Division of Molecular Imaging and Theranostics, Department of Nuclear Medicine, University Hospital, Paracelsus Medical University Salzburg, Muellner Hauptstrasse 48, 5020, Salzburg, Austria.
Joint Department of Medical Imaging, University Medical Imaging Toronto (UMIT), University Health Network, Mount Sinai Hospital & Women's College Hospital; University of Toronto, Toronto, ON, Canada.
Mol Imaging Biol. 2024 Apr;26(2):360-369. doi: 10.1007/s11307-024-01900-6. Epub 2024 Feb 15.
To assess the prognostic value of pre-treatment [Ga]Ga-PSMA-11 PET/CT and other baseline clinical characteristics in predicting prostate cancer (PCa) patients response to [Lu]Lu-PSMA (PSMA-I&T), as well as patient survival.
In this retrospective study, 81 patients who received [Lu]Lu-PSMA-I&T between October 2018 and January 2023 were reviewed. Eligible patients had metastatic castration-resistant PCa, underwent pre-treatment [Ga]Ga-PSMA-11 PET/CT, and had serum prostate-specific antigen (PSA) levels available. On PET/CT images, SUVmax, SULmax, SUVpeak, and SULpeak of the most-avid tumoral lesion, as well as SUVmean of the parotid gland (P-SUVmean) and liver (L-SUVmean), were measured. Also, whole-body PSMA tumour volume (PSMA-TV) and total lesion PSMA (TL-PSMA) were calculated. To interpret treatment response after [Lu]Lu-PSMA-I&T, a composite of PSA values and [Ga]Ga-PSMA-11 PET/CT findings were considered. The outcomes were dichotomised into progressive versus controlled (stable disease or partial response) disease. Then, the association of baseline parameters with patient response was evaluated. Also, survival analyses were performed to assess baseline parameters in predicting overall survival.
Sixty patients (age:73 ± 8, PSA:185 ± 371) were included. Patients received at least one cycle of [Lu]Lu-PSMA therapy (median = 4). Overall, half of the patients showed disease progression. In the progressive versus controlled disease evaluation, the highest SULmax, as well as SUVmax and SULmax to both backgrounds (L-SUVmean and P-SUVmean), were significantly correlated with the outcome (p-values < 0.05). In the multivariate analysis, only SULmax to the L-SUVmean remained significant (p-value = 0.038). The best cut-off was 8 (AUC = 0.71). With a median follow-up of 360 days, 11 mortal events were documented. In the multivariate survival analysis, only SULmax to P-SUVmean (cut-off = 2.4; p-value = 0.043) retained significance (hazard ratio = 4.0).
A greater level of PSMA uptake, specifically higher tumour-to-background uptake in the hottest lesion, may hold substantial prognostic significance, considering both [Lu]Lu-PSMA-I&T response and patient survival. These ratios may have the potential to be used for PCa patient selection for radioligand therapy.
评估治疗前[Ga]Ga-PSMA-11 PET/CT 和其他基线临床特征对预测前列腺癌（PCa）患者对[Lu]Lu-PSMA（PSMA-I&T）反应以及患者生存的预后价值。
本回顾性研究纳入了 2018 年 10 月至 2023 年 1 月期间接受[Lu]Lu-PSMA-I&T 治疗的 81 例转移性去势抵抗性 PCa 患者。合格患者需具备以下特征：接受治疗前[Ga]Ga-PSMA-11 PET/CT 检查、血清前列腺特异性抗原（PSA）水平可测、患有 PCa。在 PET/CT 图像上，测量最活跃肿瘤病灶的 SUVmax、SULmax、SUVpeak 和 SULpeak，以及腮腺（P-SUVmean）和肝脏（L-SUVmean）的 SUVmean。此外，计算全身 PSMA 肿瘤体积（PSMA-TV）和总病变 PSMA（TL-PSMA）。为了对[Lu]Lu-PSMA-I&T 治疗后的反应进行解释，综合考虑 PSA 值和[Ga]Ga-PSMA-11 PET/CT 结果。将结果分为进展与控制（疾病稳定或部分缓解）。然后，评估基线参数与患者反应的相关性。还进行了生存分析，以评估基线参数对总生存的预测。
60 例患者（年龄：73±8 岁，PSA：185±371）被纳入研究。患者至少接受了一个周期的[Lu]Lu-PSMA 治疗（中位数=4）。总体而言，一半的患者出现疾病进展。在进展与控制疾病的评估中，最高的 SULmax 以及 SUVmax 和 SULmax 与背景（L-SUVmean 和 P-SUVmean）之间的比值与结果显著相关（p 值均<0.05）。在多变量分析中，只有 SULmax 与 L-SUVmean 之间的比值仍然具有统计学意义（p 值=0.038）。最佳截断值为 8（AUC=0.71）。中位随访 360 天，记录到 11 例死亡事件。在多变量生存分析中，只有 SULmax 与 P-SUVmean（截断值=2.4；p 值=0.043）保留显著意义（风险比=4.0）。
在考虑[Lu]Lu-PSMA-I&T 反应和患者生存时，PSMA 摄取水平较高，特别是最活跃病灶中的肿瘤与背景摄取比值较高，可能具有重要的预后意义。这些比值可能有潜力用于选择进行放射性配体治疗的 PCa 患者。
