von Essen C F, Bagshaw M A, Bush S E, Smith A R, Kligerman M M
Int J Radiat Oncol Biol Phys. 1987 Sep;13(9):1389-98. doi: 10.1016/0360-3016(87)90235-5.
Two hundred twenty-eight patients were treated at the Los Alamos Meson Physics Facility (LAMPF) with negative pi-mesons (pions) between 1974 and 1981. Of these, 19 patients with metastatic disease were treated in pilot studies. Following the clinical determination of relative biological effectiveness (RBE) of pions, 209 patients were treated in site and dose searching studies beginning in 1977. Advanced but regionally localized cancers that were considered poorly responsive to conventional therapy were selected for treatment. A wide range of treatment fractions (22 to 45) and of total dose (1800 to 4200 cGy at the 80% isodose level) to the prescribed target volumes was explored. A follow-up observation period of between 4.5 and 9 years has been completed. The analysis focuses on 129 patients receiving pion therapy alone. Thirty-six (28%) had persisting local tumor control of which 12 (9%) suffered complications of treatment. The results varied among treatment sites, for example: prostate cancer, 18/21 (86%) locally controlled, 6/21 (29%) complications; head and neck, 8/31 (26%) locally controlled, 1/31 (3%) complications; and pancreas, none controlled and no complications. Analysis of dose-fraction response suggests a steep rising curve of complications beyond the dose level of 3750 cGy minimum, 4700 cGy maximum, in 38 fractions. The tumor control response has a broader and ill-defined curve possibly due to the heterogeneity of tumor types. The RBE for late effects in normal tissues appeared to be higher than that for acute effects although the mixture of tumor types, sites, dose, and fractionation made this estimate highly uncertain. No late secondary neoplastic changes in pion irradiated tissues were seen. It is concluded that pions can locally ablate some advanced cancers, often without significant sequelae, but that the optimum therapeutic range is critical. The Los Alamos data may be of use to ongoing pion studies in Canada and Switzerland.
1974年至1981年间，228名患者在洛斯阿拉莫斯介子物理设施（LAMPF）接受了负π介子（π介子）治疗。其中，19名患有转移性疾病的患者在试点研究中接受了治疗。在临床确定π介子的相对生物效应（RBE）后，从1977年开始，209名患者接受了局部和剂量探索性研究。选择了对传统治疗反应不佳的晚期但局部局限的癌症进行治疗。探索了对规定靶体积的广泛治疗分次（22至45次）和总剂量（80%等剂量水平下为1800至4200 cGy）。已完成4.5至9年的随访观察期。分析集中在129名单独接受π介子治疗的患者。36名（28%）患者实现了局部肿瘤持续控制，其中12名（9%）出现了治疗并发症。结果在不同治疗部位有所不同，例如：前列腺癌，18/21（86%）实现局部控制，6/21（29%）出现并发症；头颈癌，8/31（26%）实现局部控制，1/31（3%）出现并发症；胰腺癌，无一例实现控制且无并发症。剂量分次反应分析表明，在38次分次中，当剂量水平低于3750 cGy（最小值）至4700 cGy（最大值）时，并发症曲线急剧上升。肿瘤控制反应曲线更宽且定义不明确，这可能是由于肿瘤类型的异质性所致。尽管肿瘤类型、部位、剂量和分次的组合使这一估计高度不确定，但正常组织晚期效应的RBE似乎高于急性效应。在接受π介子照射的组织中未观察到晚期继发性肿瘤变化。得出的结论是，π介子可以局部消融一些晚期癌症，通常不会产生明显后遗症，但最佳治疗范围至关重要。洛斯阿拉莫斯的数据可能对加拿大和瑞士正在进行的π介子研究有用。
