PURPOSE To define positron emission tomography/computed tomography (PET/CT) imaging characteristics during follow-up of patients with metastatic breast cancer (MBC) treated with yttrium-90 (Y90) radioembolization (RE). MATERIALS AND METHODS From January 2011 to October 2017, 30 MBC patients underwent 38 Y90 glass or resin RE treatments. Pre-RE PET/CT was performed on average 51 days before RE. There were 68 PET/CTs performed after treatment. Response was assessed using modified PERCIST criteria focusing on the hepatic territory treated with RE, normalizing SUVpeak to the mean SUV of liver uninvolved by tumor. An objective response (OR) was defined as a decrease in SUVpeak by at least 30%. RESULTS Of the 68 post-RE scans, 6 were performed at 0-30 days, 15 at 31-60 days, 9 at 61-90 days, 13 at 91-120 days, 14 scans at 121-180 days, and 11 scans at > 180 days after RE. Of the 30 patients, 25 (83%) achieved OR on at least one follow-up. Median survival was 15 months after the first RE administration. Highest response rates occurred at 30-90 days, with over 75% of cases demonstrating OR at that time. After 180 days, OR was seen in only 25%. There was a median TTP of 169 days among responders. CONCLUSION In MBC, follow-up PET/CT after RE demonstrates optimal response rates at 30-90 days, with progression noted after 180 days. These results help to guide the timing of imaging and also to inform patients of expected outcomes after RE.

中文翻译：

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乳腺癌肝转移放射性栓塞后的PET / CT成像特征。

目的定义在接受Yttrium-90（Y90）放射栓塞（RE）治疗的转移性乳腺癌（MBC）患者随访期间的正电子发射断层扫描/计算机断层扫描（PET / CT）成像特征。材料与方法从2011年1月至2017年10月，30例MBC患者接受了38例Y90玻璃或树脂RE治疗。RE-RE前的PET / CT平均在RE前51天进行。治疗后进行了68例PET / CT。使用修改后的PERCIST标准评估反应，重点是RE治疗的肝区，将SUVpeak标准化为未受肿瘤累及的肝脏平均SUV。客观反应（OR）定义为SUVpeak降低至少30％。结果在68次RE后扫描中，在0-30天进行了6次扫描，在31-60天进行了15次，在61-90天进行了9次，在91-120天进行了13次，在121-180天进行了14次扫描，在RE后超过180天进行11次扫描。在30例患者中，有25例（83％）在至少一次随访中达到了OR。中位生存期为首次RE给药后15个月。最高的响应率发生在30-90天，当时超过75％的病例表现为OR。180天后，仅看到25％的OR。响应者中的TTP中位数为169天。结论在MBC中，RE后的随访PET / CT显示30-90天的最佳缓解率，并在180天后出现进展。这些结果有助于指导影像学的时机，也可以告知患者RE后的预期结果。当时有超过75％的案例显示OR。180天后，仅看到25％的OR。响应者中的TTP中位数为169天。结论在MBC中，RE后的随访PET / CT显示30-90天的最佳缓解率，并在180天后出现进展。这些结果有助于指导影像学的时机，也可以告知患者RE后的预期结果。当时有超过75％的案例显示OR。180天后，仅看到25％的OR。响应者中的TTP中位数为169天。结论在MBC中，RE后的随访PET / CT显示30-90天的最佳缓解率，并在180天后出现进展。这些结果有助于指导影像学的时机，也可以告知患者RE后的预期结果。