A joint physics and radiobiology DREAM team vision - Towards better response prediction models to advance radiotherapy

Radiotherapy developed empirically through experience balancing tumour control and normal tissue toxicities. Early simple mathematical models formalized this practical knowledge and enabled effective cancer treatment to date. Remarkable advances in technology, computing, and experimental biology now create opportunities to incorporate this knowledge into enhanced computational models. The ESTRO DREAM (Dose Response, Experiment, Analysis, Modelling) workshop brought together experts across disciplines to pursue the vision of personalized radiotherapy for optimal outcomes through advanced modelling. The ultimate vision is leveraging quantitative models dynamically during therapy to ultimately achieve truly adaptive and biologically guided radiotherapy at the population as well as individual patient-based levels. This requires the generation of models that inform response-based adaptations, individually optimized delivery and enable biological monitoring to provide decision support to clinicians. The goal is expanding to models that can drive the realization of personalized therapy for optimal outcomes. This position paper provides their propositions that describe how innovations in biology, physics, mathematics, and data science including AI could inform models and improve predictions. It consolidates the DREAM team's consensus on scientific priorities and organizational requirements. Scientifically, it stresses the need for rigorous, multifaceted model development, comprehensive validation and clinical applicability and significance. Organizationally, it reinforces the prerequisites of interdisciplinary research and collaboration between physicians, medical physicists, radiobiologists, and computational scientists throughout model development. Solely by a shared understanding of clinical needs, biological mechanisms, and computational methods, more informed models can be created. Future research environment and support must facilitate this integrative method of operation across multiple disciplines.

Online decision aid for patients with prostate cancer evaluated by 11 290 patients and 91 urologists in Germany

OBJECTIVE

To evaluate the nationwide online decision aid 'Entscheidungshilfe Prostatakrebs' (established in 2016, >11.000 users and 60 new users/week) for patients with non-metastatic prostate cancer (PCa), from the perspective of patients and urologists.

PATIENTS AND METHODS

To provide personalised information, the tool collects most of the International Consortium for Health Outcomes Measurement standard set, personal preferences, psychological features, and a validated rating of the tool. To evaluate urologists' opinions, we developed a structured two-page questionnaire. All data were collected anonymously.

RESULTS

From June 2016 to December 2020, 11 290 patients used the PCa decision aid. Their median (interquartile range [IQR]) age was 67 (61-72) years. The median (IQR) time from initial diagnosis to using the tool was 4 (3-7) weeks. In all, 87.7% of users reported high satisfaction. In a multivariable model, predictors for considering observation were higher knowledge, using the decision aid alone, lower oncological risk, normal erectile function, and respective personal preferences. Of 194 urologists, 91 (47%) had implemented the decision aid in their clinical practice. The urologists' mean (SD) satisfaction score (1 'very good'; 6 'unsatisfactory') with it was 1.45 (0.55), and 92% recommended it. Half of the urologists reported time savings.

CONCLUSION

Patients and urologists report a very high level of acceptance and satisfaction with this online tool. It offers advantages in shared decision-making and time efficiency. The usage of the decision aid might improve the adoption of active surveillance and watchful waiting when indicated.

Trends in the use of testicular prostheses in Germany: a total population analysis from 2006-2021

INTRODUCTION

Testicular tumors are the most common malignancies in young adults and their incidence is growing. The implantation of a testicular prosthesis, for example, during orchiectomy is a standard procedure but its frequency in Germany is unknown. This study aims to analyze trends of testicular prosthesis implantation in recent years in Germany.

MATERIAL AND METHODS

The nationwide German hospital billing database and the German hospital quality reports from 2006 to 2021 were studied.

RESULTS

A total of 12,753 surgical procedures with implantation of testicular prosthesis and 1,244 procedures with testicular prosthesis explantation were included. Testicular prosthesis implantation increased in total from 699 cases in 2006 to 870 cases in 2020 (+11.4 cases/year; p < 0.001). The share of implantation of testicular prosthesis due to testicular tumor decreased from 72.6% in 2006 to 67.5% in 2020 (p < 0.001). The share of implantation due to gender affirming surgery increased from 6.8% in 2006 to 23.3% in 2020 (p < 0.001). The share of implantation due to testicular atrophy decreased from 11.4% in 2006 to 3.4% in 2020 (p < 0.001). Simultaneous implantation of testicular prosthesis during orchiectomy for testicular cancer increased from 7.8% in 2006 to 11.4% in 2020 (p < 0.001). In 2006, 146 hospitals (85%) performed < 5 testicular prosthesis implantation, while 20 hospitals (12%) performed 5-15 implantation procedures and 6 hospitals (3%) performed > 15 testicular implantation surgeries. In 2021, 115 hospitals (72%) performed < 5 testicular prosthesis implantation, while 39 hospitals (25%) performed 5-15 implantation procedures and 5 hospitals (3%) performed > 15 testicular implantation surgeries.

CONCLUSION

This study shows that implantation of testicular prostheses is steadily increasing. Explantation rates are low. Besides testicular cancer transgender surgeries were the main driver for increasing case numbers in recent years.

Vibration-Based Wear Condition Estimation of Journal Bearings Using Convolutional Autoencoders

Predictive maintenance is considered a proactive approach that capitalizes on advanced sensing technologies and data analytics to anticipate potential equipment malfunctions, enabling cost savings and improved operational efficiency. For journal bearings, predictive maintenance assumes critical significance due to the inherent complexity and vital role of these components in mechanical systems. The primary objective of this study is to develop a data-driven methodology for indirectly determining the wear condition by leveraging experimentally collected vibration data. To accomplish this goal, a novel experimental procedure was devised to expedite wear formation on journal bearings. Seventeen bearings were tested and the collected sensor data were employed to evaluate the predictive capabilities of various sensors and mounting configurations. The effects of different downsampling methods and sampling rates on the sensor data were also explored within the framework of feature engineering. The downsampled sensor data were further processed using convolutional autoencoders (CAEs) to extract a latent state vector, which was found to exhibit a strong correlation with the wear state of the bearing. Remarkably, the CAE, trained on unlabeled measurements, demonstrated an impressive performance in wear estimation, achieving an average Pearson coefficient of 91% in four different experimental configurations. In essence, the proposed methodology facilitated an accurate estimation of the wear of the journal bearings, even when working with a limited amount of labeled data.

Deposit formation from evaporating urea-water droplets on substrates of different wettability

HYPOTHESIS

During the evaporation of urea water solution (UWS), the wall temperature and surface properties influence the dynamics of deposit formation by affecting the internal mass transport. These effects are expected to be reflected in the resulting deposit morphology and allow different deposit regimes to be distinguished.

EXPERIMENTS

The temperature of metallic substrates is varied for three different surface treatments to analyze the wetting, evaporation behavior and the crystallization process of single UWS droplets in situ using a high-speed camera. The deposit morphology is captured by confocal microscopy and analyzed via the power spectral density method (PSD). PSD is used to extract the height of different surface features for each deposit, providing valuable information about the local crystallization history.

FINDINGS

A significant influence of the surface properties on the crystallization process as well as on the morphology of the final deposit is found. The influence of wettability is described by the resulting internal mass transport, which determine the urea distribution. PSD analysis quantified distinct trends in the scaling tendencies of the deposit aggregates under different wall conditions. The local crystal growth history extracted by PSD agrees well with proposed crystallization mechanisms, which is further supported by high-speed and SEM imaging.

Upper tract urothelial carcinoma in Germany: epidemiological data and surgical treatment trends in a total population analysis from 2006 to 2019

PURPOSE

To report contemporary epidemiological data and treatment trends for upper tract urothelial carcinoma (UTUC) in Germany over a 14-year period.

METHODS

We analyzed data from the nationwide German hospital billing database and the German cancer registry from 2006 to 2018/2019. The significance of changes over time was evaluated via regression analysis. Survival outcomes were calculated using the Kaplan-Meier method.

RESULTS

There was a non-significant increase in the age-standardized incidence rate from 2.5/100,000 in 2006 to 2.9/100.000 in 2018. 13% of patients presented with lymph node metastasis and 7.6% of patients presented with distant metastasis at primary diagnosis. The 5-year overall survival was estimated at 45% and the 10-year overall survival at 32%. Endoscopic biopsies of the renal pelvis and ureter as well as ureteroscopies with excision/destruction of UTUC all increased significantly over the study period. The number of radical nephroureterectomies (RNU) for UTUC steadily increased from 1643 cases in 2006 to 2238 cases in 2019 (p < 0.005) with a shift from open surgery towards minimally invasive surgery. Complex reconstructive procedures like ileal ureter replacement or autotransplantation are rarely performed for urothelial carcinoma of the ureter.

CONCLUSION

Diagnostic and therapeutic procedures for UTUC have increased and minimally invasive nephroureterectomy is the predominant approach concerning radical surgery in 2019.

The Treatment Decision-making Preferences of Patients with Prostate Cancer Should Be Recorded in Research and Clinical Routine: a Pooled Analysis of Four Survey Studies with 7169 Patients

Different patients want to take different roles in the treatment decision-making process; these roles can be classified as passive, collaborative, and active. The aim of this study was to investigate the correlation between decision-making preferences among patients with prostate cancer and personal, disease-related, and structural factors. In four survey studies, we asked 7169 prostate cancer patients about their decision-making preferences using the Control Preferences Scale (CPS) and collected clinical, psychological, and quality-of-life measures. Most patients (62.2%) preferred collaborative decision-making, while 2322 (32.4%) preferred an active role, and only 391 (5.5%) preferred a passive role. Age (p < 0.001), data collection mode (p < 0.001), peer-to-peer support (p = 0.018), treatment status (p < 0.001), performed or planned radical prostatectomy (p < 0.001), metastatic disease (p = 0.001), and quality of life (p < 0.001) showed significant associations with patients' preferred decision-making roles. Oncologic risk group, anxiety, and depression were not significant in the model. In particular, younger prostate cancer patients with higher quality of life completing an online survey want to play a more active role in treatment decision-making. Before treatment has started, patients tend to prefer collaborative decision-making. Few prostate cancer patients in Germany prefer a passive role. These patients are mostly older patients, patients with a metastatic disease, and patients who have opted for prostatectomy. Whether this finding reflects a generational effect or a tendency by age group and disease phase should be investigated. Further research is also needed to describe the causalities of these relationships. The CPS offers valuable information for personal counselling and should be applied in clinical routine. In a large group of patients with prostate cancer, we found that there is a strong desire for joint decision-making with the physician before the actual treatment. Especially younger men, men with active online behaviour, and men with a high quality of life want to be actively involved in therapy decision-making processes.

Acceptance and efficacy of recommended adjuvant radiotherapy in patients with positive lymph nodes at radical prostatectomy: a preference-based study

PURPOSE

To investigate acceptance and efficacy of recommended adjuvant radiotherapy in patients with positive lymph nodes at radical prostatectomy.

METHODS

Among 495 patients with positive lymph nodes who consecutively underwent radical prostatectomy between 2007 and 2017, we investigated 347 patients who were recommended to undergo adjuvant radiotherapy by a multidisciplinary post-therapeutic tumor board and in whom information whether such treatment was eventually given was available. The median follow-up for censored patients was 5.4 years. Univariate analyses were performed using Kaplan-Meier curves, Mantel-Haenszel hazard ratios and log rank tests. Proportional hazard models for competing risks were used for multivariable analyses.

RESULTS

Adjuvant radiotherapy was independently associated with lower overall mortality and in high-risk patients (Gleason score 8-10 or three or more involved lymph nodes) also with lower prostate cancer-specific mortality. In patients with a Gleason score of 8-10 or three or more involved lymph nodes, the hazard ratio for adjuvant radiotherapy was 0.455 (95% confidence interval 0.257-0.806, p = 0.0069) for overall and 0.426 (95% confidence interval 0.201-0.902, p = 0.0259) for prostate cancer-specific mortality. Among patients receiving adjuvant radiotherapy, there was a trend to lower mortality when such treatment was combined with adjuvant androgen deprivation.

CONCLUSION

Adjuvant radiotherapy decreased mortality in patients with positive lymph nodes at radical prostatectomy with further disease factors but not in patients with low-risk disease. Simultaneous androgen deprivation might increase efficacy. Multidisciplinary recommendations may possibly increase the use of adjuvant radiotherapy in this setting.

Development of Incidence and Surgical Treatment of Penile Cancer in Germany from 2006 to 2016: Potential Implications for Future Management

BACKGROUND

Penile cancer is a rare disease and surgical treatment often entails a significant impact on quality of life. The aim of this study was to analyze trends in surgical treatment patterns in Germany.

METHODS

We analyzed data from the nationwide German hospital billing database and the German cancer registry from 2006 to 2016. All penile cancer cases with penile surgery or lymph node dissection (LND) were included. We also analyzed the distribution of cases, extent of surgery, and length of hospital stay, stratified for annual caseload. The geographical distribution of centers for 2016 was presented.

RESULTS

During the investigated timespan, tumor incidences increased from 748 to 971 (p = 0.001). We identified 11,353 penile surgery cases, increasing from 886 to 1196 (p < 0.001), and 5173 cases of LND, increasing from 332 to 590 (p < 0.001). Cases of partial amputation increased from 45.8 to 53.8% (p < 0.001), while total amputation remained stable at 11.2%. Caseload in high-volume hospitals increased from 9.0 to 18.8% for penile surgery (p < 0.001) and from 0 to 13.1% for LND (p < 0.001). The increase in LND caseload was caused by an increase in inguinal LND, from 297 to 505 (p < 0.001), with increasing sentinel LND, from 14.2 to 21.9% (p = 0.098). The assessment of geographical distribution of cases in Germany revealed extensive areas without sufficient coverage by experienced centers.

CONCLUSIONS

We saw consistent increases in penile surgery and LND, with a growing number of cases in high-volume hospitals, and, accordingly, an increase in tumor incidence. The increasing use of inguinal LND and organ-preserving surgery reflect the adaptation of current guidelines; however, geographical distribution of experienced centers could be improved.

German oncology certification system for colorectal cancer - relative survival rates of a single certified centre vs. national and international registry data

Objectives

To evaluate how the certification of specialised Oncology Centres in Germany affects the relative survival of patients with colorectal cancer (CRC) by means of national and international comparison.

Methods

Between 2007 and 2013, 675 patients with colorectal cancer, treated at the Hildesheim Hospital, an academic teaching hospital of the Hannover Medical School (MHH), were included. A follow-up of the entire patient group was performed until 2014. To obtain international data, a SEER-database search was done. The relative survival of 148,957 patients was compared to our data after 12, 36 and 60 months. For national survival data, we compared our rates with 41,988 patients of the Munich Cancer Registry (MCR).

Results

Relative survival at our institution tends to be higher in advanced tumour stages compared to national and international cancer registry data. Nationally we found only little variation in survival rates for low stages CRC (UICC I and II), colon, and rectal cancer. There were notable variations regarding relative survival rates for advanced CRC tumour stages (UICC IV). These variations were even more distinct for rectal cancer after 12, 36 and 60 months (Hildesheim Hospital: 89.9, 40.3, 30.1%; Munich Cancer Registry (MCR): 65.4, 28.7, 16.6%). The international comparison of CRC showed significantly higher relative survival rates for patients with advanced tumour stages after 12 months at our institution (77 vs. 54.9% for UICC IV; raw p<0.001).

Conclusions

Our findings suggest that patients with advanced tumour stages of CRC and especially rectal cancer benefit most from a multidisciplinary and guidelines-oriented treatment at Certified Oncology Centres. For a better evaluation of cancer treatment and improved national and international comparison, the creation of a centralised national cancer registry is necessary.

Prognostic Factors in Open Triangular Fibrocartilage Complex (TFCC) Repair

Purpose

Patients with triangular fibrocartilage complex (TFCC) injury report ulnar-sided wrist pain and impaired function. Open TFCC repair aims to improve the condition of these patients. Patients have shown reduction in pain and improvement in function at 12 months after surgery; however, results are highly variable. The purpose of this study was to relate patient (eg, age and sex), disease (eg, trauma history and arthroscopic findings), and surgery factors (type of bone anchor) associated with pain and functional outcomes at 12 months after surgery.

Methods

This study included patients who underwent an open TFCC repair between December 2011 and December 2018 in various Xpert Clinics in the Netherlands. All patients were asked to complete Patient-Rated Wrist Evaluation (PRWE) questionnaires at baseline as well as at 12 months after surgery. Patient, disease, and surgery factors were extracted from digital patient records. All factors were analyzed by performing a multivariable hierarchical linear regression.

Results

We included 274 patients who had received open TFCC repair and completed PRWE questionnaires. Every extra month of symptoms before surgery was correlated with an increase of 0.14 points on the PRWE total score at 12 months after surgery. In addition, an increase of 0.28 points in the PRWE total score at 12 months was seen per extra point of PRWE total score at baseline.

Conclusions

Increased preoperative pain, less preoperative function, and a longer duration of complaints are factors that were associated with more pain and less function at 12 months after open surgery for TFCC. This study arms surgeons with data to predict outcomes for patients undergoing open TFCC repair.

Type of study/level of evidence

Prognostic II.

Decreasing Non-bladder-cancer Mortality After Radical Cystectomy

Life expectancy is increasing in many parts of the world. Using proportional hazard models for competing risks, we investigated whether this increase has changed outcomes after radical cystectomy in a sample of 1419 consecutive patients treated between 1993 and 2018. During the observation period, the mean age and the proportion of patients with American Society of Anesthesiologists physical status class 3 or 4 increased, whereas the proportion of patients with heart disease decreased. Competing mortality (causes other than bladder cancer) decreased in all subgroups (hazard ratios [HRs] per year ranged from 0.931 to 0.963) and after controlling for increasing age (HRs ranged from 1.018 to 1.081). In an optimal model resulting from an analysis including age (HR per year 1.048, 95% confidence interval [CI] 1.027–1.070; p < 0.0001), comorbidity, tumor-related variables, body mass index, (neoadjuvant and adjuvant) chemotherapy and smoking status, the HR per increment for year of surgery was 0.928 (95% CI 0.886–0.973; p = 0.0019). The effect of year of surgery was greater than the decrease in competing mortality that may be expected with increasing life expectancy (4 yr for females, 6 yr for males).

Patient summary

In a review of data for 1993–2018, we found that death from other causes after removal of the bladder (radical cystectomy) for bladder cancer decreased over time. This decreasing trend might increase the age limit at which bladder cancer patients can benefit from radical cystectomy in the future.

Insights into the evaporation characteristics of saliva droplets and aerosols: Levitation experiments and numerical modeling

Understanding the transmission phenomena of SARS-CoV-2 by virus-laden droplets and aerosols is of paramount importance for controlling the current COVID-19 pandemic. Detailed information about the lifetime and kinematics of airborne droplets of different size is relevant in order to evaluate hygiene measures like wearing masks but also social distancing and ventilation concepts for indoor environments. However, the evaporation process of expiratory droplets and aerosols is not fully understood. Consequently, the main objective of this study is to present evaporation characteristics of saliva droplets. An acoustic levitator is utilized in conjunction with microscopic imaging for recording the temporal evolution of the evaporation of saliva droplets under well-defined ambient conditions. Following the evaporation of the water content, a saliva droplet reaches a final size, which remains stable in the timescale of hours. By investigating numerous droplets of different size, it was found that the final droplet diameter correlates well to 20 % of the initial diameter. This correlation is independent of the ambient conditions for a temperature range from 20  °C to 29  °C and a relative humidity from 6 % to up to 65 %. The experimentally obtained evaporation characteristics are implemented into a numerical model, which is based on one-dimensional droplet kinematics and a rapid mixing evaporation model. By taking into account the evaporation-falling curve as presented by Wells, the significance of the experimental results for predicting the lifetime of saliva droplets and aerosols is demonstrated. The numerical predictions may be used to determine the impact of the droplet size and the ambient conditions on the transmission risks of infectious diseases like COVID-19.

Implicit molecular stresses in weakly compressible particle-based discretization methods for fluid flow

Weakly compressible particle-based discretization methods, utilized for the solution of the subsonic Navier-Stokes equation, are gaining increasing popularity in the fluid dynamics community. One of the most popular among these methods is the weakly compressible smoothed particle hydrodynamics. Since the dynamics of a single numerical particle is determined by fluid dynamic transport equations, the particle per definition should represent a homogeneous fluid element. However, it can be easily argued that a single particle behaves only pseudo-Lagrangian as it is affected by volume partition errors and can hardly adapt its shape to the actual fluid flow. Therefore, we will assume that the kernel support provides a better representative of an actual fluid element. By means of nonequilibrium molecular dynamics (NEMD) analysis, we derive isothermal transport equations for a kernel-based fluid element. The main discovery of the NEMD analysis is a molecular stress tensor, which may serve to explain current problems encountered in applications of weakly compressible particle-based discretization methods.

Microbial Butyrate Synthesis Indicates Therapeutic Efficacy of Azathioprine in IBD Patients

BACKGROUND AND AIMS

The microbial ecosystem seems to be an important player for therapeutic intervenption in inflammatory bowel disease [IBD]. We assessed longitudinal microbiome changes in IBD patients undergoing therapy with either azathioprine [AZA] or anti-tumour necrosis factor [anti-TNF] antibodies. We predicted the metabolic microbial community exchange and linked it to clinical outcome.

METHODS

Faecal and blood samples were collected from 65 IBD patients at baseline and after 12 and 30 weeks on therapy. Clinical remission was defined as Crohn's Disease Activity Index [CDAI] < 150 in Crohn´s disease [CD], partial Mayo score <2 in ulcerative colitis [UC], and faecal calprotectin values <150 µg/g and C-reactive protein <5 mg/dl. 16S rRNA amplicon sequencing was performed. To predict microbial community metabolic processes, we constructed multispecies genome-scale metabolic network models.

RESULTS

Paired Bray-Curtis distance between baseline and follow-up time points was significantly different for UC patients treated with anti-TNF antibodies. Longitudinal changes in taxa composition at phylum level showed a significant decrease of Proteobacteria and an increase of Bacteroidetes in CD patients responding to both therapies. At family level, Lactobacilli were associated with persistent disease and Bacteroides abundance with remission in CD. In-silico simulations of microbial metabolite exchange predicted a 1.7-fold higher butyrate production capacity of patients in remission compared with patients without remission [p = 0.041]. In this model, the difference in butyrate production between patients in remission and patients without remission was most pronounced in the CD group treated with AZA [p = 0.008].

CONCLUSIONS

In-silico simulation identifies microbial butyrate synthesis predictive of therapeutic efficacy in IBD.

Treatment of post-prostatectomy urinary incontinence and erectile dysfunction: there is insufficient utilisation of care in German cancer survivors

PURPOSE

Treatment of post-prostatectomy urinary incontinence (UI) and erectile dysfunction (ED) increases quality of life (QoL). Aim of our study was to evaluate the utilisation of care among patients with post-prostatectomy UI and ED in Germany.

METHODS

The HAROW study documented treatment of patients with localised prostate cancer (≤ T2c) in Germany. 1260 patients underwent radical prostatectomy (RP). Patients answered validated questionnaires after a median follow-up of 6.3 years. Response rate was 76.8%.

RESULTS

Median age at RP was 65 (IQR 60-69) years. 14% (134/936) used more than one pad per day for UI. 25% (26/104, 30 missing) of UI patients underwent surgery to improve continence. Of patients without surgery, 41% (31/75) reported a moderate-to-severe issue concerning their incontinence with worse mental health and QoL. 81% (755/936) patients were unable to have an erection firm enough for sexual intercourse. Of all ED patients, 40% (319/793) used ED treatment regularly or tried it at least once. 49% (243/499) of patients with interest in sex never tried ED treatment. In multivariate analysis, patients not using ED treatments were older (≥ 70 years OR 4.1), and more often had preoperative ED (OR 2.3) and less interest in sex (OR 2.2). Nevertheless, 30% (73/240) of these patients had moderate-to-severe issues with their ED reporting worse mental health and QoL.

CONCLUSION

Almost half of the patients without post-prostatectomy UI and ED treatment reported moderate-to-severe issues with a significant decrease in QoL. This indicates an insufficient utilisation of care in Germany.

Generation of an iPSC line (UMGWi001-B) from a patient with Floating-Harbor Syndrome (FLHS) carrying a heterozygous SRCAP mutation (p.Arg2444)

Floating-Harbor syndrome (FLHS) is a rare genetic disease caused by mutations in the SRCAP gene. Here, we generated an induced pluripotent stem cell line from gingival fibroblasts of a male patient with a heterozygous mutation in exon 34 of the SRCAP gene (c.7330C > T, p.Arg2444*). The iPSC colonies have an atypical morphology with diffuse borders and disintegrate quickly upon touch. Still, the cell line expresses pluripotency markers and differentiates into three germ layers. The cell line can be used as patient-specific disease model and help elucidate the molecular mechanisms involving SRCAP in the context of FLHS.

Trends of Metastasis-Directed Treatments in Patients with Renal Cell Carcinoma: A Total Population-Based Analysis in Germany in the Era of Targeted Therapies

INTRODUCTION

We characterize trends of metastasis-directed treatments in patients with metastatic renal cell carcinoma (mRCC) in Germany in the targeted therapy era.

METHODS

We identified all cases with a diagnosis of renal cell carcinoma (ICD-10: C.64) and site-specific codes for secondary malignant neoplasms (C79.x) in combination with procedural codes for resection and radiation from the Institute of Hospital Remuneration and the German Federal Statistical Office (Destatis) between 2006 and 2014. We assessed site-specific temporal trends using estimated annual percent change (EAPC) linear regression.

RESULTS

Overall, 15,742 resections and 21,224 radiation treatments were recorded. These targeted lung (44.1% resections; 22.0% radiations), lymph node (14.0% resections; 12% radiations), bone (21% resections; 38% radiations), liver (9% resections; 7% radiations), adrenal (11% resections; 3% radiations), and CNS metastases (2% resections; 19% radiations). There was a significantly increasing trend for resection of lung (EAPC +1.33, p = 0.011), bone (EAPC +2.48, p = 0.014), and adrenal (EAPC +3.4, p = 0.003) metastases, while trends for resection of CNS metastases significantly decreased (EAPC -7.93, p = 0.005). Between Western and Eastern Germany linear trends of resection (EAPC +2.75, p < 0.001; EAPC -0.44, p = 0.54) and radiation (EAPC +1.08, p = 0.15; -3.41, p = 0.03) differed significantly.

CONCLUSION

We observed an increasing trend for metastasis-directed resections and slightly declining numbers for radiation therapy in Germany for mRCC in the targeted therapy era. Treatment differed by geography. These findings suggest more aggressive treatment algorithms following the availability of targeted therapies and a yet diverging treatment landscape needing further exploration.

Liquid compound refractive X-ray lens

We introduce the concept of a liquid compound refractive X-ray zoom lens. The lens is generated by pumping a suitable liquid lens material like water, alcohol or heated lithium through a line of nozzles each forming a jet with the cross section of lens elements. The system is housed, so there is a liquid-circulation. This lens can be used in white beam at high brilliance synchrotron sources, as radiation damages are cured by the continuous reformation of the lens. The focal length can be varied by closing nozzles, thus reducing the number of lens elements in the beam.

Validation of a Questionnaire-Suitable Comorbidity Index in Patients Undergoing Radical Cystectomy

OBJECTIVE

To investigate the capability of a modified self-administrable comorbidity index recommended in the standard sets for neoplastic diseases published by the International Consortium for Health Outcomes Measurement (ICHOM) to predict 90-day and long-term mortality after radical cystectomy.

METHODS

A single-center series of 1,337 consecutive patients who underwent radical cystectomy for muscle-invasive or high-risk non-muscle-invasive urothelial or undifferentiated bladder cancer were stratified by the modified self-administrable comorbidity index and Charlson score, respectively. Multivariate logit models (for 90-day mortality) and proportional-hazards models (for overall and non-bladder cancer mortality) were used for statistical workup.

RESULTS

Considering 90-day mortality, both comorbidity indexes contributed independent information when analyzed together with age (p < 0.0001). The Charlson score performed slightly better (area under the curve [AUC] 0.74 vs. 0.72 for the ICHOM-recommended comorbidity index). Considering 5-year overall mortality in 727 patients with complete observation, the performance of both measures was similar (AUC 0.63 vs. 0.62, including age AUC 0.66 for both indexes). With 6-sided stratifications, the modified self-administrable comorbidity index separated the risk groups slightly better (p values for directly neighboring curves: 0.0068-0.1043 vs. 0.0001-0.8100).

CONCLUSION

The ICHOM-recommended modified self-administrable comorbidity index is capable of predicting 90-day mortality and long-term non-bladder cancer mortality after radical cystectomy similarly to the commonly used Charlson score.

Quantifying the Relationship Between Increasing Life Expectancy and Nonprostate Cancer Mortality After Radical Prostatectomy

OBJECTIVE

To investigate the relationship between increasing life expectancy and nonprostate cancer (competing) mortality after radical prostatectomy.

PATIENTS AND METHODS

We studied a single-center sample of 6809 consecutive patients who underwent radical prostatectomy between 1992 and 2016 with a median age of 65 years and a median follow-up of 7.9 years. Multivariate competing risk analyses were performed with competing mortality as endpoint. Linear trends over the years of surgery for 5-year competing mortality rates and for mean ages were calculated using linear regression analyses. We estimated the number of live years gained over time using a heuristic model-based calculation: (hazard ratio _{year of surgery}) ^{24 calendar years} × (hazard ratio _{age at surgery}) ^{gained life years} = 1.

RESULTS

After controlling for age, nonprostate cancer mortality decreased significantly during the observation period. Accumulated over the 24 years, this decrease of mortality corresponded to the effect of 6.3 years of calendric age. Most of the decrease in nonprostate cancer mortality (predominantly attributable to noncancer causes of death) was seen in patients aged 65 years or older (8.1 years gained), whereas there was only a marginal decrease in patients younger than 65 years (only 1 year gained). The decrease in nonprostate cancer mortality was accompanied by a slight increase of mean age at surgery (2.7 years) that did not nearly compensate the decreasing risk.

CONCLUSION

Clinicians should be aware of the decreasing competing mortality risk in elderly candidates for radical prostatectomy in order to avoid undertreatment.

Long-Term Mortality in Patients with Positive Lymph Nodes at the Time of Radical Prostatectomy

BACKGROUND

The aim of this study was to determine prognostic factors and to provide long-term mortality data in patients with positive lymph nodes at the time of radical prostatectomy in a sample with long-term follow-up.

METHODS

A total of 527 patients with complete data sets treated in the years 1992-2014 were studied. The median follow-up was 7.2 years. The median number of removed lymph nodes was 15. Age, year of surgery, Gleason score, local tumor stage, prostate-specific antigen level, lymph node density, lymph node count and the number of positive lymph nodes were included in multivariable competing risk analyses with prostate cancer mortality as endpoint.

RESULTS

After 20 years, 28% of patients (95% CI 20-36%) died from non-prostate cancer (competing) causes, whereas 29% (95% CI 23-36%) died from prostate cancer. Only lymph node density (stratified by the median of 11.1%; hazard ratio [HR] 1.66, 95% CI 1.04-2.64, p = 0.0340) and Gleason score (8-10 vs. <8: HR 5.97, 95% CI 3.18-11.23, p < 0.0001) were independent predictors of prostate cancer mortality. Patients with a Gleason score <8 and a lymph node density < median had a 20-year prostate cancer mortality of only 5% (95% CI 0-10%), whereas this rate in patients with Gleason score 8-10 and a lymph node density ≥ median was 44% (95% CI 32-56%), p < 0.0001.

CONCLUSIONS

Mortality in patients with positive lymph nodes was determined by tumor aggressiveness and the relative extent of spread; neither the year of surgery nor the number of removed lymph nodes was associated with outcome. Patients with a lymph node density of <11.1% and a Gleason score <8 had an excellent long-term outcome.

Socioeconomic Status-Related Parameters as Predictors of Competing (Non-Bladder Cancer) Mortality after Radical Cystectomy

OBJECTIVE

To investigate the impact of socioeconomic status-related parameters on competing (non-bladder cancer) mortality after radical cystectomy.

PATIENTS AND METHODS

A total of 1,268 consecutive patients who underwent radical cystectomy for urothelial or undifferentiated bladder cancer at our institution between 1993 and 2016 with a mean age of 69 years (median 70 years) were studied. The mean -follow-up of the censored patients was 7.2 years (median 5.7 years). Proportional hazard models for competing risk were used to identify predictors of non-bladder cancer (competing) mortality. The following parameters were included into multivariate analyses: age, American Society of Anesthesiologists physical status classification, Charlson score, gender, level of education, smoking status, marital status, local tumour stage, lymph node status, adjuvant and neoadjuvant chemotherapy.

RESULTS

Besides age and both comorbidity classifications, the socioeconomic status-related parameters gender (female versus male, hazard ratio [HR] 0.58, 95% CI 0.40-0.84, p = 0.0042), level of education (university degree or master craftsman versus others, HR 0.76, 95% CI 0.56-0.1.03, p = 0.0801), smoking status (current smoking versus others, HR 1.47, 95% CI 1.10-1.96, p = 0.0085) and marital status (married versus others, HR 0.68, 95% CI 0.50-0.92, p = 0.0133) were independent predictors of competing mortality after radical cystectomy. If considered in combination (multiplication of HRs), the prognostic impact of socioeconomic parameters superseded that of the investigated comorbidity classifications.

CONCLUSION

Socioeconomic status-related parameters may provide important information on the long-term competing mortality risk after radical cystectomy supplementary to chronological age and comorbidity.

Centralization tendencies of retroperitoneal lymph node dissection for testicular cancer in Germany? A total population-based analysis from 2006 to 2015

INTRODUCTION

Retroperitoneal lymph node dissection (RPLND) is a standard treatment in the management of metastatic testicular cancer. Due to modified treatment algorithms, it is becoming less frequent.

MATERIALS AND METHODS

We analyzed data from the nationwide German hospital billing database covering 2006-2015. Cases with a testicular cancer diagnosis combined with RPLND were included. We assessed the length of hospital stay (LOS), blood transfusion, and in-hospital mortality stratified for surgical approach, hospital characteristics, and annual caseload. Annual hospital caseload categories were defined as low (< 4), medium (4-10), and high (> 10). We supplemented tumor incidence and staging data from the German cancer registry (60% of population).

RESULTS

4926 cases were included with decreasing annual caseload numbers from 623 in 2006 to 382 in 2015. The incidence of testicular cancer and higher tumor stages remained stable. High-volume hospitals performed 19.4%, medium-volume hospitals 43.7%, and low-volume hospitals 36.8% RPLNDs. Low- abd medium-volume hospitals declined, while high-volume hospitals (n = 5) maintained their annual caseload. Overall in-hospital mortality was 0.47%. Blood transfusion rates were higher in high-volume centers assumedly due to selection of more complex cases. However, high-volume hospitals showed a shorter LOS with 10.5 vs. 11.2 (medium volume), and 12.7 days (low volume).

CONCLUSION

Total numbers of RPLND have declined from 2006 to 2015, while tumor incidences and stages remained fairly stable. Constant reduction of indication in guidelines contributes to this finding. High-volume hospitals achieve shorter hospital stays in spite of assumedly more complex and extensive cases. There is a modest trend towards unregulated centralization.

Bacteriorhodopsin Enhances Efficiency of Perovskite Solar Cells

Recently, halide perovskites have upstaged decades of solar cell development by reaching power conversion efficiencies that surpass the performance of polycrystalline silicon. The efficiency improvement in the perovskite cells is related to repeated recycling between photons and electron-hole pairs, reduced recombination losses, and increased carrier lifetimes. Here, we demonstrate a novel approach toward augmenting the perovskite solar cell efficiency by invoking the Förster Resonance Energy Transfer (FRET) mechanism. FRET occurs in the near-field region as the bacteriorhodopsin (bR) protein, and perovskite has similar optical gaps. Titanium dioxide functionalized with the bR protein is shown to accelerate the electron injection from excitons produced in the perovskite layer. FRET predicts the strength of long-range excitonic transport between the perovskite and bR layers. Solar cells incorporating TiO₂/bR layers are found to exhibit much higher photovoltaic performance as compared to baseline cells without bR. These results open the opportunity to develop a new class of bioperovskite solar cells with improved performance and stability.

Which comorbidity classification is best suited to identify patients at risk for 90-day and long-term non-bladder cancer mortality after radical cystectomy?

PURPOSE

There is no consensus on the best comorbidity measure in candidates for radical cystectomy. The aim of this study was to identify tool best suited to identify patients at risk for 90-day or premature long-term non-bladder cancer mortality.

METHODS

We studied 1268 patients who underwent radical cystectomy to identify patients at risk for 90-day and later-than-90-day mortality, respectively. Six classifications were investigated as possible predictors of both types of mortality. Multivariable models including age as continuous variable and each classification separately were calculated. A heuristic ranking was based on the evaluation of the hazard ratios, p values, Akaike's information criteria, and concerning the logit models also the areas under the curve.

RESULTS

The median follow-up was 5.7 years. Within 90 days after surgery, the mortality rate was 4.2%. The greatest independent contribution concerning the prediction of 90-day mortality was seen with the American Society of Anesthesiologists (ASA) physical status classification (classes 3-4 versus 1-2: hazard ratio 7.98, 95% confidence interval 3.54-18.01, p < 0.0001). In the longer term, countable diseases (Canadian Cardiovascular Society classification of angina pectoris, conditions contributing the Charlson score) were of greater importance. The results of heuristic ranking were confirmed by multivariate analyses including age and all classifications together.

CONCLUSIONS

Besides to chronological age, clinicians should pay particular attention to the ASA classification to identify patients at risk for 90-day mortality after radical cystectomy, whereas long-term mortality is more determined by countable comorbid diseases.

Cross-Sectional Investigation of Stress Fractures in German Elite Triathletes

Triathlon is a popular sport for both recreational and competitive athletes. This study investigated the rates and patterns of stress fractures in the German national triathlon squad. We developed a web-based retrospective questionnaire containing questions about the frequency of stress fractures, anatomic localisation and associated risk factors. The survey was conducted as an explorative cross-sectional study. Eighty-six athletes completed the questionnaire. Twenty athletes (23%) sustained at least one stress fracture. All documented stress fractures were located in the lower extremities. Factors associated with a higher risk for stress fractures were female gender, competitive sport prior to triathlon career, Vitamin D or iron deficiency, menstrual disturbances and a high number of annual training hours. Disseminating knowledge among athletes and their professional community in order to raise awareness about early symptoms and relevant risk factors could help to improve prevention and reduce the incidence of stress fractures.