Thermal Evaluation of Multi-Antenna Systems Proposed to Treat Bone Tumors: Finite Element Analysis.

Microwave ablation is commonly used in soft tissue tumors, but its application in bone tumors has been barely analyzed. Antennas to treat bone tissue (~3 cm2), has been lately designed. Bone tumors at pathological stage T1 can reach 8 cm wide. An antenna cannot cover it; therefore, our goal is to evaluate the thermal performance of multi-antenna arrays. Linear, triangular, and square configurations of double slot (DS) and monopole (MTM) antennas were evaluated. A parametric study (finite element method), with variations in distance between antennas (ad) and bone thickness (bt) was implemented. Array feasibility was evaluated by SWR, ablated tissue volume, etc. The linear configuration with DS and MTM antennas showed SWR ≤ 1.6 for ad = 1 mm−15 mm and bt = 20 mm−40 mm, and ad = 10 mm−15 mm and bt = 25 mm−40 mm, respectively; the triangular showed SWR ≤ 1.5 for ad = 5 mm−15 mm and bt = 20 mm−40 mm and ad = 10 mm−15 mm and bt = 25 mm−40 mm. The square configuration (DS) generated SWR ≤ 1.5 for ad = 5 mm−20 mm and bt = 20 mm−40 mm, and the MTM, SWR ≤ 1.5 with ad = 10 mm and bt = 25 mm−40 mm. Ablated tissue was 4.65 cm3−10.46 cm3 after 5 min. According to treatment time and array configuration, maximum temperature and ablated tissue is modified. Bone tumors >3 cm3 can be treated by these antenna-arrays.

Parameterizing a tumor humeral prosthesis and development of a set.

BACKGROUND: The reconstruction of the proximal humerus is possible from the resection of the tumor and the placement of a prosthesis. In some cases, they do not meet the anthropometric aspects of the patients. OBJECTIVE: To determine the parameters to size the components of a humeral prosthesis and the development of a set, using design software. METHOD: Forty patients were selected for prostheses, radiographs and CT scans were analyzed and statistical tests were applied to the measurements. RESULTS: The length of the tumors was 8-20 cm. The minimum length of the humerus was 28 cm and 33 cm the maximum. Correlation was observed between the humerus and the tumor and the height of the patient with p = 0.93088 and p = 0.904564, respectively; humerus diameter, p = 0.2345. The set will include three components, diameter 6-10 mm, and length of 24, 26 and 28 cm. Three modular spacers with lengths of 6, 8.5 and 13 cm. Crowns 6.5 and 8.5 cm long, 1.3 cm in diameter and 5 mm nut. CONCLUSION: With the development of the set, poorly calculated resections and adaptation to any humerus size can be resolved.

ANTECEDENTES: La reconstrucción del húmero proximal es posible a partir de la resección del tumor y la colocación de una prótesis. En algunos casos, las prótesis no cumplen con los aspectos antropométricos de los pacientes. OBJETIVO: Determinar los parámetros para dimensionar los componentes de una prótesis de húmero y el desarrollo de un set, mediante software de diseño. MÉTODO: Se seleccionaron 40 pacientes para prótesis, se analizaron radiografías y tomografías computarizadas, y se aplicaron pruebas estadísticas a las mediciones. RESULTADOS: La longitud de los tumores fue de 8-20 cm. La longitud mínima del húmero fue de 28 cm y la máxima fue de 33 cm. Se observó correlación entre el húmero y el tumor y la altura del paciente, con p = 0.93088 y p = 0.904564, respectivamente; para el diámetro del húmero, p = 0.2345. El set incluye tres componentes, con diámetro de 6-10 mm y longitud de 24, 26 y 28 cm; tres espaciadores modulares con longitudes de 6, 8,5 y 13 cm; coronas de 6,5 y 8,5 cm de largo, 1,3 cm de diámetro y tuerca de 5 mm. CONCLUSIÓN: Con el desarrollo del set se pueden resolver resecciones mal calculadas y la adaptación a cualquier tamaño de húmero.

MicroRNA expression in relation with clinical evolution of osteosarcoma.

Osteosarcoma is the most common malignant bone tumor. Early diagnosis remains a major challenge, mainly because of the lack of specific biomarkers. We performed miRNAs expression analysis through qPCR in affected and paired healthy bone derived from osteosarcoma patients. Hierarchical clustering using the top ten miRNAs with differential expression showed two main clusters. One integrated by patients with the presence of metastasis or relapse and the other without these complications. Further pathway enrichment analysis reduced to four main miRNAs, hsa-miR-486-3p, hsa-miR-355-5p, hsa-miR-34a-5p and hsa-miR-1228-3p. Afterwards, we compared patients with and without metastasis, the function enrichment analysis along with review of relevant literature, showed that hsa-miR-93-5p and hsa-miR-28-5p were associated with metastasis development. Our results support the relevance of miRNAs in the pathogenesis of osteosarcoma and contribute with evidence regarding the potential role of miRNAs as potential biomarkers. More studies are needed to define the most informative miRNAs in osteosarcoma patients.

Circulating miR-215-5p and miR-642a-5p as potential biomarker for diagnosis of osteosarcoma in Mexican population.

Osteosarcoma is the most common malignant bone neoplasia affecting individuals in the second decade of life. The survival rate has not been improved during the last 25 years, in part because of the lack of specific markers. The microRNAs have been identified as important regulators of gene expression, experimental evidence suggests these molecules as key players in cancer development and progression. To identify miRNAs differentially expressed in serum from patients with osteosarcoma compared to healthy donors in Mexican population. Fifteen osteosarcoma patients and fifteen age and sex matched healthy individuals were recruited. Two pools of total RNA extracted from serum per study group were prepared and the miRNA expression profiles were analyzed through TaqMan Low Density Arrays. Validation was carried out through RT-qPCR using individual TaqMan assays for those miRNAs differentially expressed. Fifteen miRNAs were differentially expressed in osteosarcoma patients compared to healthy controls. Overexpression of miR-215-5p and miR-642a-5p was confirmed by validation through RT-qPCR. The expression analysis of miRNAs from serum in osteosarcoma patients revealed differential expression of miR-215-5p and miR-642a-5p. Both microRNAs are potential markers for osteosarcoma diagnosis.

Dedifferentiated giant-cell tumor of bone with an undifferentiated round cell mesenchymal component.

The dedifferentiated giant-cell tumor of the bone is a very rare variant of the giant-cell tumor (GCT). We report the clinical, radiographic and histological findings of a dedifferentiated GCT in which the dedifferentiated component consisted of small round cells. We also comment on previously reported cases of dedifferentiated GCT, discuss the clinical implications of this dual histology, and analyze the information published about the coexistence of similar genetic abnormalities in GCT and small round cell tumors of the bone.

[Quality of life in patients with bone tumors, a comparison between different treatments]. / Calidad de vida en pacientes con tumores oseos, una comparacion entre diferentes tratamientos.

INTRODUCTION. Previously, amputation was the only treatment option for patients with malignant bone tumors. Due to technological, medical and surgical advances, the number of survivors and years of survival has been increasing, and thus, the interest in evaluating the impact of this disease on quality of life. OBJECTIVE. To evaluate the health related quality of life reported by patients with bone tumors undergoing different treatments (no surgery/amputation/salvage). MATERIAL AND METHODS. Patients (n = 85) with bone tumors over the age of 18, both sexes, from the Instituto Nacional de Rehabilitación of Mexico City were included, divided into three groups according to type of treatment. The study design was cross-sectional, descriptive of a nonrandom sample. Quality of life was assessed with the Inventory of Quality of Life and Health (InCaViSa). Data were analyzed using descriptive statistics, comparisons between patients with different treatments were evaluated with multivariate analysis of covariance and Sidak post hoc tests. RESULTS. Statistically significant differences were detected in six of the twelve areas of quality of life that are assessed by the scale: physical functioning, isolation, body perception, treatment attitude leisure time and daily life. Health related quality of life in the study group is best for those patients who received amputation compared with the other treatments, while patients limb salvage procedures are those with greater impairment.

Serum tumor markers in pediatric osteosarcoma: a summary review.

Osteosarcoma is the most common primary high-grade bone tumor in both adolescents and children. Early tumor detection is key to ensuring effective treatment. Serum marker discovery and validation for pediatric osteosarcoma has accelerated in recent years, coincident with an evolving understanding of molecules and their complex interactions, and the compelling need for improved pediatric osteosarcoma outcome measures in clinical trials. This review gives a short overview of serological markers for pediatric osteosarcoma, and highlights advances in pediatric osteosarcoma-related marker research within the past year. Studies in the past year involving serum markers in patients with pediatric osteosarcoma can be assigned to one of four categories, i.e., new approaches and new markers, exploratory studies in specialized disease subsets, large cross-sectional validation studies, and longitudinal studies, with and without an intervention.Most of the studies have examined the association of a serum marker with some aspect of the natural history of pediatric osteosarcoma. As illustrated by the many studies reviewed, several serum markers are emerging that show a credible association with disease modification. The expanding pool of informative osteosarcoma-related markers is expected to impact development of therapeutics for pediatric osteosarcoma positively and, it is hoped, ultimately clinical care. Combinations of serum markers of natural immunity, thyroid hormone homeostasis, and bone tumorigenesis may be undertaken together in patients with pediatric osteosarcoma. These serum markers in combination may do better. The potential effect of an intrinsic dynamic balance of tumor angiogenesis residing within a single hormone (tri-iodothyronine) is an attractive concept for regulation of vascularization in pediatric osteosarcoma.

Diagnosis of a dedifferentiated chondrosarcoma of the pelvis by fine needle aspiration. A case report.

BACKGROUND: Dedifferentiated chondrosarcomas account for approximately 10% of all chondrosarcomas. There are few reports that describe the cytologic findings in dedifferentiated chondrosarcomas. In all these cases it was only present in the smears as a high grade sarcoma component. CASE: A 58-year-old man with a bone lesion in the right acetabular zone was admitted to the hospital. The clinical diagnosis was chondrosarcoma. A fine needle aspiration biopsy was performed. The smears of the sample had different characteristics in composition. Some slides had mostly abundant chondroid matrix with low to moderate cellularity. Other slides were cellular and contained mainly pleomorphic, spindled-shaped cells. The typical appearance of dedifferentiated chondrosarcoma was present in some slides that showed focal zones with chondroid matrix adjacent to or surrounded by pleomorphic spindled cells. The composition of the surgical specimen (slightly greater cartilaginous component than the sarcomatous one) allowed us to make a straightforward diagnosis of dedifferentiated chondrosarcoma. CONCLUSION: This is the first report that describes the presence of both components, high and low grade, by fine needle aspiration biopsy in dedifferentiated chondrosarcoma.

[Frequency of bone neoplasms in children]. / Frecuencia de neoplasias óseas en niños.

INTRODUCTION: Pediatric age is the group mainly affected by bone tumors. The objectives of this work were: (1) To determine which are the bone tumors and pseudotumoral lesions more frequent in the group of age from 0 to 14 years; (2) To determine if there are differences in the frequency of the tumors and pseudotumoral lesions between different subgroups and (3) To determine if there is any difference in the frequency of the different tumors according to gender. METHODS: We conducted a cross-sectional study based on the Pathology files of the National Institute of Rehabilitation. Inclusion criteria were: all cases between January 2000 and December 2006 diagnosed by hystopathological means as bone tumor or pseudotumoral lesion, with an age of presentation between 0 to 14 years were included. RESULTS: Frequency of bone tumors and pseudotumoral lesions in this series were: osteocondroma (44%), osteosarcoma (15.2%), fibrous dysplasia (10.4%) and encondroma (8.8%). We observed differences in the bone tumors or pseudotumor-like lesions frequency between the 3 subgroups of age studied.

[Bone tumor frequency in adults and elderly]. / Frecuencia de neoplasias óseas en adultos maduros y adultos mayores.

INTRODUCTION: We consider of great importance knowing the types of bone tumors and tumor-like lesions in adults and the elderly, which are increasing in proportion in our country. OBJECTIVES: (1) To analyze the frequency of bone tumors and tumor-like lesions in adults and elderly; (2) to determine any difference between these two groups; (3) and to analyze the most frequent sites of involvement. MATERIAL AND METHODS: We conducted a cross-sectional descriptive study that consisted in a retrolective review of all cases classified as a bone tumor or a tumorlike condition from year 2000-2006. We included all patients that presented with a bone tumor or tumor-like condition above 40 years-old. RESULTS: The most frequent diagnoses in patients between 40 and 60 years-old were plasmocytoma/myeloma (19.4%); giant cell tumor (14.1%) and metastases (12.3%). In patients older than 60 years, prevalence of bone tumor and tumor-like lesion was respectively: metastases (37.2%); plasmocytoma/myeloma (11.8%) and malignant fibrous histiocytoma (6.7%). Several differences were observed between these two groups.

[Musculoskeletal tumor evaluation with 99mTc-Tetrofosmin]. / 99mTc-Tetrofosmin en la evaluación de tumores musculoesqueléticos.

INTRODUCTION: (99m)Tc-tetrofosmin is an efficient agent as a tumor marker. Several studies have proven its efficiency in detection and localization of tumors of the breast, larynx, thyroid, parathyroid glands, lung, brain, skin, lymphatic and musculoskeletal tissues with a sensitivity and specificity of 95% to 100%. It is used as a predictor of therapy efficacy and to localize remaining and recurrent tissue as well as local and distant extension. OBJECTIVE: To determine the sensitivity, specificity and predictive values of the three-phase 99mTc-Tetrofosmin scan in detection of malignant lesions of the musculoskeletal tissue. METHODS: Seventy-three patients of both genders with suspected malignant musculoskeletal lesions were studied by three-phase (vascular, tissue and delayed images) 99mTc-tectrofosmin scans. RESULTS: One-hundred-percent sensitivity, 67.3% specificity, 55% positive predictive value, and 100% negative predictive value. CONCLUSION: Three-phase 99mTc-tectrofosmin scan is useful in detection of malignant lesions of the musculoskeletal system due to its high sensitivity and positive predictive value. Nevertheless, benign pathology such as active inflammation is a source of false positives and the attending physician must consider the aid of complementary studies such as histopathology.

[Prevalence of bone neoplasms in adolescents and young adults]. / Frecuencia de neoplasias óseas en adolescentes y adultos jóvenes.

INTRODUCTION: The objectives of this work were: (1) To determine the prevalence of bone neoplasms and pseudoneoplasms lesions in a group of adolescents (15 to 19 years), (2) To determine the more frequent bone neoplasms and pseudoneoplasms lesions in a group of young adults (29 to 39 years), (3) To determine if there are differences in the frequency of bone neoplasms and pseudoneoplasms lesions between the group of adolescents and the group of young adults and (4) To determine if there is any difference according to gender. MATERIAL AND METHODS: We conducted a descriptive, cross-sectional study that consisted in the review of the Pathology Department files in the National Institute of Rehabilitation. We included all patients with a histopathologic diagnosis of bone neoplasms or pseudoneoplasms lesion from January 2000 to December 2006 within the age of presentation from 15 to 19 or 20 to 39 years. RESULTS: The five more frequent bone neoplasms and pseudoneoplasms lesions in adolescents were osteochondroma, osteosarcoma, chondroblastoma, non-ossifying fibroma and aneurysmal bone cyst. In young adults the five more frequent were: giant cell neoplasm, osteosarcoma, osteochondroma, fibrous dysplasia and enchondroma.

[Partial internal hemipelvectomy for a secondary giant pelvic chondrosarcoma. A case report]. / Hemipelvectomía parcial interna por condrosarcoma secundario gigante de pelvis. Reporte de caso.

The purpose of this paper is to present the orthopedic-oncologic and functional outcomes of internal partial hemipelvectomy for a secondary giant pelvic chondrosarcoma in a patient with multiple hereditary osteochondromatosis.

[Epidemiology of bone and soft-part tumors of the foot and knee]. / Epidemiología de tumores óseos y partes blandas del pie y tobillo.

DESIGN: Report of cases. OBJECTIVE: Review of the cases in a period of 10 years with bone and soft tumors in foot and ankle, to knowing epidemilogical, clinic and patologic anatomy parameters to describe the behavior. MATERIALS AND METHODS: Review of 166 cases from 1991 to 2000 and been analyze with descriptive statistic, association measurment for inside stratum, with odds ratio, hipótesis test with chi square for qualitative date and t to Student for quantitative date. RESULTS: 166 patients within 2 years to 78 years old, 81 with bone tumors and 79 with soft tumors, mostly benign, the most frequent was in the soft tissue ganglion and oseal benign exostosis in bone, 6 different malignant tumors, the principal affected zone were the toes, as a difference to literature, the most affected age group was 10 to 20 years followed to the 30 to 40 years old, we report 42 different patological diagnostics results to soft tissue and osseous tissue. CONCLUSION: clinical features is not a useful parameter to differentiate between malign or benign tumors and does not allow to establish the biological behavior, we propose the diagnostic algorithm that includes the intentional clinical probe, comparative X-ray in three projections with soft technique, in suspicion to malignant lesion may require CT scan, MRI, osseous scan and finally biopsy which will improve the final outcome.

Fine needle aspiration cytology of low grade fibromyxoid sarcoma. Report of a case with histologic correlation.

BACKGROUND: Low grade fibromyxoid sarcoma, first described in 1987, is a rare sarcoma characterized by a bland and deceptively benign histologic appearance but with aggressive behavior. CASE: A 51-year-old female presented with a history of a recurrent and slowly growing mass in the left foot. Fine needle aspiration biopsy showed an abundant myxoid background with occasional thick bands of collagen. Tumor cells present in the myxoid background were spindle shaped, with focally mild or a light degree of nuclear enlargement, hyperchromasia and pleomorphism CONCLUSION: Low grade fibromyxoid sarcoma has particular cytologic features. Besides a careful cytologic evaluation of all the components, clinical and radiographic correlation is necessary to make the correct diagnosis.

Histiocitoma fibroso benigno tratado por medio de esterilización ósea e injerto de médula ósea autóloga / Benign fibrous hystiocitoma treated by steriliation, reimplantation and bone marrow. Case report

Se presenta el caso de un paciente de 12 años de edad el cual cursa con una lesión ósea en fémur distal izquierdo, diagnosticado como histiocitoma fibroso benigno de comportamiento agresivo. El tratamiento se realiza mediante resección segmentaria de la lesión ósea. El segmento se sometió a esterilización en autoclave a 125 ºC por 15 minutos. Posteriormente se aplicó sobre el injerto de médula ósea y se reimplantó en su sitio estabilizándose con clavo centromedular bloqueado de Colchero. Se vigila la evolución clínica y radiográfica del paciente, encontrándose integración del hueso esterilizado al resto del fémur así como la funcionalidad de la extremidad realizando marcha y apoyo a los 3 meses y se revisa los antecedentes bibliográficos.

Modelo tridimensional de un fémur humano por medio del método del elemento finito / Tri-dimentional model of a human femur determined by the finite element method

El método del elemento finito nos permite observar la geometría del espécimen, las propiedades mecánicas de los materiales empleados y las condiciones de carga y frontera del modelo. Analizamos el fémur de un individuo masculino sano, de 27 años. Nuestra conclusión es que el fémur trabaja predominantemente en cargas de compresión y secundariamente en flexión.

Nueva técnica de reconstrucción en hemipelvectomía parcial interna. Informe de dos casos clínicos / A new tecnique for reconstruction after partial internal hemi-pelvectomy

La cirugía conservadora de tumores óseos localizados en pelvis, representa un desafío para el equipo médico quirúrgico, del cual exige una incuestionable experiencia. La resección innominada tipo II, II-A y la IIA + III presenta serios problemas de reconstrucción, debido a que el remanente óseo es un hueso plano delgado, con una anatomía irregular, que impide efectuar una osteosíntesis estable y suficiente. El objetivo del presente trabajo es dar a conocer una nueva técnica de reconstrucción para la hemipelvectomía parcial interna, mediante el uso de un clavo en "y", bloqueado con pernos a fémur y con cerclajes de alambre al iliaco. Se presenta el reporte preliminar en dos pacientes. Se pretende asegurar la artrodesis femoroiliaca o cuando menos una pseudoartrosis no dolorosa. No hubo acortamiento significativo de la extremidad y la reincorporación a la actividad fue rápida.

Biomecánica de un fémur sometido a carga. Desarrollo de un modelo tridimensional por medio del método del elemento finito / Biomechanics of a femur submitted to load. Development of a three-dimensional model by the finite element method

Se describe el desarrollo de un modelo tridimensional de un fémur humano por medio del método del elemento finito. La geometría del hueso se determinó a través de 60 cortes tomográficos practicados al fémur de un voluntario masculino, 27 años, 1.74 m, 70 kg de peso, aparentemente sano. Una vez digitalizados los cortes tomográficos, se alimentaron los datos obtenidos al software Ansys (Ansys Inc) versión 5.3. El modelo desarrollado constó de 9 507 elementos y de 16 032 nodos. Tanto las propiedades consideradas, así como las condiciones de carga y de frontera empleadas, fueron obtenidas de la literatura especializada en el tema. Se consideraron un total de cuatro fuerzas externas correspondientes a la reacción de la cadera y a los tres grupos musculares predominantes en la fase de apoyo medio. Se obtuvieron los patrones de esfuerzos de von Mises correspondientes a la aplicación de cuatro, tres, dos y una carga, con lo que es posible establecer el papel que juegan los músculos para absorber parte de las solicitaciones que se ejercen a los huesos. De igual forma este modelo servirá como referencia para estudiar diferentes casos en los que se apliquen prótesis e implantes para cadera