放疗在低负荷转移性前列腺癌中的应用价值

目的 探讨不同放疗方法在低负荷转移性前列腺癌（LBMP）中的应用价值。 方法 回顾性分析2009年11月至2015年11月于解放军联勤保障部队第九〇〇医院经组织病理学检查诊断为LBMP的91例男性患者的临床资料，年龄53~72(67.4±4.5)岁。所有患者均接受标准的全雄激素阻断内分泌治疗，其中52例患者接受单纯前列腺直接放疗（PODT组），39例患者接受前列腺联合转移灶放疗（PMRT组）。PODT组患者的放疗靶区为前列腺和双侧精囊，即计划靶区体积（PTV），其处方总剂量为62.5 Gy（2.5 Gy/次，1次/d，25次/5周）；PMRT组患者的放疗靶区为PTV+淋巴结计划大体肿瘤体积（PGTV_nd）+椎体转移灶计划大体肿瘤体积（PGTV_m），其中，PGTV_nd处方总剂量为55 Gy（2.2 Gy/次，1次/d，25次/5周）；PGTV_m处方总剂量为45 Gy（1.8 Gy/次，1次/d，25次/5周）。采用独立样本t检验比较组间肿瘤照射体积、危及器官的照射剂量；采用扩展性前列腺癌复合指数（EPIC）量表和肿瘤放疗协作组（RTOG）标准评价2组患者各个随访时间点的生存质量和急性放射损伤；采用Mann-Whitney U秩和检验比较2组患者的生存质量，采用卡方检验比较急性放射损伤；生存分析采用Kaplan-Meier法，并行Log-rank χ2检验。 结果 PODT组总的照射体积为(264.52±86.37) cm3，显著低于PMRT组的(418.47±63.64) cm3，2组间的差异有统计学意义（t=1.362, P<0.05）。PODT组危及器官（直肠、膀胱、左侧股骨头和右侧股骨头）的照射剂量均显著低于PMRT组（t=2.01~4.78，均P<0.05）。PODT组在放疗结束当天、放疗后3个月、放疗后6个月的泌尿系统功能评分均显著高于PMRT组（Z=4.467、5.726、7.984，均 P<0.05）；PODT组在放疗结束当天、放疗后3个月、放疗后24个月的肠道功能评分均显著高于PMRT组（Z=3.826、5.693、7.874，均 P<0.05）；PMRT组的性功能评分在放疗后3个月及以后的各个随访时间点均高于PODT组（Z=2.381~9.872，均P<0.05）。PODT组和PMRT组的5年总生存（OS）率和前列腺癌特异性生存（PCSS）率的差异均无统计学意义（χ2=4.62、3.07，均P>0.05）。PODT组的5年无生化失败期间（IBF）率低于PMRT组（4.2%对14.9%），2组间的差异有统计学意义（χ2=7.68，P=0.03）。PMRT组患者白细胞、血小板计数和血红蛋白水平减少、下降的发生率均显著高于PODT组（χ2=6.09、3.12、7.58，均P<0.05）；其呕吐的发生率也显著高于PODT组（48.7%对19.2%，χ2=8.93，P<0.05）。 结论 LBMP患者接受PMRT可提高IBF时间，但无法延长PCSS和OS时间，且增加了辐射损伤的发生率。

Application of radiotherapy in low burden metastatic prostate cancer

Objective To investigate the application value of different radiotherapy modes in patients with low burden metastatic prostate cancer (LBMP). Methods The clinical data of 91 patients diagnosed with LBMP in the 900th Hospital of the Joint Logistics Support Force of PLA from November 2009 to November 2015 were retrospectively analyzed. The average age was 53–72 (67.4±4.5) years. All patients received standard maxim androgen blockade, and 52 of them received prostate-only directed radiation therapy (PODT group), whereas 39 received prostate and metastatic radiation therapy (PMRT group). The target delineation range was prostate and bilateral seminal vesicles in the PODT group, and the total dose of the planning target volume (PTV) was 62.5 Gy (2.5 Gy per fraction, once per day, 25 fractions per 5 weeks). The target delineation range in the PMRT group was PTV combined with lymph node planning gross tumor volume (PGTV_nd) and metastatic planning gross tumor volume (PGTV_m). The total dose of PGTV_nd was 55 Gy (2.2 Gy per fraction, once per day, 25 fractions per 5 weeks). The total dose of PGTV_m was 45 Gy (1.8 Gy per fraction, once per day, 25 fractions per 5 weeks). Differences in tumor radiation volume and radiation dose to organs at risk between the groups was determined with independent sample t-test. The Expanded Prostate Cancer Index Composite and Radiation Therapy Oncology Group standards were used in evaluating the quality of life and acute radiation injury. The Mann-Whitney U rank sum test was used in comparing the two groups in terms of quality of life at various follow-up time points after radiotherapy. Acute radiation injury was compared with the chi-square test, and the Kaplan-Meier method was used for survival analysis, Log-rank χ2 test was used. Results The total radiation volume of the PODT group was (264.52±86.37) cm3, which was significantly lower than that of the PMRT group (418.47±63.64) cm3 (t=1.362, P<0.05). The radiation dose of organs at risk (rectum, bladder, left femoral head, and right femoral head) in the PODT group were significantly lower than those in the PMRT group (t=2.01–4.78, all P<0.05). The scores of urinary system function in the PODT group 1 day, 3 months, and 6 months after radiotherapy were significantly higher than those in the PMRT group (Z=4.467, 5.726, 7.984; all P<0.05). The scores of intestinal system function in the PODT group were significantly higher than those in the PMRT group (Z=3.826, 5.693, 7.874; all P<0.05). The sexual function score of the PMRT group was higher than that of the PODT group at each follow-up point 3 months after radiotherapy (Z=2.381–9.872, all P<0.05). No significant differences in five-year overall survival rate and prostate cancer specific survival rate were found between the groups (χ2=4.62, 3.07; both P>0.05). The PODT group had a lower five-year interval to biochemical failure (IBF) rate than the PMRT group (4.2% vs. 14.9%), and the difference was significant (χ2=7.68, P=0.03). The incidence rates of leukopenia, thrombocytopenia, and hemoglobin decline in the PMRT group were significantly higher than those in the PODT group (χ2=6.09, 3.12, 7.58; all P<0.05). The results were consistent with the incidence of vomiting (χ2=8.93, P<0.05). Conclusions Compared with patients who received PODT, patients who received PMRT showed increased IBF time but did not show increases in PCSS and OS time. The incidence of radiation injury increased in the PMRT group.