Kimura Tomoki, Doi Yoshiko, Nakashima Takeo, Imano Nobuki, Kawabata Hideo, Nishibuchi Ikuno, Okabe Tomoyuki, Kenjo Masahiro, Ozawa Shuichi, Murakami Yuji, Nagata Yasushi
Department of Radiation Oncology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan.
Department of Radiation Oncology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan.
Int J Radiat Oncol Biol Phys. 2015 Nov 15;93(4):778-87. doi: 10.1016/j.ijrobp.2015.08.024. Epub 2015 Aug 19.
The purpose of this study was to prospectively investigate clinical correlations between dosimetric parameters associated with radiation pneumonitis (RP) and functional lung imaging.
Functional lung imaging was performed using four-dimensional computed tomography (4D-CT) for ventilation imaging, single-photon emission computed tomography (SPECT) for perfusion imaging, or both (V/Q-matched region). Using 4D-CT, ventilation imaging was derived from a low attenuation area according to CT numbers below different thresholds (vent-860 and -910). Perfusion imaging at the 10th, 30th, 50th, and 70th percentile perfusion levels (F10-F70) were defined as the top 10%, 30%, 50%, and 70% hyperperfused normal lung, respectively. All imaging data were incorporated into a 3D planning system to evaluate correlations between RP dosimetric parameters (where fV20 is the percentage of functional lung volume irradiated with >20 Gy, or fMLD, the mean dose administered to functional lung) and the percentage of functional lung volume. Radiation pneumonitis was evaluated using Common Terminology Criteria for Adverse Events version 4.0. Statistical significance was defined as a P value of <.05.
Sixty patients who underwent curative radiation therapy were enrolled (48 patients for non-small cell lung cancer, and 12 patients for small cell lung cancer). Grades 1, 2, and ≥3 RP were observed in 16, 44, and 6 patients, respectively. Significant correlations were observed between the percentage of functional lung volume and fV20 (r=0.4475 in vent-860 and 0.3508 in F30) or fMLD (r=0.4701 in vent-860 and 0.3128 in F30) in patients with grade ≥2 RP. F30∩vent-860 results exhibited stronger correlations with fV20 and fMLD in patients with grade ≥2 (r=0.5509 in fV20 and 0.5320 in fMLD) and grade ≥3 RP (r=0.8770 in fV20 and 0.8518 in fMLD).
RP dosimetric parameters correlated significantly with functional lung imaging.
本研究旨在前瞻性地探究与放射性肺炎（RP）相关的剂量学参数和肺功能成像之间的临床相关性。
使用四维计算机断层扫描（4D-CT）进行肺通气成像、单光子发射计算机断层扫描（SPECT）进行肺灌注成像，或两者结合（通气/灌注匹配区域）。利用4D-CT，根据低于不同阈值（vent-860和-910）的CT值从低衰减区域得出通气成像。第10、30、50和70百分位数灌注水平（F10-F70）的灌注成像分别定义为灌注最高的正常肺的前10%、30%、50%和70%。所有成像数据都纳入三维计划系统，以评估RP剂量学参数（其中fV20是接受>20 Gy照射的功能性肺体积百分比，或fMLD，即给予功能性肺的平均剂量）与功能性肺体积百分比之间的相关性。使用不良事件通用术语标准第4.0版评估放射性肺炎。统计学显著性定义为P值<.05。
纳入60例接受根治性放射治疗的患者（48例非小细胞肺癌患者，12例小细胞肺癌患者）。分别有16、44和6例患者出现1级、2级和≥3级RP。在≥2级RP患者中，观察到功能性肺体积百分比与fV20（vent-860中r = 0.4475，F30中r = 0.3508）或fMLD（vent-860中r = 0.4701，F30中r = 0.3128）之间存在显著相关性。在≥2级（fV20中r = 0.5509，fMLD中r = 0.5320）和≥3级RP（fV20中r = 0.8770，fMLD中r = 0.8518）患者中，F30∩vent-860结果与fV20和fMLD表现出更强的相关性。
RP剂量学参数与肺功能成像显著相关。
