Objectives:We investigated spatial patterns between primary and recurrent tumor sites and assessed long-term toxicity after dose escalation stereotactic body radiation therapy (SBRT) to the dominant intra-prostatic nodule (DIN).Materials and methods:In 33 patients with intermediate–high-risk prostate cancer (PCa), doses up to 50 Gy were administered to the DIN. Recurrence sites were determined and compared to the original tumor development sites through multiparametric MRI and68Ga-labeled prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (68Ga-PSMA-PET/CT) images. Overlap rates, categorized as 75% or higher for full overlap, and 25–74% for partial overlap, were assessed. Long-term toxicity is reported.Results: All patients completed treatment, with only one receiving concomitant androgen deprivation therapy (ADT). Recurrences were diagnosed after a median of 33 months (range: 17–76 months), affecting 13 out of 33 patients (39.4%). Intra-prostatic recurrences occurred in 7 patients (21%), with ≥75% overlap in two, a partial overlap in another two, and no overlap in the remaining three patients. Notably, five patients with intra-prostatic recurrences had synchronous bone and/or lymph node metastases, while six patients had isolated bone or lymph node metastasis without intra-prostatic recurrences. Extended follow-up revealed late grade ≥ 2 GU and GI toxicity in 18% (n = 6) and 6% (n = 2) of the patients.Conclusions: Among patients with intermediate–high-risk PCa undergoing focal dose-escalated SBRT without ADT, DIN recurrences were infrequent. When present, these recurrences were typically located at the original site or adjacent to the initial tumor. Conversely, relapses beyond the DIN and in extra-prostatic (metastatic) sites were prevalent, underscoring the significance of systemic ADT in managing this patient population.Advances in knowledge:Focal dose-escalated prostate SBRT prevented recurrences in the dominant nodule; however, extra-prostatic recurrence sites were frequent.
目的：本研究旨在探讨原发与复发肿瘤部位之间的空间分布模式，并评估对前列腺内优势结节（DIN）进行剂量递增立体定向体部放疗（SBRT）后的长期毒性反应。 材料与方法：本研究纳入33例中高危前列腺癌患者，对DIN靶区给予最高50 Gy的剂量照射。通过多参数磁共振成像及68Ga标记前列腺特异性膜抗原正电子发射断层扫描/计算机断层扫描（68Ga-PSMA-PET/CT）影像，确定复发部位并与原始肿瘤发生部位进行对比分析。评估重叠率（≥75%定义为完全重叠，25%-74%定义为部分重叠），并报告长期毒性反应。 结果：所有患者均完成治疗，仅1例患者同步接受雄激素剥夺治疗（ADT）。中位随访33个月（范围：17-76个月）后，33例患者中13例（39.4%）出现复发。其中7例（21%）发生前列腺内复发：2例为完全重叠，2例为部分重叠，3例无重叠。值得注意的是，5例前列腺内复发患者同时存在骨和/或淋巴结转移，另有6例患者出现孤立性骨或淋巴结转移而无前列腺内复发。长期随访显示，18%（n=6）和6%（n=2）的患者分别出现≥2级晚期泌尿系统与胃肠道毒性反应。 结论：在接受局部剂量递增SBRT且未联合ADT治疗的中高危前列腺癌患者中，DIN复发较为少见。当出现复发时，病灶通常位于原始部位或邻近初始肿瘤区域。相反，DIN区域外及前列腺外（转移性）部位的复发更为普遍，这凸显了系统性ADT在该患者群体治疗中的重要意义。 知识进展：局部剂量递增前列腺SBRT可有效预防优势结节内复发，但前列腺外复发部位仍较为常见。
肿瘤(癌症)患者之家