一种关于RPM放疗呼吸门控系统束流时间延迟性能的参考质控方法

目的：提出一种关于RPM放疗呼吸门控系统束流时间延迟性能的参考质控方法,给出参考条件下VB与EDGE加速器的时间延迟测量结果。方法：首先设计梯形质控呼吸曲线并加载运动模体,利用定位CT扫描由运动模体驱动的W-L模体,然后设计用于束流出束和截止延迟测量的两类质控计划,最后在加速器上执行质控计划,使用EPID采集模体的静态参考图像与运动测量图像,通过分析致密金属球在运动图像和参考图像中的位置差,反推束流的时间延迟,分别在VB与EDGE两台加速器上做方法验证。结果：VB与EDGE加速器的束流出束时间延迟均小于100 ms,截止时间延迟基本一致,VB加速器约为14 ms,EDGE约为22 ms。10FFF各剂量率的出束时间延迟基本一致,而6FFF、6 MV和10 MV则随剂量率的变化略有增加。4个能量各剂量率的束流截止时间延迟均较小且相对一致,部分能量有随剂量率变大而延迟缩小的趋势。结论：本研究提出的RPM束流时间延迟参考质控方法和条件具有较高的测量可信度和较强的临床实操性,测量结果表明RPM呼吸门控系统响应灵敏,研究结果为呼吸门控系统的时间延迟质控提供了重要的方法学指导与数据参考。     

鼻咽癌放疗后局部复发和纤维化的增强CT鉴别诊断价值

目的探讨鼻咽癌放疗后出现块影时,ＣＴ检查对鉴别肿瘤局部复发和放射性纤维化的价值。方法收集１５９例经ＣＴ检查的鼻咽癌,其中放疗后局部复发（ＲＴ）３７例,放射性纤维化（ＲＦ）５４例,以６８例未经放疗的鼻咽癌（ＰＴ）作对比。使用ＥＬＳｃｉｎｔｓｐｒｉｎｔ２０００型ＣＴ机,测量放疗后出现的块影平扫和强化的ＣＴ值,用统计学的方差分析法处理增强前后的ＣＴ值差异。结果ＲＴ组平扫ＣＴ值为５０．４０±８．１０Ｈｕ,增强为７３．７４±７．３７Ｈｕ;ＲＦ组平扫为４８．６２±１０．１５Ｈｕ,增强为５６．７４±８．６９Ｈｕ;对照组（ＰＴ）病变区平扫为４８．３２±９．２０Ｈｕ,增强为７２．３８±７．７５Ｈｕ。测量表明ＲＴ组有明显强化,ＲＴ组与ＲＦ组强化后ＣＴ值差异有非常显著性（Ｐ＜０．０１）。结论鼻咽癌放疗后出现块影时,ＣＴ增强扫描可作为鉴别诊断的重要方法。     

PF方案化放治疗晚期鼻咽癌的远期疗效

目的探索用ＰＤＤ／５－Ｆｕ方案化放治疗晚期鼻咽癌的疗效。方法１９８９年１２月～１９９０年１２月间,选择７６例Ⅲ、Ⅳ期鼻咽癌患者,先作３周期ＰＤＤ（２０ｍｇ（ｍ２）－１ｄ－１,ｉｖ,第１～５天）和５－Ｆｕ［７００ｍｇ（ｍ２）－１ｄ－１,连续静脉滴注,第１～５天］诱导化疗,随后尽快作放疗,此为综合治疗组。以１９８９年作单纯放疗的８６例晚期鼻咽癌患者作对照组。两组放疗方法、时间／剂量分割均相同。结果化疗有效率为８９．３％,完全缓解率为１８．４％。综合治疗组（综合组）总的５年生存率为４８．７％,对照组为３３．７％（Ｐ＞０．０５）。综合组Ｔ２Ｎ３和Ｔ２～４Ｎ３患者的５年生存率为４４．１％和３９．５％,均明显高于对照组的２１．６％及２０．４％（Ｐ＜０．０５）。结论ＰＦ方案化放治疗提高了Ｔ２～４Ｎ３患者的５年生存率。     

Nongastrointestinal mucosa-associated lymphoid tissue (MALT) lymphomas: Clinical and therapeutic features of 24 localized patients

Background: Peripheral B-cell lymphoma of the marginal zone (MALT, low-grade), presenting as localized, extranodal disease, usually affects the elderly. The gastrointestinal tract is the most frequently involved extranodal location, representing 70% of all MALT lymphomas. Recently, numerous other extranodal sites involved by MALT lymphomas have also been described.Patients and methods: From January 1990 to October 1995, 24 patients with untreated nongastrointestinal low-grade MALT lymphoma were submitted to treatments ranging from the local approach of radiotherapy and local -interferon (-IFN) administration to chemotherapy. The tumours were located in the lung (seven cases), conjunctiva (four cases), lachrymal gland and orbital soft tissue (four cases), salivary glands (three cases), skin (three cases), breast (two cases)' and thyroid (one case). All patients had low-grade stage IE tumours.Results: Chemotherapy was administered in 11 patients (six with lung, three with salivary gland, one with breast, and one with thyroid locations); radiation therapy was employed in seven patients (three with lachrymal gland, three with skin, and one with breast locations); local -IFN administration was administered in five patients (four with conjunctival, and one with lachrymal gland sites); and surgery was employed in one patient with a lung tumour. All patients achieved complete remissions; three local recurrences and two relapses in other sites were observed. The global five-year survival rate was 100% with a relapse-free survival rate of 79%.Conclusions: These data confirm the significant efficacy of different therapeutic approaches to specific sites inbes obtaining a good remission rate for nongastrointestinal localized low-grade MALT lymphomas.     

Intraoperative radiotherapy in the treatment of neuroblastoma: Report of a pilot study

Background: External beam radiotherapy in advanced neuroblastoma is limited by the volume of normal radiosensitive tissues included in the radiation field. Limitations to external radiation are the late effects to these tissues. Intraoperative radiotherapy (IORT) delivers a single high-radiation dose to a tumor while displacing normal tissues that would have been included in an external field. Standard external radiotherapy can still be done after boost IORT. Methods: Eight advanced-stage neuroblastoma patients who received IORT as part of their multimodality therapy were reviewed to identify the impact of IORT on operative time, complications, and tumor control in the treatment field. The IORT was accomplished by patient transport from the OR to the radiation therapy suite; these were separated by three floors. Results: IORT added 30–75 min to the operative procedure. Tumors in the resection/IORT fields showed no evidence of disease (one), stable tumor size (six), and tumor recurrence (one). Two complications were identified: a urinary fistula and CO₂ retention, which was detected and corrected before the IORT. Neither of these complications was related to the IORT. Two patients who had subsequent tumor resection after IORT demonstrated tumor differentiation to ganglioneuromatous tissue. Conclusions: IORT usually can be completed in less than an hour. No IORT-associated complications were identified. IORT along with maximal tumor resection, external radiation, and chemotherapy enhances local tumor control.Presented in part at the 47th Annual Symposium of The Society of Surgical Oncology, Houston, TX, March 17–20, 1994.     

29例髓母细胞瘤术后放射治疗

目的：回顾２９ 例髓母细胞瘤术后放疗,对影响生存情况的因素进行分析。方法：手术后病理证实的２９例髓母细胞瘤,先行卡氮芥（ＢＣＮＵ）化疗,再行６０钴常规分割照射：全脑剂量（ＤＴ）２２～４０ Ｇｙ;原发病灶追加ＤＴ１５～２２ Ｇｙ;全脊髓轴ＤＴ２５～３５ Ｇｙ。结果：１、３、５、８ 年生存率分别为８９．６％ （２６／２９）、５５．２％ （１６／２９）、３０．４％ （７／２３）、２５．０％ （４／１６）。结论：病人生存期长短与手术切除范围、术后接受放疗时间、放射剂量及是否行化疗有关。     

肾上腺区巨大肿瘤的影像学定位诊断和介入治疗评价

①目的　探讨不同影像学检查方法对肾上腺区巨大肿瘤的定位诊断及介入治疗的价值。②方法　收集经手术和病理证实、肿瘤直径＞ １０ｃｍ 的肾上腺区巨大肿瘤病人１７ 例,对其诊断和治疗进行总结分析。③结果１７例中ＣＴ定位诊断正确１１ 例,占６４．７％ ;Ｂ超诊断正确７ 例,占４１．２％ ．５ 例行ＤＳＡ 检查,定位诊断正确率达１００％ ,均行肾上腺动脉栓塞治疗后手术切除。④结论　各种影像学检查方法,对肾上腺区巨大肿瘤的定位诊断正确率由高到低依次为ＤＳＡ,ＣＴ和Ｂ超。介入治疗既可作为手术前栓塞治疗,也可作为不能手术切除肿瘤的姑息性治疗。     

骨转移癌不同分割放射治疗比较

目的比较不同分割放射治疗骨转移癌患者的时间效应,评价不同分割放疗的止病疗效。材料与方法对1992年5月～1997年5月我院收治的123例骨转移癌患者分别给予常规分割组、超分割组及大剂量低分割组不同的放射治疗,观察各组姑息止痛的放疗有效率．结果放疗1周时,止痛有效率为5．41％、10．3％及65．2％;放疗结束时为70．3％、77．3％与77．3％;放疗结束后3个月为65．0％、67．6％及74．2％．经统计学分析发现放疗1周时大剂量低分割组止痛有效率与其它组比较有明显差异。结论大剂量低分割放疗止痛率高,疗效出现早,而放疗结束时及结束后3月3组止病率无差异。故在骨转移癌的放疗中可考虑采用先大剂量低分割放疗后继常规或超分割的放疗方式。     

A New Approach to an Old Problem

A patient with progressive visual loss was found to have an optic nerve sheath meningioma. The patient was treated with stereotactic radiotherapy, a computer-guided stereotactic technique that minimizes the risk of radiation-induced optic neuropathy. Six months after treatment, the patient was doing well and showed no signs of radiation-induced optic neuropathy.     

利用独立准直器开展调强放疗算法研究

研究利用独立准直器调整射野强度分布。设计了两种递推的办法来计算射野处序列,采用模拟退火算法优化射野片的照射顺序。并以在Ｖａｒｉａｎ ６００Ｃ轲速器上实施三个临床调强射野为例,估计ＩＣ调强放疗的照射时间。照射时间一般在５至１０ｍｉｎ。它近似与机器剂量率成反比,并受调强算法,矩阵元素大小以及强度分级数的影响。