Sherertz Tracy, Wallner Kent, Merrick Gregory, Ford Eric, Sutlief Steven, Cavanagh William, Butler Wayne, True Lawrence
Radiation Oncology, Puget Sound Health Care System, Department of Veterans Affairs, 1600 S. Columbian Way, Seattle, WA 98108-1597, USA.
Brachytherapy. 2004;3(3):130-5. doi: 10.1016/j.brachy.2004.05.005.
To evaluate the contribution of various clinical and radiation treatment parameters to the likelihood of late rectal bleeding after brachytherapy plus supplemental beam radiation (EB).
A total of 161 intermediate risk patients, with Gleason score 7 or higher and/or PSA 10-20 ng/ml randomized to implantation with (103)Pd (90 versus 115 Gy) with 44 versus 20 Gy EB (2 Gy/day) were studied. Beam radiation was delivered with a four-field arrangement designed to cover the prostate and seminal vesicles with a 2 cm margin (reduced to 1.0 cm posteriorly). Isotope implantation was performed by standard techniques, using a modified peripheral loading pattern. A postimplant CT scan (3 mm slice thickness) was obtained 1-4 h after implantation. Dose volume histograms of the prostate and rectum were calculated using the outer prostatic and rectal margins identified on CT scan by one investigator (KW). Rectal doses were expressed as the R100, R200, and R300, defined as the rectal volume (cc) that received at least 100%, 200%, or 300% of the prescription dose, respectively. External beam doses were expressed as EB75% (cc)-the volume of rectum that received 75% of the beam prescription dose. Treatment-related rectal morbidity was monitored by mailed questionnaires, using Radiation Therapy Oncology Group (RTOG) criteria, at 1, 3, 6, 12, 24, and 36 months. Patients who reported Grade 1 or higher RTOG morbidity were contacted by telephone to obtain more details regarding their rectal bleeding.
In univariate analysis, rectal bleeding was statistically related to the R100, R200, and R300 values, with p-values of 0.0055, 0.0007, and 0.012, respectively. Bleeding was not related to gap times, prostate size, patient age, V100 or D90 values. The EB75% values were similar in 44 Gy patients with or without late bleeding.
Considering the potential severity of rectal morbidities and their relationship to implant dose, we urge our colleagues to routinely monitor the rectal implant doses of their own patients to make sure that such doses are kept within an accepted range.
评估各种临床和放射治疗参数对近距离放疗加补充束放射（EB）后晚期直肠出血可能性的影响。
共研究了161例中危患者，这些患者的Gleason评分≥7和/或前列腺特异性抗原（PSA）为10 - 20 ng/ml，随机接受¹⁰³Pd植入（90 Gy与115 Gy），EB剂量分别为44 Gy与20 Gy（2 Gy/天）。束放射采用四野照射方式，设计用于覆盖前列腺和精囊，并留出2 cm边界（后部减至1.0 cm）。采用标准技术并使用改良的周边加载模式进行同位素植入。植入后1 - 4小时进行CT扫描（层厚3 mm）。由一名研究者（KW）根据CT扫描确定的前列腺和直肠外边界计算前列腺和直肠的剂量体积直方图。直肠剂量用R100、R200和R300表示，分别定义为接受至少100%、200%或300%处方剂量的直肠体积（cc）。外照射剂量用EB75%（cc）表示，即接受75%束放射处方剂量的直肠体积。采用放射治疗肿瘤学组（RTOG）标准，通过邮寄问卷在1、3、6、12、24和36个月时监测与治疗相关的直肠并发症。对报告RTOG并发症≥1级的患者进行电话随访，以获取有关其直肠出血的更多详细信息。
单因素分析中，直肠出血与R100、R200和R300值具有统计学相关性，p值分别为0.0055、0.0007和0.012。出血与间隔时间、前列腺大小、患者年龄、V100或D90值无关。有或无晚期出血的44 Gy患者的EB75%值相似。
考虑到直肠并发症的潜在严重性及其与植入剂量的关系，我们敦促同行常规监测自己患者的直肠植入剂量，以确保此类剂量保持在可接受范围内。
