Yamada Yoshiya, Potters Louis, Zaider Marco, Cohen Gilad, Venkatraman Ennapadam, Zelefsky Michael J
Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
Am J Clin Oncol. 2003 Oct;26(5):e130-5. doi: 10.1097/01.coc.0000091353.67232.e5.
The purpose of this study was to prospectively evaluate intraoperative prostatic edema during prostate brachytherapy with real-time ultrasound imaging and assess its impact upon the postimplant dosimetry of computer-optimized intraoperatively planned patients. Fifty consecutive patients with early-stage favorable risk adenocarcinoma of the prostate underwent transperineal ultrasound-guided I125 brachytherapy. Ultrasound volume studies of the prostate were performed immediately before and after placement of brachytherapy needles in the operating room. Twenty-five patients underwent intraoperative computer-optimized treatment planning using a genetic algorithm. Twenty-five patients underwent preimplant ultrasound studies for preimplant treatment planning. Postimplant dosimetry was performed on computed tomography scans obtained after the implant. Statistical analysis was performed taking into account patient age, preneedle volume, increase in intraoperative edema, use of hormonal therapy, type of isotope, number of needles or seeds used, and seed activity. For the intraoperatively planned patients, a median increase of 30% in intraoperative volume was found for the entire group. No correlation between the extent of intraoperative edema and %D90 (percentage of prescribed dose that covers 90% of the target volume) was found. None of the other analyzed variables correlated with %D90. Patients whose treatment was planned preoperatively experienced a median increase of 18.4% in target volume. A negative correlation between the amount of edema and the %D90 was found to be statistically significant (-0.55, P = 0.0047). All patients who underwent prostate brachytherapy experienced intraoperative prostatic edema. When planned intraoperatively, the amount of edema had no impact on the %D90. This may be because of the ability of intraoperative computer-optimized treatment planning to account for edema related to the procedure. Preplanned patients who encountered a greater degree of intraoperative edema had less %D90 target coverage.
本研究的目的是通过实时超声成像对前列腺近距离放射治疗术中的前列腺水肿进行前瞻性评估，并评估其对术中计算机优化计划植入患者的植入后剂量测定的影响。连续50例早期低危前列腺腺癌患者接受了经会阴超声引导下的I125近距离放射治疗。在手术室中，于植入近距离放射治疗针之前和之后立即对前列腺进行超声体积研究。25例患者使用遗传算法进行术中计算机优化治疗计划。25例患者进行植入前超声研究以进行植入前治疗计划。在植入后获得的计算机断层扫描上进行植入后剂量测定。进行统计分析时考虑了患者年龄、针植入前体积、术中水肿增加情况、激素治疗的使用、同位素类型、使用的针或籽源数量以及籽源活性。对于术中计划的患者，整个组术中体积中位数增加了30%。未发现术中水肿程度与%D90（覆盖90%靶体积的处方剂量百分比）之间存在相关性。其他分析变量均与%D90无相关性。术前计划治疗的患者靶体积中位数增加了18.4%。发现水肿量与%D90之间的负相关性具有统计学意义（-0.55，P = 0.0047）。所有接受前列腺近距离放射治疗的患者均出现术中前列腺水肿。术中计划时，水肿量对%D90无影响。这可能是因为术中计算机优化治疗计划能够考虑与手术相关的水肿。术中水肿程度较高的术前计划患者%D90靶区覆盖较少。
