Influence of volumes of prostate, rectum, and bladder on treatment planning CT on interfraction prostate shifts during ultrasound image-guided IMRT
Influence of volumes of prostate, rectum, and bladder on treatment planning CT on interfraction prostate shifts during ultrasound image-guided IMRT
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DOI：
10.1118/1.3260840
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发表时间：
2009-12-01
期刊：
影响因子：
3.8
通讯作者：
Lange, Christopher S.
中科院分区：
文献类型：
--
作者：
Reddy, Nandanuri M. S.;Nori, Dattatreyudu;Lange, Christopher S.
目的：本研究的目的是分析前列腺，膀胱和直肠体积治疗计划CT日和前列腺的XYZ方向上的治疗days.Methods的变化之间的关系：前列腺，精囊，膀胱和直肠轮廓CT图像上获得仰卧位。制定调强放射治疗计划。将轮廓导出至BAT-超声成像系统。使用皮肤标记将患者定位在治疗床上。使用超声探头获得前列腺、膀胱和直肠的超声图像，并与CT图像对齐。根据BAT系统的建议，在XYZ方向上移动治疗床并进行记录。对42例患者的4698次治疗床移位进行了分析，以研究治疗间前列腺移位与计划CT.Results上膀胱、直肠和前列腺体积之间的相关性：平均体积和范围（cc）：膀胱：179（42-582），直肠：108（28-223），前列腺：55（21-154）。平均系统前列腺移位为（cm，+/- SD）右侧和左侧：-0.047 +/- 0.16（-0.361-0.251），前部和后部：0.14 +/- 0.3（-0.466-0.669），上级和下级：0.19 +/- 0.26（-0.342-0.633）。膀胱容量与前列腺的侧向、前/后和上级/下移位无关（P > 0.2）。直肠体积与前列腺前/后移位相关（P < 0.001），而与前列腺侧位和上级/下级移位无关（P > 0.2）。直肠体积或横截面积越小，前列腺前移越大，反之亦然（P < 0.001）。前列腺体积与前列腺的上级/低级相关（P < 0.05），而与前列腺的横向和前/后移位无关（P > 0.2）。前列腺体积越小，前列腺向上移位越大，反之亦然（P < 0.05）。对于计划CT显示直肠扩张或排空的患者，需要每日进行图像引导的过继放疗，以减少直肠排空情况下的直肠毒性，并最大限度地减少前列腺的几何遗漏。(C)2009年美国医学物理学家协会。[DOI电话：10.1118/1.3260840
Purpose: The purpose of this study was to analyze the relationship between prostate, bladder, and rectum volumes on treatment planning CT day and prostate shifts in the XYZ directions on treatment days.Methods: Prostate, seminal vesicles, bladder, and rectum were contoured on CT images obtained in supine position. Intensity modulated radiation therapy plans was prepared. Contours were exported to BAT-ultrasound imaging system. Patients were positioned on the couch using skin marks. An ultrasound probe was used to obtain ultrasound images of prostate, bladder, and rectum, which were aligned with CT images. Couch shifts in the XYZ directions as recommended by BAT system were made and recorded. 4698 couch shifts for 42 patients were analyzed to study the correlations between interfraction prostate shifts vs bladder, rectum, and prostate volumes on planning CT.Results: Mean and range of volumes (cc) : Bladder: 179 (42-582), rectum: 108 (28-223), and prostate: 55 (21-154). Mean systematic prostate shifts were (cm, +/- SD) right and left lateral: -0.047 +/- 0.16 (-0.361-0.251), anterior and posterior: 0.14 +/- 0.3 (-0.466-0.669), and superior and inferior: 0.19 +/- 0.26 (-0.342-0.633). Bladder volume was not correlated with lateral, anterior/posterior, and superior/inferior prostate shifts (P > 0.2). Rectal volume was correlated with anterior/posterior (P < 0.001) but not with lateral and superior/inferior prostate shifts (P > 0.2). The smaller the rectal volume or cross sectional area, the larger was the prostate shift anteriorly and vice versa (P < 0.001). Prostate volume was correlated with superior/ inferior (P < 0.05) but not with lateral and anterior/posterior prostate shifts (P > 0.2). The smaller the prostate volume, the larger was prostate shift superiorly and vice versa (P < 0.05).Conclusions: Prostate and rectal volumes, but not bladder volumes, on treatment planning CT influenced prostate position on treatment fractions. Daily image-guided adoptive radiotherapy would be required for patients with distended or empty rectum on planning CT to reduce rectal toxicity in the case of empty rectum and to minimize geometric miss of prostate. (C) 2009 American Association of Physicists in Medicine. [DOI: 10.1118/1.3260840]