Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
Faculty of Medicine, University of Zurich, Zurich, Switzerland.
Int J Radiat Oncol Biol Phys. 2022 Nov 15;114(4):596-602. doi: 10.1016/j.ijrobp.2022.06.100. Epub 2022 Jul 28.
Oligometastatic disease refers to a distinct state in patients with cancer characterized by a low metastatic burden, with diagnosis being informed by a limited number of distant metastases in radiologic imaging. However, oligometastasis remains poorly understood in terms of its biology and prevalence in the metastatic cascade. In the absence of clinically viable molecular biomarkers, this study examined the prevalence of oligometastasis using oncological imaging.
This study is based on all consecutive [fluorine-18]-fluorodeoxyglucose (FDG)- and [gallium-68]-prostate specific membrane antigen (PSMA)-positron emission tomography (PET) scans conducted at our cancer center between January and December 2020. We identified and analyzed all PET scans from patients with a maximum of 5 distant metastases from a solid malignancy and also reviewed concurrent cranial magnetic resonance imaging (cMRI) imaging in all candidate patients. Data on the number and sites of metastases were extracted from the imaging reports and verified on imaging studies in case of uncertainties.
In total, 7000 PET scans were analyzed, of which 1155 were performed in unique metastatic patients, and 637 patients showed extracranial oligometastatic disease (55%). Concurrent cMRI scans were available for 20% (130/637) of extracranial oligometastatic patients, 36 of which proved to be polymetastatic after combined PET and cMRI analysis. Prevalence of oligometastatic disease was influenced by primary tumor histology and was most frequent in pancreatic, liver and gallbladder cancers (59%), but was least frequent in cancer of unknown primary (26%). In 72% of oligometastatic cases, only 1 or 2 metastases were detected. Bone/soft tissue metastases were the most common sites of distant metastasis (41%). About 75% of patients had metachronous oligometastatic disease.
Our analysis suggests that about half of patients with metastatic cancer are characterized by a limited tumor burden detectable on PET and cMRI imaging. This finding warrants intensified research efforts to better understand the biology of oligometastatic disease and to optimize multidisciplinary treatment strategies.
寡转移疾病是指癌症患者的一种特殊状态，其特征是转移负荷低，通过影像学检查发现少量远处转移来诊断。然而，寡转移在转移级联中的生物学和普遍性方面仍知之甚少。在缺乏可行的临床分子生物标志物的情况下，本研究使用肿瘤学影像学检查来检查寡转移的患病率。
本研究基于 2020 年 1 月至 12 月在我们癌症中心进行的所有连续[氟-18]-氟脱氧葡萄糖（FDG）和[镓-68]-前列腺特异膜抗原（PSMA）正电子发射断层扫描（PET）检查。我们从实体恶性肿瘤最多有 5 个远处转移的患者中识别和分析了所有 PET 扫描，并在所有候选患者中同时审查了颅磁共振成像（cMRI）图像。从影像学报告中提取转移数量和部位的数据，并在存在不确定性的情况下在影像学研究中进行验证。
总共分析了 7000 次 PET 扫描，其中 1155 次在独特的转移性患者中进行，637 例患者显示颅外寡转移疾病（55%）。颅外寡转移患者中有 20%（130/637）有同时进行的 cMRI 扫描，其中 36 例经 PET 和 cMRI 联合分析后证实为多灶性转移。寡转移疾病的患病率受原发肿瘤组织学的影响，在胰腺、肝脏和胆囊癌中最为常见（59%），但在不明原发灶的癌症中最为少见（26%）。在 72%的寡转移病例中，仅检测到 1 或 2 个转移灶。骨/软组织转移是远处转移最常见的部位（41%）。约 75%的患者患有同步寡转移疾病。
我们的分析表明，大约一半的转移性癌症患者的肿瘤负荷可通过 PET 和 cMRI 成像检测到。这一发现需要加强研究力度，以更好地了解寡转移疾病的生物学，并优化多学科治疗策略。
