儿童股骨远端骨肉瘤保留骨骺的定制肿瘤型假体重建术

 目的 介绍儿童股骨远端骨肉瘤保留骨骺的定制肿瘤型假体重建术,并探讨其工作原理、手术操作技巧、早期临床疗效以及并发症的防治。方法 2012年8月至2013年7月期间,应用肿瘤瘤段骨切除、保留骨骺的定制肿瘤型假体重建术治疗股骨远端骨肉瘤的儿童患者3例,均为男性,年龄8岁、9岁和15岁。术前给予新辅助化疗1~2周期,化疗结束后根据X线、CT 和MR等检查结果评价化疗疗效,对于化疗效果好且符合保留骨骺手术条件者采用此术式治疗。首先通过CT、MRI确定病变范围,根据影像学检查结果利用计算机辅助定制保留骨骺的肿瘤型假体以及模具,待假体定制完毕后行肿瘤瘤段骨切除、保留骨骺的定制肿瘤型假体重建术,术后指导患者进行功能锻炼,切口愈合1周后给予术后的规范化化疗,并进行长期随访。 结果 3例患者手术时间分别为3 h、4 h和6 h,术中出血量分别为300 ml、500 ml和2 200 ml。对3例患者术后随访时间 为12~24个月,根据美国骨肿瘤学会评分系统（Musculoskeletal Tumor Society,MSTS）,术后3个月功能评分分别为24分、26分和13分,短期随访显示患者肢体功能良好。1例患者出现假体感染,经保守治疗（抗炎补液、切口换药等）无效后行大腿截肢术,余2例患者未出现假体松动等其他并发症。2例患者双下肢长度相差均< 2 cm。结论 通过严格掌握保留骨骺保肢手术的适应证,配合术前及术后的新辅助化疗,保留骨骺的定制肿瘤型假体重建术为儿童股骨远端骨肉瘤的保肢治疗提供了新的选择方案,其疗效安全、可靠,且具有手术操作简单、手术时间短、术后恢复快等优点,但长期疗效尚需进一步观察。     

Hyperbaric oxygen therapy improves angiogenesis and bone formation in critical sized diaphyseal defects

Besides the use of autologous bone grafting several osteoconductive and osteoinductive methods have been reported to improve bone healing. However, persistent non‐union occurs in a considerable number of cases and compromised angiogenesis is suspected to impede bone regeneration. Hyperbaric oxygen therapy (HBO) improves angiogenesis. This study evaluates the effects of HBO on bone defects treated with autologous bone grafting in a bone defect model in rabbits. Twenty‐four New‐Zealand White Rabbits were subjected to a unilateral critical sized diaphyseal radius bone defect and treated with autologous cancellous bone transplantation. The study groups were exposed to an additional HBO treatment regimen. Bone regeneration was evaluated radiologically and histologically at 3 and 6 weeks, angiogenesis was assessed by immunohistochemistry at three and six weeks. The additional administration of HBO resulted in a significantly increased new bone formation and angiogenesis compared to the sole treatment with autologous bone grafting. These results were apparent after three and six weeks of treatment. The addition of HBO therapy to autologous bone grafts leads to significantly improved bone regeneration. The increase in angiogenesis observed could play a crucial role for the results observed. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:513–520, 2015.     

Reduced tonicity stimulates an inflammatory response in nucleus pulposus tissue that can be limited by a COX‐2‐specific inhibitor

In intervertebral disc herniation with nucleus pulposus (NP) extrusion, the elicited inflammatory response is considered a key pain mechanism. However, inflammatory cytokines are reported in extruded herniated tissue, even before monocyte infiltration, suggesting that the tissue itself initiates the inflammation. Since herniated tissue swells, we investigated whether this simple mechanobiological stimulus alone could provoke an inflammatory response that could cause pain. Furthermore, we investigated whether sustained‐release cyclooxygenase‐2 (COX2) inhibitor would be beneficial in such conditions. Healthy bovine NP explants were allowed to swell freely or confined. The swelling explants were treated with Celecoxib, applied either as a bolus or in sustained‐release. Swelling explants produced elevated levels of interleukin‐6 (IL‐6) and prostaglandin E₂ (PGE₂) for 28 days, while confined explants did not. Both a high concentration bolus and 10 times lower concentration in sustained release completely inhibited PGE₂ production, but did not affect IL‐6 production. Swelling of NP tissue, without the inflammatory system response, can trigger cytokine production and Celecoxib, even in bolus form, may be useful for pain control in extruded disc herniation. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1724–1731, 2015.     

Liver transplantation for hepatocellular carcinoma: analysis of factors predicting outcome in 1074 patients in OPTN Region 5

Previous studies on loco‐regional therapy (LRT) and alpha‐fetoprotein (AFP) in predicting outcome after liver transplant (LT) for hepatocellular carcinoma (HCC) have shown inconsistent results. We analyzed the OPTN database in Region 5 from January 2004 to January 2009 and performed univariate and multivariate analysis of 11 pre‐transplant recipient and donor variables in 1074 patients with HCC meeting Milan criteria to detect association with post‐LT tumor recurrence or mortality. Mean waitlist time was 438 d. The 1‐ and 5‐yr post‐LT survival was 91.1% and 71.1%, respectively. In multivariate analysis, AFP before LT was the only predictor of HCC recurrence. The association between AFP and HCC recurrence was observed only in the subgroup receiving LRT but not in the subgroup without LRT. Predictors of mortality in multivariate analysis were HCC recurrence, Donor Risk Index, last AFP before LT, and MELD score. AFP before LT was the strongest predictor of post‐transplant HCC recurrence or death in multivariate analysis. In conclusion, in Region 5 with prolonged waitlist time, high AFP was the only pre‐transplant variable predicting post‐transplant tumor recurrence and mortality for HCC meeting Milan criteria. Our results also supported the importance of the effects of LRT on AFP in predicting prognosis.     

Prophylactic CMV therapy does not improve three‐yr patient and graft survival compared to preemptive therapy

Despite increasing evidence in favor of prophylactic valganciclovir treatment in kidney transplant recipients for the prevention of cytomegalovirus (CMV) infection, the impact of preemptive vs. prophylactic treatment on long‐term clinical outcomes is unclear. In this retrospective study, 187 kidney transplant recipients with serologic intermediate‐risk constellation (recipient CMV IgG positive) received either preemptive or prophylactic treatment with valganciclovir. Patient survival (primary endpoint), graft survival, viremia rates, and other CMV‐related outcomes were analyzed. Prophylactic therapy reduced the rates for CMV viremia during the first year (hazard ratio: 0.48, 95% confidence interval [CI] 0.30–0.75; p < 0.001). There was a trend for higher three‐yr patient mortality in the prophylactic group (hazard ratio: 5.08, 95% CI 0.62–41.3; p = 0.091), and the rate of graft loss was not reduced (hazard ratio: 0.93, 95% CI 0.32–2.68; p = 0.894). Estimated glomerular filtration rate over three yr was on average 6.8 mL/min/1.73 m² lower in the prophylactic group (95% CI −11.68 to −1.81; p = 0.007) using a multivariate random effects model but showed more improvement over time. Prophylactic valganciclovir treatment reduced the rate of CMV infections during the first year post‐transplant but no effects of prophylactic treatment on patient and graft survival or kidney function over three yr were observed.     

Particle radiotherapy for prostate cancer

Recent advances in external beam radiotherapy have allowed us to deliver higher doses to the tumors while decreasing doses to the surrounding tissues. Dose escalation using high‐precision radiotherapy has improved the treatment outcomes of prostate cancer. Intensity‐modulated radiation therapy has been widely used throughout the world as the most advanced form of photon radiotherapy. In contrast, particle radiotherapy has also been under development, and has been used as an effective and non‐invasive radiation modality for prostate and other cancers. Among the particles used in such treatments, protons and carbon ions have the physical advantage that the dose can be focused on the tumor with only minimal exposure of the surrounding normal tissues. Furthermore, carbon ions also have radiobiological advantages that include higher killing effects on intrinsic radio‐resistant tumors, hypoxic tumor cells and tumor cells in the G0 or S phase. However, the degree of clinical benefit derived from these theoretical advantages in the treatment of prostate cancer has not been adequately determined. The present article reviews the available literature on the use of particle radiotherapy for prostate cancer as well as the literature on the physical and radiobiological properties of this treatment, and discusses the role and the relative merits of particle radiotherapy compared with current photon‐based radiotherapy, with a focus on proton beam therapy and carbon ion radiotherapy.     

Prognostic factors and risk classifications for patients with metastatic renal cell carcinoma

The introduction of molecular‐targeted therapy has made dramatical changes to treatment for metastatic renal cell carcinoma. Currently, there are four vascular endothelial growth factor receptor‐tyrosine kinase inhibitors and two mammalian target of rapamycin inhibitors in Japan. For the appropriate clinical use of these molecular‐targeted drugs, the identification of prognostic and/or predictive factors in patients who received these drugs is required. Although molecular biological and genetic factors that determine the prognosis of patients with metastatic renal cell carcinoma have been reported, most of these factors are problematic in that the number of patients analyzed was small. In contrast, clinicopathological prognostic factors, including the practice of cytoreductive nephrectomy, pathological findings, metastatic sites and metastasectomy, and abnormal inflammatory response, have been identified by analyzing a relatively large number of patients. Several prognostic classification models that were developed by combining these clinicopathological factors are widely used in not only clinical trials, but also routine clinical practice. However, the quality of these prognostic models is considered to be insufficient regarding prognostic prediction of metastatic renal cell carcinoma patients and, thus, requires further improvements. Recently, basic and clinical studies have been extensively carried out for the identification of promising informative markers and for understanding molecular mechanisms of resistance to molecular‐targeted drugs in metastatic renal cell carcinoma patients. The present review considers ongoing translational research efforts on clinicopathological, molecular biological, and genetic prognostic and/or predictive factors for metastatic renal cell carcinoma patients in the era of molecular‐targeted therapy, and discusses the clinical implications of these findings.     

Cytomegalovirus prevention strategies in seropositive kidney transplant recipients: an insight into current clinical practice

There is notable heterogeneity in the implementation of cytomegalovirus (CMV) prevention practices among CMV‐seropositive (R+) kidney transplant (KT) recipients. In this prospective observational study, we included 387 CMV R+ KT recipients from 25 Spanish centers. Prevention strategies (antiviral prophylaxis or preemptive therapy) were applied according to institutional protocols at each site. The impact on the 12‐month incidence of CMV disease was assessed by Cox regression. Asymptomatic CMV infection, acute rejection, graft function, non‐CMV infection, graft loss, and all‐cause mortality were also analyzed (secondary outcomes). Models were adjusted for a propensity score (PS) analysis for receiving antiviral prophylaxis. Overall, 190 patients (49.1%) received preemptive therapy, 185 (47.8%) antiviral prophylaxis, and 12 (3.1%) no specific intervention. Twelve‐month cumulative incidences of CMV disease and asymptomatic infection were 3.6% and 39.3%, respectively. Patients on prophylaxis had lower incidence of CMV disease [PS‐adjusted HR (aHR): 0.10; 95% confidence interval (CI): 0.01–0.79] and asymptomatic infection (aHR: 0.46; 95% CI: 0.29–0.72) than those managed preemptively, with no significant differences according to the duration of prophylaxis. All cases of CMV disease in the prophylaxis group occurred after prophylaxis discontinuation. There were no differences in any of the secondary outcomes. In conclusion, antiviral prophylaxis was associated with a lower occurrence of CMV disease in CMV R+ KT recipients, although such benefit should be balanced with the risk of late‐onset disease.