Department of Nuclear Medicine, Heidelberg University Hospital, Heidelberg, Germany.
Department of Nuclear Medicine, Bern University Hospital, Freiburgstrasse 18, 3010, Bern, Switzerland.
Eur J Nucl Med Mol Imaging. 2018 Nov;45(12):2045-2054. doi: 10.1007/s00259-018-4079-z. Epub 2018 Jul 7.
Since the introduction of PSMA PET/CT with Ga-PSMA-11, this modality for imaging prostate cancer (PC) has spread worldwide. Preclinical studies have demonstrated that short-term androgen deprivation therapy (ADT) can significantly increase PSMA expression on PC cells. Additionally, retrospective clinical data in large patient cohorts suggest a positive association between ongoing ADT and a pathological PSMA PET/CT scan. The present evaluation was conducted to further analyse the influence of long-term ADT on PSMA PET/CT findings.
A retrospective analysis was performed of all 1,704 patients who underwent a Ga-PSMA-11 PET/CT scan at our institution from 2011 to 2017 to detect PC. Of 306 patients scanned at least twice, 10 had started and continued ADT with a continuous clinical response between the two PSMA PET/CT scans. These ten patients were included in the current analysis which compared the tracer uptake intensity and volume of PC lesions on PSMA PET/CT before and during ongoing ADT.
Overall, 31 PC lesions were visible in all ten patients before initiation of ADT. However, during ongoing ADT (duration 42-369 days, median 230 days), only 14 lesions were visible in eight of the ten patients. The average tracer uptake values decreased in 71% and increased in 12.9% of the PC lesions. Of all lesions, 33.3% were still visible in six patients with a complete PSA response (≤0.1 ng/ml).
Continuous long-term ADT significantly reduces the visibility of castration-sensitive PC on PSMA PET/CT. If the objective is visualization of the maximum possible extent of disease, we recommend referring patients for PSMA PET/CT before starting ADT.
自从引入 Ga-PSMA-11 后，这种前列腺癌（PC）成像的 PSMA PET/CT 技术已在全球范围内得到推广。临床前研究表明，短期去势治疗（ADT）可显著增加 PC 细胞上的 PSMA 表达。此外，大样本患者队列的回顾性临床数据表明，持续 ADT 与病理 PSMA PET/CT 扫描之间存在正相关。本次评估旨在进一步分析长期 ADT 对 PSMA PET/CT 结果的影响。
对 2011 年至 2017 年在我院接受 Ga-PSMA-11 PET/CT 扫描以检测 PC 的 1704 例患者进行了回顾性分析。在两次以上扫描的 306 例患者中，有 10 例在两次 PSMA PET/CT 扫描之间开始并持续接受 ADT 治疗，且具有持续的临床反应。这 10 例患者被纳入本研究，比较了 ADT 期间和 ADT 期间 PC 病变的示踪剂摄取强度和体积。
总体而言，在开始 ADT 之前，所有 10 例患者均可见 31 个 PC 病变。然而，在持续 ADT 期间（持续时间 42-369 天，中位数 230 天），10 例患者中有 8 例仅可见 14 个病变。71%的 PC 病变的示踪剂摄取值降低，12.9%的病变的示踪剂摄取值增加。在所有病变中，6 例 PSA 完全缓解（≤0.1ng/ml）的患者中仍有 33.3%可见病变。
持续的长期 ADT 显著降低了 PSMA PET/CT 对去势敏感型 PC 的可见性。如果目的是观察疾病的最大可能范围，我们建议在开始 ADT 之前让患者进行 PSMA PET/CT 检查。
