Mount Vernon Cancer Centre, Middlesex, UK.
Int J Radiat Oncol Biol Phys. 2013 Oct 1;87(2):270-4. doi: 10.1016/j.ijrobp.2013.05.022. Epub 2013 Jul 9.
To determine whether late genitourinary toxicity, biochemical control of prostate cancer, and dosimetric parameters in patients with large prostate glands is different from those variables in men with smaller glands after treatment with high-dose-rate brachytherapy alone (HDR-BT).
From November 2003 to July 2009, 164 patients with locally advanced prostate carcinoma were sequentially enrolled and treated with 34 or 36 Gy in 4 fractions and 31.5 Gy in 3 fractions of (192)Ir HDR-BT alone. The median follow-up time was 71 months. Gland size was not considered in the selection criteria for this study. Estimates of freedom from biochemical relapse (FFbR) and late morbidity, stratified by median clinical target volume (CTV), were obtained, and differences were compared.
The median CTV volume was 60 cc (range, 15-208 cc). Dose-volume parameters D90 and V100 (ie, minimum dose to 90% of the prostate volume and volume receiving 100% of the prescribed isodose) achieved in patients with glands ≥60 cc were not significantly different from those with glands <60 cc (P≥.2). Nonetheless, biochemical control in patients with larger CTV was significantly higher (91% vs 78% at 6 years; P=.004). In univariate and multivariate analysis, CTV was a significant predictor for risk of biochemical relapse. This was not at the expense of an increase in either moderate (P=.6) or severe (P=.3) late genitourinary toxicity. The use of hormonal therapy was 17% lower in the large gland group (P=.01).
Prostate gland size does not affect dosimetric parameters in HDR-BT assessed by D90 and V100. In patients with larger glands, a significantly higher biochemical control of disease was observed, with no difference in late toxicity. This improvement cannot be attributed to differences in dosimetry. Gland size should not be considered in the selection of patients for HDR-BT.
确定在接受单纯高剂量率近距离放射治疗（HDR-BT）后，大前列腺患者的晚期泌尿生殖系统毒性、前列腺癌的生化控制以及剂量学参数是否与小腺体患者的这些变量不同。
2003 年 11 月至 2009 年 7 月，连续纳入 164 例局部晚期前列腺癌患者，采用 34 或 36 Gy/4 次和 31.5 Gy/3 次（192）Ir-HDR-BT 治疗。中位随访时间为 71 个月。本研究选择标准不考虑腺体大小。获得了按中位临床靶区（CTV）分层的生化无复发生存率（FFbR）和晚期发病率的估计值，并比较了差异。
CTV 体积中位数为 60 cc（范围 15-208 cc）。≥60 cc 腺体患者的剂量体积参数 D90 和 V100（即前列腺体积的 90%接受的最小剂量和接受 100%规定等剂量的体积）与<60 cc 腺体患者无显著差异（P≥.2）。尽管如此，CTV 较大的患者的生化控制率明显更高（6 年时为 91% vs 78%；P=.004）。单变量和多变量分析表明，CTV 是生化复发风险的显著预测因子。这并没有导致中重度（P=.6）或重度（P=.3）晚期泌尿生殖系统毒性的增加。大腺体组激素治疗的使用率降低了 17%（P=.01）。
HDR-BT 中 D90 和 V100 评估的前列腺腺体大小不影响剂量学参数。在大腺体患者中，观察到疾病的生化控制明显更高，晚期毒性无差异。这种改善不能归因于剂量学的差异。腺体大小不应作为 HDR-BT 患者选择的依据。
