Adverse renal effects of check-point inhibitors (ICI) in cancer patients: Recommendations of the Onco-nephrology Working Group of the Spanish Society of Nephrology.

The most widely used approach in the immunotherapy treatment of cancer is the administration of monoclonal antibodies directed against regulatory molecules of immune control that inhibit the activation of T cells, the so-called check point inhibitors (ICI). ICI nephrotoxicity epidemiology and pathology; its diagnosis with or without kidney biopsy; the type and duration of treatment; the possibility of rechallenging after kidney damage; and its indication in patients with cancer and renal transplantation are certainly controversial. In the absence of definitive studies, this document is intended to specify some recommendations agreed by the group of Onconephrology experts of the Spanish Society of Nephrology in those areas related to ICI nephrotoxicity, in order to help decision-making in daily clinical practice in Onconephrology consultations.

Efectos renales adversos por inhibidores del check-point (ICP) en pacientes con cáncer. Recomendaciones del grupo de Onconefrología de la Sociedad Española de Nefrología (SEN) / Adverse renal effects of check-point inhibitors (ICI) in cancer patients: Recommendations of the Onco-nephrology Working Group of the Spanish Society of Nephrology

El enfoque más utilizado en el tratamiento inmunoterápico del cáncer es la administración de anticuerpos monoclonales dirigidos contra moléculas reguladoras del control inmunitario que inhiben la activación de las células T, los llamados inhibidores del check-point (ICP). La epidemiología y patología de la nefrotoxicidad por los ICP, su diagnóstico con o sin biopsia renal, el tipo y la duración del tratamiento, la posibilidad de retratar después del daño renal, y su indicación en pacientes con cáncer y trasplante renal son ciertamente controvertidas. En ausencia de estudios definitivos, este documento está destinado a concretar unas recomendaciones consensuadas por el grupo de expertos de Onconefrología de la SEN en aquellas áreas relacionadas con la nefrotoxicidad por los ICP, con la finalidad de ayudar en la toma de decisiones en la práctica clínica diaria de las consultas de Onconefrología. (AU)

The most widely used approach in the immunotherapy treatment of cancer is the administration of monoclonal antibodies directed against regulatory molecules of immune control that inhibit the activation of T cells, the so-called check point inhibitors (ICI). ICI nephrotoxicity epidemiology and pathology; its diagnosis with or without kidney biopsy; the type and duration of treatment; the possibility of rechallenging after kidney damage; and its indication in patients with cancer and renal transplantation are certainly controversial. In the absence of definitive studies, this document is intended to specify some recommendations agreed by the group of onconephrology experts of the Spanish Society of Nephrology in those areas related to ICI nephrotoxicity, in order to help decision-making in daily clinical practice in onconephrology consultations. (AU)

Biophysical modeling of the electric field magnitude and distribution induced by electrical stimulation with intracerebral electrodes.

Intracranial electrodes are used clinically for diagnostic or therapeutic purposes, notably in drug-refractory epilepsy (DRE) among others. Visualization and quantification of the energy delivered through such electrodes is key to understanding how the resulting electric fields modulate neuronal excitability, i.e. the ratio between excitation and inhibition. Quantifying the electric field induced by electrical stimulation in a patient-specific manner is challenging, because these electric fields depend on a number of factors: electrode trajectory with respect to folded brain anatomy, biophysical (electrical conductivity / permittivity) properties of brain tissue and stimulation parameters such as electrode contacts position and intensity. Here, we aimed to evaluate various biophysical models for characterizing the electric fields induced by electrical stimulation in DRE patients undergoing stereoelectroencephalography (SEEG) recordings in the context of pre-surgical evaluation. This stimulation was performed with multiple-contact intracranial electrodes used in routine clinical practice. We introduced realistic 3D models of electrode geometry and trajectory in the neocortex. For the electrodes, we compared point (0D) and line (1D) sources approximations. For brain tissue, we considered three configurations of increasing complexity: a 6-layer spherical model, a toy model with a sulcus representation, replicating results from previous approaches; and went beyond the state-of-the-art by using a realistic head model geometry. Electrode geometry influenced the electric field distribution at close distances (∼3 mm) from the electrode axis. For larger distances, the volume conductor geometry and electrical conductivity dominated electric field distribution. These results are the first step towards accurate and computationally tractable patient-specific models of electric fields induced by neuromodulation and neurostimulation procedures.

Kidney Biopsy in Patients with Cancer along the Last Decade: A Multicenter Study.

BACKGROUND: Currently, following the new advances in cancer treatments and the increasing prevalence of kidney disease in the population, more kidney biopsies are being performed. The aim of our study is to analyze clinical and histological characteristics of patients with active solid organ malignancy who underwent kidney biopsy. This is a multi-center collaborative retrospective study supported by groups GLOSEN/Onconephrology from the Spanish Society of Nephrology. Clinical, demographical and histological data were collected. RESULTS: A total of 148 patients with cancer who underwent a kidney biopsy from 12 hospitals were included. 64.3% men and mean age of 66.9 years old. The indications for biopsy were acute renal injury (67.1%), proteinuria (17.1%), exacerbated chronic kidney disease (8.2%), and chronic kidney disease (7.5%). Most frequent malignances were lung (29.1%) and abdominal (25%), with 49.7% metastatic cancer. As oncospecific treatment, 28% received chemotherapy, 29.3% immunotherapy, 19.3% specific therapies, and 2.1% conservative treatment. At the time of kidney biopsy, median creatinine was of 2.58 mg/dL [1.81-4.1 (IQ 25-75)], median urine protein-to-creatinine ratio of 700 mg/g [256-2463 (IQ 25-75)] and 53.1% presented hematuria. The most frequent renal biopsy diagnoses were: acute interstitial nephritis (39.9%), acute tubular necrosis (8.8%), IgA nephropathy (7.4%) and membranous nephropathy (6.1%). Median follow-up was 15.2 months [5.7-31.4 (IQ 25-75)]. CONCLUSIONS: There is a new trend in kidney disease and cancer patients in terms of diagnosis and treatment. Acute interstitial nephritis has established itself as the most common kidney injury in patients with cancer who underwent a kidney biopsy. Renal biopsy is a valuable tool for diagnosis, treatment, and prognosis of solid organ cancer patients with kidney damage.

Influence of Virchow-Robin spaces on the electric field distribution in subthalamic nucleus deep brain stimulation.

Patient MRI from DBS implantations in the subthalamic nucleus (STN) were reviewed and it was found that around 10% had Virchow-Robin spaces (VRS). Patient-specific models were developed to evaluate changes in the electric field (EF) around DBS leads. The patients (n = 7) were implanted bilaterally either with the standard voltage-controlled lead 3389 or with the directional current-controlled lead 6180. The EF distribution was evaluated by comparing simulations using patient-specific models with homogeneous models without VRS. The EF, depicted with an isocontour of 0.2 V/mm, showed a deformation in the presence of the VRS around the DBS lead. For patient-specific models, the radial extension of the EF isocontours was enlarged regardless of the operating mode or the DBS lead used. The location of the VRS in relation to the active contact and the stimulation amplitude, determined the changes in the shape and extension of the EF. It is concluded that it is important to take the patients' brain anatomy into account as the high conductivity in VRS will alter the electric field if close to the DBS lead. This can be a cause of unexpected side effects.

Consulta monográfica de onconefrología. Justificación y puesta en marcha / Monographic consultation of onconephrology. Rationale and implementation

El incremento de la demanda asistencial por afección renal asociada a enfermedades neoplásicas es una realidad en la mayoría de los servicios de nefrología. Para dar respuesta a esta situación, debe considerarse la creación de modelos asistenciales como consultas monográficas y desarrollar programas de formación en onconefrología que permitan optimizar la atención de estos pacientes. A través de un estudio exploratorio y descriptivo, identificamos cuál es la situación actual de la afectación renal en pacientes con cáncer. El objetivo del presente estudio es establecer los criterios para la asistencia específica en el ámbito de la onconefrología. Para ello hemos revisado aspectos clave y analizado la situación actual en nuestro entorno, mediante una encuesta dirigida a todos los nefrólogos a través de la SEN, junto a la experiencia de 2 centros españoles. A partir de esta información hemos establecido una serie de requisitos y recomendaciones para la puesta en marcha de estas consultas

The increase in demand for medical care for renal complications associated with neoplastic diseases is a reality in most nephrology departments. In response to this overall situation, the creation of healthcare models such as monographic consultations and develop training programs in onconephrology could improve the care of these patients. Through an exploratory and descriptive study, we identified current situation of kidney involvement in cancer patients. The objective of the present study is to establish the criteria for specific assistance in the field of onconephrology. For this, we have reviewed key aspects and analyzed the current situation in our country, through a survey addressed to all nephrologists through the Spanish Society of Nephrology, together with the experience of 2 Spanish centers. From this information, we have established some requirements and recommendations for the start-up of these consultations

Monographic consultation of onconephrology. Rationale and implementation.

The increase in demand for medical care for renal complications associated with neoplastic diseases is a reality in most nephrology departments. In response to this overall situation, the creation of healthcare models such as monographic consultations and develop training programs in Onconephrology could improve the care of these patients. Through an exploratory and descriptive study, we identified current situation of kidney involvement in cancer patients. The objective of the present study is to establish the criteria for specific assistance in the field of Onconephrology. For this, we have reviewed key aspects and analyzed the current situation in our country, through a survey addressed to all nephrologists through the Spanish Society of Nephrology., together with the experience of two Spanish centers. From this information, we have established some requirements and recommendations for the start-up of these consultations.

Monographic consultation of onconephrology. Rationale and implementation. / Consulta monográfica de onconefrología. Justificación y puesta en marcha.

The increase in demand for medical care for renal complications associated with neoplastic diseases is a reality in most nephrology departments. In response to this overall situation, the creation of healthcare models such as monographic consultations and develop training programs in onconephrology could improve the care of these patients. Through an exploratory and descriptive study, we identified current situation of kidney involvement in cancer patients. The objective of the present study is to establish the criteria for specific assistance in the field of onconephrology. For this, we have reviewed key aspects and analyzed the current situation in our country, through a survey addressed to all nephrologists through the Spanish Society of Nephrology, together with the experience of 2 Spanish centers. From this information, we have established some requirements and recommendations for the start-up of these consultations.

Stimulation maps: visualization of results of quantitative intraoperative testing for deep brain stimulation surgery.

Deep brain stimulation (DBS) is an established therapy for movement disorders such as essential tremor (ET). Positioning of the DBS lead in the patient's brain is crucial for effective treatment. Extensive evaluations of improvement and adverse effects of stimulation at different positions for various current amplitudes are performed intraoperatively. However, to choose the optimal position of the lead, the information has to be "mentally" visualized and analyzed. This paper introduces a new technique called "stimulation maps," which summarizes and visualizes the high amount of relevant data with the aim to assist in identifying the optimal DBS lead position. It combines three methods: outlines of the relevant anatomical structures, quantitative symptom evaluation, and patient-specific electric field simulations. Through this combination, each voxel in the stimulation region is assigned one value of symptom improvement, resulting in the division of stimulation region into areas with different improvement levels. This technique was applied retrospectively to five ET patients in the University Hospital in Clermont-Ferrand, France. Apart from identifying the optimal implant position, the resultant nine maps show that the highest improvement region is frequently in the posterior subthalamic area. The results demonstrate the utility of the stimulation maps in identifying the optimal implant position. Graphical abstract.

Onco-Nefrología: cáncer, quimioterapia y riñón / Onco-Nephrology: Cancer, chemotherapy and kidney

La enfermedad renal crónica (ERC), el cáncer y las enfermedades hematológicas comparten áreas de influencia recíproca. El cáncer puede afectar al riñón bien como lesiones glomerulares o como consecuencia de los efectos tóxicos de la medicación o radiación, con procesos agudos (microangiopatía trombótica, insuficiencia renal aguda, nefropatías intersticiales, entre otros) o crónicos (empeoramiento de la ERC tras la nefrectomía por cáncer renal, fibrosis intersticial, trastornos hidroelectrolíticos). En sentido opuesto, los pacientes que precisan tratamiento renal sustitutivo con diálisis y particularmente con trasplante renal son de alto riesgo para la aparición de cáncer debido a la situación de inmunosupresión que generan. Además de la quimioterapia convencional, se han desarrollado tratamientos innovadores: agentes diana contra factores de crecimiento y su receptor, fármacos antiangiogénicos, proteínas inmunorreguladoras, reguladoras del ciclo celular o bloqueantes enzimáticos. También otros enfoques inmunoterapéuticos, como vacunas, terapia celular adoptiva (células CAR T) o desarrollo de anticuerpos. Todas estas novedades terapéuticas mejorarán los resultados frente al cáncer y enfermedades hematológicas pero no están exentas de problemas secundarios con afectación renal. La Onco-Nefrología es ya un área importante para la Sociedad Española de Nefrología, con gran número de interconsultas. El especialista en Nefrología precisa una mejor comprensión de áreas de tan rápida evolución de la biología del cáncer y su tratamiento, para convertirse en miembro valioso del equipo de atención del cáncer y proporcionar la mejor atención nefrológica posible

Chronic kidney disease (CKD), cancer and haematological diseases share areas of reciprocal influence. Cancer can affect the kidney either as glomerular lesions or as a result of the toxic effects of medication or radiation with acute (thrombotic microangiopathy, acute kidney injury, interstitial nephropathies among others) or chronic processes (worsening of CKD after nephrectomy due to renal cancer, interstitial fibrosis, hydroelectrolytic disorders). On the other hand, patients who require renal replacement therapy with dialysis and particularly with kidney transplantation are at high risk of onset of cancer due to the immunosuppression situation that they generate. In addition to conventional chemotherapy, innovative treatments have been developed: target agents against growth factors and their receptor; anti-angiogenic drugs; immunoregulatory proteins; cell cycle regulators; and enzyme inhibitors. Other immunotherapeutic approaches have also been developed, such as vaccines, adoptive cell therapy (CAR T cells) or development of antibodies. All these therapeutic advances will improve the outcomes against cancer and haematological diseases, but they are not free from secondary renal problems. Onco-Nephrology is already an important area for the Spanish Society of Nephrology with a large number of inter-consultations. Nephrologists need a better understanding of rapidly evolving areas of cancer biology and its treatment in order to become valued members of the cancer care team and to provide the best nephrology care possible

Onco-Nephrology: Cancer, chemotherapy and kidney. / Onco-Nefrología: cáncer, quimioterapia y riñón.

Chronic kidney disease (CKD), cancer and haematological diseases share areas of reciprocal influence. Cancer can affect the kidney either as glomerular lesions or as a result of the toxic effects of medication or radiation with acute (thrombotic microangiopathy, acute kidney injury, interstitial nephropathies among others) or chronic processes (worsening of CKD after nephrectomy due to renal cancer, interstitial fibrosis, hydroelectrolytic disorders). On the other hand, patients who require renal replacement therapy with dialysis and particularly with kidney transplantation are at high risk of onset of cancer due to the immunosuppression situation that they generate. In addition to conventional chemotherapy, innovative treatments have been developed: target agents against growth factors and their receptor; anti-angiogenic drugs; immunoregulatory proteins; cell cycle regulators; and enzyme inhibitors. Other immunotherapeutic approaches have also been developed, such as vaccines, adoptive cell therapy (CAR T cells) or development of antibodies. All these therapeutic advances will improve the outcomes against cancer and haematological diseases, but they are not free from secondary renal problems. Onco-Nephrology is already an important area for the Spanish Society of Nephrology with a large number of inter-consultations. Nephrologists need a better understanding of rapidly evolving areas of cancer biology and its treatment in order to become valued members of the cancer care team and to provide the best nephrology care possible.

Patient-Specific Simulations of Deep Brain Stimulation Electric Field with Aid of In-house Software ELMA.

Deep brain stimulation (DBS) is an established technique for reduction of symptoms in movement disorders. Finite element method (FEM) simulations of the electric field magnitude (EF) are useful for estimating the affected tissue around the DBS lead and this can help optimize the therapy. This paper describes how patient-specific FEM models can be set up with the aid of the Matlab-based in-house software tool ELMA. Electrode placement is determined from two coordinates in postoperative medical imaging and electric conductivity is assigned from preoperative magnetic resonance imaging (MRI) and patient-specific DBS data. Simulations are performed using the equation for steady currents in Comsol Multiphysics (CM). The simulated EF is superimposed on the preoperative MRI for evaluation of affected structures. The method is demonstrated with patient-specific simulations in the zona incerta and a globus pallidus example containing cysts with higher conductive which causes considerable distortion of the EF. The improved software modules and precise lead positioning simplifies and reduces the time for DBS EF modelling and simulation.

Analysis of adverse effects of stimulation during DBS surgery by patient-specific FEM simulations.

Deep brain stimulation (DBS) represents today a well-established treatment for movement disorders. Nevertheless the exact mechanism of action of DBS remains incompletely known. During surgery, numerous stimulation tests are frequently performed in order to evaluate therapeutic and adverse effects before choosing the optimal implantation site for the DBS lead. Anatomical structures responsible for the induced adverse effects have been investigated previously, but only based on stimulation data obtained with the implanted DBS lead. The present study introduces a methodology to identify these anatomical structures during intraoperative stimulation tests based on patient-specific electric field simulations and visualization on the patient specific anatomy. The application to 4 patients undergoing DBS surgery and presenting dysarthria, paresthesia or pyramidal effects shows the different anatomical structures, which might be responsible for the adverse effects. Several of the identified structures have been previously described in the literature. To draw any statistically significant conclusions, the methodology has to be applied to further patients. Together with the visualization of the therapeutic effects, this new approach could assist the neurosurgeons in the future in choosing the optimal implant position.

Electric Field Comparison between Microelectrode Recording and Deep Brain Stimulation Systems-A Simulation Study.

The success of deep brain stimulation (DBS) relies primarily on the localization of the implanted electrode. Its final position can be chosen based on the results of intraoperative microelectrode recording (MER) and stimulation tests. The optimal position often differs from the final one selected for chronic stimulation with the DBS electrode. The aim of the study was to investigate, using finite element method (FEM) modeling and simulations, whether lead design, electrical setup, and operating modes induce differences in electric field (EF) distribution and in consequence, the clinical outcome. Finite element models of a MER system and a chronic DBS lead were developed. Simulations of the EF were performed for homogenous and patient-specific brain models to evaluate the influence of grounding (guide tube vs. stimulator case), parallel MER leads, and non-active DBS contacts. Results showed that the EF is deformed depending on the distance between the guide tube and stimulating contact. Several parallel MER leads and the presence of the non-active DBS contacts influence the EF distribution. The DBS EF volume can cover the intraoperatively produced EF, but can also extend to other anatomical areas. In conclusion, EF deformations between stimulation tests and DBS should be taken into consideration as they can alter the clinical outcome.

Patient-Specific Electric Field Simulations and Acceleration Measurements for Objective Analysis of Intraoperative Stimulation Tests in the Thalamus.

Despite an increasing use of deep brain stimulation (DBS) the fundamental mechanisms of action remain largely unknown. Simulation of electric entities has previously been proposed for chronic DBS combined with subjective symptom evaluations, but not for intraoperative stimulation tests. The present paper introduces a method for an objective exploitation of intraoperative stimulation test data to identify the optimal implant position of the chronic DBS lead by relating the electric field (EF) simulations to the patient-specific anatomy and the clinical effects quantified by accelerometry. To illustrate the feasibility of this approach, it was applied to five patients with essential tremor bilaterally implanted in the ventral intermediate nucleus (VIM). The VIM and its neighborhood structures were preoperatively outlined in 3D on white matter attenuated inversion recovery MR images. Quantitative intraoperative clinical assessments were performed using accelerometry. EF simulations (n = 272) for intraoperative stimulation test data performed along two trajectories per side were set-up using the finite element method for 143 stimulation test positions. The resulting EF isosurface of 0.2 V/mm was superimposed to the outlined anatomical structures. The percentage of volume of each structure's overlap was calculated and related to the corresponding clinical improvement. The proposed concept has been successfully applied to the five patients. For higher clinical improvements, not only the VIM but as well other neighboring structures were covered by the EF isosurfaces. The percentage of the volumes of the VIM, of the nucleus intermediate lateral of the thalamus and the prelemniscal radiations within the prerubral field of Forel increased for clinical improvements higher than 50% compared to improvements lower than 50%. The presented new concept allows a detailed and objective analysis of a high amount of intraoperative data to identify the optimal stimulation target. First results indicate agreement with published data hypothesizing that the stimulation of other structures than the VIM might be responsible for good clinical effects in essential tremor. (Clinical trial reference number: Ref: 2011-A00774-37/AU905).

Investigation into Deep Brain Stimulation Lead Designs: A Patient-Specific Simulation Study.

New deep brain stimulation (DBS) electrode designs offer operation in voltage and current mode and capability to steer the electric field (EF). The aim of the study was to compare the EF distributions of four DBS leads at equivalent amplitudes (3 V and 3.4 mA). Finite element method (FEM) simulations (n = 38) around cylindrical contacts (leads 3389, 6148) or equivalent contact configurations (leads 6180, SureStim1) were performed using homogeneous and patient-specific (heterogeneous) brain tissue models. Steering effects of 6180 and SureStim1 were compared with symmetric stimulation fields. To make relative comparisons between simulations, an EF isolevel of 0.2 V/mm was chosen based on neuron model simulations (n = 832) applied before EF visualization and comparisons. The simulations show that the EF distribution is largely influenced by the heterogeneity of the tissue, and the operating mode. Equivalent contact configurations result in similar EF distributions. In steering configurations, larger EF volumes were achieved in current mode using equivalent amplitudes. The methodology was demonstrated in a patient-specific simulation around the zona incerta and a "virtual" ventral intermediate nucleus target. In conclusion, lead design differences are enhanced when using patient-specific tissue models and current stimulation mode.