Bayouth John E, Pena John, Culp Laura, Brack Collin, Sanguineti Giuseppe
Department of Radiation Oncology, University of Iowa Health Care, Iowa City, IA 52242, USA.
Med Dosim. 2008 Autumn;33(3):180-90. doi: 10.1016/j.meddos.2007.05.006.
Utilizing available dosimetric and acute toxicity data, we confirm the feasibility of intensity modulated radiotherapy (IMRT) to include treatment of the pelvic nodes (PN) while escalating the dose to the prostate. Data were obtained from 35 consecutive patients with prostate cancer with > or =15% risk of PN involvement. Patients received an initial boost to the prostate, delivering 16 Gy over 8 fractions using a 6-field conformal technique, followed by an 8-field coplanar inverse planning IMRT technique delivering an additional 60 Gy over 30 fractions to the prostate (76 Gy total) and 54 Gy over 30 fractions to the seminal vesicles (SV) and PN. Dose-volume histogram analysis was performed for planning target volumes and organs at risk. Acute toxicity (RTOG/EORTC scale) was prospectively and independently scored weekly for each patient. The maximum, mean, minimum dose, and D95 to each planning target volume is provided: prostate (82.2, 78.2, 72.6, 75.2 Gy), SV (79.0, 72.5, 56.9, 61.1 Gy), and PN (80.4, 59.7, 46.5, 53.3 Gy), respectively. The percent volume receiving a dose at or above "x" Gy (Vx) was recorded for V75, V70, V65, V60, and V50 as: bladder (14%, 24%, 32%, 39%, and 54%) and rectum (3%, 18%, 26%, 34%, and 51%), respectively. Acute toxicity was as follows: 54% grade 2+ GI (n = 19), 25% grade 2+ GU (n = 9). IMRT enables treatment of pelvic nodes while escalating dose to the prostate and is clinically feasible with acute toxicity within expected ranges.
利用现有的剂量测定和急性毒性数据，我们证实了调强放射治疗（IMRT）在增加前列腺剂量的同时包括盆腔淋巴结（PN）治疗的可行性。数据来自35例连续的前列腺癌患者，其PN受累风险≥15%。患者首先接受前列腺局部加量，采用6野适形技术在8次分割中给予16 Gy，随后采用8野共面逆向计划IMRT技术在30次分割中再给予前列腺60 Gy（总计76 Gy），给予精囊（SV）和PN 54 Gy，分30次分割。对计划靶区和危及器官进行剂量体积直方图分析。前瞻性地并独立地每周对每位患者的急性毒性（RTOG/EORTC标准）进行评分。给出了每个计划靶区的最大、平均、最小剂量和D95：前列腺分别为（82.2、78.2、72.6、75.2 Gy），SV为（79.0、72.5、56.9、61.1 Gy），PN为（80.4、59.7、46.5、53.3 Gy）。记录了膀胱和直肠在V75、V70、V65、V60和V50时接受“x”Gy及以上剂量的体积百分比（Vx）：膀胱分别为（14%、24%、32%、39%和54%），直肠分别为（3%、18%、26%、34%和51%）。急性毒性情况如下：54%为2级及以上胃肠道毒性（n = 19），25%为2级及以上泌尿生殖系统毒性（n = 9）。IMRT能够在增加前列腺剂量的同时治疗盆腔淋巴结，且临床可行，急性毒性在预期范围内。
