双时相^(18)F—FDG符合线路显像在肿瘤良恶性鉴别诊断中的应用

Dual phase ^(18)F-FDG MCD SPECT imaging for differentiating malignant from benign lesions

目的评价双时相 ^(18)F-脱氧葡萄糖(FDG)符合线路显像在肿瘤良恶性鉴别诊断中的应用价值。方法对100例临床拟诊为恶性肿瘤的患者,静脉注射^(18)F-FDG 185～370 MBq 后40～65min 和100～140min,采用 Philips IREX 三探头符合线路 SPECT 仪分别行早期和延迟显像。测定2次显像病灶(L)和对侧正常组织(B)的感兴趣区(ROI)放射性计数,并计算 L/B 比值和 L/B 变化率(△L/B)。结果最后经病理检查或临床随访证实恶性肿瘤75例,良性病变25例。恶性肿瘤组早期显像 L/B 比值为3.62±2.07,延迟显像为5.67±3.20,△L/B 为(57.59±31.91)%;良性病生组2次显像的 L/B 比值分別为2.47±1.53(早期)和2.72±1.93(延迟),△L/B 为(7.23±23.14)%。以△L/B>30%作为良恶性病变鉴别诊断的阈值,灵敏度为97.3%,特异性为92.0%,准确性为96.0%。结论恶性肿瘤延迟显像 L/B 比值的增高幅度明显大于良性病变,且双时相符合线路显像方法简便、实用,能提高^(18)F-FDG 符合线路显像鉴別良恶性病变的灵敏度、特异性和准确性,有较高的临床应用价值。

Objective To evaluate the usefulness of dual phase ^18F-fluorodeoxyglucose （FDG） molecular coincidence detection （MCD） SPECT imaging in differentiation of malignant from benign lesions. Methods One hundred patients, including proved 75 malignant and 25 benign patients underwent coincidence SPECT imaging at 2 time phase： early image at 40 -65 min and delay image at 100～140 min after the intravenous injection of 185～ 370 MBq^18F-FDG. All imaging was performed on a Philips triple head SPECT with MCD. Region of interest （ROI） was drawn over the lesions （L） and contralateral normal tissue （B） on the coronal view, and then L/B value change rate（AL/B） was calculated for both images. Results The average L/B values of early and delay images in malignant tumors were 3.62 ±2.07 and 5.67 ± 3.20 respectively with AL/B value （57.59 ± 31.91 ）%. In contrast, values for the benign lesions were 2.47 ± 1.53 and 2.72 ± 1.93 respectively with AL/B （7.23 ± 23. 14 ） %. If taking AL/B value 30% as the threshold for malignancy, the sensitivity,specificity and accuracy were 97.3% ,92.0% and 96.0% ,respectively. Conclusions Malignant tumor has a greater rise of L/B value in both delay and early images. Dual phase MCD SPECT imaging is a simple, practical modality and it can improve the sensitivity,specificity and accuracy for detection of malignant tumor.