X—刀治疗颅内肿瘤116例报告

作者应用Ｘ－刀治疗颅内肿瘤１１６例，大部分为中、小肿瘤、部分颅内巨大肿瘤采用联合开颅手术方式，随访１￣６个月地结果显示，Ｘ－刀治疗后，９６例（８２．８％）肿瘤有影像学改变，其中部分肿瘤囊性变和缩小，对于巨大肿瘤，Ｘ－刀治疗后再手术可降低手术难度，部分病例的病理检查亦提示该结果，根据最大剂量与周边剂量之比和治疗体积与靶体积之比，进行治疗计划的优化，可以有效地减少并发症及提高疗效。     

X—刀治疗颅内恶性肿瘤32例报告

目的：分析Ｘ－刀颅内恶性肿瘤的治疗效果。方法：３２例颅内恶性肿瘤（胶质瘤２１例，转移瘤１１例）行Ｘ－刀治疗，平均剂量２２Ｇｙ（１８～３２Ｇｙ），其中１７例Ｘ－刀治疗后续继行全脑常规体外放射治疗，平均剂量２０Ｇｙ。结果：２１例胶质瘤，１５例在治疗后６个月肿瘤缩小，６例无变化，２例在Ｘ－刀治疗后２个月内行开颅肿瘤切除术；１１例脑转移瘤Ｘ－刀治疗后病灶全部消失７例，明显缩小４例（≥５％）。全部病人中治疗     

X刀治疗胶质瘤61例临床分析

目的：通过对61例脑胶质瘤X刀治疗效果的临床分析,提高X刀治疗胶质瘤的认识。方法：C地61例胶质瘤病人进行X刀治疗,单次治疗54例,多次治疗7例,治疗体积5－110cm^3,单次治疗周边剂量16－22Gy,分治疗周边剂量12－16Gy,分3－6次,所有病灶80％的体积均为70－110％等剂量线覆盖肿瘤边缘,随访6－26月。结果：完全缓解6例（9．84）,部分缓解29例（47．54％）,无变化11例（18．03％）,进展14例（22．95％）,总有效率77．0％,生存期14－26月,平均21．5月。结论：X刀是治疗脑胶质瘤的一种有效方法,肿瘤直径小,亚性度低疗效好;直径大,恶性度高疗效欠佳.     

X—刀治疗脑转移瘤临床分析

目的　探讨Ｘ－ 刀对脑转移瘤的治疗作用及其适应症。方法　对５６例脑转移病人采用Ｘ－ 刀治疗。结果　４９例病人获得１～２４个月的随访,其随访中位生存期为８．７ 个月,半年局控率为８７．１％ 。Ｘ－ 刀治疗后３个月头颅ＣＴ、ＭＲＩ复查显示肿瘤控制,有效率８４．３８％ （２７／３２）,且转移灶体积≤７ｃｍ ３ 与＞ ７ｃｍ ３ 比较有效率明显提高（Ｐ＜ ０．０１）。结论　病人生存率与Ｘ－ 刀治疗前ＫＰＳ评分级别、是否行全脑放疗有关。脑转移瘤是否辅以全脑放疗应视病理和病情而定;对较大的转移灶（直径＞ ３．５ｃｍ ）可采用Ｘ－ 刀分次治疗,以减少并发症发生率。     

X—刀治疗脑深部肿瘤（附68例）

目的 阐明Ｘ－刀治疗胸深部肿瘤的方法、优越性、疗效及并发症。方法 对６８例脑深部肿瘤患者行Ｘ－刀治疗，随访１－１８个月，结合文献进行临床分析及疗效评价。结果 得到随访的５５例病人中，症状好转３７例，无变化１０例，加重５例，死亡３例。其显效率为６３．７％，有效率为８５．５％。结论 对于脑深部肿瘤Ｘ－刀是一种完全有效的治疗方法。     

颅内肿瘤X—刀治疗并发症的防治

目的分析Ｘ－刀治疗颅内肿瘤的并发症情况及处理措施。方法Ｘ－刀治疗颅内肿瘤１５８例，随访２５．３±９．２月。分析神经系统损害的症状和体征，行影像检查。结果Ｘ－刀治疗颅内肿瘤总有效率为８１．６５％，共有１４例发生并发症。其中９例为急性反应，５例为迟发性并发症。结论急性并发症主要与病灶部位有关，一旦发生可采取激素及对症处理；而迟发性并发症则主要与病灶体积有关，尚无有效的处理方法，应通过选择适应症及适当的治疗方法尽可能地避免。     

X—刀治疗胰腺癌14例临床分析

目的：评价Ｘ－刀立体放疗在晚期胰腺癌治疗中的价值。方法：１４例患者（原发肿瘤３例，转移肿瘤１１例），均采用高剂量分割治疗，每周３次，分４～１０次进行，处方剂量为５～８Ｇｙ，总量２８～４５Ｇｙ。结果：原发肿瘤３例，瘤体明显缩小，转移肿瘤１１例，局控１０例（７例明显缩小，３例稳定）。中位生存期１０个月。结论：Ｘ－刀有大地提高了胰腺癌放疗疗效，特别是为了不能手术的胰腺癌治疗提供了一种有效的手段。     

颅底囊性肿瘤的γ-刀治疗

背景与目的：颅底囊性肿瘤的治疗原则上首选手术切除。有手术禁忌或不愿开颅手术的患者，则应选择其他治疗方法。本文探讨γ-刀治疗颅底囊性肿瘤的临床疗效。方法：使用γ-刀治疗颅底囊性肿瘤15例，肿瘤周边剂量13—16Gy(平均14Gy)，中心剂量28—40Gy(平均34Gy)，等剂量曲线35％-50％(平均40％)，治疗靶点3-9个(平均5个)，随访1—7年。结果：11例(73．3％)病灶缩小50％以上，2例(13．3％)病灶无变化，2例(13．3％)囊腔增大。结论：应用γ-刀治疗颅底囊性肿瘤，是神经外科手术治疗的有效补充。     

X—刀治疗颅底肿瘤的临床探讨

目的：探讨位于颅底中线和／或近中线区的肿瘤用Ｘ－刀立体定向放射外科方法治疗的效果。方法：采用Ｘ－刀立体定向放射外科方法，对６例肿瘤７个病灶进行了治疗。该７个病灶皆为颅底上区和颅底骨本身的肿瘤，包括脑膜瘤１例，垂体瘤２例，黑色素瘤１例，转移癌３个病灶。为减轻Ｘ－刀术后脑水肿等并发症，采用了分次分割，多靶点的放射治疗方法。结果：所有患者随访６￣１６月，除１例脑膜瘤外，余５例６个病灶或消失或不同程度的缩     

X刀加全脑常规放疗治疗脑转移瘤

1997年3月－1999年12月利用JX－100X刀系统加全脑放疗共治疗40例脑转移瘤患者。20例先行全脑常规放疗35－40Gy，而后行X刀治疗；11例X刀治疗后，再加全脑放疗。X刀治疗采用单次或分次照射，其中单次照射28例，处方剂量16－22Gy，平均19．2Gy，分次照射12例，分割2－3次，处方剂量6－12Gy／次，每周1次，总剂量达20－30Gy，平均25．4Gy。全组40例均获3－26个月的随访，中位12个月。40例患者生存期为2－26个月，中位11．5个月，其中36例生存期超过6个月，占90％，27例超过12个月，占67．5％。2例超过26个月，4例在治疗后2－5个月内死亡；治疗后6个月CT或MRI复查，32例病灶明显缩小或消失，占80％。3例出现新的转移灶，占7．5％。4例无明显变化占10％。4例死亡。在随访期间，有26例死亡。死亡病例中，脑部肿瘤复发或出现新病灶者仅5例，其余病例均因有其他脏器转移或原发肿瘤进展合并脏器衰竭而死亡。结果提示，X刀与常规放疗相结合治疗脑转移瘤优于单纯常规放疗。     

立体定向放射治疗技术在前列腺增生症治疗中的应用探索

目的：观察立体定向放射治疗（X刀）前列腺增生症（BPH）的有效性及安全性。方法：应用X刀治疗12例重度BPH，靶区为整个前列腺，采用90％的等剂量曲线包绕靶区，（1．5—2）Gy／f，共（5—8）f，隔日一次，每周3次。治疗前、后比较国际前列腺症状评分、生活质量指数、前列腺体积、膀胱残余尿量、最大尿流速。结果：临床治愈8例，显效4例，各项指标变化显著（P〈0．01）。结论：立体定向放射治疗BPH安全、有效。     

Stereotactic radiosurgery, X: clinical isodosimetry of gamma knife versus linear accelerator X-knife for pituitary and acoustic tumours

Several review articles have compared gamma unit versus linear accelerator (linac)-based radiosurgery systems, concluding that the dose gradient 'fall-off' at the margin of the target (expressed as the distance between isodoses) is very similar for both techniques as far as single isocentre treatment volumes up to 1.5 cm diameter are concerned, and that the two radiosurgical systems are, in general, comparable. 'Fine tuning' of the gamma unit can be carried out by using multiple isocentre plans, the differential use of small collimator sizes (down to 4 mm) and field weightings, and adroit use of the gamma angle, and selective beam blocking. Multiple isocentre plans, beam modification, restriction of gantry angles and arc lengths, and microcollimation can similarly improve the isodose gradients from linac units. In both instances, the dosimetric advantages occur along selected aspects of the target perimeter border. However, the more frequent use of multiple isocentred 'shots' on the gamma unit achieves greater conformity indices for more complex target volumes, but at the expense of steeper internal dose gradients. We studied two patients with tumours close to or arising from radiosensitive special sensory nerves (optic and cochlear) to compare and contrast fine tuning of the two technologies. In a previously irradiated patient with a pituitary adenoma, the dose gradient achieved at the rostral margin, adjacent to the optic chiasma, was steeper on the gamma unit (due to the concentration of small collimator shots rostrally and beam blocking), which was therefore the dosimetrically preferred technique. In contrast, the vastly smaller internal dose gradient (11% for linac/X-knife versus 100% for Gamma Knife) and the ability to fractionate on the X-knife system, gave a large dosimetric advantage to the X-knife plan in the treatment of an acoustic neuroma, where the intracanalicular component of the cochlear nerve traversed the target volume. This advantage also pertains to the cochlear ramus of the internal auditory (labyrinthine) artery and the facial nerve. Our published work on X-knife radiosurgery of acoustic neuroma has documented improvement of hearing after therapy and may be relevant in this regard. That there are advantages in physical dose distribution and fractionation, producing a reduction in the biological dose in normal tissue, argues for the use of linac technology in acoustic neuromas. Craniopharyngiomas enveloping the optic nerve/chiasma will similarly be better treated by the linac X-knife system. It is apparent that different radiosurgery systems may be indicated in particular neuro-oncological situations.     

后程X-刀治疗DP方案化疗后无进展局部晚期非小细胞肺癌的疗效

目的探讨序贯后程X刀治疗多烯紫杉醇加顺铂(DP方案)4周期化疗后无进展局部晚期非小细胞肺癌(non-small cell lung cancer, NSCLC)的疗效及不良反应。方法57例4周期DP方案化疗后无进展患者随机分为两组,常规组行常规分割照射,2Gy/次、1次/日,5次/周,总量64Gy;后程X刀组前四周治疗同常规组,4周后改用X刀,6Gy/次,3次/周,共6次,总量76Gy。比较两组的疗效及副作用。结果后程X刀组完全缓解率38.7%,高于常规组15.4%(P=0.047),后程X刀组三年生存率35.5%高于常规组15.4%(P=0.035),两组不良反应差异均无显著性。结论与常规放射治疗相比,序贯后程X刀治疗可提高化疗后无进展局部晚期NSCLC患者的完全缓解率及三年生存率,不良反应未增加,可作为化疗后无进展NSCLC患者的主要治疗手段。     

Quality assurance in radiotherapy by in vivo dosimetry. 1. Entrance dose measurements, a reliable procedure

Entrance dose measurements were performed with semiconductor detectors on patients treated for head and neck and brain tumors with a 6 MV X-ray beam. A total number of 554 treatment set-ups were measured. The results showed a gaussian distribution with a mean value of 97.8% and a standard deviation of 2.8%. A systematic error of 2.2% on the mean value was shown to be due to a systematic deficiency in the algorithm used in the planning system and to a systematic error in the application of the dosimetry protocol. Two treatment techniques were identified leading to an erroneous dose delivery. Finally, large deviations (more than 2 S.D.) of the measured dose from the expected dose were detected in 3% of the measured treatment set-ups, the sources of the errors could in all cases be identified and eliminated in the further treatment sessions. This study demonstrated the reliability of the use of semiconductor detectors for in vivo dosimetry and its usefulness as part of a departmental quality assurance program.     

Conservative treatment of uveal melanoma: local recurrence after proton beam therapy

Twenty-three of 1006 (2.3%) uveal melanoma patients treated with proton beam therapy at the Harvard Cyclotron Laboratory between July 1975 and December 31, 1986 received additional treatment for documented (15 patients) or suspected (eight patients) tumor growth in the irradiated eye. Growth within the initially irradiated volume was documented at Massachusetts Eye and Ear Infirmary in 12 patients. Documented growth occurred in nine of 665 (1.4%) patients with small and intermediate size tumors, at times after treatment ranging from 6 to 48 months (median 16 months), and in three of 341 (.9%) patients with large tumors at 7, 11, and 12 months after treatment. Melanoma growing totally outside the treated volume was also documented in three additional patients at 7, 9, and 45 months; two of these were thought to be "ring melanomas". Eight patients had the treated eye removed elsewhere for suspected tumor growth. The additional treatment in these 23 patients was conservative in nine patients (repeat proton irradiation in five and laser photocoagulation in four). Thirteen underwent immediate enucleation and one had orbital exenteration. Ultimately, 17 of the 23 eyes (74%) were removed. Estimated probability of local control of the melanoma within the irradiated eye at 60 months was 96.3 +/- 1.5%. Dose distributions to the 12 patients with documented local failure within the irradiated volume were analyzed. Ten tumors recurred marginally in an area receiving less than the prescribed dose of 70 CGE (CGE = Cobalt Gray Equivalents = proton Gy X RBE 1.1), whereas only two recurred in the volume receiving full dose. Based on these data, it appears that a dose of 70 CGE in five fractions is associated with very high rates of local control in human uveal melanoma. It is reasonable to consider initiating studies using a lower total dose or a more protracted course, to determine if some of the observed complications are dose-related.     

Serial megavoltage CT imaging during external beam radiotherapy for non-small-cell lung cancer: observations on tumor regression during treatment

PURPOSE: The ability to obtain soft-tissue imaging in the treatment room, such as with megavoltage CT imaging, enables the observation of tumor regression during a course of external beam radiation therapy. In this current study, we report on the most extensive study looking at the rate of regression of non-small-cell lung cancers during a course of external beam radiotherapy by analyzing serial megavoltage CT images obtained on 10 patients. METHODS AND MATERIALS: The analysis is performed on 10 patients treated with the Helical Tomotherapy Hi*Art device. All 10 patients had non-small-cell lung cancer. A total of 274 megavoltage CT sets were obtained on the 10 patients (average, 27 scans per patient; range, 9-35). All patients had at least a scan at beginning and at the end of treatment. The frequency of scanning was determined by the treating physician. The treatment was subsequently delivered with the Tomotherapy Hi*Art system. The gross tumor volumes (GTVs) were later contoured on each megavoltage CT scan, and tumor volumes were calculated. Although some patients were treated to draining nodal areas in addition to the primary tumor, only the primary GTVs were tracked. Response to treatment was quantified by the relative decrease in tumor volume over time, i.e., elapsed days from the first day of therapy. The individual GTVs ranged from 5.9 to 737.2 cc in volume at the start of treatment. In 6 of the 10 patients, dose recalculations were also performed to document potential variations in delivered doses within the tumors. The megavoltage CT scans were used, and the planned treatment was recalculated on the daily images. The hypothesis was that dose deposited in the target would increase throughout the course of radiotherapy because of tumor shrinkage and subsequent decreasing attenuation. Specifically, the dose received by 95% of the GTV (D95) was monitored over time for each of the 6 patients treated at M. D. Anderson Cancer Center Orlando. RESULTS: Regression of all 10 lung tumors could be observed on the serial megavoltage CT scans. The decrease in volume was observed at a relatively constant rate throughout the treatments, with no obvious initial or final plateaus. For all 10 tumors, the average decrease in volume was 1.2% per day. However, individual tumor regression rates were observed with a range of 0.6% to 2.3% per day. The lowest rate of shrinkage was observed for the smallest lesion, and the highest rate was observed in the largest lesion. Of the 6 cases in which dose recalculations were performed, 5 demonstrated a small but noticeable gradual increase in deposited doses within the tumor, with the D95 increases ranging from 0.02% to 0.1% per day. CONCLUSION: With the advent of in-room soft-tissue imaging techniques such as megavoltage CT imaging with a helical tomotherapy unit, daily documentation of the status of a grossly visible targeted tumor becomes possible. The current study demonstrated that tumor regression can be documented for patients with non-small-cell lung cancer treated with helical tomotherapy. Clinical correlations between the observations made during the course of treatment and ultimate outcomes, e.g. local control, should be investigated.     

调强适形放射治疗在临床的应用

目的：介绍调强适形放射治疗（intensity modulated radiation therapy,IMRT）在美国Stanford大学医学中心放疗科的临床应用情况。方法：详细描述制作Corvus IMRT治疗计划、质量控制和质量监测的整个过程;利用该IMRT,联合外照射和X-刀根治性治疗T4NOMO鼻咽癌1例,及单纯IMRT治疗胸椎体转移癌1例。结果：从靶区各个剖面可见高剂量等剂量曲线按计划设计紧扣靶区,重要器官和敏感组织受到保护,治疗计划统计表显示靶区、重要器官和敏感组织的最高及最低受量和受照射体积,而剂量体积直方图则直观地提示肿瘤组织和周围器官的受量比较。结论：IMRT靶区剂量分布均匀,正常组织及敏感器官受到最大限度的保护,可对某些病种的肿瘤组织施以高剂量放疗。     

X-刀治疗脑深部肿瘤(附68例报告)

目的阐明X-刀治疗脑深部肿瘤的方法、优越性、疗效及并发症。方法对68例脑深部肿瘤患者行X刀治疗,随访1～18个月,结合文献进行临床分析及疗效评价。结果得到随访的55例病人中,症状好转37例,无变化10例,加重5例,死亡3例。其显效率为63．7％,有效率为85．5％。结论对于脑深部肿瘤X-刀是一种安全有效的治疗方法。     

肝部肿瘤三维立体定向适形放疗计划设计探讨

 目的 探讨肝部肿瘤的三维适形放射治疗计划设计。方法 对50例肝部原发及转移性肿瘤患者，根据医师要求的CTV和周围正常的敏感器官限制受量设计三维适形放射治疗计划，结合剂量-体积直方图选择最佳方案。结果 以ICRU剂量参考点（肿瘤中心点剂量）剂量归一，80 % ~ 90 %剂量线均能包绕90 %以上的PTV。90 %剂量线包绕PTV的程度和靶区的大小及所在部位有关。结论 肝部肿瘤的治疗计划设计时，对位于不同部位的病灶采用不同的设计；正常肝组织的受照体积的大小和受照剂量直接影响着患者的放射治疗反应，同时对处方剂量、剂量分割方式的选择有重要影响。