淋巴瘤化疗后行受侵区域PET-CT扫描评价疗效的可行性研究

目的 为降低辐射剂量,探讨淋巴瘤化疗后采用受侵区域PET-CT扫描评价疗效的可行性。方法 回顾性分析53例化疗前、后均行全身PET-CT扫描的淋巴瘤初诊患者。将化疗前PET-CT所示的淋巴瘤侵犯范围定义为受侵区域,化疗后假设采用受侵区域PET-CT扫描,比较其与全身PET-CT扫描在疗效评价方面的差异。对全身和受侵区域PET-CT扫描疗效评价结果一致者,比较其有效剂量和扫描时间的差异。结果 在评价淋巴瘤化疗后疗效方面,全身PET-CT扫描示37例达到完全缓解(CR)、13例部分缓解(PR)、3例进展(PD),受侵区域PET-CT示37例达到CR、14例PR、2例PD。37例CR者全身和受侵区域PET-CT扫描的有效剂量分别为(15.0±1.7)和(12.0±2.5)mSv(Z=-5.307,P<0.05)、扫描时间分别为(19.5±2.6)与(11.3±4.4)s(Z=-5.324,P<0.05)。结论 化疗后达到CR者行受侵区域PET-CT扫描,其疗效与全身PET-CT扫描相同,减少了PET-CT扫描的有效剂量和时间。化疗后PR或PD者受侵区域PET-CT扫描的疗效评价结果与全身扫描不同,应行全身PET-CT扫描评价化疗后疗效。

Minimizing radiation dose with PET-CT limited to involved sites in the assessment of postchemotherapy lymphoma

Objective To assess PET-CT scanning limited to involved sites in postchemotherapy lymphoma and explore possible radiation dose reductions. Methods Fifty-three lymphoma patients with prechemotherapy and postchemotherapy whole-body PET-CT were analyzed retrospectively. The involved sites were determined on prechemotherapy PET-CT scanning. Whole-body PET-CT scanning and hypothetical PET-CT limited to involved sites were compared in assessing clinical response to chemotherapy. The potential reductions in effective dose and total acquisition time achieved with PET-CT scanning limited to involved sites were calculated. Results Whole-body PET-CT scanning revealed CR in 37 cases, PR in 13 cases and PD in 3 cases in postchemotherapy lymphoma patients, while PET-CT scanning limited to involved sites revealed CR in 37 cases, PR in 14 cases and PD in 2 cases. The mean effective dose was (15.0±1.7) mSv for per patients of CR with whole-body PET-CT scanning, and was (12.0±2.5) mSv for per patients of CR with PET-CT scanning limited in involved sites (Z=-5.307,P<0.05). The mean acquisition time was (19.5±2.6)s for per patients of CR with whole-body PET-CT scanning, and (11.3±4.4)s for per patient of CR with PET-CT scanning limited in involved sites (Z=-5.324,P<0.05).Conclusions Response assessment with PET-CT scanning limited in involved sites has good agreement with whole-body PET-CT scanning in postchemotherapy lymphoma patients with CR. Lymphoma patients with CR may benefit from reduced radiation dose and total acquisition time. PET-CT scanning limited in involved sites is not advisable in patients with PR or PD for poor agreement with whole-body PET-CT scanning in response assessment.