4月17日，据《美国医学会杂志》（JAMA）发表的对3种非转移性前列腺癌放疗方法的比较研究结果，虽然调强放疗(IMRT)比适形放疗(CRT)可导致较多患者出现勃起功能障碍，但仍支持IMRT广泛用于前列腺癌治疗。与IMRT相比，费用最高的最新质子治疗方法会产生较多的胃肠道副作用，且未见疗效优势。
费用较高但靶向性更佳的IMRT已经逐渐替代CRT，其应用率从2000年的0.15%增至2008年的95.9%。然而，IMRT正面临着备受关注且治疗费用更高的质子治疗的竞争。自2007年以来，多家质子治疗中心相继成立，直接面向消费者的广告在很大程度上促进了该治疗方法的应用。但迄今尚没有对这些治疗方法进行有效性比较研究。
为此，北卡罗来纳大学教堂山分校的Nathan C. Sheets博士及其同事应用倾向得分方法分析了美国监测、流行病学和最终结果(SEER)数据库登记的12,976例确诊男性前列腺癌患者资料。他们均在2002~2006年接受治疗，其中6,666例为IMRT，6,310例为CRT。研究者发现，IMRT治疗患者接受附加癌症治疗的比例较CRT治疗患者约低20%，绝对风险为2.5 vs. 3.1/100(人·年)(P<0.001)。IMRT治疗患者胃肠道疾病和髋骨骨折确诊病例明显较少，绝对风险分别为13.4 vs. 14.7/100(人·年)和0.8 vs. 1.0/100(人·年)，但勃起功能障碍风险较高，绝对风险为5.9 vs. 5.3/100(人·年)。此外，对1,368例IMRT或质子治疗患者进行的小规模倾向得分匹配比较分析结果显示，IMRT治疗患者胃肠道发病率较低，绝对风险为12.2 vs. 17.8/100(人·年)，但疗效未见组间差异。
该项以人群为基础的研究表明，IMRT相对于CRT而言，能够改善疾病控制程度且没有增加副作用风险；但最近日益广泛用于前列腺癌治疗的质子治疗则没有显示出额外益处。
Sheets博士在2月份由美国临床肿瘤学会、美国放射肿瘤学学会和泌尿肿瘤学学会联合主办的生殖泌尿肿瘤研讨会上报告了上述结果。该研究结果以及另外一项针对体外放射治疗、前列腺切除术和近距离放疗的比较研究引发了有关新技术成本效益的讨论。
该研究由美国医疗保健研究与质量局(AHRQ)资助，论文发表得到国立护理研究所(NINR)资助。2位共同作者报告与制药公司存在利益关系。（生物谷Bioon.com）
doi:10.1001/jama.2012.460
PMC:
PMID:
Intensity-Modulated Radiation Therapy, Proton Therapy, or Conformal Radiation Therapy and Morbidity and Disease Control in Localized Prostate Cancer
Nathan C. Sheets, MD; Gregg H. Goldin, MD; Anne-Marie Meyer, PhD; Yang Wu, PhD; YunKyung Chang, PhD; Til Stürmer, MD, PhD; Jordan A. Holmes, BS; Bryce B. Reeve, PhD; Paul A. Godley, MD, PhD; William R. Carpenter, PhD; Ronald C. Chen, MD, MPH
Context There has been rapid adoption of newer radiation treatments such as intensity-modulated radiation therapy (IMRT) and proton therapy despite greater cost and limited demonstrated benefit compared with previous technologies.
Objective To determine the comparative morbidity and disease control of IMRT, proton therapy, and conformal radiation therapy for primary prostate cancer treatment.
Design, Setting, and Patients Population-based study using Surveillance, Epidemiology, and End Results–Medicare-linked data from 2000 through 2009 for patients with nonmetastatic prostate cancer.
Main Outcome Measures Rates of gastrointestinal and urinary morbidity, erectile dysfunction, hip fractures, and additional cancer therapy.
Results Use of IMRT vs conformal radiation therapy increased from 0.15% in 2000 to 95.9% in 2008. In propensity score–adjusted analyses (N = 12 976), men who received IMRT vs conformal radiation therapy were less likely to receive a diagnosis of gastrointestinal morbidities (absolute risk, 13.4 vs 14.7 per 100 person-years; relative risk [RR], 0.91; 95% CI, 0.86-0.96) and hip fractures (absolute risk, 0.8 vs 1.0 per 100 person-years; RR, 0.78; 95% CI, 0.65-0.93) but more likely to receive a diagnosis of erectile dysfunction (absolute risk, 5.9 vs 5.3 per 100 person-years; RR, 1.12; 95% CI, 1.03-1.20). Intensity-modulated radiation therapy patients were less likely to receive additional cancer therapy (absolute risk, 2.5 vs 3.1 per 100 person-years; RR, 0.81; 95% CI, 0.73-0.89). In a propensity score–matched comparison between IMRT and proton therapy (n = 1368), IMRT patients had a lower rate of gastrointestinal morbidity (absolute risk, 12.2 vs 17.8 per 100 person-years; RR, 0.66; 95% CI, 0.55-0.79). There were no significant differences in rates of other morbidities or additional therapies between IMRT and proton therapy.
Conclusions Among patients with nonmetastatic prostate cancer, the use of IMRT compared with conformal radiation therapy was associated with less gastrointestinal morbidity and fewer hip fractures but more erectile dysfunction; IMRT compared with proton therapy was associated with less gastrointestinal morbidity.
