithm. We then introduce a method for outlier detection in time series data based on CLOSE. We demonstrate the practicality of our approaches on three real world data sets and one generated data set.

Mechanical properties of polycaprolactone (PCL) scaffolds for hybrid 3D-bioprinting with alginate-gelatin hydrogel.

The generation of artificial human tissue by 3D-bioprinting has expanded significantly as a clinically relevant research topic in recent years. However, to produce a complex and viable tissue, in-depth biological understanding and advanced printing techniques are required with a high number of process parameters. Here, we systematically evaluate the process parameters relevant for a hybrid bioprinting process based on fused-deposition modeling (FDM) of thermoplastic material and microextrusion of a cell-laden hydrogel. First, we investigated the effect of the printing temperature of polycaprolactone (PCL), on the junction strength between individual fused filaments and on the viability of immortalized mesenchymal stem cells (iMSC) in the surrounding alginate-gelatin-hydrogel. It was found that a printing temperature of 140 °C and bonds with an angle of 90° between the filaments provided a good compromise between bonding strength of the filaments and the viability of the surrounding cells. Using these process parameters obtained from individual fused filaments, we then printed cubic test structures with a volume of 10 × 10 × 10 mm3 with different designs of infill patterns. The variations in mechanical strength of these cubes were measured for scaffolds made of PCL-only as well as for hydrogel-filled PCL scaffolds printed by alternating hybrid bioprinting of PCL and hydrogel, layer by layer. The bare scaffolds showed a compressive modulus of up to 6 MPa, close to human hard tissue, that decreased to about 4 MPa when PCL was printed together with hydrogel. The scaffold design suited best for hybrid printing was incubated with cell-laden hydrogel and showed no degradation of its mechanical strength for up to 28 days.

Variation across operating sites in urinary and sexual outcomes after radical prostatectomy in localized and locally advanced prostate cancer.

PURPOSE: The extent of variation in urinary and sexual functional outcomes after radical prostatectomy (RPE) between prostate cancer (PC) operating sites remains unknown. Therefore, this analysis aims to compare casemix-adjusted functional outcomes (EPIC-26 scores incontinence, irritative/obstructive function and sexual function) between operating sites 12 months after RPE. MATERIALS AND METHODS: Analysis of a cohort of 7065 men treated with RPE at 88 operating sites (prostate cancer centers, "PCCs") between 2016 and 2019. Patients completed EPIC-26 and sociodemographic information surveys at baseline and 12 months after RPE. Survey data were linked to clinical data. EPIC-26 domain scores at 12 months after RPE were adjusted for relevant confounders (including baseline domain score, clinical and sociodemographic information) using regression analysis. Differences between sites were described using minimal important differences (MIDs) and interquartile ranges (IQR). The effects of casemix adjustment on the score results were described using Cohen's d and MIDs. RESULTS: Adjusted domain scores at 12 months varied between sites, with IQRs of 66-78 (incontinence), 89-92 (irritative/obstructive function), and 20-29 (sexual function). Changes in domain scores after casemix adjustment for sites ≥ 1 MID were noted for the incontinence domain (six sites). Cohen's d ranged between - 0.07 (incontinence) and - 0.2 (sexual function), indicating a small to medium effect of casemix adjustment. CONCLUSIONS: Variation between sites was greatest in the incontinence and sexual function domains for RPE patients. Future research will need to identify the factors contributing to this variation. TRIAL REGISTRY: The study is registered at the German Clinical Trial Registry ( https://www.drks.de/drks_web/ ) with the following ID: DRKS00010774.

Artificial intelligence-based automatic assessment of lower limb torsion on MRI.

Abnormal torsion of the lower limbs may adversely affect joint health. This study developed and validated a deep learning-based method for automatic measurement of femoral and tibial torsion on MRI. Axial T2-weighted sequences acquired of the hips, knees, and ankles of 93 patients (mean age, 13 ± 5 years; 52 males) were included and allocated to training (n = 60), validation (n = 9), and test sets (n = 24). A U-net convolutional neural network was trained to segment both femur and tibia, identify osseous anatomic landmarks, define pertinent reference lines, and quantify femoral and tibial torsion. Manual measurements by two radiologists provided the reference standard. Inter-reader comparisons were performed using repeated-measures ANOVA, Pearson's r, and the intraclass correlation coefficient (ICC). Mean Sørensen-Dice coefficients for segmentation accuracy ranged between 0.89 and 0.93 and erroneous segmentations were scarce. Ranges of torsion as measured by both readers and the algorithm on the same axial image were 15.8°-18.0° (femur) and 33.9°-35.2° (tibia). Correlation coefficients (ranges, .968 ≤ r ≤ .984 [femur]; .867 ≤ r ≤ .904 [tibia]) and ICCs (ranges, .963 ≤ ICC ≤ .974 [femur]; .867 ≤ ICC ≤ .894 [tibia]) indicated excellent inter-reader agreement. Algorithm-based analysis was faster than manual analysis (7 vs 207 vs 230 s, p < .001). In conclusion, fully automatic measurement of torsional alignment is accurate, reliable, and sufficiently fast for clinical workflows.

Tool changing 3D printer for rapid prototyping of advanced soft robotic elements.

In the field of soft robotics, pneumatic elements play an important role due to their sensitive and adaptive behavior. Nevertheless, the rapid prototyping of such actuators is still challenging since conventional 3D printers are not designed to fabricate airtight objects or to specify their bending behavior by combining materials of different stiffness. In order to address this challenge, a tool changing multi-material 3D printer has been constructed, which can be equipped with various print-heads fitted to the specific application. By alternately processing filaments with varying mechanical properties, a series of pneumatic elements was produced. The actuators were printed in thermoplastic polyurethane with shore hardness A70 for flexible parts and D65 for stiff parts. A novel procedure for the feature adaptation of the flow rate allowed the fabrication of vertically printed flexible membranes with a thickness of just 500µm. This way the bending and expanding printed structures can all be actuated with a pressure of 100 kPa or less. Furthermore, a new kind of generic actuator that is customizable to specific tasks and can perform complex motion behavior was designed. All together, these actuators demonstrate the high potential of the developed platform for further research on and production of soft robotic elements and complex pressurized systems.

Automated Analysis of Alignment in Long-Leg Radiographs by Using a Fully Automated Support System Based on Artificial Intelligence.

PURPOSE: To develop and validate a deep learning-based method for automatic quantitative analysis of lower-extremity alignment. MATERIALS AND METHODS: In this retrospective study, bilateral long-leg radiographs (LLRs) from 255 patients that were obtained between January and September of 2018 were included. For training data (n = 109), a U-Net convolutional neural network was trained to segment the femur and tibia versus manual segmentation. For validation data (n = 40), model parameters were optimized. Following identification of anatomic landmarks, anatomic and mechanical axes were identified and used to quantify alignment through the hip-knee-ankle angle (HKAA) and femoral anatomic-mechanical angle (AMA). For testing data (n = 106), algorithm-based angle measurements were compared with reference measurements by two radiologists. Angles and time for 30 random radiographs were compared by using repeated-measures analysis of variance and one-way analysis of variance, whereas correlations were quantified by using Pearson r and intraclass correlation coefficients. RESULTS: Bilateral LLRs of 255 patients (mean age, 26 years ± 23 [standard deviation]; range, 0-88 years; 157 male patients) were included. Mean Sørensen-Dice coefficients for segmentation were 0.97 ± 0.09 for the femur and 0.96 ± 0.11 for the tibia. Mean HKAAs and AMAs as measured by the readers and the algorithm ranged from 0.05° to 0.11° (P = .5) and from 4.82° to 5.43° (P < .001). Interreader correlation coefficients ranged from 0.918 to 0.995 (r range, P < .001), and agreement was almost perfect (intraclass correlation coefficient range, 0.87-0.99). Automatic analysis was faster than the two radiologists' manual measurements (3 vs 36 vs 35 seconds, P < .001). CONCLUSION: Fully automated analysis of LLRs yielded accurate results across a wide range of clinical and pathologic indications and is fast enough to enhance and accelerate clinical workflows.Supplemental material is available for this article.© RSNA, 2020See also commentary by Andreisek in this issue.

[SUDEP in brief - knowledge and practice recommendations on sudden unexpected death in epilepsy]. / SUDEP kompakt ­ praxisrelevante Erkenntnisse und Empfehlungen zum plötzlichen, unerwarteten Tod bei Epilepsie.

Sudden unexpected death in epilepsy (SUDEP) is the sudden and unexpected death of an epilepsy patient, which occurs under benign circumstances without evidence of typical causes of death. SUDEP concerns all epilepsy patients. The individual risk depends on the characteristics of the epilepsy and seizures as well as on living conditions. Focal to bilateral and generalized tonic-clonic seizures (TCS), nocturnal seizures and lack of nocturnal supervision increase the risk. Most SUDEP cases are due to a fatal cascade of apnea, hypoxemia and asystole in the aftermath of a TCS. Two thirds of SUDEP cases in unsupervised epilepsy patients with TCS could probably be prevented. Wearables can detect TCS and alert caregivers. SUDEP information is desired by most patients and relatives, has a favorable impact on treatment adherence and behavior and has no negative effects on mood and quality of life.Recommendations of the committee on patient safety of the German Society of Epileptology: the ultimate treatment goal is seizure freedom. If this cannot be achieved, control of TCS should be sought. All epilepsy patients and their relatives should be informed about SUDEP and risk factors. Patients and relatives should be informed about measures to counteract the elevated risk and imminent SUDEP. The counselling should be performed during a face-to-face discussion, at the time of first diagnosis or during follow-up visits. The counselling should be documented. Wearables for TCS detection can be recommended. If TCS persist, therapeutic efforts should be continued. The bereaved should be contacted after a SUDEP.

Use of a Digital Medication Management System for Effective Assessment and Enhancement of Patient Adherence to Therapy (ReX): Feasibility Study.

BACKGROUND: Medication nonadherence is a major problem in health care, imposing poor clinical outcomes and a heavy financial burden on all stakeholders. Current methods of medication adherence assessment are severely limited: they are applied only periodically, do not relate to actual pill intake, and suffer from patient bias due to errors, misunderstanding, or intentional nonadherence. ReX is an innovative medication management system designed to address poor patient adherence and enhance patient engagement with their therapy. ReX controls and tracks pills from the point of packaging right through to the patient's mouth. ReX generates robust, real-time adherence data. The system enables patients to report outcomes, complete surveys, and receive messages and instructions. ReX includes a reusable drug dispensing unit, disposable cassette containing pills, and a cloud-based data portal. OBJECTIVE: We aimed to evaluate ReX feasibility by human factor studies including evaluation of ReX safety; ReX acceptance and usability; and ReX efficacy of providing pills according to a preprogrammed dose regimen, managing reminders and adherence data, and enhancing the adherence rate compared with the standard of care. METHODS: The ReX system was evaluated in 2 human factor, nonclinical feasibility studies. Human subjects used ReX for the administration of pill-shaped Tic Tac sweets. The initial study evaluated ReX use and pill intake administration; second was a self-controlled, 4-day home-use study. All subjects took pills at home, according to a preprogrammed dose regimen, for 4 days each via the device (ReX test) or from standard packaging (control test). The adherence rate (percent of pills taken) was measured by the study subject's report, remaining pills count, and ReX records (in the ReX test). ReX safety and usability were evaluated by a questionnaire filled out by the subject. RESULTS: The initial feasibility study evaluated usability and acceptance of the ReX novel approach to pill dispensing. All subjects successfully managed 2 pill intakes. The ReX device was rated as easy to use by 81% (48/59) of subjects. The 4-day home-use study evaluated the safety, efficacy, and usability of the ReX system. No adverse event occurred; no pill overdose or pill malformation was reported. The overall adherence rate in the ReX test was 97.6% compared with 76.3% in the control test (P<.001). Real-time, personalized reminders provided in the event of a delay in pill intake contributed to 18.0% of doses taken during the ReX test. The ReX system was found easy to use by 87% (35/40) of subjects; 90% (36/40) felt comfortable using it for their medication. CONCLUSIONS: ReX's novel "tracking to the mouth" technology was found usable and accepted by subjects. The assessment of adherence rates was reliable; adherence of subjects to the dose regimen was significantly enhanced when using ReX compared with the standard of care.

Clinical Evaluation of a Novel Technology for Oral Patient-Controlled Analgesia, the PCoA® Acute Device, for Hospitalized Patients with Postoperative Pain, in Pilot Feasibility Study.

Background: Acute postoperative pain delays recovery and increases morbidity and mortality. Traditional administration of postoperative analgesics by nurses is often inefficient. The present study evaluated the safety, efficacy, and usability of a novel, patient-controlled analgesic dispenser, the PCoA Acute. Methods: A controlled pilot study was conducted at three medical centers. Patients scheduled for elective surgery were enrolled into two groups, both taking oral analgesics: a control group (n = 43), opioids dispensed by nurses, and a test group (n = 27), opioids dispensed via the PCoA Acute. Pill intake data were recorded. Pain ratings at rest and during movement were surveyed. Results: No severe adverse events were recorded. Average pill intake time was reduced from 8 : 58 minutes in the control group to 1 : 17 minutes in the test group (P value < 0.05). The test group took 67% more pills than the control group, indicating enhanced compliance. Pain scores were significantly lower for patients in the test group (P value < 0.05). Over 90% of PCoA Acute users were satisfied with its use. Conclusions: The study confirmed that PCoA Acute is safe and effective. It is well accepted by patients and medical staff. Its use can optimize pain medication administration.

Long-term intravesical adjuvant chemotherapy further reduces recurrence rate compared with short-term intravesical chemotherapy and short-term therapy with Bacillus Calmette-Guérin (BCG) in patients with non-muscle-invasive bladder carcinoma.

OBJECTIVE: We present a randomised, parallel group, multicentre phase 4 trial comparing short- and long-term chemoprophylaxis with Mitomycin C (MMC) with short-term immunoprophylaxis with Bacillus Calmette-Guérin (BCG) after transurethral resection of the bladder for non-muscle-invasive bladder carcinoma. METHODS: Four hundred ninety-five patients with intermediate- to high-risk non-muscle-invasive bladder cancer (recurrent and/or multifocal pTaG1, TaG2-3, and T1G1-3) were randomised to BCG RIVM 2 x 10(8) CFU weekly for 6 wk, MMC 20 mg weekly for 6 wk, or MMC 20 mg weekly for 6 wk followed by monthly instillations for 3 yr. RESULTS: The 3-yr recurrence-free rates were 65.5% (95%CI, 55.9-73.5%) for short-term BCG, and 68.6% (59.9-75.7%) for short-term MMC, whereas recurrence-free rates were significantly increased to 86.1% (77.9-91.4%) in patients with MMC long-term therapy (log-rank test, p=0.001). CONCLUSIONS: Long-term MMC significantly reduced the risk of tumour recurrence without enhanced toxicity compared with both short-term BCG and MMC in patients with intermediate- and high-risk non-muscle-invasive bladder carcinoma. Our data provide a rationale for maintenance intravesical chemotherapy in this population.

CXCR3 and CCR5 positive T-cell recruitment in acute human renal allograft rejection.

BACKGROUND: Experimental studies suggest that the infiltration of activated T cells into the allograft, the key event in the development of acute renal allograft rejection, depends on the expression of chemokines and their interaction with chemokine receptors expressed on T cells. METHODS: For a more detailed comprehension of the pathogenesis of T-cell recruitment in human acute rejection, the in situ expression of chemokines and chemokine receptors in allografts of 26 patients between day 3 and 9 after renal transplantation was examined in the present prospective study. RESULTS: Immunohistochemical staining showed a significantly increased number of CXCR3 (P<0.01) and CCR5 positive T cells (P<0.01) in the tubulointerstitium of patients with acute allograft rejection according to Banff grade Ia-IIb. Likewise the intrarenal RNA expression of the CXCR3 ligands IP-10 (5.2-fold) and I-TAC (7.2-fold) and the CCR5 ligand RANTES (5.7-fold), was significantly up-regulated in rejecting organs. In situ hybridization revealed that IP-10 but not I-TAC was predominantly expressed by infiltrating leukocytes in the tubulointerstitial area, co-localizing with CXCR3 positive T cells. To a lesser degree expression by tubular cells could be detected, providing a possible explanation for the increased urinary IP-10 excretion we found in patients with rejecting organs. CONCLUSIONS: These data from a prospective, biopsy-controlled study indicate that the local expression of IP-10 and RANTES leads to the directional movement of activated CXCR3 and CCR5 bearing T cells into the renal allograft and mediates acute rejection. Our data provide a rationale that blocking CXCR3 and CCR5 may offer a unique therapeutic approach to prevent episodes of acute rejection in the early phase after renal transplantation.

Clinical use of urinary markers for the detection and prognosis of bladder carcinoma: a comparison of immunocytology with monoclonal antibodies against Lewis X and 486p3/12 with the BTA STAT and NMP22 tests.

PURPOSE: The noninvasive detection of urothelial carcinoma remains challenging. We prospectively evaluated urine markers for bladder carcinoma. We compared the NMP22 (Matritech, Cambridge, Massachusetts) and BTA Stat (Bard Diagnostics, Redmond, Washington) tests with immunocytology using mAbs 486p3/12 and BG7 against Lewis X antigen. MATERIALS AND METHODS: The NMP22 and BTA Stat tests were performed in urine samples and immunocytology with mAbs 486p3/12 and BG7 staining were performed in bladder washing specimens in 146 samples of 115 patients undergoing transurethral resection for suspected bladder carcinoma (70) or 45 undergoing followup cystoscopy for a history of bladder carcinoma (76). Bladder carcinoma was detected in 54 patients, including stages pTa in 25, pT1 in 20, pT2 in 8 and carcinoma in situ in 1, while 61 had no evidence of bladder carcinoma. The cutoff was 10 units per ml. for the NMP22, 30% positive cells for 486p3/12 and 5% positive cells for the Lewis X tests. RESULTS: BTA Stat was positive in 65 samples (44.5%) and NMP22 was positive in 69 (47.3%). Immunocytology with mAbs 486p3/12 and BG7 against Lewis X was positive in 52 (35.6%) and 109 (74.7%) samples, respectively. Sensitivity was 70.3% for BTA Stat, 68.5% for NMP22, 68.5% for 486p3/12 and 94.4% for Lewis X. Specificity was 70.6% for BTA Stat, 65.2% for NMP22, 83.6% for 486p3/12 and 36.9% for Lewis X. Area under the receiver operating characteristics curve was 0.6804 for NMP22, 0.7226 for Lewis X and 0.8002 for 486p3/12. False-positive results on BTA Stat in 2 of 22 patients (9%), on NMP22 in 2 of 25 (8%), on 486p3/12 in 3 of 11 (27%) and on Lewis X in 4 of 43 (9.3%) were associated with tumor recurrence. Furthermore, negative results on BTA Stat in 2 of 39 patients (2%), on NMP22 in 2 of 36 (0.5%), on Lewis X in 0 of 18 (0%) and on 486p3/12 in 1 of 50 (2%) was associated with tumor recurrence during followup. CONCLUSIONS: Immunocytology with mAbs against Lewis X showed higher sensitivity than all commercially available tests evaluated. Because of its high sensitivity and high negative predictive value, it may be useful for screening in a high risk population. Patients with a false-positive 486p3/12 test results are at increased risk for tumor recurrence compared with those with negative results.

Urinary concentration and tissue messenger RNA expression of monocyte chemoattractant protein-1 as an indicator of the degree of hydronephrotic atrophy in partial ureteral obstruction.

PURPOSE: To find a potential prognostic marker of the induction of hydronephrotic atrophy in congenital hydronephrosis we investigated whether the messenger (m)RNA expression and urinary concentration of monocyte chemoattractant protein-1 (MCP-1) correlated with the degree of partial ureteral obstruction, and subsequent hydronephrotic atrophy and interstitial fibrosis. MATERIALS AND METHODS: We created left partial ureteral obstruction in 96 juvenile Wistar rats and complete ureteral obstruction in 18, while 16 underwent sham operation. Depending on excretion of contrast medium into the renal pelvis after 3 days we defined 2 degrees of hydronephrosis. Renal mRNA expression of MCP-1, and renal pelvic and bladder urinary concentrations of MCP-1 were measured after 1, 2 and 3 weeks, and compared with the degree of hydronephrotic atrophy. RESULTS: Grade 1 partial ureteral obstruction resulted in mild histological changes. Grade 2 partial and complete obstruction resulted in significant hydronephrotic atrophy. MCP-1 mRNA expression in the kidney remained unchanged in grade 1 partial obstruction but was moderately increased in grade 2 partial obstruction and clearly over expressed in complete ureteral obstruction. The renal pelvic urinary concentration of MCP-1 was not higher in rats with grade 1 partial obstruction than in sham operated animals but it was significantly increased in those with grade 2 partial and complete obstruction. CONCLUSIONS: mRNA expression and the urinary concentration of MCP-1 correlate with the degree of obstruction and subsequent renal damage in hydronephrosis. They may serve as prognostic markers in children with congenital hydronephrosis.

Prospective validation of an algorithm with systematic sextant biopsy to predict pelvic lymph node metastasis in patients with clinically localized prostatic carcinoma.

PURPOSE: We prospectively validate an algorithm to predict pelvic lymph node metastasis in patients with clinically localized prostatic carcinoma. MATERIAL AND METHODS: A total of 293 patients with prostatic cancer were identified before pelvic lymph node dissection according to an algorithm developed with the classification and regression tree analysis as high-greater than 3 sextant biopsies containing any Gleason grade 4 or 5 cancer, intermediate-at least 1 biopsy dominated by Gleason grade 4 or 5 cancer but not high risk and low risk-all other patients. Observed and predicted frequencies of pelvic lymph node metastasis were compared. RESULTS: The observed frequencies of lymph node metastasis were remarkably similar to the predicted frequencies, including 2.8% versus 2.2% in 85.7% of patients in the low risk group, 16.7% versus 19.4% in 10.2% intermediate and 41.7% versus 45.5% in 4.1% high, respectively. If patients in the low risk group were considered to have node negative disease the specificity and negative predictive value of the algorithm were 88.4% and 97.2%, respectively. CONCLUSIONS: Our algorithm is valid as a simple and accurate tool for the prediction of pelvic lymph node metastasis in patients with clinically localized prostatic cancer. Those 85.7% of patients classified by the algorithm to have a low risk of lymphatic spread should not undergo pelvic lymph node dissection before definitive local treatment.