Implementation of an image-guided radiation therapy program: Lessons learnt and future challenges

The aim of this paper is to detail the experience obtained in implementing an image-guided radiation therapy program at the Northern Sydney Cancer Centre. This required retrofitting a Varian Clinac 21EX with an on-board imager. The commissioning and quality assurance procedures, organisation of a multidisciplinary image guided radiation therapy group, and the development of clinical protocols for orthogonal kV and cone beam computed tomography implementation are described. Reassessment of the image-guided radiation therapy program has continued as new equipment and software versions were made available in the department.     

Optimal stem cell source for allogeneic stem cell transplantation for hematological malignancies

Hematopoietic stem cell transplant (HSCT) is a standard treatment for many hematological malignancies. Three different sources of stem cells, namely bone marrow (BM), peripheral blood stem cells (PBSC) and cord blood (CB) can be used for HSCT, and each has its own advantages and disadvantages. Randomized controlled trials (RCTs) suggest that there is no significant survival advantage of PBSC over BM in Human Leukocyte Antigen-matched sibling transplant for adult patients with hematological malignancies. PBSC transplant probably results in lower risk of relapse and hence better disease-free survival, especially in patients with high risk disease at the expense of higher risks of both severe acute and chronic graft-versus-host disease (GVHD). In the unrelated donor setting, the only RCT available suggests that PBSC and BM result in comparable overall and disease-free survivals in patients with hematological malignancies; and PBSC transplant results in lower risk of graft failure and higher risk of chronic GVHD. High level evidence is not available for CB in comparison to BM or PBSC. The risks and benefits of different sources of stem cells likely change with different conditioning regimen, strategies for prophylaxis and treatment of GVHD and manipulation of grafts. The recent success and rapid advance of double CB transplant and haploidentical BM and PBSC transplants further complicate the selection of stem cell source. Optimal selection requires careful weighing of the risks and benefits of different stem cell source for each individual recipient and donor. Detailed counseling of patient and donor regarding risks and benefits in the specific context of the patient and transplant method is essential for informed decision making.     

Differential BMP-1 expression in injured anterior cruciate ligament and medial collateral ligament fibroblasts induced by TGF-β1

目的 观察在转化生长因子-β1(transforming growth factor betal,TGF-β1)作用下,损伤的前交叉韧带(anterior cruciate ligament,ACL)和内侧副韧带(medial collateral ligament,MCL)中骨形态发生蛋白-1(bone morphogenetic protein-1,BMP-1)基因的表达,找出TGF-31、BMP-1之间的关系,揭示机械损伤后ACL和MCL细胞中BMP-1的表达差异.方法 采用反转录PCR(RT-PCR)和实时荧光定量PCR方法检测1、5、50 ng/ml TGF-β1处理后2h受损的ACL和MCL细胞中BMP-1的表达以及5 ng/ml TGF-β1作用2、6、12、24h受损的ACL和MCL细胞中BMP-1的表达;Western blot检测5 ng/mlTGF-β1处理48 h后受损的ACL和MCL细胞中BMP-1的表达.结果 受损的ACL和MCL细胞中BMP-1的基因表达比正常状态下偏高,并随着TGF-β1浓度的增大而增高,在MCL中的增高程度比在ACL中高出近1倍(P＜0.05);与正常组相比,在5 ng/ml TGF-β1处理24h后,ACL细胞中BMP-1的表达在24h达到最高比例(约为6.1倍),而在MCL中12h达到最高比例(约为9.84倍,P＜0.05).5 ng/ml TGF-β1处理48 h后BMP-1蛋白也明显上调,与无TGF-β1处理的对照组相比,ACL细胞中BMP-1上调2.32倍,MCL细胞中BMP-1上调3.84倍(P＜0.05).结论 TGF-β1刺激BMP-1的变化可能直接影响到细胞外基质中活性赖氨酰氧化酶的表达,对损伤ACL和MCL的修复有极其重要的参考价值和临床意义.     

Minimally invasive technology in the management of breast disease

Minimally invasive surgery is gaining popularity around the world because it achieves the same or even superior results when compared to standard surgery but with less morbidity. Minimally invasive breast surgery is a broad concept encompassing new developments in the field of breast surgery that work on this minimally invasive principle. In this regard, breast-conserving surgery and sentinel lymph node biopsy are good illustrations of this concept. There are three major areas of progress in the minimally invasive management of breast disease. First, percutaneous excisional devices are now available that can replace the surgical excision of breast mass lesions. Second, various ablative treatments are capable of destroying breast cancers in situ instead of surgical excision. Third, mammary ductoscopy provides a new approach to the investigation of mammary duct pathology. Clinical experience and potential applications of these new technologies are reviewed.     

Vasodilator agents and supracollicular transection fail to inhibit cortical spreading depression in the cat

It remains an open question as to whether cortical spreading depression (CSD) is the pathophysiological correlate of the neurological symptoms in migraine with aura. In the experimental animal, CSD is an electrophysiological phenomenon mainly mediated via NMDA receptors. However, according to case reports in humans, visual aura in migraine can be alleviated by vasodilator substances, such as amyl nitrite and isoprenaline. There is also circumstantial evidence that brainstem nuclei (dorsal raphe nucleus and locus coeruleus) may play a pivotal role in the initiation of aura. In this study, CSD was elicited in alpha-chloralose anesthetized cats by cortical needle stab injury and monitored by means of laser Doppler flowmetry. Topical application of isoprenaline (0.1-1%) and amyl nitrite (0.05%) onto the exposed cortex had no effect on the elicitation or propagation of CSD. Also, after supracollicular transection, subsequent CSDs showed no differences in the speed of propagation and associated flow changes. We conclude from these data that--given CSD probably exists in humans during migraine--spreading neurological deficits during migraine aura are independent of brainstem influence and have a primarily neuronal rather than vascular mechanism of generation.     

Is homozygous α-thalassaemia a lethal condition in the 1990s?

Two cases of homozygous α-thalassaemia who received active treatment in accordance with parental wishes are reported. One infant survived and the other, although successfully weaned off mechanical respiratory support, unexpectedly developed portal vein thrombosis and died. Homozygous a-thalassaemia, a condition previously considered to be universally fatal, and an indication for therapeutic abortion, is now potentially curable with advances in diagnostic technology and treatment. However, active management of these cases raises serious ethical questions and has major financial implications on the health-care system. Invasive prenatal and intensive postnatal interventions should remain experimental and cannot be recommended as routine clinical practice until the questions of long-term neurodevelopmental outcome, and the morbidity and mortality associated with bone-marrow transplantation have been fully addressed. As a result of advances in information technology, more and more parents of affected foetuses are likely to request active treatment.