Buch Karen, Morancy Tye, Kaplan Irving, Qureshi Muhammad M, Hirsch Ariel E, Rofksy Neil M, Holupka Edward, Oismueller Renee, Hawliczek Robert, Helbich Thomas H, Bloch B Nicolas
Department of Radiology, Boston University Medical Center, Boston, USA.
Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Boston, USA.
J Contemp Brachytherapy. 2015 Jan;6(4):337-43. doi: 10.5114/jcb.2014.46555. Epub 2014 Oct 28.
To assess detailed dosimetry data for prostate and clinical relevant intra- and peri-prostatic structures including neurovascular bundles (NVB), urethra, and penile bulb (PB) from postbrachytherapy computed tomography (CT) versus high resolution contrast enhanced magnetic resonance imaging (HR-CEMRI).
Eleven postbrachytherapy prostate cancer patients underwent HR-CEMRI and CT imaging. Computed tomography and HR-CEMRI images were randomized and 2 independent expert readers created contours of prostate, intra- and peri-prostatic structures on each CT and HR-CEMRI scan for all 11 patients. Dosimetry data including V100, D90, and D100 was calculated from these contours.
Mean V100 values from CT and HR-CEMRI contours were as follows: prostate (98.5% and 96.2%, p = 0.003), urethra (81.0% and 88.7%, p = 0.027), anterior rectal wall (ARW) (8.9% and 2.8%, p < 0.001), left NVB (77.9% and 51.5%, p = 0.002), right NVB (69.2% and 43.1%, p = 0.001), and PB (0.09% and 11.4%, p = 0.005). Mean D90 (Gy) derived from CT and HR-CEMRI contours were: prostate (167.6 and 150.3, p = 0.012), urethra (81.6 and 109.4, p = 0.041), ARW (2.5 and 0.11, p = 0.003), left NVB (98.2 and 58.6, p = 0.001), right NVB (87.5 and 55.5, p = 0.001), and PB (11.2 and 12.4, p = 0.554).
Findings of this study suggest that HR-CEMRI facilitates accurate and meaningful dosimetric assessment of prostate and clinically relevant structures, which is not possible with CT. Significant differences were seen between CT and HR-CEMRI, with volume overestimation of CT derived contours compared to HR-CEMRI.
通过近距离放射治疗后的计算机断层扫描（CT）与高分辨率对比增强磁共振成像（HR-CEMRI），评估前列腺以及前列腺内部和周围临床相关结构（包括神经血管束（NVB）、尿道和阴茎球部（PB））的详细剂量测定数据。
11例近距离放射治疗后的前列腺癌患者接受了HR-CEMRI和CT成像。将CT和HR-CEMRI图像随机排列，两位独立的专家读者在所有11例患者的每次CT和HR-CEMRI扫描上绘制前列腺、前列腺内部和周围结构的轮廓。根据这些轮廓计算包括V100、D90和D100在内的剂量测定数据。
CT和HR-CEMRI轮廓的平均V100值如下：前列腺（98.5%和96.2%，p = 0.003）、尿道（81.0%和88.7%，p = 0.027）、直肠前壁（ARW）（8.9%和2.8%，p < 0.001）、左侧NVB（77.9%和51.5%，p = 0.002）、右侧NVB（69.2%和43.1%，p = 0.001）以及PB（0.09%和11.4%，p = 0.005）来自CT和HR-CEMRI轮廓的平均D90（Gy）分别为：前列腺（167.6和150.3，p = 0.012）、尿道（81.6和109.4，p = 0.041）、ARW（2.5和0.11，p = 0.003）、左侧NVB（98.2和58.6，p = 0.001）、右侧NVB（87.5和55.5，p = 0.001）以及PB（1i.2和12.4，p = 0.554）。
本研究结果表明，HR-CEMRI有助于对前列腺和临床相关结构进行准确且有意义的剂量测定评估，而CT无法做到这一点。CT和HR-CEMRI之间存在显著差异，与HR-CEMRI相比，CT得出的轮廓存在体积高估的情况。
