Anwar Mekhail, Weinberg Vivian, Seymour Zachary, Hsu I Joe, Roach Mack, Gottschalk Alex R
Department of Radiation Oncology, University of California San Francisco, 1825 4th Street, San Francisco, CA, 94158, USA.
Department of Radiation Oncology, University of California San Francisco, 1600 Divisadero St. Suite H1031, San Francisco, CA, 94143-1708, USA.
Radiat Oncol. 2016 Jan 21;11:8. doi: 10.1186/s13014-016-0585-y.
Treatment of intermediate and high-risk prostate cancer with a high BED has been shown to increase recurrence free survival (RFS). While high dose rate (HDR) brachytherapy, given as a boost is effective in delivering a high BED, many patients are not candidates for the procedure or wish to avoid an invasive procedure. We evaluated the use of stereotactic body radiotherapy (SBRT) as a boost, with dosimetry modeled after HDR-boost.
Fifty patients were treated with two fractions of SBRT (9.5-10.5 Gy/fraction) after 45 Gy external-beam radiotherapy, with 48 eligible for analysis at a median follow-up of 42.7 months.
The Kaplan-Meier estimates of biochemical control post-radiation therapy (95 % Confidence Interval) at 3, 4 and 5 years were 95 % (81-99 %), 90 % (72-97 %) and 90 % (72-97 %), respectively (not counting 2 patients with a PSA bounce as failures). RFS (defined as disease recurrence or death) estimates at 3, 4 and 5 years were 92 % (77-97 %), 88 % (69-95 %) and 83 % (62-93 %) if patients with PSA bounces are not counted as failures, and were 90 % (75-96 %), 85 % (67-94 %) and 75 % (53-88 %) if they were. The median time to PSA nadir was 26.2 months (range 5.8-82.9 months), with a median PSA nadir of 0.05 ng/mL (range <0.01-1.99 ng/mL). 2 patients had a "benign PSA bounce", and 4 patients recurred with radiographic evidence of recurrence beyond the RT fields. Treatment was well tolerated with no acute G3 or higher GI or GU toxicity and only a single G3 late GU toxicity of urinary obstruction.
SBRT boost is well-tolerated for intermediate and high-risk prostate cancer patients with good biochemical outcomes and low toxicity.
已证明采用高生物等效剂量（BED）治疗中高危前列腺癌可提高无复发生存率（RFS）。虽然作为一种追加剂量给予的高剂量率（HDR）近距离放射治疗在给予高BED方面有效，但许多患者不适合进行该手术或希望避免侵入性手术。我们评估了立体定向体部放射治疗（SBRT）作为追加剂量的应用情况，并根据HDR追加剂量进行了剂量测定建模。
50例患者在接受45 Gy外照射放疗后接受了两分割的SBRT（9.5 - 10.5 Gy/分割），48例符合分析条件，中位随访时间为42.7个月。
放疗后3年、4年和5年的生化控制的Kaplan - Meier估计值（95%置信区间）分别为95%（81 - 99%）、90%（72 - 97%）和90%（72 - 97%）（不将2例出现PSA反弹的患者计为失败病例）。若不将出现PSA反弹的患者计为失败病例，3年、4年和5年的RFS（定义为疾病复发或死亡）估计值分别为92%（77 - 97%）、88%（69 - 95%）和83%（62 - 93%）；若将其计为失败病例，则分别为90%（75 - 96%）、85%（67 - 94%）和75%（53 - 88%）。PSA最低点的中位时间为26.2个月（范围5.8 - 82.9个月），PSA最低点的中位数为0.05 ng/mL（范围<0.01 - 1.99 ng/mL）。2例患者出现“良性PSA反弹”，4例患者复发，影像学显示复发超出放疗野范围。治疗耐受性良好，无急性3级或更高等级的胃肠道或泌尿生殖系统毒性，仅1例出现3级晚期泌尿生殖系统毒性即尿路梗阻。
对于中高危前列腺癌患者，SBRT追加剂量耐受性良好，生化结果良好且毒性低。
