Brain metastases

Opinion statement Metastatic tumors to the brain are an increasing cause of morbidity and mortality in patients with systemic cancers. Many new therapies used to treat systemic cancers do not penetrate the central nervous system (CNS) and do not protect patients from the development of brain metastases. Surgery, radiosurgery, and radiation therapy are all used to treat brain metastases. It is in our opinion a mistake to use only one or two of these modalities to the exclusion of other(s). The role of systemic chemotherapy is still limited, due to both the issues of drug delivery caused by the blood brain barrier and to the relative resistance of many of these tumors to chemotherapy. Traditionally, brain metastases have been grouped together regardless of the origin of the tumor and have been treated with a single algorithm. As we encounter more patients for whom treatment of the brain metastases is an important determinant of survival, we must tailor our treatment strategies to individual tumor types. Also, we must recognize differences in each tumor’s sensitivity to chemotherapy and radiotherapy and differences in their biology.     

Brain metastases

The topic of brain metastases has recently become a popular subject for review. The reasons for this most likely include technical advances in therapy, notably radiosurgery, as well as recently-published reports of phase III studies, which have addressed certain aspects of management, notably the combination of surgery and radiotherapy in the treatment of patients with a single metastasis. The main purpose of treatment is to reverse the patient's neurological deficits and prolong life. Nevertheless, opinions remain divided on whether meaningful clinical progress has been achieved overall. A clinician working in a tertiary referral center offering radiosurgery for a selected group of favorable patients may believe that the therapeutic nihilism of the past is no longer warranted, whereas another, whose experience is based on the management of patients dying from metastatic lung cancer, may still question the value of active treatment. The purpose of this review will be to try to reconcile these opinions by providing a critical analysis of the available evidence, identify current problems in management, and suggest future directions for clinical investigation.     

Brain tumors

Brain tumors generally arise as the culmination of a multistep process that involves a variety of genetic abnormalities. Theoretically, replacement of abnormal genes with normal genes is essential to brain tumor treatment. However, it is very difficult to replace all damaged genes. Currently, most clinical protocols for gene therapy in brain tumors include transfer of a gene which can induce tumor cells to die or which can enhance the environment to generate a systemic immune response against the tumor. The former strategy includes suicide gene therapies, tumor suppressor gene therapy and oncolytic virus therapy. The latter adopts immunogene therapy. In this report, we also focus on other gene therapies, such as therapies to control the cell cycle or apoptosis, and promote antiangiogenesis. Gene therapy is generally accepted to be rather safe in recent years. In fact, the current single-gene therapies for brain tumor are limited and probably restricted to a few tumors. Several agents with different mechanisms of action would be necessary to kill heterogenously mixed tumor cells. Further molecular techniques and basic studies may overcome the malignancy of cancers.     

Brain metastases

Opinion statement Brain metastases are an increasingly common complication in patients with systemic cancer. The optimal treatment for each patient depends on careful evaluation of several factors: the location, size, and number of brain metastases; the patient's age, general condition, and neurologic status; and the extent of systemic cancer to name a few. For patients with a single brain metastasis and limited systemic disease, the standard treatment is surgical resection followed by whole brain radiation therapy. In patients with a small, single metastasis, stereotactic radiosurgery is probably comparable to surgery. Patients with several metastases (up to three) and controlled systemic disease can be treated with whole-brain radiation and stereotactic radiosurgery. Patients with multiple metastases (more than three) are generally treated with whole-brain radiation alone. Radiosurgery is effective in treating patients with a limited number of recurrent brain metastases and stable systemic diseases. Surgery may have a role in patients with a large symptomatic recurrent lesion producing mass effect. Reirradiation and chemotherapy may have a limited role in patients with multiple recurrent metastases.     

脑瘤的组胺研究及其临床意义

报告36份脑瘤组织的组胺测定结果,其中包括低恶度及高恶度星形细胞瘤22份,不同亚型脑膜瘤14份;并以10份正常脑组织为对照.结果发现脑瘤组织的组胺含量显著增高,其增高水平与肿瘤的恶性程度明显相关;故认为脑瘤组织的组胺可以作为评估肿瘤恶性程度的生化标志物,而且也为今后进一步研究H_2受体阻断剂治疗脑瘤提供线索及实验依据.     

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 10 0X刀系统加全脑放疗共治疗 40例脑转移瘤患者。 2 9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 2 8例 ,处方剂量 16～ 2 2Gy ,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 2 0～ 30Gy ,平均 2 5 4Gy。全组 40例均获 3～ 2 6个月的随访 ,中位 12个月。 40例患者生存期为 2～ 2 6个月 ,中位 11.5个月 ,其中 36例生存期超过 6个月 ,占 90 % ,2 7例超过 12个月 ,占 67.5 %。 2例超过 2 6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 2 6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。     

Primary Brain Lymphoma

The broad spectrum of C.T. findings in a group of 15 patients with primary brain lymphoma are reviewed. An attempt has been made to emphasize the more typical lesion characteristics, including location, definition, multiplicity and attenuation, both prior to and following contrast administration. Clinical presentation, changing C.T. appearances following radiotherapy and ultimate prognosis are briefly described. Differential diagnoses and their significance for management are discussed.     

放射性脑损伤

放射性脑损伤是放射治疗的严重并发症之一。综述了放射性脑损伤的研究进展 ,分析了放射性脑损伤产生的原因、临床表现、影像学表现及治疗进展。     

Brain metastasis in hypernephroma

Of 926 patients with hypernephroma, 36 (3.9%) had metastasis to the brain. The median age at presentation was 61 years (range, 34 to 82). Nineteen patients had a single lesion metastatic to the brain, and 16 of these lesions were supratentorial. In 28% of the patients, computed tomography showed hyperdense lesions before contrast material was injected. All patients, except 2 with incomplete records, had evidence of widespread disease involving bone, liver, or lung. The median time interval between the initial diagnosis and the discovery of brain metastasis was 65.5 weeks (range, 0 to 462), with only 2 patients initially presenting with brain metastasis. Twenty-five of the patients who received only radiation therapy had a median survival of 13 weeks (range, 4 to 146), while 7 selected patients who underwent surgical resection and postoperative radiation had a median survival of 66 weeks (range, 18 to 260). In 5 of the 7 patients, scans demonstrated recurrent tumor from 6 to 23 weeks postoperatively. One patient had a pronounced reduction in the size of the tumor after radiation therapy only. This study shows that brain metastasis is usually a late complication of hypernephroma and is associated with a poor prognosis.Abstract published in Proceedings of American Society of Clinical Oncology 3:158, 1984.     

X线立体定向放射治疗与全脑放射治疗脑转移瘤的疗效比较

目的 评价X线立体定向放射治疗脑转移瘤的疗效。方法 单纯全脑照射20例（WBI组），单纯X线立体定向放射治疗19例（SRI组），X线立体定向放射加全脑放射治疗39例（SRT＋WBI组）。WBI组和SRT＋WBI组全脑放疗总剂量均为30－40Gy／2－4周。SRT组和SRT＋WBI组立体定向放射治疗，每次剂量为4．5－7．5Gy，每周3次，总剂量21－42Gy。结果 局部控制率、局部复发率和因脑转移所致率，WBI组分别为65．0％、25．0％和52．9％；SRT组分别为94．7％、5．3％和116．7％；SRT＋WBI组分别为89．75、0和8．7％。WBI组与其它2组比较，局部控制率、局部复发率和因脑转移所致死亡率均有显著性差异（P＜0．05）。结论 X线立体定向放射治疗脑转移瘤，在提高局部控制率、降低局复发率方面优于全脑放疗。     

VEGF in Brain Tumors

Vascular endothelial growth factor (VEGF) is a regulator of angiogenesis, vasculogenesis and vascular permeability. In this contribution, molecular and biological properties of VEGF are described. Furthermore, this article focuses on the evidence that angiogenesis in brain tumors is mediated by VEGF. Among the topics discussed are expression patterns of VEGF and its receptors in different brain tumors, possible regulatory mechanism involved in the VEGF-driven tumor angiogenesis and the involvement of VEGF in the genesis of peritumoral edema. Finally, anti-angiogenesis approaches to target VEGF/VEGF receptors are discussed.     

Brain metastasis radiotherapy]

Brain metastases are an important cause of mortality and morbidity. The prognosis is poor with a median survival of less than one year in the majority of cases. From this review, whole-brain irradiation clearly appears as the standard treatment. However, its role could be discussed according to newer treatment modalities, radiosurgery or new chemotherapies. Post irradiation neurocognitive status remains insufficiently known.