This study evaluated the ability of 18F-Fluorodeoxyglucose (FDG) and 18F-Fluorothymidine (FLT) imaging with positron emission tomography (PET) to measure early response to endocrine therapy from baseline to just prior to surgical resection in estrogen receptor positive (ER+) breast tumors. In two separate studies, women with early stage ER+ breast cancer underwent either paired FDG-PET (n = 22) or FLT-PET (n = 27) scans prior to endocrine therapy and again in the pre-operative setting. Tissue samples for Ki-67 were taken for all patients both prior to treatment and at the time of surgery. FDG maximum standardized uptake value (SUVmax) declined in 19 of 22 lesions (mean 17% (range −45 to 28%)). FLT SUVmax declined in 24 of 27 lesions (mean 26% (range −77 to 7%)). The Ki-67 index declined in both studies, from pre-therapy (mean 23% (range 1 to 73%)) to surgery [mean 8% (range < 1 to 41%)]. Pre- and post-therapy PET measures showed strong rank-order agreement with Ki-67 percentages for both tracers; however, the percent change in FDG or FLT SUVmax did not demonstrate a strong correlation with Ki-67 index change or Ki-67 at time of surgery. A window-of-opportunity approach using PET imaging to assess early response of breast cancer therapy is feasible. FDG and FLT-PET imaging following a short course of neoadjuvant endocrine therapy demonstrated measurable changes in SUVmax in early stage ER+ positive breast cancers. The percentage change in FDG and FLT-PET uptake did not correlate with changes in Ki-67; post-therapy SUVmax for both tracers was significantly associated with post-therapy Ki-67, an established predictor of endocrine therapy response.

中文翻译：

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18F-氟脱氧葡萄糖 (FDG) PET 或 18F-氟胸苷 (FLT) PET 在机会窗口研究中评估 ER+ 可手术乳腺癌女性对芳香化酶抑制剂 (AI) 的早期反应

本研究评估了 18F-氟脱氧葡萄糖 (FDG) 和 18F-氟胸苷 (FLT) 成像与正电子发射断层扫描 (PET) 测量雌激素受体阳性 (ER+) 乳腺从基线到手术切除前对内分泌治疗的早期反应的能力肿瘤。在两项独立的研究中，患有早期 ER+ 乳腺癌的女性在内分泌治疗前和术前环境中再次接受配对 FDG-PET (n = 22) 或 FLT-PET (n = 27) 扫描。在治疗前和手术时对所有患者采集 Ki-67 的组织样本。FDG 最大标准化摄取值 (SUVmax) 在 22 个病灶中的 19 个中下降（平均 17%（范围 -45 至 28%））。FLT SUVmax 在 27 个病灶中有 24 个下降（平均 26%（范围 -77 至 7%））。Ki-67 指数在两项研究中均有所下降，从治疗前（平均 23%（范围 1 至 73%））到手术 [平均 8%（范围 < 1 至 41%）]。治疗前和治疗后的 PET 测量显示两种示踪剂与 Ki-67 百分比的排序一致；然而，FDG 或 FLT SUVmax 的百分比变化并未证明与 Ki-67 指数变化或手术时 Ki-67 有很强的相关性。使用 PET 成像评估乳腺癌治疗早期反应的机会窗口方法是可行的。短期新辅助内分泌治疗后的 FDG 和 FLT-PET 成像显示早期 ER+ 阳性乳腺癌的 SUVmax 发生了可测量的变化。FDG 和 FLT-PET 摄取的百分比变化与 Ki-67 的变化无关；两种示踪剂的治疗后 SUVmax 与治疗后 Ki-67 显着相关，