Pfannenberg A C, Oechsle K, Kollmannsberger C, Dohmen B M, Bokemeyer C, Bares R, Vontheim R, Claussen C D
Abteilung für Radiologische Diagnostik, Eberhard-Karls-Universität Tuebingen.
Rofo. 2004 Jan;176(1):76-84. doi: 10.1055/s-2004-814665.
To assess the ability of [(18)F]FDG-PET, CT/MRI and serum tumor marker (TM) for the early prediction of response in patients with metastatic germ cell tumors (GCT) undergoing salvage high-dose chemotherapy (HD-CTX).
Before commencement of HD-CTX, 19 patients with metastases from GCT were evaluated with [(18)F]FDG-PET, CT or MRI and TM after 2-3 cycles of induction chemotherapy and the results compared with those of the baseline examinations. PET was analyzed visually and quantitatively by calculating the standard uptake value (SUV). CT or MRI was evaluated for changes in tumor size (progressive disease/stable disease PD/SD = viable lesion; partial remission/complete remission PR/CR = nonviable lesion), density or signal intensity, homogeneity and contrast enhancement. For the prognosis, the worse case, i.e., the most vital lesion detected in a patient, was considered. The reference standard was the result of the histology after resection of any residual masses (N = 10) and/or the clinical-radiological follow-up for at least 6 months after completion of the treatment (N = 9).
Six of nineteen patients (32 %) remained progression-free for over 6 months following treatment, whereas 13 (68 %) progressed. The outcome of HD-CTX was correctly predicted by PET, CT and TM in 89 %, 67 % and 88 %, respectively. In 5 of 6 patients with successful HD-CTX, PET was negative (mean SUV = 1.8), with CT or MRI showing a partial regression of the tumor in 4 of 5 patients. Of the 13 patients not cured by HD-CTX, the PET data were positive in all (mean SUV = 2.7), and the CT/MRI results were true positive (PD or SD) in 8 and false negative (PR) in 5 patients. The combined assessment of CT and TM corrected 3 false negative prognoses and 1 false positive CT prognosis. Two patients with unfavorable outcome despite a favorable response by CT and TM criteria were exclusively identified by PET. The resultant sensitivities and specificities for the prediction of therapy response are as follows: PET 100% and 67%; CT/MRI 62% and 80%; TM 83% and 100%; CT+TM 85% and 83%.
FDG-PET has a high prognostic value for predicting the response to chemotherapy in patients with metastatic GCT early in the course of treatment and may improve patient selection for subsequent HD-CTX protocols. Especially in patients with response to induction chemotherapy according to CT or TM evaluation, PET offers additional information to detect patients with an overall unfavorable outcome.
评估[(18)F]氟代脱氧葡萄糖正电子发射断层扫描（[(18)F]FDG-PET）、计算机断层扫描（CT）/磁共振成像（MRI）及血清肿瘤标志物（TM）对接受挽救性大剂量化疗（HD-CTX）的转移性生殖细胞肿瘤（GCT）患者早期反应预测的能力。
在HD-CTX开始前，对19例GCT转移患者在诱导化疗2 - 3个周期后进行[(18)F]FDG-PET、CT或MRI及TM评估，并将结果与基线检查结果进行比较。通过计算标准摄取值（SUV）对PET进行视觉和定量分析。对CT或MRI评估肿瘤大小变化（疾病进展/疾病稳定PD/SD = 存活病灶；部分缓解/完全缓解PR/CR = 非存活病灶）、密度或信号强度、均匀性及对比增强情况。对于预后，考虑最差情况，即患者中检测到的最关键病灶。参考标准为切除任何残留肿块后的组织学结果（N = 10）和/或治疗完成后至少6个月的临床 - 放射学随访结果（N = 9）。
19例患者中有6例（32%）治疗后无进展超过6个月，而13例（68%）病情进展。PET、CT和TM对HD-CTX结果的正确预测率分别为89%、67%和88%。在6例HD-CTX成功的患者中，5例PET为阴性（平均SUV = 1.8），5例中有4例CT或MRI显示肿瘤部分消退。在13例未通过HD-CTX治愈的患者中，所有患者的PET数据均为阳性（平均SUV = 2.7），CT/MRI结果在8例中为真阳性（PD或SD），5例为假阴性（PR）。CT和TM的联合评估纠正了3例假阴性预后和1例假阳性CT预后。PET单独识别出2例尽管CT和TM标准显示反应良好但预后不良的患者。预测治疗反应的敏感性和特异性结果如下：PET为100%和67%；CT/MRI为62%和80%；TM为83%和100%；CT + TM为85%和83%。
FDG-PET在转移性GCT患者治疗早期对化疗反应预测具有较高的预后价值，可能改善后续HD-CTX方案的患者选择。特别是在根据CT或TM评估对诱导化疗有反应的患者中，PET可提供额外信息以检测总体预后不良的患者。
