RESUMO
While the benefits of early palliative care for patients with metastatic cancer are well established, cancer survivorship remains inadequately integrated into the care of patients with distant metastases. Moreover, the optimal model of care delivery is poorly defined. A prognostic model previously developed and validated at Good Samaritan University Hospital identified four groups of patients with metastatic solid tumor malignancy having very favorable, favorable, standard or unfavorable prognoses with median survival of 31, 14, 4 and 1 month, respectively. This framework holds promise for the personalized delivery of supportive, palliative and survivorship care services in the context of radiation therapy. We review the published literature providing the rationale for a novel multidisciplinary care model where the radiation oncology Clinical Nurse Specialist identifies and coordinates interventions to address unmet physical and emotional issues faced by survivors with metastatic cancer with the goal of improving quality of life and overall survival.
Assuntos
Segunda Neoplasia Primária , Neoplasias , Humanos , Sobrevivência , Qualidade de Vida , Neoplasias/radioterapia , Cuidados PaliativosRESUMO
Phase change materials that leverage the latent heat of solid-liquid transition have many applications in thermal energy transport and storage. When employed as particles within a carrier fluid, the resulting phase change slurries (PCSs) could outperform present-day single-phase working fluidsâprovided that viscous losses can be minimized. This work investigates the rheological behavior of encapsulated and nonencapsulated phase change slurries (PCSs) for applicability in flowing thermal energy systems. The physical and thermal properties of the PCS candidates, along with their rheological behavior, are investigated below and above their phase transition points at shear rates of 1-300 s-1, temperatures of 20-80 °C, and concentrations of 15-37.5 wt %. The effect of shell robustness and melting on local shear thickening and global shear thinning is discussed, followed by an analysis of the required pumping power. A hysteresis analysis is performed to test the transient response of the PCS under a range of shear rates. We assess the complex viscoelastic behavior by employing oscillatory flow tests and by delineating the flow indicesâflow consistency index (K) and flow behavior index (n). We identify a viscosity limit of 0.1 Pa·s for optimal thermal performance in high-flow applications such as renewable geothermal energy.
RESUMO
Alternating electric fields have been successfully applied to cancer cells in-vitro to disrupt malignant progression and this antimitotic therapy has now been proven to be efficacious in Phase II and Phase III randomized clinical trials of patients with glioblastoma. With additional clinical trials ongoing in a number of other malignancies, there is a crucial need for a better understanding of the radiographic predictors of response and standardization of surveillance imaging interpretation. However, many radiologists have yet to become familiarized with this emerging cancer therapy and there is little active investigation to develop prognostic or predictive imaging biomarkers. This article provides an overview of the pre-clinical data that elucidate the biologic mechanisms of alternating electric fields as a cancer therapy. Results from clinical trials in patients with glioblastoma are then reviewed while elaborating on the several limitations to adoption of this promising line of treatment. Finally, a proposal for the development of imaging markers as a means of overcoming some of these limitations is made, which may improve treatment utilization by augmenting patient selection not only in glioblastoma, but also other malignant conditions for which this therapy is currently being evaluated.
Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/terapia , Terapia por Estimulação Elétrica/métodos , Glioblastoma/diagnóstico por imagem , Glioblastoma/terapia , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral/efeitos da radiação , Glioblastoma/patologia , Humanos , Neoplasias/diagnóstico por imagem , Neoplasias/terapia , Neuroimagem/métodos , PrognósticoRESUMO
BACKGROUND: Whole-brain radiotherapy (WBRT) in patients with brain metastases (BM) is associated with neurocognitive decline. Given its crucial role in learning and memory, efforts to mitigate this toxicity have mostly focused on sparing radiation to the hippocampus. We hypothesized that BM are not evenly distributed across the brain and that several additional areas may be avoided in WBRT based on a low risk of developing BM. METHODS: We contoured 2757 lesions in a large, single-institution database of patients with newly diagnosed BM. BM centroids were mapped onto a standard brain atlas of 55 anatomic subunits and the observed percentage of BM was compared with what would be expected based on that region's volume. A region of interest (ROI) analysis was performed in a validation cohort of patients from 2 independent institutions using equivalence and one-sample hypothesis tests. RESULTS: The brainstem and bilateral thalami, hippocampi, parahippocampal gyri, amygdala, and temporal poles had a cumulative risk of harboring a BM centroid of 4.83% in the initial cohort. This ROI was tested in 157 patients from the validation cohort and was found to have a 4.1% risk of developing BM, which was statistically equivalent between the 2 groups (P < 1 × 10-6, upper bound). CONCLUSION: Several critical brain structures are at a low risk of developing BM. A risk-adapted approach to WBRT is worthy of further investigation and may mitigate the toxicities of conventional radiation.
Assuntos
Neoplasias Encefálicas/secundário , Encéfalo/patologia , Irradiação Craniana/efeitos adversos , Neoplasias/radioterapia , Planejamento da Radioterapia Assistida por Computador/normas , Lobo Temporal/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Encéfalo/efeitos da radiação , Neoplasias Encefálicas/radioterapia , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/patologia , Prognóstico , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Lobo Temporal/efeitos da radiaçãoRESUMO
BACKGROUND: Traditional beliefs of androgen's stimulating effects on the growth of prostate cancer (PCa) have been challenged in recent years. Our previous in vitro study indicated that physiological normal levels of androgens inhibited the proliferation of PCa cells. In this in vivo study, the ability of testosterone (T) to inhibit PCa growth was assessed by testing the tumor incidence rate and tumor growth rate of PCa xenografts on nude mice. METHODS: Different serum testosterone levels were manipulated in male nude/nude athymic mice by orchiectomy or inserting different dosages of T pellets subcutaneously. PCa cells were injected subcutaneously to nude mice and tumor incidence rate and tumor growth rate of PCa xenografts were tested. RESULTS: The data demonstrated that low levels of serum T resulted in the highest PCa incidence rate (50%). This PCa incidence rate in mice with low T levels was significantly higher than that in mice treated with higher doses of T (24%, P < 0.01) and mice that underwent orchiectomy (8%, P < 0.001). Mice that had low serum T levels had the shortest tumor volume doubling time (112 h). This doubling time was significantly shorter than that in the high dose 5 mg T arm (158 h, P < 0.001) and in the orchiectomy arm (468 h, P < 0.001). CONCLUSION: These results indicated that low T levels are optimal for PCa cell growth. Castrate T levels, as seen after orchiectomy, are not sufficient to support PCa cell growth. Higher levels of serum T inhibited PCa cell growth.
Assuntos
Antineoplásicos Hormonais/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Testosterona/farmacologia , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Humanos , Incidência , Masculino , Camundongos , Camundongos Nus , Orquiectomia , Neoplasias da Próstata/sangue , Testosterona/sangue , Carga Tumoral , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Prostate-specific antigen (PSA) testing has been widely used to screen men for prostate cancer (PCa) and to monitor PCa progression. However, more studies have shown that around 15% of men with low or normal PSA levels have PCa. In this study, we aimed to investigate the relationship of androgen and PSA levels and to better understand the reason that some PCa patients have low serum PSA values. The in vitro data demonstrated that cultured LNCaP cells ceased to produce PSA after androgen withdrawal and resumed PSA production after androgen was re-added. The in vivo experiment results showed that 48% of PCa xenografts carrying mice have serum PSA level lower than 4 ng ml-1 . The serum PSA levels increased significantly with rises in testosterone (T) levels 1 week after T pellet implantation. These data indicated that the androgen is a key factor controlling the production of PSA. Low serum PSA levels in mice with PCa xenografts are associated with low serum T levels. Raising serum T levels in tumor caring mice will also significantly increase serum PSA level. This may have clinical implications when screening PSA in men, who have occult PCa.
Assuntos
Antígeno Prostático Específico/sangue , Neoplasias da Próstata/diagnóstico , Testosterona/sangue , Animais , Biomarcadores Tumorais/sangue , Linhagem Celular Tumoral , Progressão da Doença , Xenoenxertos , Humanos , Masculino , Camundongos , Camundongos Nus , Neoplasias da Próstata/sangue , Neoplasias da Próstata/patologiaRESUMO
We study an evolutionary model of a complex system that evolves under catalytic dynamics and Darwinian selection and exhibits spontaneous growth, stasis and then a collapse of its structure. We find that the typical lifetime of the system increases sharply with the diversity of its components or species. We also find that the prime reason for crashes is a naturally occurring internal fragility of the system. This fragility is captured in the network organizational character and is related to a reduced multiplicity of pathways or feedback loops between its components. These results apply to several generalizations of the model as well. This work suggests new parameters for understanding the robustness of evolving molecular networks, ecosystems, societies and markets.