Department of Radiation Oncology, Regina Elena National Cancer Institute, Rome, Italy.
Int J Radiat Oncol Biol Phys. 2012 Dec 1;84(5):1172-8. doi: 10.1016/j.ijrobp.2012.02.049. Epub 2012 Apr 24.
To report long-term results and patterns of failure after conventional and hypofractionated radiation therapy in high-risk prostate cancer.
This randomized phase III trial compared conventional fractionation (80 Gy at 2 Gy per fraction in 8 weeks) vs hypofractionation (62 Gy at 3.1 Gy per fraction in 5 weeks) in combination with 9-month androgen deprivation therapy in 168 patients with high-risk prostate cancer. Freedom from biochemical failure (FFBF), freedom from local failure (FFLF), and freedom from distant failure (FFDF) were analyzed.
In a median follow-up of 70 months, biochemical failure (BF) occurred in 35 of the 168 patients (21%) in the study. Among these 35 patients, local failure (LF) only was detected in 11 (31%), distant failure (DF) only in 16 (46%), and both LF and DF in 6 (17%). In 2 patients (6%) BF has not yet been clinically detected. The risk reduction by hypofractionation was significant in BF (10.3%) but not in LF and DF. We found that hypofractionation, with respect to conventional fractionation, determined only an insignificant increase in the actuarial FFBF but no difference in FFLF and FFDF, when considering the entire group of patients. However, an increase in the 5-year rates in all 3 endpoints-FFBF, FFLF, and FFDF-was observed in the subgroup of patients with a pretreatment prostate-specific antigen (iPSA) level of 20 ng/mL or less. On multivariate analysis, the type of fractionation, iPSA level, Gleason score of 4+3 or higher, and T stage of 2c or higher have been confirmed as independent prognostic factors for BF. High iPSA levels and Gleason score of 4+3 or higher were also significantly associated with an increased risk of DF, whereas T stage of 2c or higher was the only independent variable for LF.
Our results confirm the isoeffectiveness of the 2 fractionation schedules used in this study, although a benefit in favor of hypofractionation cannot be excluded in the subgroup of patients with an iPSA level of 20 ng/mL or less. The α/β ratio might be more appropriately evaluated by FFLF than FFBF results, at least in high-risk disease.
报告高风险前列腺癌患者接受常规放疗和低分割放疗后的长期结果和失败模式。
这项随机的三期临床试验比较了常规分割（8 周内 80Gy，每次 2Gy）和低分割（5 周内 62Gy，每次 3.1Gy）联合 9 个月雄激素剥夺治疗在 168 例高危前列腺癌患者中的疗效。分析了生化无失败率（FFBF）、局部无失败率（FFLF）和远处无失败率（FFDF）。
在中位随访 70 个月时，研究中的 168 例患者中有 35 例（21%）发生了生化失败（BF）。在这 35 例患者中，仅检测到局部失败（LF）的有 11 例（31%），仅检测到远处失败（DF）的有 16 例（46%），同时检测到 LF 和 DF 的有 6 例（17%）。在 2 例患者（6%）中，BF 尚未在临床上检测到。低分割与常规分割相比，BF 的风险降低具有统计学意义（10.3%），但 LF 和 DF 无差异。我们发现，考虑到所有患者，低分割与常规分割相比，仅能显著提高 5 年时的生化无失败率（FFBF）的累积发生率，但对局部无失败率（FFLF）和远处无失败率（FFDF）没有影响。然而，在前列腺特异性抗原（iPSA）水平为 20ng/ml 或更低的患者亚组中，观察到所有 3 个终点（FFBF、FFLF 和 FFDF）的 5 年累积发生率均有增加。多变量分析证实，分割方式、iPSA 水平、Gleason 评分 4+3 或更高、T 分期 2c 或更高是 BF 的独立预后因素。高 iPSA 水平和 Gleason 评分 4+3 或更高与 DF 的风险增加显著相关，而 T 分期 2c 或更高是 LF 的唯一独立变量。
我们的结果证实了这两种分割方案在本研究中的等效性，尽管在 iPSA 水平为 20ng/ml 或更低的患者亚组中，低分割可能具有优势。至少在高危疾病中，FFLF 结果比 FFBF 结果更能适当地评估 α/β 比值。
