^(18)F-FDG符合探测显像与CT显像在淋巴瘤分期和疗效评价中的比较

Comparison of ^(18)F-FDG coincidence SPECT imaging and computed tomography in the initial staging and therapeutic evaluation of lymphomas

目的比较18F-脱氧葡萄糖(18F-FDG)符合探测显像与CT在淋巴瘤首次分期、早期疗效监测、治疗结束后评估和长期随访中的价值。方法回顾性分析61例恶性淋巴瘤患者在诊断、治疗和随访中的18F-FDG符合探测显像结果,并与同期CT显像进行对比分析。共161例次18F-FDG符合探测显像,其中首次分期61例次,化疗早期42例次,化疗结束后26例次,长期随访32例次。结果(1)首次分期中,61例患者共探查到212处病灶,18F-FDG符合探测显像检测出92.0%的病灶,高于CT显像81.1%的检出率(P<0.01)。18F-FDG符合探测显像与骨髓活检一致性为80.3%。18F-FDG符合探测显像使34.4%的患者分期正确上调,上调的原因为其探查到CT未能发现的骨髓浸润17例,淋巴结病灶3例,肝脏侵犯1例;1例分期错误上调,2例分期错误下调。(2)化疗后早期,42例患者中,18F-FDG符合探测显像阴性17例,其中完全缓解(CR)13例,部分缓解(PR)3例;显像阳性25例,其中病情进展13例。18F-FDG符合探测显像的准确性为85.7%,而CT显像为64.3%。18F-FDG符合探测显像指导临床医生改变了21.4%(9/42)患者的治疗方案。(3)化疗结束后和随访中,14例CT提示残余灶,其中8例18F-FDG符合探测显像持续阴性,判断为CR,其余6例18F-FDG符合探测显像阳性的患者中,仅有1例CR(假阳性),2例PR,1例未缓解,2例进展。18F-FDG符合探测显像和CT显像的特异性分别为85.7%和59.5%,阳性预测值分别为68.4%和43.3%。结论18F-FDG符合探测显像对恶性淋巴瘤分期、早期治疗反应评估和长期随访均有重要价值,尤其在鉴别残余灶性质方面意义显著,且明显优于CT显像。

Objective To investigate the clinical value of ^18F-fluorodeoxyglucose （^18F-FDG） coincidence SPECT imaging versus computed tomography （CT） for malignant lymphoma in the initial staging, early response to therapy , evaluation after completion of therapy and long - term follow - up. Methods ^18F-FDG SPECT scans was performed on 61 patients with pathologically proven malignant lymphoma. The mean age of this series was 55 years ranged from 12 to 85 years. The data of these patients were retrospectively analyzed, and the result of ^18F-FDG SPECT scan was compared with the CT imaging result performed within 2 weeks before or after FDG scan. 161 ^18F-FDG SPECT scans were performed for initial tumor staging （ n = 61 ）, early response to therapy （ n = 42 ） , evaluation after completion of therapy （ n = 26 ） and long-term follow-up （ n = 32）. Each patient had a follow-up 〉 6 months. Results （ 1 ） Compared with CT scan, ^18F-FDG SPECT imaging accurately upstaged the disease for 34.4% （21/61） of these patients at initial staging. It detected the lesions which were undetected by CT including bone marrow infiltration （ n = 17） , loci of lymph node （ n = 3 ） and liver involvement （ n = 1 ）. However, 3 patients were incorrectly staged, either downstaged or upstaged by ,^18F-FDG SPECT imaging. Of 212 lesions in 61 patients, ^18F-FDG SPECT imaging detected more lesions than CT （P 〈 0. 01 ）. The correspondence rate of ^18F-FDG SPECT imaging with marrow histology was 80.3% （49/61）. （2） In early evaluation of the response to treatment, the accuracy, positive predictive value and negative predictive value of ^18F-FDG SPECT imaging was 85.7%, 92.0% and 76.5% , respectively, which is much higher than that of CT （64.3% , 75.0% and 50.0% ）, therefore, the therapeutic scheme in 21.4% （9/42） of these patients was changed by ^18F-FDG SPECT imaging. Of 17 cases with negative ^18F-FDG SPECT scan in early evaluation of therapy, clinical remission （13 complete remission and 3 partial remission） were achieved in 16 patients. Of the 25 patients with positive ones, 13 were considered as having progressive disease. （3）In the evaluation at the end of therapy or during follow-up, 58 ^18F-FDG SPECT imagings were performed in 26 patients. The specificity and positive predictive value were 85.7% and 68.4% versus 59.5% and 43.3%, respectively, by CT scan. Of 14 patients with residual masses detected by CT scan, 8 were diagnosed as complete remission （CR） by ^18F- FDG SPECT imaging based on persistently negative FDG scans ; The other 6 were interpreted as CR （ n = 1 ）, partial remission （ PR, n = 2）, non-remission （ n = 1 ） and progressive disease （ n = 2）, thus there was only one false-positive FDG scan in these 14 patients. Conclusion ^18F-FDG imaging is quite effective and superior to CT scan for malignant lymphoma in initial staging, evaluation of early response to therapy and after completion of therapy, and long-term follow-up, especially for evaluating the residual masse.