全脑照射对幼鼠海马神经元树突棘形态及密度的影响

目的:了解电离辐射对幼鼠海马齿状回(DG)区和CA1区树突棘形态及结构随时间变化的特点,为研究放射性认知功能障碍发生的分子机制提供详尽直接的形态学依据。方法:给予21 d龄SD大鼠单次剂量10 Gy全脑照射,观察照射后1、3个月大鼠认知功能改变,海马DG区和CA1区中树突棘密度及形态学变化。Western blot检测...     

肺灌注显像观察肺癌三维适形放疗对患者近期肺功能的影响

背景与目的:对胸部肿瘤进行放射治疗时,正常肺组织会受到部分照射,出现不同程度的放射性肺损伤。临床上常用肺功能测试(pulmonaryfunctiontests,PFTs)来评估放疗后全肺功能变化,往往不够准确。核素肺灌注扫描与其它影像学方法相比能更好地反映肺的局部生理功能,而三维适形放疗计划系统能定量计算肿瘤和周围肺组织的照射剂量。本研究目的是利用肺灌注显像来初步观察肺癌患者三维适形放疗前后的局部肺功能早期变化。方法:19例行三维适形放疗的肺癌患者,放疗前及照射40～50Gy时行肺灌注显像检查,并将结果与同期的X片或CT检查比较。将放疗前肺灌注图像与同期的X片、CT片相比较,按缺损区与肿瘤病灶的大小分为:0级,无灌注受损;1级,肿瘤及其周围局部肺灌注受损;2级,达1叶肺灌注受损;3级,超过1叶肺灌注受损。在肺灌注的断层图像上将照射剂量大于20Gy以上范围在断层图像上勾画感兴趣区(regionofinterest,ROI),以ROI内的放射性计数占同层面双肺放射性总计数的比值来比较照射前后肺灌注的变化,并用配对t检验来进行统计学分析。结果:(1)19例患者均有不同程度的肺动脉血流灌注受损,其中1级9例,2级5例,3级5例。(2)肺灌注的定量分析:19例行放疗前及放疗中肺灌注检查的患者,放疗前ROI的放射性比值平均为(53.67±29.81)%,     

Half-body and local chest irradiation as consolidation following response to standard induction chemotherapy for disseminated small cell lung cancer: an Eastern Cooperative Oncology Group pilot report

A two-institution Phase 11 Pilot Study for the Eastern Cooperative Oncology Group (ECOG) used standard induction chemotherapy (cyclophosphamide and CCNU) followed by consolidation radiation therapy (RT) (600 rad of upper half-body irradiation plus 2000 rad in one week of localized chest irradiation) followed by maintenance chemotherapy in patients with extensive small cell bronchogenic carcinoma (SCBC). Nineteen patients were entered and 9 (47%) had partial responses (PR) after induction chemotherapy. No complete responses (CR) were seen. The 10 patients whose disease progressed were ineligible for consolidation RT and died with a short median survival time (MST) of 15 weeks. Of the 9 patients who were consolidated, 7(78%) had complete responses in the chest; five (63%) became overall complete responders. The MST of all consolidated responders was 44 weeks. At this writing, two of the 5 patients who achieved CR after RT consolidation were alive without disease for more than one year; another patient was alive with disease for almost one year. A control group consisting of patients with extensive SCBC was used for comparison; these patients were treated by the two participating institutions in an earlier ECOG protocol with the same chemotherapy regimen but without RT consolidation.     

Concurrent and subsequent tumors in the same host: A model to evaluate the host tumor interaction

There is evidence which demonstrates an immune rejection response (IRR) directed against tumor cells in some experimental and human tumors. In the case of FSa-1, a methylcholanthrene-induced fibrosarcoma of the C₃Hf/Sed mouse, the IRR is manifested by a decrease in the dose of radiation expected to control half of the treated tumors (TCD₅₀) and an increase in the number of tumor cells expected to transplant the tumor in half of the transplanted recipients (TD₅₀) in immunized hosts. FSaI was transplanted simultaneously in the right and left legs of male and female C₃Hf/Sed mice and each tumor was given 3750 rad when it measured 8 mm. in diameter (viz the TCD₅₀ value for 8 mm FSaI growing as one isotransplant per animal). The two tumors in any one animal usually responded similarly with either permanent regression or local recurrence after irradiation. In a second experiment, a group of animals received also concurrent tumors. This time an immunogenic FSaI was transplanted in one side and a non immunogenic mammary carcinoma (MDAH-MCaIV) on the opposite side. The tumors were irradiated with TCD₅₀ doses (3750 rad for FSaI and 6500 for the less radioresponsive MCa). The distribution of local control and recurrence was probabilistic; 50% of the animals exhibited one tumor destroyed and one recurring. In a third experimental group mice were subsequently transplanted with FSaI Mice who showed no recurrence after irradiation of their first FSaI showed a stronger tendency to reject the second implantation than those who previously had local recurrence and subsequent amputation. Retransplants were controlled more easily by irradiation in the group that had been successfully treated for the first transplant. These data indicate that within the inbred population of C₃Hf/Sed mice there is a relatively broad distribution of capacities to react effectively against the FSaI challenge. This was not predicted by the delayed hypersensitivity skin reaction (DHSR) to the FSaI antigen.     

Local control of embryonal rhabdomyosarcoma in children by radiation therapy when combined with chemotherapy

Between August 1970 and March 1978, 58 patients with embryonal rhabdomyosarcoma (ERMS) were treated at the Radiation Therapy and Pediatric Departments of MSKCC. Chemotherapy was given according to T2 protocol (sequential administration of dactinomycin, vincristine, adriamycin and cyclophosphamide) or the T6 protocol (simultaneous administration of the previous drugs plus bleomycin, methotrexate and BCNU), which was introduced in 1975. The primary tumor or regional metastases were completely or partially removed in 43 patients, while biopsy was the only surgical procedure in 15. There were 41 boys and 17 girls, between 4 months and 19 years old. Eight had stage I-B disease, (microscopic residual), 16 stage II, (gross residual), 24 stage III, (node metastases), and 10 patients stage IV (disseminated tumors). Thirty-five patients were treated with T2 protocol, twenty-three with T6 protocol. Sixteen patients received more than 5000 rad, 21 had between 4000 and 5000 rad and 21 had less than 4000 rad. Forty-four patients are alive, 38 of them disease free. Local tumor control was not achieved in 14 patients, 10 of them were treated with T2 and 4 with T6. There were no local failures in patients treated for microscopic disease with doses between 3000 and 4000 rad. In patients treated for bulky tumors with 4000–5000 rad there were 3 failures out of 11 tumors and 3 out of 17 in those treated with higher doses. Radiation doses 3000–4000 rad were sufficient for local control of microscopic disease and 4000–5000 rad were as effective for control of bulky tumors as higher doses.     

Restoration of teeth with more-viscous glass ionomer cements following radiation-induced caries

OBJECTIVE: To assess the suitability of more-viscous conventional restorative glass ionomer cements (GICs) in a high-caries risk group of patients. METHODS: Fifteen adult patients with radiation-induced caries were treated at a dental hospital by one dentist. Two encapsulated aesthetic GICs were used in each patient to restore 146 carious lesions in the exposed dentine and cementum of 93 teeth. The restorations were assessed directly over two years for their retention, secondary caries, anatomic form, marginal integrity, marginal discolouration, and surface texture. RESULTS: Both GICs were placed in similar sized cavities (P = 0.63). After two years, although 30.0% of Ketac-Molar Aplicap and 12.5% of Fuji IX GP restorations had been lost (P = 0.01), there were no instances of secondary caries. The remaining GICs showed ongoing marginal deterioration, but there were very few instances where this required the repair or replacement of the restorations. No restorations failed from surface erosion. CONCLUSIONS: In these high-caries risk patients the placement of more-viscous GICs appeared to prevent secondary caries, even when the restorations were subsequently lost.     

医用加速器机房迷路辐射水平的测量与分析

目的 通过医用加速器机房迷路内辐射水平的测量与分析,为职业照射的控制提供科学依据,为理论模拟计算积累实验数据。方法 利用剂量率仪测量加速器机房迷路内的辐射水平,并对测量结果进行理论分析。结果 医用加速器机房出入口处杂散X-γ射线剂量率与机头朝向有关,并随照射野的减小而降低;杂散中子剂量率水平主要取决于加速器粒子的能量和输出剂量,随照射野的变化不明显。同时,医用加速器机房出入口处杂散X-γ射线和中子剂量率与医用加速器机房迷路的辐射防护设计密切相关。结论 合理改善医用加速器机房迷路的辐射防护设计是降低医用加速器机房出入口处X-γ射线和中子剂量率水平的行之有效的措施。     

Significance of plasma transforming growth factor-β levels in radiotherapy for non–small-cell lung cancer

PURPOSE: In dose-escalation studies of radiotherapy (RT) for non-small-cell lung cancer (NSCLC), radiation pneumonitis (RP) is the most important dose-limiting complication. Transforming growth factor-beta1 (TGF-beta1) has been reported to be associated with the incidence of RP. It has been proposed that serial measurements of plasma TGF-beta1 can be valuable to estimate the risk of RP and to decide whether additional dose-escalation can be safely applied. The aim of this study was to evaluate prospectively the time course of TGF-beta1 levels in patients irradiated for NSCLC in relation to the development of RP and dose-volume parameters. METHODS AND MATERIALS: Plasma samples were obtained in 68 patients irradiated for medically inoperable or locally advanced NSCLC (dose range, 60.8-94.5 Gy) before and 4, 6, and 18 weeks after the start of RT. Plasma TGF-beta1 levels were determined using a bioassay on the basis of TGF-beta1-induced plasminogen activator inhibitor-1 expression in mink lung cells. All patients underwent chest computed tomography scans before RT that were repeated at 18 weeks after RT. The computed tomography data were used to calculate the mean lung dose (MLD) and to score the radiation-induced radiologic changes. RP was defined on the basis of the presence of either radiographic changes or clinical symptoms. Symptomatic RP was scored according to the Common Toxicity Criteria (Grade 1 or worse) and the Southwestern Oncology Group criteria (Grade 2 or worse). Multivariate analyses were performed to investigate which factors (pre- or posttreatment TGF-beta1 level, MLD) were associated with the incidence of RP. To improve our understanding of the time course of TGF-beta1 levels, we performed a multivariate analysis to investigate which factors (pre-RT TGF-beta1 level, MLD, RP) were independently associated with the posttreatment TGF-beta1 levels. RESULTS: The pre-RT TGF-beta1 levels were increased in patients with NSCLC (median 21 ng/mL, range, 5-103 ng/mL) compared with healthy individuals (range, 4-12 ng/mL). On average, the TGF-beta1 levels normalized toward the end of treatment and remained stable until 18 weeks after RT. In 29 patients, however, TGF-beta1 was increased at the end of RT with respect to the pre-RT value. The multivariate analyses revealed that the MLD was the only variable that correlated significantly with the risk of both radiographic RP (p = 0.05) and symptomatic RP, independent of the scoring system used (p = 0.05 and 0.03 for Southwestern Oncology Group and Common Toxicity Criteria systems, respectively). The TGF-beta1 level at the end of RT was significantly associated with the MLD (p <0.001) and pre-RT TGF-beta1 level (p = 0.001). CONCLUSION: The MLD correlated significantly with the incidence of both radiographic and symptomatic RP. The results of our study did not confirm the reports that increased levels of TGF-beta1 at the end of RT are an independent additional risk factor for developing symptomatic RP. However, the TGF-beta1 level at the end of a RT was significantly associated with the MLD and the pre-RT level.     

Clinicopathological examination of glioma by proton magnetic resonance spectroscopy background

Automation of proton magnetic resonance spectroscopy (MRS) in recent years has made it possible for MRS measurement to be performed in a shorter time than before, and the number of reports of its usefulness for the assessment of glioma malignancy has been increasing in the past several years. We studied the efficacy of proton MRS when used for glioma and conducted clinicopathological examination of glioma. The subjects were 15 patients who had received a pathological diagnosis of glioma at our hospital (6 cases of glioblastoma, 1 case of anaplastic astrocytoma, 4 cases of low-grade astrocytoma, and 4 cases of radiation necrosis); Siemens Magnetom Vision 1.5T was used for the study. Regions of interest (ROIs) were defined as the areas where abnormal signals were found on magnetic resonance imaging (MRI). Areas of primary peaks, such as choline (Cho),N-acetylaspartate (NAA), and lactate (Lac), were measured, and the ratios to normal brain tissue were examined. This study revealed a tendency of increased malignancy of glioma with a decrease in NAA. Some cases also displayed a decrease in Cho with an increase in malignancy. Assessment of malignancy must not be based on a single ROI alone, but several ROIs should be assessed comprehensively. Measurement was difficult when the tumor volume was small. Because diagnosis of very early glioma by MRS seemed difficult, other adjunctive diagnoses may be necessary. Proton MRS is very useful for diagnosis of glioblastoma.     

CM治疗计划系统照射野剂量计算的验证

目的　对美国CMS公司生产的肿瘤治疗计划系统 (TPS)计算结果值与实际测量值进行比较。方法　按照测量条件下的带有Farmer型电离室的固体水模在螺旋CT下进行扫描 ,图像通过网络数字传输系统传入TPS中 ,分别进行 10cm× 10cm规则野与不规则野、均匀组织与不均匀组织(分别含骨和肺 )、源轴距 10 0cm中心轴上深度 6和 10cm、野内任意点、机架角 30°、楔形板、MLC、铅挡、源皮距 90和 12 0cm条件下 6和 15MVX线计划设计并采用卷积和叠加两种算法计算 ,再与加速器治疗机上实际测量结果进行比较。结果　对于均匀组织和含骨的不均匀组织卷积和叠加算法的计算结果值具有良好的一致性 ,两种计算方法的结果偏差在 0 .5 %以内。多数实测值与计算值偏差在2 .5 %以内 ,个别计算与实测结果偏差在 3%以内 ,含肺的不均匀组织做不均匀组织校准后卷积算法与实测偏差较大 ,6MVX线为 7.8% ,15MVX线为 4 .5 % ,而叠加算法与实测偏差在 1.5 %以内。结论　除了卷积算法不能用于含肺组织或含气空腔剂量计算以外 ,卷积和叠加算法均可用于剂量计算 ,且偏差符合临床要求。