Controversies concerning the application of brachytherapy in central nervous system tumors.
BACKGROUND
Brachytherapy (BRT) is defined as a therapy technique where a radioactive source is placed a short distance from or within the tumor being treated. Much expectation has been placed on its efficacy to improve the outcome for patients with central nervous system (CNS) tumors due to the initial promising results from single institution retrospective studies. However, these optimistic findings have been highly debated since the selection criteria itself is preferable to other therapeutic modalities. The fact that BRT demonstrated no significant survival advantage in two prospective studies, together with the emerging role of stereotactic convergence therapy as a promising alternative, has further decreased the enthusiasm for BRT. Despite all the negative aspects, BRT continues to be conducted for the management of CNS tumors including gliomas, meningiomas and brain metastases.


METHODS
As many controversies have been aroused concerning the experience and future application of BRT, this article reviews the existing heterogeneities in terms of implants choice, optimal dose rate, targeting volume, timing of BRT, patients selection, substantial efficacy, BRT in comparison with stereotactic convergence therapy techniques and BRT in combination with other treatment modalities (data were identified by Pubmed searches).


CONCLUSIONS
Though it is inconvincible to argue for the routine use of BRT, BRT may provide a choice for patients with large recurrent or inoperable deep-seated tumors, especially with the Glia-site technique. Radiotherapies including BRT may hold more promise if biologic mechanisms of radiation could be better understand and biologic modifications could be added in clinical trials.
Liu
Bo-Lin
BL
Department of Neurosurgery, Xijing Institute of Clinical Neuroscience, Xijing Hospital, Fourth Military Medical University, West Changle Road, Shaanxi Province, People's Republic of China.
Cheng
Jin-Xiang
JX
Zhang
Xiang
X
Zhang
Wei
W
D001254:Astrocytoma / Q000532:radiotherapy; D001918:Brachytherapy / Q000009:adverse effects; D001932:Brain Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D015986:Confounding Factors, Epidemiologic; D019583:Dose Fractionation, Radiation; D004307:Dose-Response Relationship, Radiation; D005909:Glioblastoma / Q000532:radiotherapy; D006801:Humans; D009837:Oligodendroglioma / Q000532:radiotherapy; D011868:Radioisotopes / Q000627:therapeutic use*; D016634:Radiosurgery; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D015983:Selection Bias; D013997:Time Factors; D016896:Treatment Outcome
D011868:Radioisotopes