儿童髓母细胞瘤全脑全脊髓放疗36Gy与23．4Gy甲状腺功能低下发生率比较

患有髓母细胞瘤的儿童在接受全脑全脊髓放疗(ＣＳＩ)后易发生内分泌功能障碍。虽然生长激素分泌不足最常见 ,但直接照射甲状腺 (原发性 )或照射下丘脑 垂体轴 (中枢性 )都可能引起甲状腺功能减低。为分析比较低剂量全脑全脊髓照射 (2 3.4Ｇｙ)合并化疗与标准剂量 (36Ｇｙ)照射合并或不合并化疗是否可降低甲状腺功能低下的发生率 ,对 32例行全脑全脊髓放疗加或不加化疗且年龄≤ 2 0岁的髓母细胞瘤患者进行了回顾性分析。其中 2 0例全脑全脊髓照射的剂量为 36Ｇｙ ,另外 12例为 2 3.4Ｇｙ ,分割剂量均为 1.8Ｇｙ 次 ,对后颅窝区则用平行的两…     

髓母细胞瘤临床治疗现状

髓母细胞瘤是儿童中最常见的颅内肿瘤,手术切除程度是重要的预后相关因素;术后单纯放疗对普通风险患者可取得较好的疗效,再辅以化疗,在提高疗效的同时,可以降低全脑全脊髓的照射剂量;术后放化疗结合是高风险患者的标准治疗方案;对于复发患者,高剂量化疗联合干细胞移植可以取得较好的疗效。普通风险组（AR）患者以及联合化疗预后较好。     

螺旋断层放疗治疗髓母细胞瘤的疗效观察

目的 探讨螺旋断层放疗技术治疗髓母细胞瘤的剂量学优势、不良反应及疗效。方法 2011年2月至2011年10月,4例髓母细胞瘤患者接受螺旋断层放射治疗。术后瘤床临床靶区（CTV1）剂量：50.4Gy／28f,每次18Gy,5次／周;全脑全脊髓临床靶区（CTV2）剂量：30.6Gy／17f,每次1.8Gy,5次／周。结果 4例患者接受照射的均匀性和适形性较好,重要器官的照射剂量低,治疗时间均小于15min。4例患者均获随访,中位随访9个月（4～15个月）,至随访截止时间无1例复发。主要不良反应为骨髓抑制和恶心呕吐,4例患者均可耐受。结论 螺旋断层放疗治疗髓母细胞瘤的疗效和剂量分布较好,为治疗髓母细胞瘤开辟了一个新的治疗平台。     

髓母细胞瘤的放疗和化疗

目的：探讨髓母细胞瘤对放疗和化疗的敏感性及提高髓母细胞瘤治愈的可能性。方法：回顾性分析了1987年2月－1997年2月我院用放射治疗和化疗的方法治疗了61例病例,儿童50例,中位年龄4．5岁（1－12岁）,其中男性30例,女性20例,成人11例,中位年龄19岁（13－36岁）,男性4例,女性7例。完全切除肿瘤有8例,部分切除肿瘤有3例,所有病人都采用全颅全脊髓分野照射。全颅照射30－35Gy,后颅窝局部增量20－25Gy,成人每次照射剂量为1．8－2Gy,儿童每次照射剂量为1．6－1．8Gy,儿童病人都采用联合用药,成人病人主要应用VM26＋CDDP＋CCNU。结果：儿童髓母细胞瘤病人放疗结束时CT片检查均发现肿瘤有明显退缩约50％,但无一例安全退缩,经过化疗后CT片复查发现肿瘤退缩不明显,生存期为3个月－7年,中位生存期为3年。成人髓母细胞放疗后肿瘤嫁缩没有像儿童髓母细胞瘤那么明显,几乎没有改变,放疗后CT片有肿瘤存在的3例病人平均生存期为1年,CT片无肿瘤的8例病人均存活5年以上。结论：髓母细胞瘤对放射线仅有部分敏感性,有一部分髓母细胞瘤细胞对放射线具有抵抗性。提高肿瘤手术切除率是提高病人生存率的重要因素。     

髓母细胞瘤的综合治疗

目的全中枢放疗加鞘内和静脉化疗以提高髓母细胞瘤的疗效.方法8例髓母细胞瘤患者接受全脑和全脊髓放疗DT30Gy/3～3.5周,然后瘤床局部追加20～25Gy/2～2.5周,总量为DT50～55Cy,疗终予MTX12mg/m2,鞘内注射,每周1次共5周,VCR1.5mg/m2iv,每周1次共5次,CCHU130 mg/m2口服,6周1次.结果(1)CR:7/8(87.5%),PR:1/8(12.5%).(2)放、化疗均无明显不适.(3)2年生存率100%,5年生存率4/6(66.7%).结论该方法明显提高局控率和生存率且无明显并发症,值得推广.     

髓母细胞瘤54例临床分析

目的　回顾分析髓母细胞瘤的临床特点 ,探讨合理治疗方案及影响预后的因素。方法　 1979年 12～ 1998年 12月 ,本科收治髓母细胞瘤 5 4例 ,男 35例 ,女 19例 ,年龄 2 .5～ 2 3.0岁 ,中位年龄 9岁。全部病例先经手术切除 ,(2 5例肉眼全切除 ,2 9例次全切除或部分切除 ) ,病理证实为髓母细胞瘤。术后均接受全脑、全脊髓放射治疗。 32例后颅窝剂量≥ 5 0Gy。 2 2例后颅窝剂量 <5 0Gy。 结果　全部病例 1、3、5和 10年生存率分别为 86 .9%、5 8.8%、5 5 .5 %和 4 8.3%。其中 12例放疗后复发 ,1例放疗后远处转移 (经病理证实 )。多因素分析显示照射剂量 (<) 4 5Gy分组时手术切除程度 (即有无残留 )以及肿瘤部位均对预后有影响(P值分别为 0 .0 2 5和 0 .0 4 9)。剂量 (≤ ) 5 0Gy分组时仅手术切除程度对预后有影响 (P =0 .0 4 3) ,但P值趋大。结论　髓母细胞瘤首选手术 ,术后全脑、全脊髓放射治疗的方法是神经外科及放射治疗医师共同推荐的治疗方案 ,对肿瘤未能完整切除者 ,可通过增加局部放射治疗剂量改善生存。     

髓母细胞瘤的放射治疗：附34例疗效分析

背景与目的：髓母细胞瘤是儿童后颅窝常见的恶性肿瘤，手术联合术后放疗是公认的治疗方法，化疗的作用尚不肯定。本文回顾性分析34例髓母细胞瘤术后放疗和化疗的疗效。方法：1992年1月至2002年12月，34例经术后病理证实的小脑髓母细胞瘤患者在我院接受了术后放疗，全脑照射剂量为2850～3500cGy，后颅窝瘤床缩野加量照射2000-2500cGy，全脊髓照射剂量2960—3210cGy。14例接受了术后全身化疗。采用Kaplan—Meier法计算生存率，生存率之间的差异采用log—rank法检验。结果：全组5年总生存率58．8％，无瘤生存率53．2％；其中术后化疗组和未化疗组的5年总生存率分别是71．4％和50．1％(x^2=1．24，p=0．2662)，无瘤生存率分别是57．1％和50．2％(x^2=0．32，P=0．5714)。结论：髓母细胞瘤手术联合术后全脑全脊髓放疗的疗效确定，术后全身化疗未显著提高总生存率和无瘤生存率。     

髓母细胞瘤的放疗和化疗

目的探讨髓母细胞瘤对放疗和化疗的敏感性及提高髓母细胞瘤治愈的可能性。方法回顾性分析了1987年2月～1997年2月我院用放射治疗和化疗的方法治疗了61例病例,儿童50例,中位年龄4．5岁（1～12岁）,其中男性30例,女性20例。成人11例,中位年龄19岁（13～36岁）,男性4例,女性7例。完全切除肿瘤有8例,部分切除肿瘤有3例。所有病人都采用全颅全脊髓分野照射。全依照射30～35Gy,后颅窝局部增量20～25Gy。成人每次照射剂量为1．8～2Gy,儿童每次照射剂量为1．6～1．8Gy。儿童病人都采用联合用药,成人病人主要应用VM26＋CDDP＋CCNU。结果儿童髓母细胞瘤病人放疗结束时CT片检查均发现肿瘤有明显退缩约50％,但无一例完全退缩。经过化疗后CT片复查发现肿瘤退缩不明显,生存期为3个月～7年,中位生存期为3年。成人髓母细胞瘤放疗后肿病退缩没有像儿童髓母细胞瘤那么明显,几乎没有改变。放疗后CT片有肿瘤存在的3例病人平均生存期为1年。CT片无肿瘤的8例病人均存活5年以上。结论髓母细胞瘤对放射线仅有部分敏感性。有一部分髓母细胞瘤细胞对放射线具有抵抗性。提高肿瘤手术切除率是提高病人生存率的重要因素。     

34例儿童髓母细胞瘤三维适形放射治疗的疗效分析

背景与目的:髓母细胞瘤(medulloblastoma,MB)属于原始神经外胚层肿瘤,是儿童最常见的头部恶性肿瘤,诊断时的患者平均年龄为6岁.近年来随着放化疗策略的巨大进步,5年生存率已由20世纪70年代的20%上升至70%.多数学者认为局部复发、术前是否存在转移、术后残存肿瘤体积以及患者年龄等因素都对预后有显著影响.本研究探讨髓母细胞瘤行三维适形放射治疗的疗效、毒副作用及其失败的原因.方法:2001年8月-2007年8月,共34例(男性23人,女性11人)髓母细胞瘤术后患者(3～16岁,平均年龄9.5岁)在我院就治,其中高风险组16例,低风险组18例.所有患者均于放疗前行肿瘤全切或次全切除术,术前从未接受过放、化疗.患者均于术后3周内行三维适形放射治疗.先予以患者全脑全脊髓放疗至30 Gy后,于后颅窝处补量20～25 Gy,中位分次剂量180 cGy/f.所有息儿于放疗后接受长春新碱、环己亚硝脲、顺铂方案化疗,所有患者均未行鞘内化疗.患者于每次化疗前常规行全血细胞计数、血生化和肝肾功能等检查.结果:5年总生存率(5-year overall survival,OS)和5年无病生存率(5-year disease free survival,DFS)分别为71%、62%,中位随访时间36.5个月.高风险组和低风险组的5年生存率分别为88.996、50.0%,两者之间差异有显著性(P=0.01).34例患者中13例失败,其中有3例(8.8%)在筛板区域发生复发.完全缓解率为70.5%,部分缓解率为14%.而术前存在转移患者的5年生存率为12.5%(1/8);术后残存肿瘤体积≥1.5 cm3患者的5年生存率为0%(0/5).术前存在转移与术后残存肿瘤体积对患者的预后均有显著性影响(P<0.05).而性别对患者的预后无显著影响.放疗不良反应主要为血液系统毒性反应(7/34 20.6%)及胃肠道反应(11.8%,4/34).结论:采用三维适形放疗治疗术后儿童髓母细胞瘤患者,严重不良反应的发生率较低.低风险组患者预后较好,而高风险组、术后残存肿瘤体积>1.5 Cm3以及术前存在转移的患者经综合治疗其预后仍较差.应注意放疗中筛板区域脑组织的放疗剂量可能偏低.     

儿童松果体母细胞瘤术后全脑全脊髓放疗的疗效及预后分析

目的:提高对儿童松果体母细胞瘤临床特征及预后的认识。方法:对2011年12月至2015年12月首都医科大学附属北京世纪坛医院放疗科收治的10例儿童松果体母细胞瘤术后患者的一般资料、肿瘤切除程度、放疗靶区和剂量以及预后进行回顾性分析。结果:10例患者均顺利完成术后全脑全脊髓放疗。全脑全脊髓中位放疗剂量为30.6（25.5～36.0）Gy,瘤床区的中位放疗剂量为55.8（50.4～60.0）Gy。4 例患者在放疗结束1 个月行化疗,化疗方案为依托泊苷+ 顺铂+ 异环磷酰胺。随访1.5～49.0 个月,10例患者均获无病生存,未出现肿瘤局部复发或者脊髓播散。结论:松果体母细胞瘤是比较少见的中枢神经系统恶性肿瘤,容易出现脊髓播散。手术、术后全脑全脊髓放疗加辅助化疗的综合治疗模式是目前标准的治疗方法。综合治疗的疗效尚可,预后满意。      

Survival of very young children with medulloblastoma (primitive neuroectodermal tumor of the posterior fossa) treated with craniospinal irradiation

Purpose: Very young children with medulloblastoma are considered to have a worse prognosis than older children. As radiotherapy remains an important part of the treatment, the adverse prognosis could be due to inadequate radiation treatment rather than biological factors. We analyzed the published literature to examine the impact of radiotherapy on survival in this group.

Methods and Materials: A Medline search was performed and we reviewed studies of treatment of medulloblastoma where radiotherapy was delivered using megavoltage equipment and the minimum follow-up allowed the calculation of 5-year survival rates.

Results: Thirty-nine studies were published between 1979 and 1996 with a treatment including craniospinal irradiation and boost to the posterior fossa. Eleven studies comprising 1366 patients analyzed survival by age at diagnosis. Eight of 11 studies showed a worse 5-year survival for the younger patient group which reached statistical significance in two. There is also a suggestion of a higher proportion of children with metastatic disease at presentation in the very young age group. The usual policy in younger children was to give a lower dose of radiotherapy to the craniospinal axis (CSA) and posterior fossa (PF) with reduction of dose in the range of 15 to 25% compared to standard treatment. As dose reduction to the posterior fossa is associated with worse survival and local recurrence is the predominant site of failure, the major determinant of worse survival in very young children with medulloblastoma may be suboptimal radiotherapy. Protocols including postoperative chemotherapy with delayed, omitted, or only local tumor irradiation do not reach survival rates of protocols with standard radiotherapy, also suggesting a continued importance for irradiation.

Conclusion: Very young children with medulloblastoma have a worse prognosis than older children. Inadequate radiation dose and technique to the primary tumor region may be a major contributing factor. Current chemotherapeutic regimes alone are not sufficient to compensate for reduced radiation doses and volumes.     

Low-dose craniospinal radiation therapy for medulloblastoma

At the University of California, San Francisco, 65 children with medulloblastoma of the posterior fossa were treated postoperatively with craniospinal irradiation; the dose to the posterior fossa was 54 Gy. The 26 children initially treated had only radiation therapy, receiving 30 to 40 Gy to the spine and 40 to 50 Gy to the brain. Subsequently, 39 children were treated with low-dose craniospinal irradiation and chemotherapy; 24 to 30 Gy was directed to the whole brain and 24 to 26 Gy to the spinal axis. Chemotherapy generally consisted of procarbazine just before, and hydroxyurea during, radiation therapy. Poor-risk and good-risk patients (defined by tumor resection less than 75% or greater than 75%, positive or negative myelogram, positive or negative cerebrospinal fluid analysis, age less than or greater than 2 years, respectively) were evenly distributed between the low-dose and high-dose craniospinal radiation therapy groups. Median follow-up was 51 months (range, 24 to 228 months). Kaplan-Meier actuarial survival for all patients was 73% at 5 years, 70% at 10 years. Freedom from disease progression was 68% at 5 years, 65% at 10 years. Whereas poor-risk patients treated with low-dose craniospinal irradiation and chemotherapy had a 5-year survival of 58% and a 5-year freedom from disease progression of 39%, those figures in the comparable good-risk patients were 83% and 77%, respectively. For both good-risk and poor-risk patients, the posterior fossa was the primary site of recurrence. Tumors recurred in the frontal region, probably under blocks, in three patients receiving low-dose irradiation and in two receiving the higher dose. Reducing the dose of whole-brain and spinal irradiation and giving chemotherapy did not result in a higher rate of recurrence in the brain or spinal cord. Intellectual and social function appeared better in patients receiving the lower dose. We did not study whether chemotherapy benefitted good-risk patients. Craniospinal axis irradiation at a lower dose than conventionally used does not compromise local control or survival in patients with medulloblastoma, and may reduce toxicity.     

乳腺癌根治术后单纯胸壁复发放疗和胸壁再复发的预后分析

目的 探究乳腺癌根治术后单纯胸壁复发(ICWR)患者的照射野及剂量选择,同时分析胸壁再复发的预后因素。方法 回顾性分析1998—2018年间解放军总医院第五医学中心和医科院肿瘤医院收治的乳腺癌改良根治术后ICWR患者 201例,患者术后均未行辅助放疗。胸壁复发后 48例(73.6%)患者接受手术治疗,155例(77.1%)患者接受放疗。无进展生存(PFS)率的计算采用Kaplan-Meier法和log-rank检验,多因素分析采用Cox回归法。胸壁再复发的计算采用竞争风险模型和Gray检验,多因素分析采用F&G回归法。结果 复发后中位随访时间92.8个月,5年PFS率为23.2%,5年胸壁再复发率为35.7%。多因素分析显示联合手术+放疗和复发间隔时间>12个月患者有较低的胸壁再复发率,复发间隔时间>48个月、联合局部+全身治疗及联合手术+放疗的患者有较高PFS率。155例患者ICWR后接受胸壁放疗,全胸壁照射+局部补量比全胸壁照射可以改善首次胸壁复发后的 5年PFS率(34.0%∶15.4%,P=0.004)。胸壁放疗剂量(≤60Gy∶>60Gy)对胸壁再复发率及PFS率无明显影响(P>0.05)。53例未手术患者胸壁瘤床剂量≤60Gy和>60Gy的 5年PFS率分别为9.1%和20.5%(P=0.061)。结论 乳腺癌根治术后ICWR患者局部放疗建议包括全胸壁照射+局部补量,复发灶剂量需加至60Gy,对未行手术切除者需>60Gy。ICWR患者仍有较高的胸壁再复发风险,需要探索更有效的治疗方法。     

64例髓母细胞瘤放疗的回顾性分析

目的分析髓母细胞瘤放疗疗效及预后影响因素,观察最常见的放疗副反应。方法回顾性分析接受放疗的髓母细胞瘤64例,年龄均≥4岁。术前中枢神经系统MRI检查无蛛网膜下腔播散迹象,属Chang’sM分期M0～M1期。所有病例均在外院接受了原发肿瘤的全切或次全切除手术。放疗先予全脑全脊髓照射30Gy,然后缩野至后颅窝局部加量20～25Gy,中位分次剂量为180cGy。结果所有病例均完成了放疗,全组3、5年总生存率分别为68.8%和55.7%,无病生存率分别为57.8%和51.4%,27例(42.2%)在3年内复发。通过分析年龄、性别、原发肿瘤大小、手术与放疗间隔时间对生存率影响发现,只有手术与放疗间隔时间有一定影响,手术与放疗间隔时间≤25、>25d的3年总生存率分别为81.5%、59.5%(P=0.110),3年无病生存率分别为74.1%、46.0%(P=0.030)。放疗中最常见的副反应主要为白细胞下降,92.2%的病例在治疗中出现了白细胞下降(<4.0×109/dl),其中2～3级的血液系统毒性占64.0%。结论髓母细胞瘤通过手术与放疗结合能取得较好疗效,但治疗失败率较高。手术与放疗间隔延长对总生存率和无病生存率均有影响,年龄、性别、原发肿瘤大小不是明显预后因素,放疗中最常见的副反应为血液毒性。     

Medulloblastoma and supratentorial primitive neuroectodermal tumors: an institutional experience.

BACKGROUND: To the authors' knowledge there are relatively few data concerning supratentorial primitive neuroectodermal tumors (PNET). The authors retrospectively reviewed all cases of PNET of the brain treated at the study institution to determine whether there was a difference in presentation, overall survival, and recurrence-free survival with regard to tumor location (supratentorium vs. posterior fossa). METHODS: Between 1977-1996 33 patients with PNET were diagnosed and treated at 1 radiotherapy center. The median age of the patients was 9 years. The location of the tumor was in the posterior fossa in 25 patients and the supratentorium in 8 patients. The tumor had spread to the neuraxis in six patients; four patients with disseminated neuraxis disease had a supratentorial PNET and two had a posterior fossa PNET. All but three patients received craniospinal irradiation. The primary tumor received > or = 5000 centigray in 27 patients and chemotherapy was employed in 26 patients. The median follow-up was 60 months. RESULTS: The 5-year overall and recurrence-free survival rates for all patients were 77.2% and 79.6%, respectively. The 5-year overall survival rates were 86.3% for patients with medulloblastoma (posterior fossa PNET) and 46.9% for patients with supratentorial PNET (P = 0.01, log rank test). For overall survival, prognostic factors included radiotherapy dose to the primary site, metastases (M) status, and location of the primary tumor. The 5-year recurrence free survival rates were 89.8% for patients with medulloblastoma and 46.9% for patients with supratentorial PNET (P = 0.003, log rank test). For recurrence free survival, prognostic factors included M status and primary tumor site location; radiation dose to the primary tumor site and patient gender were of borderline significance. In the ten patients with inadequate posterior fossa boost fields judged by Children's Cancer Group criteria, there were two failures, both of which were in the original tumor bed. CONCLUSIONS: Supratentorial PNET has a worse overall survival and recurrence free survival than medulloblastoma. There is a suggestion that radiotherapy boosts in medulloblastoma may not need to encompass the entire posterior fossa because posterior fossa failures primarily are in the tumor bed. Larger studies with longer follow-up are needed to determine whether craniospinal irradiation followed by a boost to the tumor bed is adequate for medulloblastoma patients.     

Treatment of children with medulloblastomas with reduced-dose craniospinal radiation therapy and adjuvant chemotherapy: A Children's Cancer Group Study.

PURPOSE: Medulloblastoma is the most common malignant brain tumor of childhood. After treatment with surgery and radiation therapy, approximately 60% of children with medulloblastoma are alive and free of progressive disease 5 years after diagnosis, but many have significant neurocognitive sequelae. This study was undertaken to determine the feasibility and efficacy of treating children with nondisseminated medulloblastoma with reduced-dose craniospinal radiotherapy plus adjuvant chemotherapy. PATIENTS AND METHODS: Over a 3-year period, 65 children between 3 and 10 years of age with nondisseminated medulloblastoma were treated with postoperative, reduced-dose craniospinal radiation therapy (23.4 Gy) and 55.8 Gy of local radiation therapy. Adjuvant vincristine chemotherapy was administered during radiotherapy, and lomustine, vincristine, and cisplatin chemotherapy was administered during and after radiation. RESULTS: Progression-free survival was 86% +/- 4% at 3 years and 79% +/- 7% at 5 years. Sites of relapse for the 14 patients who developed progressive disease included the local tumor site alone in two patients, local tumor site and disseminated disease in nine, and nonprimary sites in three. Brainstem involvement did not adversely affect outcome. Therapy was relatively well tolerated; however, the dose of cisplatin had to be modified in more than 50% of patients before the completion of treatment. One child died of pneumonitis and sepsis during treatment. CONCLUSION: These overall survival rates compare favorably to those obtained in studies using full-dose radiation therapy alone or radiation therapy plus chemotherapy. The results suggest that reduced-dose craniospinal radiation therapy and adjuvant chemotherapy during and after radiation is a feasible approach for children with nondisseminated medulloblastoma.     

Risk-adapted craniospinal radiotherapy followed by high-dose chemotherapy and stem-cell rescue in children with newly diagnosed medulloblastoma (St Jude Medulloblastoma-96): long-term results from a prospective, multicentre trial

BACKGROUND: Current treatment for medulloblastoma, which includes postoperative radiotherapy and 1 year of chemotherapy, does not cure many children with high-risk disease. We aimed to investigate the effectiveness of risk-adapted radiotherapy followed by a shortened period of dose-intense chemotherapy in children with medulloblastoma. METHODS: After resection, patients were classified as having average-risk medulloblastoma (< or = 1.5 cm2 residual tumour and no metastatic disease) or high-risk medulloblastoma (> 1.5 cm2 residual disease or metastatic disease localised to neuraxis) medulloblastoma. All patients received risk-adapted craniospinal radiotherapy (23.4 Gy for average-risk disease and 36.0-39.6 Gy for high-risk disease) followed by four cycles of cyclophosphamide-based, dose-intensive chemotherapy. Patients were assessed regularly for disease status and treatment side-effects. The primary endpoint was 5-year event-free survival; we also measured overall survival. This study is registered with ClinicalTrials.gov, number NCT00003211. FINDINGS: Of 134 children with medulloblastoma who underwent treatment (86 average-risk, 48 high-risk), 119 (89%) completed the planned protocol. No treatment-related deaths occurred. 5-year overall survival was 85% (95% CI 75-94) in patients in the average-risk group and 70% (54-84) in those in the high-risk group (p=0.04); 5-year event-free survival was 83% (73-93) and 70% (55-85), respectively (p=0.046). For the 116 patients whose histology was reviewed centrally, histological subtype correlated with 5-year event-free survival (p=0.04): 84% (74-95) for classic histology, 77% (49-100) for desmoplastic tumours, and 57% (33-80) for large-cell anaplastic tumours. INTERPRETATION: Risk-adapted radiotherapy followed by a shortened schedule of dose-intensive chemotherapy can be used to improve the outcome of patients with high-risk medulloblastoma.     

A pilot study of risk-adapted radiotherapy and chemotherapy in patients with supratentorial PNET

We undertook this study to estimate the event-free survival (EFS) of patients with newly diagnosed supratentorial primitive neuroectodermal tumor (SPNET) treated with risk-adapted craniospinal irradiation (CSI) with additional radiation to the primary tumor site and subsequent high-dose chemotherapy supported by stem cell rescue. Between 1996 and 2003, 16 patients with SPNET were enrolled. High-risk (HR) disease was differentiated from average-risk (AR) disease by the presence of residual tumor (M(0) and tumor size > 1.5 cm(2)) or disseminated disease in the neuraxis (M(1)-M(3)). Patients received risk-adapted CSI: those with AR disease received 23.4 Gy; those with HR disease, 36-39.6 Gy. The tumor bed received a total of 55.8 Gy. Subsequently, all patients received four cycles of high-dose cyclophosphamide, cisplatin, and vincristine with stem cell support. The median age at diagnosis was 7.9 years; eight patients were female. Seven patients had pineal PNET. Twelve patients are alive at a median follow-up of 5.4 years. The 5-year EFS and overall survival (OS) estimates for all patients were 68% +/- 14% and 73% +/- 13%. The 5-year EFS and OS estimates were 75% +/- 17% and 88% +/- 13%, respectively, for the eight patients with AR disease and 60% +/- 19% and 58% +/- 19%, respectively, for the eight with HR disease. No deaths were due to toxicity. High-dose cyclophosphamide-based chemotherapy with stem cell support after risk-adapted CSI results in excellent EFS estimates for patients with newly diagnosed AR SPNET. Further, this chemotherapy allows for a reduction in the dose of CSI used to treat AR SPNET without compromising EFS.     

Improving the therapeutic ratio of craniospinal irradiation in medulloblastoma

Radiation therapy delivered to the entire cerebrospinal axis is indicated for a number of pediatric brain tumors, especially medulloblastoma. Improved radiotherapy techniques have changed the near fatal prognosis for children with medulloblastoma to a 50%, 5-year survival. Nevertheless, the treatment results in substantial acute toxicity, and many survivors have serious sequelae. Further improvement in survival with optimal surgery and radiotherapy is not expected unless chemotherapy is added. Refinements in radiotherapy technique, however, can improve the therapeutic ratio of the treatment by lowering its side effects. In the last year children who required craniospinal irradiation at M. D. Anderson Hospital were treated with 6 MV photons to the brain and primary tumor and with 15-17 MeV electrons to the spinal canal. The elective dose to the whole brain was 30 Gy in 17 fractions and 30 Gy in 20 fractions to the spine. The primary tumor received an additional 20-25 Gy. An electron-beam dose distribution was drawn on a computerized tomography (CT) reconstructed sagittal plane. The electron energy was selected so that the 90% isodose line was at least 3 mm anterior to the cord after correction for bone heterogeneity. The treatment was well tolerated in the first five patients. It is projected that the current technique will cause fewer late effects and improve the tolerance to chemotherapy.