Risk factors for bladder neck contracture after transurethral resection of the prostate

INTRODUCTION

Transurethral resection of the prostate (TURP) is the most frequently used treatment of benign prostate hyperplasia with a prostate volume of <80 mL. A long-term complication is bladder neck contracture (BNC). The aim of the present study was to identify the risk factors for BNC formation after TURP.

METHODS

We conducted a retrospective analysis of all TURP primary procedures which were performed at one academic institution between 2013 and 2018. All patients were analyzed and compared with regard to postoperative formation of a BNC requiring further therapy. Uni- and multivariable logistic regression analyses (MVAs) were performed to identify possible risk factors for BNC development.

RESULTS

We included 1368 patients in this analysis. Out of these, 88 patients (6.4%) developed BNC requiring further surgical therapy. The following factors showed a statistically significant association with BNC development: smaller preoperative prostate volume (p = 0.001), lower resected prostate weight (p = 0.004), lower preoperative levels of prostate-specific antigen (PSA, p < 0.001), shorter duration of the surgery (p = 0.027), secondary transurethral intervention (due to urinary retention or gross hematuria) during inpatient stay (p = 0.018), positive (≥100  CFU/mL) preoperative urine culture (p = 0.010), and urethral stricture (US) formation requiring direct visual internal urethrotomy (DVIU) postoperatively after TURP (p < 0.001), in particular membranous (p = 0.046) and bulbar (p < 0.001) strictures. Preoperative antibiotic treatment showed a protective effect (p = 0.042). Histopathological findings of prostate cancer (PCA) in the resected prostate tissue were more frequent among patients who did not develop BNC (p = 0.049). On MVA, smaller preoperative prostate volume (p = 0.046), positive preoperative urine culture (p = 0.021), and US requiring DVIU after TURP (p < 0.001) were identified as independent predictors for BNC development.

CONCLUSION

BNC is a relevant long-term complication after TURP. In particular, patients with a smaller prostate should be thoroughly informed about this complication.

The Search for the Optimal cut-off Value of p53-Immunohistochemistry to Predict Prognosis of Invasive Bladder Cancer: A Multi-Center, Multi-Laboratory Analysis

Introduction: Mutations in the TP53 gene are indicative of worse outcome in bladder cancer and are usually assessed by immunohistochemistry. To define p53-overexpression, a threshold of >10% is most commonly used (cut-off1). Recently, a novel cut-off (aberrant = 0% or ≥50%) (cut-off2) showed better correlation to clinical outcome. In this study, we evaluate the association between p53-immunohistochemistry cut-offs, clinico-pathological variables and disease-specific survival (DSS). Methods: Seven-hundred-fifty chemotherapy-naïve patients who underwent radical cystectomy were included (92% muscle-invasive bladder cancer. In addition to cut-off1 and cut-off2, a third cut-off (cut-off3) was determined based on the highest Youden-index value. Cut-off values were associated with clinico-pathological variables and FGFR3 mutation status. The Kaplan-Meier method was used to estimate DSS. Results: Aberrant p53-expression was found in 489 (65%) (cut-off1) and 466 (62%) (cut-off2) tumors. Cut-off3 was determined at 25% and aberrant p53-expression in 410 cases (55%) (cutoff3). p53-expression levels were significantly associated with higher pT-stage (cut-off1/2/3: P = 0.047, P = 0.006 and P = 0.0002, respectively), higher grade (all, P < 0.0001), and FGFR3 wild-type (cut-off1: P = 0.02, cut-offs2&3: P = 0.001). Median follow-up was 5.3 years (interquartile range, 4.0-6.0 years). p53-expression was not associated with DSS for any of the three cut-offs (cut-off1/2/3: P-log-rank = 0.566, 0.77 and 0.50, respectively). If we only considered locally advanced bladder cancer, results on DSS remained non-significant. Conclusion: This multi-center, multi-laboratory study showed that, regardless of the cut-off used, p53-immunohistochemistry did not enable selection of patients with worse outcome. Our results suggest that p53-immunohistochemistry alone is not suitable to guide clinical decision making after radical cystectomy.

Critical Evaluation of a microRNA-Based Risk Classifier Predicting Cancer-Specific Survival in Renal Cell Carcinoma with Tumor Thrombus of the Inferior Vena Cava

(1) Background: Clear cell renal cell carcinoma extending into the inferior vena cava (ccRCCIVC) represents a clinical high-risk setting. However, there is substantial heterogeneity within this patient subgroup regarding survival outcomes. Previously, members of our group developed a microRNA(miR)-based risk classifier—containing miR-21-5p, miR-126-3p and miR-221-3p expression—which significantly predicted the cancer-specific survival (CSS) of ccRCCIVC patients. (2) Methods: Examining a single-center cohort of tumor tissue from n = 56 patients with ccRCCIVC, we measured the expression levels of miR-21, miR-126, and miR-221 using qRT-PCR. The prognostic impact of clinicopathological parameters and miR expression were investigated via single-variable and multivariable Cox regression. Referring to the previously established risk classifier, we performed Kaplan–Meier analyses for single miR expression levels and the combined risk classifier. Cut-off values and weights within the risk classifier were taken from the previous study. (3) Results: miR-21 and miR-126 expression were significantly associated with lymphonodal status at the time of surgery, the development of metastasis during follow-up, and cancer-related death. In Kaplan–Meier analyses, miR-21 and miR-126 significantly impacted CSS in our cohort. Moreover, applying the miR-based risk classifier significantly stratified ccRCCIVC according to CSS. (4) Conclusions: In our retrospective analysis, we successfully validated the miR-based risk classifier within an independent ccRCCIVC cohort.

Effects of Individualised High Positive End-Expiratory Pressure and Crystalloid Administration on Postoperative Pulmonary Function in Patients Undergoing Robotic-Assisted Radical Prostatectomy: A Prospective Randomised Single-Blinded Pilot Study

OBJECTIVES

Robotic-assisted laparoscopic prostatectomy (RALP) is typically conducted in steep Trendelenburg position (STP). The aim of the study was to evaluate whether crystalloid administration and individual management of positive end-expiratory pressure (PEEP) improve peri- and post-operative pulmonary function in patients undergoing RALP.

DESIGN

Prospective randomised single-centre single-blinded explorative study.

SETTING

Patients were either allocated to a standard PEEP (5 cmH₂O) group or an individualised high PEEP group. Furthermore, each group was divided into a liberal and a restrictive crystalloid group (8 vs. 4 mL/kg/h predicted body weight). Individualised PEEP levels were determined by means of preoperative recruitment manoeuvre and PEEP titration in STP.

PARTICIPANTS

Informed consent was obtained from 98 patients scheduled for elective RALP.

INTERVENTIONS

The following intraoperative parameters were analysed in each of the four study groups: ventilation setting (peak inspiratory pressure [PIP], plateau pressure, driving pressure [P_driv], lung compliance [LC] and mechanical power [MP]) and postoperative pulmonary function (bed-side spirometry). The spirometric parameters Tiffeneau index (FEV₁/FVC ratio) and mean forced expiratory flow (FEF_25-75) were measured pre- and post-operatively. Data are shown as mean ± standard deviation (SD), and groups were compared with ANOVA. A p-value of <0.05 was considered significant.

RESULTS

The two individualised high PEEP groups (mean PEEP 15.5 [±1.71 cmH₂O]) showed intraoperative significantly higher PIP, plateau pressure and MP levels but significantly decreased P_driv and increased LC. On the first and second postoperative day, patients with individualised high PEEP levels had a significantly higher mean Tiffeneau index and FEF_25-75. Perioperative oxygenation and ventilation and postoperative spirometric parameters were not influenced by restrictive or liberal crystalloid infusion in either of the two respective PEEP groups.

CONCLUSIONS

Individualised high PEEP levels (≥14 cmH₂O) during RALP improved intraoperative blood oxygenation and resulted in more lung-protective ventilation. Furthermore, postoperative pulmonary function was improved for up to 48 h after surgery in the sum of the two individualised high PEEP groups. Restrictive crystalloid infusion during RALP seemed to have no effect on peri- and post-operative oxygenation and pulmonary function.

[Adrenal tumors: diagnostics, perioperative management and surgical treatment]

Space-occupying lesions of the adrenal glands are one of the most frequent tumors; however, only a fraction of approximately 20% need further diagnostics and treatment. The diagnostic standard is native computed tomography (CT). For larger tumors and those that cannot be clearly classified as benign, the supplementary radiological modalities magnetic resonance imaging (MRI), contrast CT and ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG-PET) should be used. Adrenal gland neoplasms can be hormone-active or hormone-inactive. The most important hormone-active adrenal gland neoplasms are those with autonomous cortisol secretion and autonomous aldosterone secretion as well as pheochromocytomas. Several laboratory tests are available each for the respective hormone activity. The indications for surgery are dependent on the dignity, size and hormone activity. Minimally invasive surgical techniques have become more important due to advantages such as lower blood loss; nevertheless, open surgery is still indispensable for large suspected tumors. Care must be taken preoperatively and postoperatively, particularly in cases of hormone-active tumors.

Prognosis of Primary Papillary Ta Grade 3 Bladder Cancer in the Non-muscle-invasive Spectrum

BACKGROUND

Ta grade 3 (G3) non-muscle-invasive bladder cancer (NMIBC) is a relatively rare diagnosis with an ambiguous character owing to the presence of an aggressive G3 component together with the lower malignant potential of the Ta component. The European Association of Urology (EAU) NMIBC guidelines recently changed the risk stratification for Ta G3 from high risk to intermediate, high, or very high risk. However, prognostic studies on Ta G3 carcinomas are limited and inconclusive.

OBJECTIVE

To evaluate the prognostic value of categorizing Ta G3 compared to Ta G2 and T1 G3 carcinomas.

DESIGN, SETTING, AND PARTICIPANTS

Individual patient data for 5170 primary Ta-T1 bladder tumors from 17 hospitals were analyzed. Transurethral resection of the tumor was performed between 1990 and 2018.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Time to recurrence and time to progression were analyzed using cumulative incidence functions, log-rank tests, and multivariable Cox-regression models with interaction terms stratified by institution.

RESULTS AND LIMITATIONS

Ta G3 represented 7.5% (387/5170) of Ta-T1 carcinomas of which 42% were classified as intermediate risk. Time to recurrence did not differ between Ta G3 and Ta G2 (p = 0.9) or T1 G3 (p = 0.4). Progression at 5 yr occurred for 3.6% (95% confidence interval [CI] 2.7-4.8%) of Ta G2, 13% (95% CI 9.3-17%) of Ta G3, and 20% (95% CI 17-23%) of T1 G3 carcinomas. Time to progression for Ta G3 was shorter than for Ta G2 (p < 0.001) and longer than for T1 G3 (p = 0.002). Patients with Ta G3 NMIBC with concomitant carcinoma in situ (CIS) had worse prognosis and a similar time to progression as for patients with T1 G3 NMIBC with CIS (p = 0.5). Multivariable analyses for recurrence and progression showed similar results.

CONCLUSIONS

The prognosis of Ta G3 tumors in terms of progression appears to be in between that of Ta G2 and T1 G3. However, patients with Ta G3 NMIBC with concomitant CIS have worse prognosis that is comparable to that of T1 G3 with CIS. Our results support the recent EAU NMIBC guideline changes for more refined risk stratification of Ta G3 tumors because many of these patients have better prognosis than previously thought.

PATIENT SUMMARY

We used data from 17 centers in Europe and Canada to assess the prognosis for patients with stage Ta grade 3 (G3) non-muscle-invasive bladder cancer (NMIBC). Time to cancer progression for Ta G3 cancer differed from both Ta G2 and T1 G3 tumors. Our results support the recent change in the European Association of Urology guidelines for more refined risk stratification of Ta G3 NMIBC because many patients with this tumor have better prognosis than previously thought.

Generation of multiple obstruction-free channels for free space optical communication

Multi-filament structures produced by vortical high-power femtosecond pulses propagating through clouds and fog can simultaneously clear two channels with cylindrical and annular profile. We present a method to achieve Free Space Optical (FSO) communications through such highly scattering media by propagating appropriately shaped laser modes through these channels. As a proof of concept, we implemented a Laguerre-Gaussian beam as information signal carrier to demonstrate transmission of 543-nm CW laser beam through a 1-m long cloud chamber using both channels. The low power of the information signal in this experiment allows considering applications in Earth-satellite FSO communication.

Body Composition as a Comorbidity-Independent Predictor of Survival following Nephroureterectomy for Urothelial Cancer of the Upper Urinary Tract

Radical nephroureterectomy (NUE) is the gold standard treatment for high-risk urothelial cancer of the upper urinary tract (UTUC). Besides sarcopenia and frailty, fat distribution is moving increasingly into focus. Components of body composition were assessed in patients undergoing NUE due to UTUC. The study cohort included 142 patients. By using CT-based measurements, the skeletal muscle index (SMI), subcutaneous adipose tissue index (SATI), and visceral adipose tissue index (VATI) were measured at the height of the third lumbar vertebra. Overall survival (OS) and cancer-specific survival (CSS) were estimated using univariable und multivariable Cox regression models. The prevalence of sarcopenia in the study population (n = 142) was 37%. OS and CSS were significantly reduced in sarcopenic patients. In the multivariable cox regression analysis, including age, ACE-27, T-stage, R-stage, LVI and necrosis, sarcopenia remained a significant risk factor of OS (HR, 1.77; 95% CI 1.02-3.07; p = 0.042) and CSS (HR, 2.17; 95% CI 1.18-3.99; p = 0.012). High visceral adipose tissue seems to be protective, although not statistically significant. Sarcopenia is a comorbidity-independent risk factor in patients who underwent NUE due to UTUC. Visceral fat represents a potentially protective factor. These results suggest that specific factors of body composition can be used for better risk stratification.

Short-Term and Long-Term Morbidity after Radical Cystectomy in Patients with NMIBC and Comparison with MIBC: Identifying Risk Factors for Severe Short-Term Complications

INTRODUCTION

RC represents a viable treatment option for certain NMIBC patients. However, studies investigating morbidity in the context of RC for NMIBC are scarce. The goal of the current study was to assess and compare morbidity after RC performed in patients with NMIBC and patients with MIBC and to identify risk factors for severe short-term complications.

METHODS

Medical records of 521 patients who underwent RC for bladder cancer were retrospectively reviewed. Patients were divided into patients with NMIBC and patients with MIBC. The groups were compared and risk factors for severe complications were identified.

RESULTS

RC for NMIBC was performed in 123 patients (23.6%). Histological upstaging was seen in 47 NMIBC patients (38.2%) and in 231 MIBC patients (58%, p < 0.001). OS was 29.8% and CSS was 15.5%. Both endpoints were higher for RC for MIBC (p < 0.001). More complications affecting the urinary diversion were seen with RC for NMIBC (p = 0.033) and more continent urinary diversions (p = 0.040) were performed in those patients. Obesity (p = 0.008), a higher ASA score (p = 0.004), and preoperative medical drug anticoagulation (p = 0.025) were risk factors for severe short-term morbidity after both, RC for NMIBC and for MIBC.

CONCLUSION

Patients who underwent RC for NMIBC are exposed to a comparably high perioperative risk than patients with MIBC. RC seems to be a viable treatment option for certain NMIBC patients with a significant histological upstaging in both groups. In patients with obesity, a high ASA score, and with medical drug anticoagulation, the indication for surgery should be confirmed especially strict and possible treatment alternatives should be considered particularly thorough.

T1G1 Bladder Cancer: Prognosis for this Rare Pathological Diagnosis Within the Non-muscle-invasive Bladder Cancer Spectrum

BACKGROUND

The pathological existence and clinical consequence of stage T1 grade 1 (T1G1) bladder cancer are the subject of debate. Even though the diagnosis of T1G1 is controversial, several reports have consistently found a prevalence of 2-6% G1 in their T1 series. However, it remains unclear if T1G1 carcinomas have added value as a separate category to predict prognosis within the non-muscle-invasive bladder cancer (NMIBC) spectrum.

OBJECTIVE

To evaluate the prognostic value of T1G1 carcinomas compared to TaG1 and T1G2 carcinomas within the NMIBC spectrum.

DESIGN, SETTING, AND PARTICIPANTS

Individual patient data for 5170 primary Ta and T1 bladder tumors from 17 hospitals in Europe and Canada were analyzed. Transurethral resection (TUR) was performed between 1990 and 2018.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Time to recurrence and progression were analyzed using cumulative incidence functions, log-rank tests, and multivariable Cox regression models stratified by institution.

RESULTS AND LIMITATIONS

T1G1 represented 1.9% (99/5170) of all carcinomas and 5.3% (99/1859) of T1 carcinomas. According to primary TUR dates, the proportion of T1G1 varied between 0.9% and 3.5% per year, with similar percentages in the early and later calendar years. We found no difference in time to recurrence between T1G1 and TaG1 (p = 0.91) or between T1G1 and T1G2 (p = 0.30). Time to progression significantly differed between TaG1 and T1G1 (p < 0.001) but not between T1G1 and T1G2 (p = 0.30). Multivariable analyses for recurrence and progression showed similar results.

CONCLUSIONS

The relative prevalence of T1G1 diagnosis was low and remained constant over the past three decades. Time to recurrence of T1G1 NMIBC was comparable to that for other stage/grade NMIBC combinations. Time to progression of T1G1 NMIBC was comparable to that for T1G2 but not for TaG1, suggesting that treatment and surveillance of T1G1 carcinomas should be more like the approaches for T1G2 NMIBC in accordance with the intermediate and/or high risk categories of the European Association of Urology NMIBC guidelines.

PATIENT SUMMARY

Although rare, stage T1 grade 1 (T1G1) bladder cancer is still diagnosed in daily clinical practice. Using individual patient data from 17 centers in Europe and Canada, we found that time to progression of T1G1 cancer was comparable to that for T1G2 but not TaG1 cancer. Therefore, our results suggest that primary T1G1 bladder cancers should be managed with more aggressive treatment and more frequent follow-up than for low-risk bladder cancer.

Patients Regret Their Choice of Therapy Significantly Less Frequently after Robot-Assisted Radical Prostatectomy as Opposed to Open Radical Prostatectomy: Patient-Reported Results of the Multicenter Cross-Sectional IMPROVE Study

Patient’s regret (PatR) concerning the choice of therapy represents a crucial endpoint for treatment evaluation after radical prostatectomy (RP) for prostate cancer (PCA). This study aims to compare PatR following robot-assisted (RARP) and open surgical approach (ORP). A survey comprising perioperative-functional criteria was sent to 1000 patients in 20 German centers at a median of 15 months after RP. Surgery-related items were collected from participating centers. To calculate PatR differences between approaches, a multivariate regressive base model (MVBM) was established incorporating surgical approach and demographic, center-specific, and tumor-specific criteria not primarily affected by surgical approach. An extended model (MVEM) was further adjusted by variables potentially affected by surgical approach. PatR was based on five validated questions ranging 0−100 (cutoff >15 defined as critical PatR). The response rate was 75.0%. After exclusion of patients with laparoscopic RP or stage M1b/c, the study cohort comprised 277/365 ORP/RARP patients. ORP/RARP patients had a median PatR of 15/10 (p < 0.001) and 46.2%/28.1% had a PatR >15, respectively (p < 0.001). Based on the MVBM, RARP patients showed PatR >15 relative 46.8% less frequently (p < 0.001). Consensual decision making regarding surgical approach independently reduced PatR. With the MVEM, the independent impact of both surgical approach and of consensual decision making was confirmed. This study involving centers of different care levels showed significantly lower PatR following RARP.

Expression of nectin-4 in papillary renal cell carcinoma

BACKGROUND

Nectin-4 contributes to tumor proliferation, lymphangiogenesis and angiogenesis in malignant tumors and is an emerging target in tumor therapy. In renal cell carcinoma (RCC) VEGF-directed tyrosine kinase inhibitors and checkpoint inhibitors are currently treatments of choice. Enfortumab vedotin-ejf (EV) is an antibody drug conjugate that targets Nectin-4. The aim of our study was to investigate the expression of Nectin-4 in a large cohort of papillary RCC specimens.

PATIENTS AND METHODS

Specimens were derived from the PANZAR consortium (Erlangen, Heidelberg, Herne, Homburg, Mainz, Mannheim, Marburg, Muenster, LMU Munich, TU Munich, and Regensburg). Clinical data and tissue samples from n = 190 and n = 107 patients with type 1 and 2 pRCC, respectively, were available. Expression of Nectin-4 was determined by immunohistochemistry (IHC).

RESULTS

In total, Nectin-4 staining was moderately or strongly positive in of 92 (48.4%) of type 1 and 39 (36.4%) type 2 of pRCC cases. No associations between Nectin-4 expression and age at diagnosis, gender, grading, and TNM stage was found. 5 year overall survival rate was not statistically different in patients with Nectin-4 negative versus Nectin-4 positive tumors for the overall cohort and the pRCC type 2 subgroup, but higher in patient with Nectin-4 positive pRCC type 1 tumors compared to Nectin-4 negative tumors (81.3% vs. 67.8%, p = 0.042).

CONCLUSION

Nectin-4 could not be confirmed as a prognostic marker in pRCC in general. Due to its high abundance on pRCC specimens Nectin-4 is an interesting target for therapeutical approaches e.g. with EV. Clinical trials are warranted to elucidate its role in the pRCC treatment landscape.

PL02.1.A EO2401, a novel microbiome-derived therapeutic vaccine for patients with recurrent glioblastoma: ROSALIE study

Background

EO2401 (EO) was designed to activate existing commensal memory T-cells cross-reacting with tumor associated antigens (TAAs). EO includes microbial-derived, synthetically produced peptides corresponding to HLA-A2 restricted epitopes with molecular mimicry to three TAAs upregulated in glioblastoma (GB), IL13Rα2, BIRC5 and FOXM1, with the CD4 helper peptide UCP2 and the adjuvant Montanide. Pre-clinically EO generated strong immune responses and cross-reactive CD8 cells recognizing the targeted TAAs.

Methods

This ongoing Ph 1/2 trial (NCT04116658) investigates the safety and tolerability (primary) of EO (300 µg/peptide, SC Q2W X 4, then Q4W), EO with nivolumab (3 mg/kg Q2W; EN), and EN with bevacizumab (10 mg/kg Q2W; ENB) among four Cohorts (Cs) of pts with GB at first progression/recurrence after radiotherapy/temozolomide. Treatment was delivered until progression, or 24 months. After the Ph 1 of EO followed by EN (C1), C2 investigated EN without (C2a) or with (C2b) surgery while C3 investigated ENB (population as C2a).

Results

Among 40 treated pts (C1 n=3, C2a n=23, C2b n=3, C3 n=11), median age was 60 years, 53% were male, 40% had KPS 90-100%, 35% had O6-methylguanine DNA-methyltransferase promotor hypermethylated tumors, and 5% isocitrate dehydrogenase 1 mutated tumors. All evaluable pts demonstrated strong CD8 T-cell ELISPOT responses against the 3 vaccine peptides; response was shown with tetramer staining of specific CD8 in 24/25 investigated pts after in vitro stimulation and in 19/20 pts directly ex vivo. Cross-reactivity against targeted TAAs was confirmed in 20/21 pts. Majority of response were detected by week 4 after 1st dose and as early as 2 weeks in some pts. EO, EN, and ENB were well tolerated (max exposure EN 86 wks, ENB 47 wks) with EO associated toxicity limited to local administration site reactions (48%; all grade 1-2). The frequency and severity of nivolumab- or bevacizumab-associated AEs was consistent with historical single-agent profiles. With a median follow-up of 13.6 months, median progression-free survival (mPFS), and median survival for EN (C1+C2a+C2b) were 1.8 months (2 ongoing at 7.3, and 18.5 months), and 11.0 months (survival at 12 months 42%), respectively. With a median follow-up of 7.3 months (range, 3.0-10.5), pts on ENB (C3) have mPFS and survival at 6 months of 5.5 months (3 ongoing at 5.6, 7.3 and 9.1 months), and 82% (9/11 alive), respectively. ORR/DCR (ORR+SD) for EN and ENB were 10%/34% and 55%/82%, respectively.

Conclusion

EO2401 generated strong systemic immune responses and was well tolerated in combination with nivolumab ± bevacizumab. Preliminary ORR/DCR and mPFS for ENB, and survival for EN seem encouraging. Updated results from the current 40 patients and results from additional 35 patients who already started treatment with EN with the option for low-dose bevacizumab edema treatment at neurological symptoms will be presented.

Iterative wavefront optimization of ultrafast laser beams carrying orbital angular momentum

Structured intense laser beams offer degrees of freedom that are highly attractive for high-field science applications. However, the performance of high-power laser beams in these applications is often hindered by deviations from the desired spatiotemporal profile. This study reports the wavefront optimization of ultrafast Laguerre-Gaussian beams through the synergy of adaptive optics and genetic algorithm-guided feedback. The results indicate that the intensity fluctuations along the perimeter of the target ring-shaped profile can be reduced up to ∼15%. Furthermore, the radius of the ring beam profile can be tailored to a certain extent by establishing threshold fitting criteria. The versatility of this approach is experimentally demonstrated in conjunction with different focusing geometries.

Ultra-broadband long-wave-infrared pulse production using a chirped-pulse difference-frequency generation

We present a broadband light source based on near-infrared chirped-pulse difference-frequency mixing that is suitable for seeding long-wave-infrared (LWIR) optical parametric chirped-pulse amplification (OPCPA). A nitrocellulose pellicle is used in a Ti:sapphire regenerative amplifier to generate dual-frequency output pulses, which are subsequently mixed in a 0.4-mm thick AgGaS₂ crystal. LWIR pulses with ∼1 µm full width at half maximum (FWHM) bandwidth centered at 10.5 µm are generated by mixing transform-limited pulses. Assisted by genetic algorithm optimization, the bandwidth is broadened to ∼3 µm FWHM within the 8-12 µm atmospheric transmission window. The seed source paves the path towards tabletop ultrafast terawatt-class passively carrier-envelope-phase stabilized OPCPA in the LWIR region.

[Disseminated tumour cells in bladder cancer]

Molecular analysis of disseminated tumour cells (DTC) may aid in predicting the course of the disease and response to therapies in individual patients. It has been shown in bladder cancer and many other cancer types that the presence of disseminated tumour cells or occult micrometastases in bone marrow or lymph nodes is associated with shorter survival. This type of analysis is particularly important for patients who have been declared disease-free after postsurgery histopathological and clinical imaging analysis. However, comprehensive molecular analysis of disseminated tumour cells is challenging due to the low amount of material and great heterogeneity of the disease. Therefore, currently the routine molecular analysis of these cells is hardly possible in daily clinical practice. Nevertheless, we see daily advances in clinical utility of analysis of cellular or cell-free liquid biopsy analytes taken before, during or after surgery. These advances will enable an integration of translational research workflows into clinical decision-making.