Feasibility and potential advantages using VMAT in SRS metastasis treatments.

BACKGROUND: Utilization of stereotactic radiosurgery (SRS) for brain metastases (BM) has become the technique of choice as opposed to whole brain radiation therapy (WBRT). The aim of this work is to evaluate the feasibility and potential benefits in terms of normal tissue (NT) and dose escalation of volumetric modulated arc therapy (VMAT) in SRS metastasis treatment. A VMAT optimization procedure has therefore been developed for internal dose scaling which minimizes planner dependence. MATERIALS AND METHODS: Five patient-plans incorporating treatment with frame-based SRS with dynamic conformal arc technique (DA) were re-planned for VMAT. The lesions selected were between 4-6 cm3. The same geometry used in the DA plans was maintained for the VMAT cases. A VMAT planning procedure was performed attempting to scale the dose in inner auxiliary volumes, and to explore the potential for dose scaling with this technique. Comparison of dose-volume histogram (DVH) parameters were obtained. RESULTS: VMAT allows a superior NT sparing plus conformity and dose scaling using the auxiliary volumes. The VMAT results were significantly superior in NT sparing, improving both the V10 and V12 values in all cases, with a 2-3 cm3 saving. In addition, VMAT improves the dose coverage D95 by about 0.5 Gy. The objective of dose escalation was achieved with VMAT with an increment of the Dmean and the Dmedian of about 2 Gy. CONCLUSIONS: This work shows a benefit of VMAT in SRS treatment with significant NT sparing. A VMAT optimization procedure, based on auxiliary inner volumes, has been developed, enabling internal dose escalation.

Cranioplasty with Autologous Bone Flaps Cryopreserved with Dimethylsulphoxide: Does Tissue Processing Matter.

OBJECTIVE: The aim of this article was to study the outcome of patients who underwent cranioplasty with cryopreserved autologous bone after decompressive craniectomy. METHODS: Data from 74 patients were retrospectively analyzed. They were divided into groups according to the storage time and the age at cranioplasty. To assess the predictive potential for complication, factors were related to successive stages (preoperative, craniectomy, tissue processing, cranioplasty, and postoperative). Cooling and warming rates applied on bone flap were calculated. The ability to inhibit microbial growth was determined exposing bone fragments to a panel of microorganisms. The concentration of antibiotics eluted from the bone was also determined. A bone explant culture method was used to detect living cells in the thawed cranial bone. RESULTS: Hydrocephalus was significantly more frequent in pediatric patients (26.7%) than in adults (5.1%). The overall rate of bone flap resorption was 21.6% (43.7% of which required reoperation). Surgical site infection after cranioplasty was detected in 6.8% of patients. There was no correlation between infection as a postoperative complication and previous microbiological-positive culture during processing. The cause of craniectomy did not influence the risk of bone flap contamination. Vancomycin was the only antibiotic detected in the supernatant where the bone was incubated. Outgrowth from bone explants was observed in 36.8% of thawed skulls. An early start of bone flap processing at the tissue bank had a positive effect on cell viability. CONCLUSIONS: The outcome after autologous cranioplasty is a multifactorial process, which is modulated by patient-related, surgery-related, and bone-related factors.

The storage of skull bone flaps for autologous cranioplasty: literature review.

The use of autologous bone flap for cranioplasty after decompressive craniectomy is a widely used strategy that allows alleviating health expenses. When the patient has recovered from the primary insult, the cranioplasty restores protection and cosmesis, recovering fluid dynamics and improving neurological status. During this time, the bone flap must be stored, but there is a lack of standardization of tissue banking practices for this aim. In this work, we have reviewed the literature on tissue processing and storage practices. Most of the published articles are focused from a strictly clinical and surgical point of view, paying less attention to issues related to tissue manipulation. When bone resorption is avoided and the risk of infection is controlled, the autograft represents the most efficient choice, with the lowest risk of complication. Otherwise, depending on the degree of involvement, the patient may have to undergo new surgery, assuming further risks and higher healthcare costs. Therefore, tissue banks must implement protocols to provide products with the highest possible clinical effectiveness, without compromising safety. With a centralised management of tissue banking practices there may be a more uniform approach, thus facilitating the standardization of procedures and guidelines.

Covid-19 / No disponible

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Robust association between vascular habitats and patient prognosis in glioblastoma: An international multicenter study.

BACKGROUND: Glioblastoma (GBM) is the most aggressive primary brain tumor, characterized by a heterogeneous and abnormal vascularity. Subtypes of vascular habitats within the tumor and edema can be distinguished: high angiogenic tumor (HAT), low angiogenic tumor (LAT), infiltrated peripheral edema (IPE), and vasogenic peripheral edema (VPE). PURPOSE: To validate the association between hemodynamic markers from vascular habitats and overall survival (OS) in glioblastoma patients, considering the intercenter variability of acquisition protocols. STUDY TYPE: Multicenter retrospective study. POPULATION: In all, 184 glioblastoma patients from seven European centers participating in the NCT03439332 clinical study. FIELD STRENGTH/SEQUENCE: 1.5T (for 54 patients) or 3.0T (for 130 patients). Pregadolinium and postgadolinium-based contrast agent-enhanced T1 -weighted MRI, T2 - and FLAIR T2 -weighted, and dynamic susceptibility contrast (DSC) T2 * perfusion. ASSESSMENT: We analyzed preoperative MRIs to establish the association between the maximum relative cerebral blood volume (rCBVmax ) at each habitat with OS. Moreover, the stratification capabilities of the markers to divide patients into "vascular" groups were tested. The variability in the markers between individual centers was also assessed. STATISTICAL TESTS: Uniparametric Cox regression; Kaplan-Meier test; Mann-Whitney test. RESULTS: The rCBVmax derived from the HAT, LAT, and IPE habitats were significantly associated with patient OS (P < 0.05; hazard ratio [HR]: 1.05, 1.11, 1.28, respectively). Moreover, these markers can stratify patients into "moderate-" and "high-vascular" groups (P < 0.05). The Mann-Whitney test did not find significant differences among most of the centers in markers (HAT: P = 0.02-0.685; LAT: P = 0.010-0.769; IPE: P = 0.093-0.939; VPE: P = 0.016-1.000). DATA CONCLUSION: The rCBVmax calculated in HAT, LAT, and IPE habitats have been validated as clinically relevant prognostic biomarkers for glioblastoma patients in the pretreatment stage. This study demonstrates the robustness of the hemodynamic tissue signature (HTS) habitats to assess the GBM vascular heterogeneity and their association with patient prognosis independently of intercenter variability. LEVEL OF EVIDENCE: 3 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;51:1478-1486.

Multi-parametric MR Imaging Biomarkers Associated to Clinical Outcomes in Gliomas: A Systematic Review.

PURPOSE: To systematically review evidence regarding the association of multiparametric biomarkers with clinical outcomes and their capacity to explain relevant subcompartments of gliomas. MATERIALS AND METHODS: Scopus database was searched for original journal papers from January 1st, 2007 to February 20th, 2017 according to PRISMA. Four hundred forty-nine abstracts of papers were reviewed and scored independently by two out of six authors. Based on those papers we analyzed associations between biomarkers, subcompartments within the tumor lesion, and clinical outcomes. From all the articles analyzed, the twenty-seven papers with the highest scores were highlighted to represent the evidence about MR imaging biomarkers associated with clinical outcomes. Similarly, eighteen studies defining subcompartments within the tumor region were also highlighted to represent the evidence of MR imaging biomarkers. Their reports were critically appraised according to the QUADAS-2 criteria. RESULTS: It has been demonstrated that multi-parametric biomarkers are prepared for surrogating diagnosis, grading, segmentation, overall survival, progression-free survival, recurrence, molecular profiling and response to treatment in gliomas. Quantifications and radiomics features obtained from morphological exams (T1, T2, FLAIR, T1c), PWI (including DSC and DCE), diffusion (DWI, DTI) and chemical shift imaging (CSI) are the preferred MR biomarkers associated to clinical outcomes. Subcompartments relative to the peritumoral region, invasion, infiltration, proliferation, mass effect and pseudo flush, relapse compartments, gross tumor volumes, and highrisk regions have been defined to characterize the heterogeneity. For the majority of pairwise cooccurrences, we found no evidence to assert that observed co-occurrences were significantly different from their expected co-occurrences (Binomial test with False Discovery Rate correction, α=0.05). The co-occurrence among terms in the studied papers was found to be driven by their individual prevalence and trends in the literature. CONCLUSION: Combinations of MR imaging biomarkers from morphological, PWI, DWI and CSI exams have demonstrated their capability to predict clinical outcomes in different management moments of gliomas. Whereas morphologic-derived compartments have been mostly studied during the last ten years, new multi-parametric MRI approaches have also been proposed to discover specific subcompartments of the tumors. MR biomarkers from those subcompartments show the local behavior within the heterogeneous tumor and may quantify the prognosis and response to treatment of gliomas.

Nuestra experiencia en reconstrucción autóloga mamaria con colgajo latissimus dorsi e injerto de tejido adiposo tras mastectomía y radioterapia / Our experience in autologous breast reconstruction with latissimus dorsi flap and lipofilling after mastectomy and radiotherpay

Introducción y Objetivo: El colgajo de Latisimus Dorsi (LAT) es uno de los pilares en la reconstrucción mamaria; si bien el colgajo TRAM (transverse rectus abdominis myocutaneous flap) y en los últimos años el auge del colgajo de perforantes de la arteria epigástrica inferior profunda (DIEAP: deep inferior epigastric artery perforator flap) disminuyó su uso, continúa siendo una herramienta básica de la reconstrucción mamaria que incrementa su aplicación al asociarlo al injerto de tejido adiposo (ITA) prescindiendo del uso de prótesis. Presentamos y analizamos nuestros resultados con el uso del colgajo LAT asociado al ITA como alternativa en reconstrucción mamaria autóloga. Material y método: Recogemos de forma retrospectiva 35 casos de reconstrucción mamaria mediante colgajo pediculado LAT y varias sesiones de ITA en un periodo de 5 años en el Servicio de Cirugía Plástica del Hospital Clínico Universitario de Valencia (España). Resultados: La edad media de las pacientes fu 49.17 años. Todas habían sufrido mastectomía radical o subcutánea y recibido radioterapia posterior. El número medio de sesiones para lograr el volumen deseado fue de 3.23, siendo también 3 el número más frecuente de sesiones necesarias (15 pacientes, 42.86% del total). El volumen de injerto osciló entre 30 y 365 cc (media de 177.52 cc de injerto por sesión). El tiempo de espera medio entre sesiones fue de 5 meses. El resultado estético final ha sido muy satisfactorio, con mejoría evidente en las secuelas de la radioterapia. No registramos complicaciones mayores reseñables. Conclusiones: El empleo de ITA asociado al colgajo pediculado LAT permite, en nuestra experiencia, alcanzar un volumen final adecuado en la mama reconstruida y mejora la calidad de los tejidos radiados, suponiendo una alternativa comparable a los colgajos microquirúrgicos abdominales, y minimizando la complejidad quirúrgica del procedimiento

Background and Objective: The Latissimus Dorsi (LAT) flap represents one of the pillars in breast reconstruction; although TRAM (transverse rectus abdominis myocutaneous) flap and, in recent years, the rise of deep inferior epigastric perforator (DIEP) flap has decreased its use, it continues to constitute a basic tool of breast reconstruction, which increases its application when associated with the adipose tissue graft, not needing the use of breast implants. We present and analyze our results in the use of the LAT flap associated with the adipose tissue graft (ATG) as an alternative to other techniques of autologous reconstruction. Methods: We retrospectively collected 35 cases of patients with LAT flap reconstruction followed by several ATG sessions over a period of 5 years at the Plastic Surgery Department of the Hospital Clínico Universitario de Valencia (Spain). Results: Patients' average age was 49.17 years. All of them have undergone a radical or subcutaneous mastectomy and subsequent radiotherapy. The average number of adipose tissue graft sessions to achieve the desired volume was 3.23, with 3 being the most frequent number of sessions required (15 patients, 42.86% of the total). The graft volume ranged between 30 and 365 cc per session, with an average of 177.52 cc of graft per session. The average waiting time between sessions was 5 months. The final aesthetic result has been very satisfactory, obtaining an evident improvement in the sequels of radiotherapy. No major complications were reported. Conclusions: In our experience, the use of ATG associated with the LAT flap achieves an adequate final volume in the breast and improves the quality of the radiated tissues, assuming an alternative comparable to abdominal microsurgical flaps and minimizing surgical complexity of the procedure

Respuesta al Comentario del Dr. G. Betti-Kraemer / No disponible

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Nuestra técnica de colgajo miocutáneo de pectoral mayor para reconstrucción de defectos cervicales / Our technique of pectoralis major myocutaneous flap for reconstruction of cervical defects

Introducción y Objetivos. Las técnicas actuales para reconstrucción de cabeza y cuello se basan principalmente en colgajos libres, fasciocutáneos o viscerales según el defecto. La evolución de la microcirugía ha relegado a un segundo plano a los colgajos pediculados. El colgajo miocutáneo pediculado de pectoral mayor ha sido uno de los más empleados hasta que se ha extendido el uso de los colgajos libres. Las desventajas que presenta, tales como su volumen o sus secuelas funcionales y estéticas, son responsables de su desuso actual. Presentamos una modificación de la técnica clásica del pectoral mayor para minimizar sus desventajas. Material y Método. Hacemos una descripción técnica de la modificación desarrollada por Márquez-Cañada del colgajo de pectoral mayor para reconstrucción de defectos cervicales y un estudio descriptivo sobre un grupo de pacientes sometidos a la misma. Resultados. Recogimos 6 casos, 5 varones y 1 mujer (edad media de 52.5 años), en los que se empleó la técnica descrita. El defecto más frecuente (66.7%) fue el faringostoma secundario a laringuectomía total y vaciamiento cervical por carcinoma epidermoide de laringe. Tiempo medio entre intervenciones quirúrgicas de 5 semanas. En 2 casos hubo como complicación serohematoma en zona donante tras el primer tiempo quirúrgico, No hubo pérdida de injertos ni necrosis, fístulas o estenosis secundarias. Resultado estético aceptable; los pacientes conservaron movilidad completa del brazo. Conclusiones. Observamos una reducción en el número de complicaciones respecto del uso del pectoral mayor clásico y los colgajos libres Creemos que la modificación técnica que presentamos, por su reproducibilidad y su baja tasa de complicaciones, podría emplearse en reconstrucción de cuello como colgajo de elección en pacientes de alto riesgo, no candidatos a técnicas microquirúrgicas (AU)

Background and Objective. Current techniques for head and neck reconstruction are mainly based on free flaps, fasciocutaneous or visceral according to the defect. The evolution of microsurgery has relegated to the background the pedicled flaps. The pedicled myocutaneous pectoralis major flap has been one of the most employed until the generalization of free flaps. Their disadvantages such as bulky or functional and aesthetic sequelae, are responsible for its current disuse. We present a modification to the classic technique of pectoralis major flap to reduce its disadvantages. Methods. We make a technical description of the modification developed by Márquez-Cañada of the pectoralis major flap for cervical defects reconstruction and a descriptive study on a group of patients submitted to it. Results. We collected 6 cases, 5 males and 1 females (mean age 52.5 years), in which the described technique was used. The most frequent defect (66.7%) was the pharyngostoma secondary to total laryngectomy and cervical emptying secondary a epidermoid carcinoma of the larynx. Mean time between surgeries was 5-week. In 2 cases, there was serohematoma in the donor site after the first surgical time. There was no loss of grafts or necrosis, fistulas or secondary stenoses. Acceptable esthetic result; patients maintained complete arm mobility. Conclusions. We observed a reduction in the number of complications with respect to the use of the classic pectoralis and free flaps. We believe that the technical modification that we present, due to its reproducibility and its low complication rate, could be used in neck reconstruction as a flap of choice in patients of high risk, not candidates for microsurgical techniques (AU)

Expansor tisular como solución definitiva en defecto lumbar. Caso clínico / Tissue expander as a final solution in lumbar defect. Case report

Los expansores tisulares han sido muy empleados en el ámbito de la Cirugía Plástica desde que Neumann describió sus primeras aplicaciones en el ámbito médico en 1957, siendo su principal indicación la obtención de mayor extensión de los tejidos superficiales para cubrir defectos tisulares importantes en los que un cierre directo resulta inviable. Presentamos un caso clínico en el que empleamos un expansor tisular como espaciador, en el contexto de un defecto lumbar de partes blandas de gran tamaño tras exéresis de sarcoma. Lo más interesante de este caso, es que el expansor no se empleó con el fin de aumentar la superficie de tejido suprayacente, sino para ocupar la cavidad resultante tras una exéresis amplia (AU)

Tissue expanders have been broadly used in Plastic Surgery since Neumann described their first applications in medical environment in 1957, being their main indication to obtain a bigger surface of outer layers, in order to cover major defects in which a direct closure is not feasible. We report a clinical case in which a tissue expander was used as a spacer, in the context of a large lumbar soft tissue defect, after sarcoma excision. The most interesting thing about this case is that the expander was not used in order to increase the surface of overlying tissue, but to fill the resulting cavity after a wide surgical excision (AU)

Acute human brain responses to intracortical microelectrode arrays: challenges and future prospects.

The emerging field of neuroprosthetics is focused on the development of new therapeutic interventions that will be able to restore some lost neural function by selective electrical stimulation or by harnessing activity recorded from populations of neurons. As more and more patients benefit from these approaches, the interest in neural interfaces has grown significantly and a new generation of penetrating microelectrode arrays are providing unprecedented access to the neurons of the central nervous system (CNS). These microelectrodes have active tip dimensions that are similar in size to neurons and because they penetrate the nervous system, they provide selective access to these cells (within a few microns). However, the very long-term viability of chronically implanted microelectrodes and the capability of recording the same spiking activity over long time periods still remain to be established and confirmed in human studies. Here we review the main responses to acute implantation of microelectrode arrays, and emphasize that it will become essential to control the neural tissue damage induced by these intracortical microelectrodes in order to achieve the high clinical potentials accompanying this technology.