Pignol J P, Chauvel P, Paquis P, Courdi A, Iborra-Brassart N, Lonjon M, Lebrun-Frenay C, Frenay M, Grellier P, Chatel M, Hérault J, Bensadoun R J, Milano G, Nepveu F, Patau J P, Demard F, Breteau N
Centre Antoine-Lacassagne, Cyclotron Biomédical, Nice, France.
Bull Cancer Radiother. 1996;83 Suppl:201s-6s. doi: 10.1016/0924-4212(96)84913-9.
Neutron capture irradiation aims to selectively destroy tumor cells using 10B(n,alpha)7Li nuclear reactions produced within themselves. Following the capture reaction, an alpha particle and a, 7Li ion are emitted. Carrying an energy of 2.79 MeV, they destroy all molecular structures along their path close to 10 microns. These captures, used exclusively with a 'slow' neutron irradiation, provide a neutron capture therapy (BNCT). If they are used in addition to a fast neutron beam irradiation, they provide a neutron capture potentiation (NCP). The Centre Antoine-Lacassagne in Nice is actively involved in the European Demonstration Project for BNCT of grade IV glioblastomas (GBM) after surgical excision and BSH administration. Taking into account the preliminary results obtained in Japan, work on an 'epithermal' neutron target compatible with various cyclotron beams is in progress to facilitate further developments of this technique. For NCP, thermalized neutron yield has been measured in phantoms irradiated in the fast neutron beam of the biomedical cyclotron in Nice. A thermal peak appears after 5 cm depth in the tissues, delayed after the fast neutron peak at 1.8 cm depth. Thus, a physical overdosage of 10% may be obtained if 100 ppm of 10B are assumed in the tissues. Our results using CAL 58 GBM cell line demonstrate a dose modification factor (DMF) of 1.19 when 100 ppm of boric acid are added to the growth medium. Thus for the particles, issued from neutron capture, a biological efficiency at least twice that of fast neutrons can be derived. These results, compared with historical data on fast neutron irradiation of glioblastoma, suggest that a therapeutic window may be obtained for GBM.
中子俘获辐照旨在利用肿瘤细胞自身产生的¹⁰B(n,α)⁷Li核反应来选择性地破坏肿瘤细胞。俘获反应后，会发射出一个α粒子和一个⁷Li离子。它们携带2.79兆电子伏特的能量，能破坏其路径上近10微米范围内的所有分子结构。这些俘获反应仅在“慢”中子辐照时使用，可提供中子俘获疗法（BNCT）。如果将它们与快中子束辐照联合使用，则可提供中子俘获增强作用（NCP）。尼斯的安托万 - 拉卡萨涅中心积极参与了针对IV级胶质母细胞瘤（GBM）手术切除并给予硼酸钠硫醇（BSH）后进行BNCT的欧洲示范项目。考虑到在日本获得的初步结果，正在开展与各种回旋加速器束兼容的“超热”中子靶的研究工作，以促进该技术的进一步发展。对于NCP，已在尼斯生物医学回旋加速器的快中子束中辐照的体模中测量了热化中子产额。在组织深度5厘米处出现一个热峰，比深度1.8厘米处的快中子峰延迟出现。因此，如果假设组织中¹⁰B的含量为100 ppm，则可能会出现10%的物理过量剂量。我们使用CAL 58 GBM细胞系的结果表明，当向生长培养基中添加100 ppm硼酸时，剂量修正因子（DMF）为1.19。因此，对于中子俘获产生的粒子，其生物学效率至少是快中子的两倍。这些结果与胶质母细胞瘤快中子辐照的历史数据相比，表明可能为GBM获得一个治疗窗口。
