Radiation Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD.
Molecular Imaging Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD.
Brachytherapy. 2022 Jul-Aug;21(4):442-450. doi: 10.1016/j.brachy.2022.03.009. Epub 2022 May 4.
PURPOSE/OBJECTIVE(S): This study describes the pattern of failure in patients with biochemical (BCR) recurrence after low-dose-rate (LDR) brachytherapy as a component of definitive treatment for prostate cancer.
Patients with BCR after LDR brachytherapy ± external beam radiation therapy (EBRT) were enrolled on prospective IRB approved advanced imaging protocols. Patients underwent 3T multiparametric MRI (mpMRI); a subset underwent prostate specific membrane antigen (PSMA)-based PET/CT. Pathologic confirmation was obtained unless contraindicated.
Between January 2011 and April 2021, 51 patients with BCR after brachytherapy (n = 36) or brachytherapy + EBRT (n = 15) underwent mpMRI and were included in this analysis. Of 38 patients with available dosimetry, only two had D90<90%. The prostate and seminal vesicles were a site of failure in 66.7% (n = 34) and 39.2% (n = 20), respectively. PET/CT (n = 32 patients) more often identified lesions pelvic lymph nodes (50%; n = 16) and distant metastases (18.8%; n = 6), than mpMRI. Isolated nodal disease (9.8%; n = 5) and distant metastases (n = 1) without local recurrence were uncommon. Recurrence within the prostate was located in the transition zone in 48.5%, central or midline in 45.5%, and anterior in 36.4% of patients.
In this cohort of patients with BCR after LDR brachytherapy ± EBRT, the predominant recurrence pattern was local (prostate ± seminal vesicles) with frequent occurrence in the anterior prostate and transition zone. mpMRI and PSMA PET/CT provided complementary information to localize sites of recurrence, with PSMA PET/CT often confirming mpMRI findings and identifying occult nodal or distant metastases.
本研究描述了低剂量率（LDR）近距离放射治疗后生化复发（BCR）患者的失败模式，作为前列腺癌确定性治疗的一部分。
纳入了 LDR 近距离放射治疗后发生 BCR 的患者，这些患者接受了前瞻性 IRB 批准的高级影像学方案。所有患者均接受了 3T 多参数 MRI（mpMRI）检查；部分患者还接受了前列腺特异性膜抗原（PSMA）PET/CT 检查。除非有禁忌证，否则均进行了病理证实。
2011 年 1 月至 2021 年 4 月，51 例接受 LDR 近距离放射治疗（n=36）或近距离放射治疗+外照射放射治疗（n=15）后发生 BCR 的患者接受了 mpMRI 检查，并纳入本分析。在 38 例可获得剂量学数据的患者中，只有 2 例的 D90<90%。前列腺和精囊分别是 66.7%（n=34）和 39.2%（n=20）失败的部位。PET/CT（n=32 例患者）比 mpMRI 更常识别出盆腔淋巴结（50%；n=16）和远处转移（18.8%；n=6）的病变。孤立的淋巴结疾病（9.8%；n=5）和无局部复发的远处转移（n=1）则较为少见。前列腺内复发位于移行区 48.5%、中央或中线区 45.5%、前区 36.4%。
在 LDR 近距离放射治疗±外照射放射治疗后发生 BCR 的患者队列中，主要的复发模式是局部（前列腺+精囊），在前部和移行区常见。mpMRI 和 PSMA PET/CT 提供了定位复发部位的互补信息，PSMA PET/CT 通常可证实 mpMRI 发现，并可识别隐匿性淋巴结或远处转移。
