Wenz F, Lohr F, Peschke P, Wolber G, Höver K H, Hahn E W
Forschungsschwerpunkt Radiologische Diagnostik und Therapie, Deutsches Krebsforschungszentrum, Heidelberg.
Strahlenther Onkol. 1993 Jul;169(7):412-7.
Human prostate tumors are known to be good candidates for neutron therapy. The Dunning rat prostate tumor system R3327 was found in many studies to be an excellent model for human prostate tumors. There is still a paucity of studies on the response of the Dunning tumors to fast neutrons. Tumors of the R3327-HI subline are moderately well differentiated and mucin producing. They show one euploid cell population, a bromodeoxyuridine labelling index of 5%, a potential doubling time of 8.9 days, a volume doubling time of about ten days and a cell loss rate of 10%. Tumors were transplanted s.c. in the distal thigh of Copenhagen rats and treated with 60Co-photons (10, 20, 30, 40 Gy, 45 cGy/min) and 14-MeV-neutrons (8, 10, 12 Gy, 7 to 11 cGy/min). Tumor volumes were measured twice weekly. Growth delay was defined as time in days until the tumors reached twice their treatment volume. Linear regressions on the median growth delays of the different treatment groups were calculated. The ratio of the neutron- and photon-slopes yielded an RBE of 3.1 +/- 0.3. Additionally isoeffect-RBE values between 2.3 and 2.6 were graphically estimated.
已知人类前列腺肿瘤是中子治疗的良好候选对象。在许多研究中发现，邓宁大鼠前列腺肿瘤系统R3327是人类前列腺肿瘤的优秀模型。关于邓宁肿瘤对快中子反应的研究仍然很少。R3327-HI亚系的肿瘤分化程度中等，能产生粘蛋白。它们显示出一个整倍体细胞群，溴脱氧尿苷标记指数为5%，潜在倍增时间为8.9天，体积倍增时间约为10天，细胞丢失率为10%。将肿瘤移植到哥本哈根大鼠大腿远端的皮下，并用60Co光子（10、20、30、40 Gy，45 cGy/分钟）和14-MeV中子（8、10、12 Gy，7至11 cGy/分钟）进行治疗。每周测量两次肿瘤体积。生长延迟定义为肿瘤达到其治疗体积两倍所需的天数。计算了不同治疗组中位生长延迟的线性回归。中子斜率与光子斜率的比值得出的相对生物效应（RBE）为3.1±0.3。此外，通过图形估计得出等效应RBE值在2.3至2.6之间。
