Department of Radiation Oncology, University of Florida, Gainesville, Florida, USA.
Acta Oncol. 2013 Apr;52(3):492-7. doi: 10.3109/0284186X.2013.767983.
To investigate post-treatment changes in serum testosterone in low- and intermediate-risk prostate cancer patients treated with hypofractionated passively scattered proton radiotherapy.
Between April 2008 and October 2011, 228 patients with low- and intermediate-risk prostate cancer were enrolled into an institutional review board-approved prospective protocol. Patients received doses ranging from 70 Cobalt Gray Equivalent (CGE) to 72.5 CGE at 2.5 CGE per fraction using passively scattered protons. Three patients were excluded for receiving androgen deprivation therapy (n = 2) or testosterone supplementation (n = 1) before radiation. Of the remaining 226 patients, pretreatment serum testosterone levels were available for 217. Of these patients, post-treatment serum testosterone levels were available for 207 in the final week of treatment, 165 at the six-month follow-up, and 116 at the 12-month follow-up. The post-treatment testosterone levels were compared with the pretreatment levels using Wilcoxon's signed-rank test for matched pairs.
The median pretreatment serum testosterone level was 367.7 ng/dl (12.8 nmol/l). The median changes in post-treatment testosterone value were as follows: +3.0 ng/dl (+0.1 nmol/l) at treatment completion; +6.0 ng/dl (+0.2 nmol/l) at six months after treatment; and +5.0 ng/dl (0.2 nmol/l) at 12 months after treatment. None of these changes were statistically significant.
Patients with low- and intermediate-risk prostate cancer treated with hypofractionated passively scattered proton radiotherapy do not experience testosterone suppression. Our findings are consistent with physical measurements demonstrating that proton radiotherapy is associated with less scatter radiation exposure to tissues beyond the beam paths compared with intensity-modulated photon radiotherapy.
研究低危和中危前列腺癌患者接受低分割被动散射质子放射治疗后血清睾酮的治疗后变化。
2008 年 4 月至 2011 年 10 月，228 例低危和中危前列腺癌患者入组机构审查委员会批准的前瞻性方案。患者接受的剂量范围为 70 钴当量（CGE）至 72.5 CGE，每次 2.5 CGE，采用被动散射质子。3 例因接受雄激素剥夺治疗（n = 2）或睾酮补充治疗（n = 1）而在放疗前被排除在外。在 226 例患者中，有 217 例患者的治疗前血清睾酮水平可用于分析。在这些患者中，207 例在治疗结束的最后一周，165 例在治疗后 6 个月，116 例在治疗后 12 个月可获得治疗后血清睾酮水平。采用配对符号秩检验比较治疗后与治疗前的睾酮水平。
中位治疗前血清睾酮水平为 367.7ng/dl（12.8nmol/l）。治疗后睾酮值的中位数变化如下：治疗结束时+3.0ng/dl（+0.1nmol/l）；治疗后 6 个月+6.0ng/dl（+0.2nmol/l）；治疗后 12 个月+5.0ng/dl（0.2nmol/l）。这些变化均无统计学意义。
接受低分割被动散射质子放射治疗的低危和中危前列腺癌患者不会出现睾酮抑制。我们的研究结果与物理测量结果一致，表明与强度调制光子放射治疗相比，质子放射治疗与射线束路径以外的组织散射辐射暴露量较少有关。
