What is an adequate margin for infiltrative soft-tissue sarcomas?

ObjectivesWhat constitutes an adequate margin of resection for infiltrative subtypes of soft-tissue sarcomas remains unclear. We aimed to determine the prognostic significance of the margin in millimetres for myxofibrosarcoma (MFS) and undifferentiated pleomorphic sarcoma (UPS).Methods305 patients diagnosed with either a high-grade, localised MFS (n = 98) or UPS (n = 207) were included. The relationship of closest margin in millimetres to viable tumour and oncological outcomes was analysed.ResultsThe overall local recurrence (LR) rate for all patients were 12%: 19% with positive margin and 10% with negative margin (p = 0.051). The LR rate was similar in patients with negative but <10 mm margin; 13%, 6%, 15%, 17% with 0.1–0.9 mm, 1.0–1.9 mm, 2.0–4.9 mm, and 5.0–9.9 mm margin, respectively. However, the LR rate decreased to 3% if the margin was ≥10 mm. By the R- or R+1-classification, the 10-year cumulative probability of LR was 9%, 15%, 48% for R0, R1, R2 resections, respectively, which was not sensitive enough to stratify the LR risk in patients with negative margins. However, the cumulative probability of LR was significantly stratified by metric distance; the 10-year cumulative LR probability was 3%, 14%, 25% with ≥10.0 mm, 0.1–9.9 mm, and 0 mm, respectively (p = 0.026). A trend towards improved local control by adjuvant radiotherapy was seen in patients with 0–9.9 mm margin (p = 0.078).ConclusionThe resection margin, when measured as a metric distance, correlates with a reduction in LR, and appears to be more significant on local control than radiotherapy. To minimise the risk of LR, a margin distance of at least 10 mm is advocated for MFS and UPS.     

Dynamic stability control in forward falls: postural corrections after muscle fatigue in young and older adults

Many studies report that muscle strength loss may alter the human system’s capacity to generate rapid force for balance corrections after perturbations, leading to deficient recovery behaviours. Yet little is known regarding the effect of modifications in the neuromuscular system induced by fatigue on dynamic stability control during postural perturbations. This study investigates the effect of muscle strength decline induced by fatiguing contractions on the dynamic stability control of young and older adults during forward falls. Eleven young and eleven older male adults had to regain balance after sudden falls before and after submaximal fatiguing knee extension–flexion contractions. Young subjects had a higher margin of stability than older ones before and after the fatiguing task. This reflects their enhanced ability in using mechanisms for maintaining dynamic stability (i.e. a greater base of support). The margin of stability, the boundary of the base of support and the position of the extrapolated centre of mass, remained unaffected by the reduction in muscle strength induced by the fatiguing contractions, indicating an appropriate adjustment of the motor commands to compensate the deficit in muscle strength. Both young and older adults were able to counteract the decreased horizontal ground reaction forces after the fatiguing task by flexing their knee to a greater extent, leading to similar decreases in the horizontal velocity of centre of mass as in the pre fatigue condition. The results demonstrate the ability of the central nervous system to rapidly modify the execution of postural corrections including mechanisms for maintaining dynamic stability.     

卫生资源配置的经济学思考

鉴于卫生保健领域资源的有限性,人们提出了各种配置卫生资源的方法。但是,对这些方法进行比较的文献却很少见,而且多数决策者对这些方法并不很了解。该文从经济理论方面对现有的一些资源配置方法,如需要评价法、疾病负担法、基本医疗服务法进行了剖析,指出这些方法都存在一个共同的缺憾,即忽视了机会成本和边际理论。文章建议:更多地关注基本经济学原理将有助于优先领域的资源配置。     

Consequences of introducing geometric GTV to CTV margin expansion in DAHANCA contouring guidelines for head and neck radiotherapy

Background and purpose

Defining margins around the Gross Tumour Volume (GTV) to create a Clinical Target Volume (CTV) for head and neck cancer radiotherapy has traditionally been based on presumed knowledge of anatomical routes of spread. However, using a concentric geometric expansion around the GTV may be more reproducible. The purpose of this study was to analyse the inter-observer consistency of geometric CTV delineation with adaptation for anatomical boundaries versus anatomically defined CTVs.

Dynamic prediction of overall survival for patients with high-grade extremity soft tissue sarcoma

Purpose

There is increasing interest in personalized prediction of disease progression for soft tissue sarcoma patients. Currently, available prediction models are limited to predictions from time of surgery or diagnosis. This study updates predictions of overall survival at different times during follow-up by using the concept of dynamic prediction.

四肢创伤手术切口感染8例临床分析

目的：如何减少四肢创伤手术切口感染的发生率。方法：主要根据我院骨科2007—2009年度进行四肢创伤手术的200例患者进行回顾性系统分析。结果及结论：调查的患者中发生院内手术切口感染的患者有8名,占全部手术病人的4％,对其原因分析高龄,手术清创不够彻底,术前未使用有效的抗生素进行预防,有基础疾病,四肢主干血管损伤缺血严重未及时再通,手术季节和情绪与伤口感染有确切关系。     

Dynamic stability during walking in children with and without cerebral palsy

BackgroundCerebral palsy (CP) is associated with a high risk of falling during walking. Many gait abnormalities associated with CP likely alter foot placement and center of mass (CoM) movement in a way that affects anterior or lateral dynamic stability, in turn influencing fall risk.Research questionDo children with CP demonstrate altered anterior or lateral dynamic stability compared to typically-developing (TD) children?MethodsIn this case-control, observational study, we measured gait kinematics of two groups of children (15 CP, 11 GMFCS level I, 4 GMFCS level II; 14 TD; age 5–12) in walking conditions of a preferred speed, a fast speed, and a preferred speed while completing a cognitive task. For dominant and non-dominant limbs, the margin of stability (MoS), a spatial measure of dynamic stability, was calculated as the distance between the edge of the base of support and the CoM position after accounting for scaled velocity. Statistical comparisons of were made using mixed factorial ANOVAs. Post hoc comparisons were Sidak adjusted.ResultsThe anterior MoS before foot strike and at mid-swing differed between each condition but not between groups. Based on the minimum lateral MoS, children with CP had more stability when bearing weight on their non-dominant limb compared to TD children. These differences were not apparent when on the dominant limb.SignificanceThis high-functioning group of children with CP exhibited a more conservative lateral stability strategy during walking when bearing weight with the non-dominant limb. This strategy may be protective against lateral falls. We observed no between-group differences in anterior stability. Because CP has been previously associated with impaired anterior balance reactions, and there was no observed compensation in anterior gait stability, this lack of group differences could contribute to a higher risk of falling in that direction.     

直肠癌环周切缘组织中CD133的表达及临床意义

目的检测直肠癌环周切缘组织内是否含有肿瘤干细胞,并观察环周切缘浸润对患者预后的影响。方法取直肠癌患者手术切除标本的环周切缘,4%甲醛固定后做成病理切片;根据环周切缘有无浸润分为环周切缘阳性组和环周切缘阴性组,2组均做免疫组织化学标记CD133肿瘤干细胞,观察CD133表达情况;随访2组患者术后1～2年复发情况。结果环周切缘阳性组免疫组织化学标记CD133+,存在CD133+肿瘤干细胞,但与环周切缘阴性组相比无统计学意义(P>0.05)。环周切缘阳性组患者1～2年复发率显著高于阴性组(P<0.05)。结论环周切缘浸润是导致直肠癌患者术后复发的重要因素,部分环周切缘浸润中存在肿瘤干细胞。