Richter M P, Laramore G E, Griffin T W, Goodman R L
Cancer. 1984 Dec 1;54(11 Suppl):2814-22. doi: 10.1002/1097-0142(19841201)54:2+<2814::aid-cncr2820541429>3.0.co;2-g.
Based on laboratory investigations, high linear energy transfer (LET) particle irradiation is capable of more efficient cell kill than that associated with conventional or low LET irradiation. The advantages of high LET irradiation include: (1) a greater ability to damage hypoxic cells; (2) a lesser ability for repair of sublethal and potentially lethal radiation-induced damage; (3) less variation in radiation sensitivity relative to the cell cycle; and (4) a greater ability to deposit the radiation dose in the region of the tumor as opposed to the normal surrounding tissue (neutrons do not have this advantage compared to other particle therapy). Despite these laboratory advantages, it has been difficult to demonstrate any advantage of high LET irradiation in the clinic. A number of new developments have occurred to test the role of high LET: (1) sophisticated technology to enable treatment delivery with higher dose rate and improved depth dose; (2) the construction of hospital-based facilities; and (3) the development of randomized studies involving diseases in which the risk of early metastasis is minimized. It is hoped that careful study in the clinic over the next decade will elucidate the role of high LET particle therapy.
基于实验室研究，高传能线密度（LET）粒子照射比传统或低LET照射更能有效地杀伤细胞。高LET照射的优势包括：（1）对缺氧细胞的损伤能力更强；（2）对亚致死性和潜在致死性辐射损伤的修复能力较弱；（3）相对于细胞周期，辐射敏感性的变化较小；（4）与周围正常组织相比，在肿瘤区域沉积辐射剂量的能力更强（与其他粒子治疗相比，中子不具有此优势）。尽管有这些实验室优势，但在临床上很难证明高LET照射有任何优势。为了测试高LET的作用，出现了一些新进展：（1）能够以更高剂量率和改善深度剂量进行治疗的先进技术；（2）基于医院的设施建设；（3）开展涉及早期转移风险最小化疾病的随机研究。希望在未来十年在临床上进行的仔细研究将阐明高LET粒子治疗的作用。
