Department of Medical Oncology, Peter MacCallum Cancer Centre, 305 Grattan St, 3031, Melbourne, VIC, Australia.
Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, VIC, Australia.
Cancer Imaging. 2022 Oct 8;22(1):58. doi: 10.1186/s40644-022-00496-w.
Survivors of testicular cancer may experience long-term morbidity following treatment. There is an unmet need to investigate techniques that can differentiate individuals who need additional therapy from those who do not. 2-fluoro-deoxy-D-glucose (FDG) positron emission tomography (PET) with computerised tomography (CT) may be helpful in select settings and may be used outside of current evidence-based recommendations in real-world practice.
A institutional FDG-PET/CT database of scans performed between 2000 and 2020 for adults with testicular seminoma was interrogated. Endpoints of interest included the positive (PPV) and negative (NPV) predictive value of FDG-PET/CT for identifying active seminoma (defined by progressive radiology, response to treatment or biopsy); or no active seminoma within 24-months for patients with stage 1 and advanced seminoma. An exploratory analysis examining predictive role of SUV was also performed.
249 patients met eligibility criteria for the analysis, including 184 patients with stage 1 and 77 patients with advanced testicular seminoma. Of 193 FDG-PET/CT performed in stage 1 seminoma with available follow-up data, 79 were performed during active surveillance. 18 (23%) of these were positive, all of which had confirmed recurrent seminoma (PPV 100%). Of 45 negative FDG-PET/CT during active surveillance, 4 recurrences developed corresponding to a NPV 91%. When clinical suspicion precipitated FDG-PET/CT (n = 36): PPV 100%, NPV 86%. Of 145 FDG-PET/CT in advanced seminoma with available follow-up data, 25 (17%) were performed at baseline (within 2 months of diagnosis), 70 (48%) post-treatment for evaluation of treatment response and 50 (34%) during follow-up following prior curative treatment. 10 (14%) post-treatment FDG-PET/CT were positive corresponding to a PPV 60%. Of 46 negative FDG-PET/CT, 5 recurrences occurred (NPV 89%). During follow-up after prior curative treatment, 24 (50%) FDG-PET/CT were positive corresponding to a PPV 83%; of 20 negative FDG-PET/CT, 1 recurrence occurred, NPV 95%. When clinical suspicion indicated FDG-PET/CT (n = 36): PPV 100%, NPV 94%.
FDG-PET/CT offers high PPV for identifying seminoma and accurately predicts non-recurrence across a clinically relevant 24-months. Notably, FDG-PET/CT may prevent unnecessary treatment in 45% of patients undergoing investigation for clinical suspicion of recurrence during follow-up of advanced seminoma. The use of FDG-PET/CT in selected patients now, may help prevent unnecessary treatment of people with testicular seminoma.
睾丸癌幸存者在治疗后可能会长期出现发病。目前需要研究能够区分需要额外治疗和不需要额外治疗的个体的技术。2-氟脱氧-D-葡萄糖（FDG）正电子发射断层扫描（PET）结合计算机断层扫描（CT）在某些情况下可能会有所帮助，并且可能在实际实践中超出当前基于证据的建议而被使用。
对 2000 年至 2020 年间进行的患有睾丸精原细胞瘤的成年人的机构 FDG-PET/CT 数据库进行了查询。感兴趣的终点包括 FDG-PET/CT 对识别活跃精原细胞瘤（定义为影像学进展、对治疗的反应或活检）的阳性（PPV）和阴性（NPV）预测值；或对于 1 期和晚期精原细胞瘤患者，24 个月内无活跃精原细胞瘤。还进行了探索性分析，以检查 SUV 的预测作用。
249 名患者符合分析条件，包括 184 名 1 期和 77 名晚期睾丸精原细胞瘤患者。在有随访数据的 193 例 1 期精原细胞瘤的 FDG-PET/CT 中，79 例在主动监测期间进行。其中 18 例（23%）为阳性，均证实为复发性精原细胞瘤（PPV 100%）。在 45 例主动监测期间的阴性 FDG-PET/CT 中，有 4 例发生了复发，NPV 为 91%。当临床怀疑引发 FDG-PET/CT 时（n=36）：PPV 100%，NPV 86%。在有随访数据的 145 例晚期精原细胞瘤的 FDG-PET/CT 中，25 例（17%）在基线（诊断后 2 个月内）进行，70 例（48%）在治疗后进行以评估治疗反应，50 例（34%）在先前治愈性治疗后进行随访。在治疗后进行的 10 例 FDG-PET/CT 中有 10 例（14%）为阳性，相应的 PPV 为 60%。在 46 例阴性 FDG-PET/CT 中，有 5 例发生复发（NPV 89%）。在先前治愈性治疗后的随访中，有 24 例（50%）FDG-PET/CT 为阳性，相应的 PPV 为 83%；在 20 例阴性 FDG-PET/CT 中，有 1 例发生复发，NPV 为 95%。当临床怀疑指示 FDG-PET/CT 时（n=36）：PPV 100%，NPV 94%。
FDG-PET/CT 对识别精原细胞瘤具有高 PPV，并能准确预测 24 个月内的非复发情况。值得注意的是，FDG-PET/CT 可能会阻止在晚期精原细胞瘤随访中因临床怀疑复发而接受调查的 45%的患者接受不必要的治疗。现在在选定的患者中使用 FDG-PET/CT，可能有助于防止不必要的睾丸精原细胞瘤治疗。
