From the Department of Radiology and Imaging Sciences, Emory University, Atlanta, GA.
Biostatics Shared Resource.
Clin Nucl Med. 2023 Apr 1;48(4):e153-e159. doi: 10.1097/RLU.0000000000004590. Epub 2023 Feb 8.
We aimed to evaluate the impact of 18 F-fluciclovine PET/CT imaging on failure-free survival (FFS) post-salvage radiotherapy (SRT) for prostate cancer (PCa) recurrence.
Seventy-nine patients were recruited in a phase 2/3 clinical trial to undergo 18 F-fluciclovine PET/CT before SRT for PCa. Four patients with extrapelvic disease were excluded. All patients were followed up at regular intervals up to 48 months. Treatment failure was defined as a serum prostate-specific antigen level of ≥0.2 ng/mL above the nadir after SRT, confirmed with an additional measurement, requiring systemic treatment or clinical progression. Failure-free survival was computed and compared between patients grouped according to 18 F-fluciclovine PET/CT imaging findings.
Eighty percent (60/75) of patients had a positive finding on 18 F-fluciclovine PET/CT, of which 56.7% (34/60) had prostate bed-only uptake, whereas 43.3% (26/60) had pelvic nodal ± bed uptake. Following SRT, disease failure was detected in 36% (27/75) of patients. There was a significant difference in FFS between patients who had a positive versus negative scan (62.3% vs 92.9% [ P < 0.001] at 36 months and 59.4% vs 92.9% [ P < 0.001] at 48 months). Similarly, there was a significant difference in FFS between patients with uptake in pelvic nodes ± bed versus prostate bed only at 36 months (49.8% vs 70.7%; P = 0.003) and at 48 months (49.8% vs 65.6%; P = 0.040). Failure-free survival was also significantly higher in patients with either negative PET/CT or prostate bed-only disease versus those with pelvic nodal ± prostate bed disease at 36 (78% vs 49.8%, P < 0.001) and 48 months (74.4% vs 49.8%, P < 0.001).
Findings on pre-SRT 18 F-fluciclovine PET/CT imaging, even when acted upon to optimize the treatment decisions and treatment planning, are predictive of post-SRT FFS in men who experience PCa recurrence after radical prostatectomy. A negative 18 F-fluciclovine PET/CT is most predictive of a lower risk of failure, whereas the presence of pelvic nodal recurrence portends a higher risk of SRT failure.
我们旨在评估 18 F-氟代赖氨酸 PET/CT 成像对前列腺癌（PCa）复发后挽救性放疗（SRT）后无失败生存（FFS）的影响。
79 名患者参加了一项 2/3 期临床试验，在 SRT 前接受 18 F-氟代赖氨酸 PET/CT 检查。排除 4 名患有骨盆外疾病的患者。所有患者均定期随访，最长随访时间为 48 个月。治疗失败定义为 SRT 后血清前列腺特异性抗原（PSA）水平高于最低点且上升≥0.2ng/ml，需要进行全身治疗或临床进展。计算并比较了根据 18 F-氟代赖氨酸 PET/CT 成像结果分组的患者的无失败生存率。
80%（75 例中有 60 例）的患者 18 F-氟代赖氨酸 PET/CT 检查结果阳性，其中 56.7%（60 例中有 34 例）仅前列腺床摄取，而 43.3%（60 例中有 26 例）为骨盆淋巴结±床摄取。SRT 后，36%（75 例中有 27 例）的患者出现疾病复发。与扫描阴性的患者相比，扫描阳性的患者的 FFS 有显著差异（36 个月时为 62.3%比 92.9%[P<0.001]，48 个月时为 59.4%比 92.9%[P<0.001]）。同样，在 36 个月时（49.8%比 70.7%；P=0.003）和 48 个月时（49.8%比 65.6%；P=0.040），骨盆淋巴结±床摄取与仅前列腺床摄取的患者的 FFS 有显著差异。在 36 个月（78%比 49.8%，P<0.001）和 48 个月（74.4%比 49.8%，P<0.001）时，PET/CT 阴性或仅前列腺床疾病的患者的 FFS 也显著高于骨盆淋巴结±前列腺床疾病的患者。
SRT 前 18 F-氟代赖氨酸 PET/CT 成像的结果，即使在优化治疗决策和治疗计划时得到应用，也可预测根治性前列腺切除术后 PCa 复发患者的 SRT 后 FFS。阴性 18 F-氟代赖氨酸 PET/CT 对失败风险较低的预测性最强，而骨盆淋巴结复发预示着 SRT 失败的风险更高。
