鼻咽癌颅底骨侵犯SPECT及MRI检测对比研究

Comparison between SPECT and MRI in detecting skull-base invasion in nasopharyngeal carcinoma

目的探讨SPECT及MRI对鼻咽癌颅底骨侵犯的检测能力及诊断价值。方法对61例鼻咽癌初治患者于放疗前同期进行SPECT全身前后位、左右头侧位平面显像和颅底断层骨显像及MRI鼻咽、颅底横断和冠状检查，采用双盲法对两者检测结果进行比较。结果SPECT和MRI对颅底骨侵犯的阳性检出率在全部患者中分别为51％、46％（P=0．508），在头痛、颅神经损害及两者并存患者中分别为83％、80％、88％和86％、80％、94％（P值均为1．000），在T1＋T2和T3＋T4期患者中分别为22％、74％和0.82％（P=0．031、0．250），在N0＋N1和N2＋N3期患者中分别为50％、53％和48％、40％（P=1．000、0．500）。SPECT与MRI检测符合率为85％。Binary Logistic回归分析显示T分期是SPECT对颅底骨侵犯阳性检出的关联因素（X^2=4．23，P=0．040；OR值=3．04），头痛有成为SPECT和MRI对颅底骨侵犯阳性检出关联因素的趋势（X^2=3．13，P=0．077，OR=4．54；X^2=3．64，P=0．056，OR=12．00）。结论SPECT对鼻咽癌颅底骨侵犯的检测敏感性与MRI相当，检测结果与MRI有较高符合率，且与T分期有良好相关性，其临床应用价值值得进一步研究。对头痛明显、T分期晚、CT榆测颅底阴性、无条件接受MRI检查的鼻咽癌患者行SPECT颅底断层骨显像阳性应考虑早期颅底骨侵犯，并以此指导放疗靶区（GTV）的确定。

Objective To investigate the ability of single photon emission computed tomography （SPECT） and MRI in detecting skull-base invasion in nasopharyngeal carcinoma. Methods Sixty-one patients with nasopharyngeal carcinoma received whole body and skull-base tomography SPECT, and nasopharynx and skull-base MRI before radiotherapy. The results were double-blind compared and evaluated. Resuits The overall positive rates of skull-base invasion detected by SPECT and MRI were 51% and 46% （P =0.508）. In paitents with headache, cranial nerve palsy or both, the rates were 83% and 86% （P = 1. 000） ,80% and 80% （ P = 1. 000）, 88% and 94% （ P = 1. 000）, respectively. In patients with T1 ＋ T2 and T3 ＋ T4 lesions,the rates were 22% and 0（P =0. 031 ） ,74% and 82% （P =0. 250） ,repectively, In patients with N0 ＋ N1 and N2 ＋ N3 lesions,they were 50% and 48% （P = 1.000） ,53% and 40% （P = 0. 500） ,respectively. The conformation rate between SPECT and MRI was 85%. Binary Logistic regression analysis showed that T stage was a risk factor for positive SPECT （ X^2 =4.23, P = 0. 040, OR = 3.04 ）. Headache tended to be a risk factor for both positive SPECT and positive MRI （ X^2 = 3.13, P = 0. 077, OR = 4.54 ; X^2 = 3.64, P = 0.056, OR = 12.00）. Conclusions The detection sensitivity of SPECT in skull-base invasion in nasopharyngeal carcinoma is equivalent to that of MRI. The consistency between SPECT and MRI is good. Moreover, there is a good correlation between SPECT and symptoms, signs and stage. SPECT of skullbase tomography is necessary for patients with severe headache, negative CT and those who can not receive MRI. When SPECT result is positive,skull-base should be considered to be invaded and should be defined as gross tumor volume in radiotherapy planning.