Cancer is a major societal public health and economic problem, responsible for one in every six deaths. Radiotherapy is the main technique of treatment for more than half of cancer patients. To achieve a successful ou...Cancer is a major societal public health and economic problem, responsible for one in every six deaths. Radiotherapy is the main technique of treatment for more than half of cancer patients. To achieve a successful outcome, the radiation dose must be delivered accurately and precisely to the tumor, within ± 5% accuracy. Smaller uncertainties are required for better treatment outcome. The objective of the study is to investigate the uncertainty of measurement of external radiotherapy beam using a standard ionization chamber under reference conditions. Clinical farmers type ionization chamber measurement was compared against the National Reference standard, by exposing it in a beam 60Co gamma source. The measurement set up was carried out according to IAEA TRS 498 protocol and uncertainty of measurement evaluated according to GUM TEDDOC-1585. Evaluation and analysis were done for the identified subjects of uncertainty contributors. The expanded uncertainty associated with 56 mGy/nC ND,W was found to be 0.9% corresponding to a confidence level of approximately 95% with a coverage factor of k = 2. The study established the impact of dosimetry uncertainty of measurement in estimating external radiotherapy dose. The investigation established that the largest contributor of uncertainty is the stability of the ionization chamber at 36%, followed by temperature at 22% and positioning of the chamber in the beam at 8%. The effect of pressure, electrometer, resolution, and reproducibility were found to be minimal to the overall uncertainty. The study indicate that there is no flawless measurement, as there are many prospective sources of variation. Measurement results have component of unreliability and should be regarded as best estimates of the true value. .展开更多
This retrospective analysis compared standard regimen of doxorubicin, bleomycin, vin- blastine, and dacarbazine （ABVD） with the dose-dense ABVD regimen （ABVD-21） in terms of effi- cacy and toxicity. Patients who h...This retrospective analysis compared standard regimen of doxorubicin, bleomycin, vin- blastine, and dacarbazine （ABVD） with the dose-dense ABVD regimen （ABVD-21） in terms of effi- cacy and toxicity. Patients who had early-stage unfavorable or advanced Hodgkin＇s lymphoma （HL） according to German Hodgkin Study Group criteria from March 1999 to February 2011 were ana- lyzed for treatment response, long-term survival and hematological toxicity. There were 85 patients in the ABVD-21 group and 118 patients in the ABVD group respectively. The complete remission rates aider completion of treatment were 92.9% and 90.7% for ABVD-21 and ABVD, respectively. During a median follow-up period of 62 months, no significant difference was found in projected 10-year progression-free survival （PFS） and overall survival （OS） rates （84.7% and 94.1% respectively for ABVD-21; 81.4% and 91.5% for ABVD）. Subgroup analyses showed that ABVD-21 was signifi- cantly better than ABVD for patients with IPS〉3 in terms of PFS and OS rates. Grade 3 to 4 leuko- penia （51.8% vs. 28.8%, P=0.001） and neutropenia （57.6% vs. 39.0%, P=0.009） were more common with ABVD-21. We were led to conclude that dose-dense ABVD did not result in better tumor con- trol and overall survival than did ABVD for early-stage unfavorable HL. However, patients at high risk, for example, with IPS〉3, may benefit from dose-dense ABVD.展开更多
目前国内大多数放射治疗剂量只能溯源到^(60)Co γ射线空气比释动能,与溯源至空气比释动能相比,将放射治疗剂量直接溯源至水吸收剂量的不确定度要小很多。为了解决^(60)Co γ射线水吸收剂量量值溯源与传递问题,进一步提升^(60)Co γ射...目前国内大多数放射治疗剂量只能溯源到^(60)Co γ射线空气比释动能,与溯源至空气比释动能相比,将放射治疗剂量直接溯源至水吸收剂量的不确定度要小很多。为了解决^(60)Co γ射线水吸收剂量量值溯源与传递问题,进一步提升^(60)Co γ射线水吸收剂量的量值溯源与传递能力,中国测试技术研究院(National Institute of Measurement and Testing Technology,NIMTT)采用水量热法建立了^(60)Co γ射线水吸收剂量绝对测量装置,实现了水吸收剂量的绝对测量,复现了^(60)Co γ射线水吸收剂量,其量值复现的相对标准不确定度为0.45%。为了进一步验证^(60)Co γ射线水吸收剂量复现结果的准确性与一致性,将NIMTT实验室与加拿大国家研究委员会(National Research Council,NRC)实验室的复现结果进行了实验室之间的比对,结果在相对标准不确定度0.71%以内呈现一致性,归一化误差En值为-0.45。表明NIMTT具有^(60)Co γ射线水吸收剂量量值溯源与传递的能力,本研究结果也为^(60)Co γ射线吸收剂量的绝对测量提供了参考。展开更多
目的探讨发病4.5~9.0 h的急性缺血性脑卒中(acute ischemic stroke,AIS)患者经多模式CT筛选下超时间窗应用小剂量或标准剂量阿替普酶静脉溶栓的有效性和安全性。方法回顾性分析2021年1月—2023年1月在临沂市中心医院卒中中心就诊的发病...目的探讨发病4.5~9.0 h的急性缺血性脑卒中(acute ischemic stroke,AIS)患者经多模式CT筛选下超时间窗应用小剂量或标准剂量阿替普酶静脉溶栓的有效性和安全性。方法回顾性分析2021年1月—2023年1月在临沂市中心医院卒中中心就诊的发病时间在4.5~9.0 h的104例AIS患者。均完善一站式多模式CT检查,采用F-stroke软件处理分析脑CT灌注成像,存在核心/灌注不匹配者,给予阿替普酶静脉溶栓,并按照采用剂量大小分为小剂量组(0.6 mg/kg体质量,n=53)与标准剂量组(0.9 mg/kg体质量,n=54)。通过对比改良RanKin评分量表(modified RanKin scale,mRS)、美国国立卫生研究院卒中量表(the National Institutes of Health stroke scale,NIHSS)评分评估临床有效性,通过比较出血性转化(hemorrhagic transformation,HT)率、症状性颅内出血(symptomatic intracranial hemorrhage,SICH)率、泌尿道出血率、消化道出血率、病死率评估临床安全性。结果小剂量组预后良好率为58.49%(31/53),标准剂量组预后良好率为59.26%(32/54),差异无统计学意义(P>0.05)。2组溶栓后7 d NIHSS评分低于基线NIHSS评分,溶栓后90 d mRS评分低于入院时mRS评分,差异有统计学意义(P<0.05)。2组溶栓后7 d NIHSS评分、溶栓后90 d mRS评分比较,差异无统计学意义(P>0.05)。小剂量组24 h HT发生率、24 h SICH发生率、泌尿道出血发生率、消化道出血发生率、90 d病死率分别为1.89%(1/53)、1.89%(1/53)、3.77%(2/53)、1.89%(1/53)、1.89%(1/53),标准剂量组分别为9.26%(5/54)、7.41%(4/54)、1.85%(1/54)、5.56%(3/54)、1.85%(1/54),差异无统计学意义(P>0.05)。结论多模式CT筛选指导下发病在4.5~9.0 h的AIS患者超时间窗应用小剂量和标准剂量阿替普酶静脉溶栓有相似的临床疗效,小剂量更安全。展开更多
文摘Cancer is a major societal public health and economic problem, responsible for one in every six deaths. Radiotherapy is the main technique of treatment for more than half of cancer patients. To achieve a successful outcome, the radiation dose must be delivered accurately and precisely to the tumor, within ± 5% accuracy. Smaller uncertainties are required for better treatment outcome. The objective of the study is to investigate the uncertainty of measurement of external radiotherapy beam using a standard ionization chamber under reference conditions. Clinical farmers type ionization chamber measurement was compared against the National Reference standard, by exposing it in a beam 60Co gamma source. The measurement set up was carried out according to IAEA TRS 498 protocol and uncertainty of measurement evaluated according to GUM TEDDOC-1585. Evaluation and analysis were done for the identified subjects of uncertainty contributors. The expanded uncertainty associated with 56 mGy/nC ND,W was found to be 0.9% corresponding to a confidence level of approximately 95% with a coverage factor of k = 2. The study established the impact of dosimetry uncertainty of measurement in estimating external radiotherapy dose. The investigation established that the largest contributor of uncertainty is the stability of the ionization chamber at 36%, followed by temperature at 22% and positioning of the chamber in the beam at 8%. The effect of pressure, electrometer, resolution, and reproducibility were found to be minimal to the overall uncertainty. The study indicate that there is no flawless measurement, as there are many prospective sources of variation. Measurement results have component of unreliability and should be regarded as best estimates of the true value. .
文摘This retrospective analysis compared standard regimen of doxorubicin, bleomycin, vin- blastine, and dacarbazine （ABVD） with the dose-dense ABVD regimen （ABVD-21） in terms of effi- cacy and toxicity. Patients who had early-stage unfavorable or advanced Hodgkin＇s lymphoma （HL） according to German Hodgkin Study Group criteria from March 1999 to February 2011 were ana- lyzed for treatment response, long-term survival and hematological toxicity. There were 85 patients in the ABVD-21 group and 118 patients in the ABVD group respectively. The complete remission rates aider completion of treatment were 92.9% and 90.7% for ABVD-21 and ABVD, respectively. During a median follow-up period of 62 months, no significant difference was found in projected 10-year progression-free survival （PFS） and overall survival （OS） rates （84.7% and 94.1% respectively for ABVD-21; 81.4% and 91.5% for ABVD）. Subgroup analyses showed that ABVD-21 was signifi- cantly better than ABVD for patients with IPS〉3 in terms of PFS and OS rates. Grade 3 to 4 leuko- penia （51.8% vs. 28.8%, P=0.001） and neutropenia （57.6% vs. 39.0%, P=0.009） were more common with ABVD-21. We were led to conclude that dose-dense ABVD did not result in better tumor con- trol and overall survival than did ABVD for early-stage unfavorable HL. However, patients at high risk, for example, with IPS〉3, may benefit from dose-dense ABVD.
文摘目前国内大多数放射治疗剂量只能溯源到^(60)Co γ射线空气比释动能,与溯源至空气比释动能相比,将放射治疗剂量直接溯源至水吸收剂量的不确定度要小很多。为了解决^(60)Co γ射线水吸收剂量量值溯源与传递问题,进一步提升^(60)Co γ射线水吸收剂量的量值溯源与传递能力,中国测试技术研究院(National Institute of Measurement and Testing Technology,NIMTT)采用水量热法建立了^(60)Co γ射线水吸收剂量绝对测量装置,实现了水吸收剂量的绝对测量,复现了^(60)Co γ射线水吸收剂量,其量值复现的相对标准不确定度为0.45%。为了进一步验证^(60)Co γ射线水吸收剂量复现结果的准确性与一致性,将NIMTT实验室与加拿大国家研究委员会(National Research Council,NRC)实验室的复现结果进行了实验室之间的比对,结果在相对标准不确定度0.71%以内呈现一致性,归一化误差En值为-0.45。表明NIMTT具有^(60)Co γ射线水吸收剂量量值溯源与传递的能力,本研究结果也为^(60)Co γ射线吸收剂量的绝对测量提供了参考。
文摘目的探讨发病4.5~9.0 h的急性缺血性脑卒中(acute ischemic stroke,AIS)患者经多模式CT筛选下超时间窗应用小剂量或标准剂量阿替普酶静脉溶栓的有效性和安全性。方法回顾性分析2021年1月—2023年1月在临沂市中心医院卒中中心就诊的发病时间在4.5~9.0 h的104例AIS患者。均完善一站式多模式CT检查,采用F-stroke软件处理分析脑CT灌注成像,存在核心/灌注不匹配者,给予阿替普酶静脉溶栓,并按照采用剂量大小分为小剂量组(0.6 mg/kg体质量,n=53)与标准剂量组(0.9 mg/kg体质量,n=54)。通过对比改良RanKin评分量表(modified RanKin scale,mRS)、美国国立卫生研究院卒中量表(the National Institutes of Health stroke scale,NIHSS)评分评估临床有效性,通过比较出血性转化(hemorrhagic transformation,HT)率、症状性颅内出血(symptomatic intracranial hemorrhage,SICH)率、泌尿道出血率、消化道出血率、病死率评估临床安全性。结果小剂量组预后良好率为58.49%(31/53),标准剂量组预后良好率为59.26%(32/54),差异无统计学意义(P>0.05)。2组溶栓后7 d NIHSS评分低于基线NIHSS评分,溶栓后90 d mRS评分低于入院时mRS评分,差异有统计学意义(P<0.05)。2组溶栓后7 d NIHSS评分、溶栓后90 d mRS评分比较,差异无统计学意义(P>0.05)。小剂量组24 h HT发生率、24 h SICH发生率、泌尿道出血发生率、消化道出血发生率、90 d病死率分别为1.89%(1/53)、1.89%(1/53)、3.77%(2/53)、1.89%(1/53)、1.89%(1/53),标准剂量组分别为9.26%(5/54)、7.41%(4/54)、1.85%(1/54)、5.56%(3/54)、1.85%(1/54),差异无统计学意义(P>0.05)。结论多模式CT筛选指导下发病在4.5~9.0 h的AIS患者超时间窗应用小剂量和标准剂量阿替普酶静脉溶栓有相似的临床疗效,小剂量更安全。
