Zelefsky Michael J, Chan Heather, Hunt Margie, Yamada Yoshiya, Shippy Alison M, Amols Howard
Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
J Urol. 2006 Oct;176(4 Pt 1):1415-9. doi: 10.1016/j.juro.2006.06.002.
We report on the long-term results and late toxicity outcomes of high dose intensity modulated radiation therapy for patients with clinically localized prostate cancer.
Between 1996 and 2000 a total of 561 patients with clinically localized prostate cancer were treated with intensity modulated radiation therapy. All patients were treated to a dose of 81 Gy prescribed to the planning target volume. Prostate specific antigen relapse was defined according to the American Society for Therapeutic Radiology and Oncology consensus and Houston definitions (absolute nadir plus 2 ng/ml dated at the call). Median followup was 7 years (range 5 to 9).
The 8-year actuarial PSA relapse-free survival rates for patients in favorable, intermediate and unfavorable risk groups according to the American Society for Therapeutic Radiology and Oncology definition were 85%, 76% and 72%, respectively (p <0.025). The 8-year actuarial prostate specific antigen relapse-free survival rates for patients in favorable, intermediate and unfavorable risk groups according to the Houston definition were 89%, 78% and 67%, respectively (p = 0.0004). The 8-year actuarial likelihood of grade 2 rectal bleeding was 1.6%. Three patients (0.1%) experienced grade 3 rectal toxicity requiring either 1 or more transfusions or a laser cauterization procedure. No grade 4 rectal complications have been observed. The 8-year likelihood of late grade 2 and 3 (urethral strictures) urinary toxicities were 9% and 3%, respectively. Among patients who were potent before intensity modulated radiation therapy, erectile dysfunction developed in 49%. The cause specific survival outcomes for favorable, intermediate and unfavorable risk cases were 100%, 96% and 84%, respectively.
These long-term results confirm our previous observations regarding the safety of high dose intensity modulated radiation therapy for clinically localized prostate cancer. Despite the application of high radiation doses, the incidence of rectal bleeding at 8 years was less than 2%. Despite the increased conformality of the dose distribution associated with intensity modulated radiation therapy, excellent long-term tumor control outcomes were achieved.
我们报告了高剂量调强放射治疗临床局限性前列腺癌患者的长期结果和晚期毒性结局。
1996年至2000年间，共有561例临床局限性前列腺癌患者接受了调强放射治疗。所有患者均接受了81 Gy的计划靶体积处方剂量。前列腺特异性抗原复发根据美国放射肿瘤学会共识和休斯顿定义（最低点绝对值加2 ng/ml，以随访时为准）进行定义。中位随访时间为7年（范围5至9年）。
根据美国放射肿瘤学会定义，有利、中等和不利风险组患者的8年精算无前列腺特异性抗原复发生存率分别为85%、76%和72%（p<0.025）。根据休斯顿定义，有利、中等和不利风险组患者的8年精算无前列腺特异性抗原复发生存率分别为89%、78%和67%（p = 0.0004）。8年精算2级直肠出血发生率为1.6%。3例患者（0.1%）出现3级直肠毒性，需要1次或更多次输血或激光烧灼治疗。未观察到4级直肠并发症。8年2级和3级（尿道狭窄）晚期泌尿毒性发生率分别为9%和3%。在调强放射治疗前有性功能的患者中,49%出现勃起功能障碍。有利、中等和不利风险病例的病因特异性生存结局分别为100%、96%和84%。
这些长期结果证实了我们之前关于高剂量调强放射治疗临床局限性前列腺癌安全性的观察结果。尽管应用了高辐射剂量，但8年直肠出血发生率仍低于2%。尽管调强放射治疗使剂量分布的适形性增加，但仍实现了出色的长期肿瘤控制效果。
