Navigator-assisted hypofractionation (NAVAH) to address radiation therapy access disparities facing African-Americans with breast cancer

BackgroundAfrican-Americans have the highest overall cancer death rate and shortest survival time of any racial or ethnic group in the United States. The most common cancer studied in African-American radiation therapy (RT) access disparities research is breast cancer. The goal of this study is to evaluate the impact of patient navigation on RT access for African-American breast cancer patients.Material and methodsThis study is a prospective survey-based evaluation of the impact of patient navigation on access to hypofractionated RT and financial toxicity in African-American breast cancer patients. The impact of patient navigation on RT access will be collated and analyzed from survey results pre-RT versus post-RT as well as for patients with versus without receipt of patient navigation. The validated COST-Functional Assessment of Chronic Illness Therapy score will be used to compare hypofractionation versus standard fractionated RT financial toxicity for patients with early-stage breast cancer who have received lumpectomy.ConclusionThis is the first study to investigate the impact of patient navigation on reducing RT access disparities facing African-American breast cancer patients. The natural progression of this work will be to expand this model to include additional breast cancer populations most vulnerable to suffering RT access disparities (Native American, Hispanic American, Appalachian) within the United States.     

The outcome of radiation therapy as a primary treatment in orbital lymphoma: a systematic review

BackgroundThe extranodal marginal-zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) is the most common orbital and adnexal lymphomas. Radiotherapy is one of the most preferred treatment options for orbital lymphomas since they are localized and radiation sensitive. The objective of this study is to evaluate how radiation therapy affected the outcome of orbital MALT lymphoma.Materials and methodsPRISMA guideline was used to conduct this systematic review of electronic databases (PubMed, EMBASE and Cochrane Library), then we assessed the quality of evidence of each paper.ResultsTwenty-five studies were finally included. 94% studies were intended for definitive therapy and almost all of the studies used external radiation sources. The total doses given to the tumor bed ranged from 4 Gy to 55 Gy and were divided into three groups: ultra-low dose (4–6 Gy), standard-dose (24–30.6 Gy), and high-dose (> 30.6 Gy). 75–90% patients showed CR and local relapse was only reported at 3.5–5%. Higher 5-year PFS was reported in the patients group with lens shielding (90.1% vs. 82.1%) and an increase in Meiboscore after RT courses. Toxicities, including dry eye and cataract, were reported in several patients. Acute toxicities subsided gradually over a few months with artificial tears. The risk of early cataract formation increases in patients who received > 30 Gy and lower in the IMRT group.ConclusionRT is a successful primary definitive therapy for low-grade orbital MALT lymphoma, with a high survival rate, low recurrence rate, and typically acceptable toxicity.     

Anatomy-based prediction method for determining ipsilateral lung doses in postoperative breast radiation therapy assisted by diagnostic computed tomography images

BackgroundThis study aimed to investigate whether ipsilateral lung doses (ILDs) could be predicted by anatomical indexes measured using diagnostic computed tomography (CT) prior to the planning stage of breast radiation therapy (RT).Materials and methodsThe thoracic diameters and the length of lines drawn manually were measured on diagnostic CT images. The parameters of interest were the skin maximum lung distance (sMLD), central lung distance (CLD), Haller index (HI), and body mass index (BMI). Lung dose-volume histograms were created with conformal planning, and the lung volumes receiving 5–40 Gy (V5–V40) were calculated. Linear regression models were used to investigate the correlations between the anatomical indexes and dose differences and to estimate the slope and 95% confidence intervals (CIs).ResultsA total of 160 patients who had undergone three-dimensional conformal RT after breast-conserving surgery were included. Univariable analysis revealed that the sMLD (p < 0.001), CLD (p < 0.001), HI (p = 0.002), and BMI (p < 0.001) were significantly correlated with the V20. However, multivariable analysis revealed that only the sMLD (slope: 0.147, p = 0.001, 95% CI: 0.162–0.306) and CLD (0.157, p = 0.005, 0.048–0.266) were strongly correlated with the V20. The p-value for the sMLD was the lowest among the p-values for all indexes, thereby indicating that the sMLD had the best predictive power for ILD.ConclusionssMLD and CLD are anatomical markers that can be used to predict ILD in whole breast RT. An sMLD > 20.5 mm or a CLD > 24.3 mm positively correlated with a high ILD.     

Intraoperative electron radiation therapy after salvage surgery in gynecological cancers and retroperitoneal sarcomas: outcomes and adverse effects

BackgroundSalvage surgery is considered an option for isolated recurrences of retroperitoneal and pelvic tumors, in patients who have undergone previous radiotherapy. In order to increase local control intra operative electron radiation therapy (IOERT) can be used in these patients to administer additional radiation dose. We evaluated the outcomes and adverse effects in patients with retroperitoneal sarcoma and gynecologic tumors after salvage surgery and IOERT.Materials and methodsTwenty patients were retrospectively analyzed. Twenty-three IOERT treatments were performed after surgery. Six (30%) were sarcoma and 14 (70%) were gynecological carcinoma. Administered dose depended on previous dose received with external beam radiotherapy (EBRT) and proximity to critical structures. The toxicities were scored using the Common Terminology Criteria for Adverse Events version 4.0.ResultsThe median age of the patients was 51 years (range 34–70). After a median follow-up of 32 months (range 1–68), in the sarcoma group the local control rate was 66.6%; while in the gynecological group the local control rate was 64.3%. In relation to late toxicity, one patient had a Grade 2 vesicovaginal fistula, and one patient presented Grade 4 enterocolitis and enteric intestinal fistula.ConclusionsIOERT could have a role in the treatment of retroperitoneal sarcomas in primary tumors after EBRT, as it may suggest a benefit in local control or recurrences after surgical resection in those at high risk of microscopic residual disease. The addition of IOERT to salvage resection for isolated recurrence of gynecologic cancers suggest favorable local control in cases with concern for residual microscopic disease.     

夏季绿洲生态环境对荒漠背景地表能量过程的扰动

利用观测试验资料,对比分析了夏季典型晴天敦煌绿洲与周围荒漠戈壁背景地表过程的差异,揭示了绿洲生态系统对干旱区荒漠背景地表过程的扰动特征。结果表明:绿洲地表净辐射日平均要高出周围荒漠戈壁背景60 W/m2以上,约占绿洲净辐射的1/4以上。对绿洲高出的净辐射贡献最大的是绿洲相对低的地表长波辐射,其次是较高的太阳总辐射。而绿洲相对较低的大气长波辐射对高出的净辐射有较大的负贡献,特别是地表反射辐射也有很小的负贡献。绿洲高出的地表净辐射主要贡献于加强潜热和地热流量,还有一部分被绿洲地表能量不平衡差额所占,它实际上可能由一般地表热量平衡所不考虑的垂直热量平流来输送。而绿洲明显低于荒漠背景的感热通量则节省了一部分净辐射能量。     

安吉毛竹林水汽通量变化特征及其与环境因子的关系

以浙江省安吉县毛竹(Phyllostachys edulis)林生态系统为研究对象,利用涡度相关技术进行观测,获取2011年毛竹林的水汽通量数据,同时结合常规气象观测数据,分析了水汽通量全年变化。结果表明:毛竹林全年水汽通量基本为正值,月尺度上,水汽通量呈单峰型变化趋势,且各月的最大值均在12:00—14:00出现,呈现一定规律性,7月(0.1116 g m-2s-1)最高,12月(0.0209 g m-2s-1)最低;季节尺度上,夏季最高(0.0873 g m-2s-1),呈现典型单峰型变化趋势,春秋季(均为0.0541 g m-2s-1)次之,变化特征与夏季相似,冬季最低(0.0221 g m-2s-1),曲线变化复杂,波动较大。毛竹林全年蒸散量占全年降水量48.26%。2、4、5、11、12月蒸散量略大于降水量,其余月份蒸散量均小于降水量,6月份降水量与蒸散量差别最大。季节尺度上,对毛竹林水汽通量与净辐射进行回归关系分析,夏季最大,R2为0.6111,秋季为0.5295,春季为0.2605,冬季最小0.0455。通过F检验,水汽通量与净辐射有极显著线性关系。在植物生长期,毛竹林水汽通量随饱和水汽压差的增大而增大,植物发育成熟后,当饱和水汽压差增大到一定程度时,其增大反而抑制了水分的蒸散。     

UV-B辐射和NaCl胁迫对绿豆幼苗叶片DNA损伤的复合效应

研究了0·4W/m2UV-B辐射和0·4%NaCl胁迫对两绿豆品种中绿_1和秦豆-20(PhaseolusraditusL.cv.Zhongl櫣-1andQindou-20)幼苗叶片DNA损伤的复合效应。结果表明:(1)中绿-1抗UV-B辐射和NaCl胁迫的能力均强于秦豆-20;NaCl胁迫能降低中绿-1UV-B敏感性,但对秦豆-20UV-B敏感性无明显影响。(2)两逆境因子单独胁迫或复合胁迫下DNA增色效应均明显降低,但中绿-1降低程度小于秦豆-20,复合胁迫下降低程度小于单独NaCl胁迫下。(3)UV-B辐射诱导的中绿-1DNA链内环丁烷嘧啶二聚体(CPD)累积量明显低于秦豆-20;NaCl胁迫能降低UV-B诱导的中绿-1CPD累积,而对UV-B诱导的秦豆-20CPD累积无影响。(4)各种胁迫处理均导致两品种幼苗DNA含量降低,但两品种间相比中绿-1降低程度较大。结果说明UV-B辐射不仅能诱导DNA链内交联形成CPD,而且能诱导DNA链间交联和DNA含量降低,且不同绿豆品种或同一品种在有无NaCl胁迫时UV-B敏感性的差异主要与CPD累积量和DNA链间交联程度有关。     

晋西黄土区果农间作的种间主要竞争关系及土地生产力

以晋西黄土区核桃×花生、核桃×大豆、苹果×花生和苹果×大豆4种典型果农间作模式为研究对象,分析果农间作模式中作物光合有效辐射（PAR）、净光合速率（P_n）、土壤水分和产量情况.结果表明：与农作物单作相比,间作模式中作物的PAR和P_n均出现不同程度的降低,并且离树体越近,PAR和P_n越小;P_n与作物产量呈显著正相关,说明光照是影响作物产量的重要因素之一;从整体趋势来看,核桃间作农作物0～100 cm土壤水分与相应单作模式间无明显差异,而苹果间作农作物0～100 cm土壤水分与相应单作模式间差异显著,说明苹果对作物土壤水分的竞争比核桃剧烈.研究区果农间作的土地利用效率平均提高70%,经济效益平均提高14%,且核桃间作模式优于苹果间作模式.为了提高间作作物产量,应加强水肥管理、增加树体与作物的间作距离或设置根障、定期适当修剪果树并种植耐荫作物.     

Response of physiological integration in Trifolium repens to heterogeneity of UV-B radiation

Physiological integration has been documented in many clonal plants growing under resource heterogeneity. Little is still known about the response of physiological integration to heterogeneous ultraviolet-B radiation. In this paper, the changes in intensity of physiological integration and of physiological parameters under homogeneous and heterogeneous ultraviolet-B radiation (280-315 nm) were measured in order to test the hypothesis that in addition to resource integration a defensive integration in Trifolium repens might exist as well. For this purpose, homogeneous and heterogeneous ultraviolet-B radiation was applied to pairs of connected and severed ramets of the stoloniferous herb Trifolium repens. Changes in intensity of water and nutrient integration were followed with acid fuchsin dye and ¹⁵N-isotope labeling of the xylem water transport. In order to assess the patterns of physiological integration contents of chlorophyll, ultraviolet-B absorbing compounds, soluble sugar and protein were determined and activities of superoxide dismutase (SOD) and peroxidase (POD) measured. When ramets were connected and exposed to heterogeneous UV-B radiation, the velocity of water transportation from the UV-B treated ramet to its connected sister ramet was markedly lower and the percentage of ¹⁵N left in labelled ramets that suffered from enhanced UV-B radiation was higher and their transfer to unlabelled ramets lower. In comparison with clones under homogeneous ultraviolet-B radiation, the content of chlorophyll, ultraviolet-B absorbing compounds, soluble sugar and activities of SOD and POD increased notably if ultraviolet-B stressed ramets were connected to untreated ramets. Chlorophyll and UV-B absorbing compounds were shared between connected ramets under heterogeneous UV-B radiation. This indicated that physiological connection improved the performance of whole clonal plants under heterogeneous ultraviolet-B radiation. The intensity of physiological integration of T. repens for resources decreased under heterogeneous ultraviolet-B radiation in favor of the stressed ramets. Ultraviolet-B stressed ramets benefited from unstressed ramets by physiological integration, supporting the hypothesis that clonal plants are able to optimize the efficiency of their resistance maintaining their presence also in less favorable sites. The results could be helpful for further understanding of the function of heterogeneous UV-B radiation on growth regulation and microevolution in clonal plants.     

60Coγ射线辐照花魔芋球茎的早期诱变效应研究

本试验开展了花魔芋早期诱变效应研究。通过^60Coγ射线辐照后的植株苗期发育观察和根尖细胞学检测分析,结果表明魔芋辐射诱变效应显著：辐照诱发核畸变和染色体畸变,且变异频率与剂量呈二次曲线关系;低剂量时对细胞分裂有刺激作用;辐照抑制芽体发育、苗期生长,抑制效应随剂量增加而加大,直至产生致死作用。依据花魔芋的辐射敏感性,建立了魔芋辐照诱变体系,以催芽球茎为诱变材料,诱变剂量范围为0Gy～50Gy,剂量率为1Gy／min,中等适宜剂量为7Gy～10Gy,致死剂量50Gy。