Abstract：
OBJECTIVE: To assess the early metabolic response of the primary tumor using Gallium-68 (68Ga)-labeled-prostate-specific membrane antigen positron emission tomography (68Ga-PSMA-PET/CT), as well as the relationship between PSMA change in the primary tumor and PSA response after definitive radiotherapy (RT), either alone or in combination with androgen deprivation therapy (ADT) in intermediate risk prostate cancer (IR-PCa) patients.
METHODS: The clinical data of 71 IR-PCa patients treated with RT alone (36 patients, 50.7%) or RT and ADT (35 patients, 49.3%) were retrospectively analyzed. The difference between pre- and Posttreatment primary tumor PSMA expression and serum PSA values measured 4 months after completion of treatment were compared between treatment arms. Correlation between primary tumor metabolic response and serum PSA changes was analyzed.
RESULTS: The median duration between pre- and Posttreatment 68Ga-PSMA-PET/CT for the entire patient population was 6.9 months (range, 5.6-8.4 months), and it was similar in both treatment arms. A decrease in primary tumor maximum standardized uptake value (SUVmax) was seen in 66 patients (93.0%), with a median value of 61.2%, which is significantly lower in patients undergoing RT alone than those undergoing RT and ADT (45.1 ± 30.6% vs. 59.1 ± 24.7%; p = 0.004). The complete metabolic response rate was significantly higher in patients undergoing RT and ADT than those treated with RT alone (40% vs. 0%; p < 0.001). Although moderate and positive correlation between pretreatment SUVmax and oosttreatment SUVmax was observed, there was no significant correlation between SUV change and PSA change. For patients treated with RT and ADT, posttreatment SUVmax was significantly lower and SUV change was significantly higher in patients with PSA nadir than in those without.
CONCLUSIONS: Our preliminary results show that RT, with or without ADT, significantly reduces primary tumor SUVmax and serum PSA levels. Nonetheless, our findings indicate that early treatment response using 68Ga-PSMA-PET/CT is not feasible for those treated with RT alone, and it may only be useful in better distinguishing patients with and without PSA nadir for those who received both RT and ADT.
METHODS: The clinical data of 71 IR-PCa patients treated with RT alone (36 patients, 50.7%) or RT and ADT (35 patients, 49.3%) were retrospectively analyzed. The difference between pre- and Posttreatment primary tumor PSMA expression and serum PSA values measured 4 months after completion of treatment were compared between treatment arms. Correlation between primary tumor metabolic response and serum PSA changes was analyzed.
RESULTS: The median duration between pre- and Posttreatment 68Ga-PSMA-PET/CT for the entire patient population was 6.9 months (range, 5.6-8.4 months), and it was similar in both treatment arms. A decrease in primary tumor maximum standardized uptake value (SUVmax) was seen in 66 patients (93.0%), with a median value of 61.2%, which is significantly lower in patients undergoing RT alone than those undergoing RT and ADT (45.1 ± 30.6% vs. 59.1 ± 24.7%; p = 0.004). The complete metabolic response rate was significantly higher in patients undergoing RT and ADT than those treated with RT alone (40% vs. 0%; p < 0.001). Although moderate and positive correlation between pretreatment SUVmax and oosttreatment SUVmax was observed, there was no significant correlation between SUV change and PSA change. For patients treated with RT and ADT, posttreatment SUVmax was significantly lower and SUV change was significantly higher in patients with PSA nadir than in those without.
CONCLUSIONS: Our preliminary results show that RT, with or without ADT, significantly reduces primary tumor SUVmax and serum PSA levels. Nonetheless, our findings indicate that early treatment response using 68Ga-PSMA-PET/CT is not feasible for those treated with RT alone, and it may only be useful in better distinguishing patients with and without PSA nadir for those who received both RT and ADT.
摘要：
目的：使用镓68（68Ga）标记的前列腺特异性膜抗原正电子发射断层扫描（68Ga-PSMA-PET/CT）评估原发性肿瘤的早期代谢反应，以及原发性肿瘤PSMA变化与明确放疗（RT）后PSA反应之间的关系，中危前列腺癌（IR-PCa）患者单独或联合雄激素剥夺治疗（ADT）。
方法：单用RT治疗的71例IR-PCa患者的临床资料（36例，50.7%)或RT和ADT(35例患者，49.3%)进行回顾性分析。在治疗组之间比较治疗前和治疗后原发性肿瘤PSMA表达和完成治疗后4个月测量的血清PSA值之间的差异。分析原发性肿瘤代谢反应与血清PSA变化的相关性。
结果：整个患者人群的治疗前后68Ga-PSMA-PET/CT的中位持续时间为6.9个月（范围，5.6-8.4个月)，在两个治疗组中都是相似的。在66例患者中观察到原发肿瘤最大标准化摄取值（SUVmax）降低（93.0%），中位数为61.2%，仅接受RT的患者明显低于接受RT和ADT的患者（45.1±30.6％vs.59.1±24.7%；p=0.004）。接受RT和ADT的患者的完全代谢反应率显着高于仅接受RT治疗的患者（40％vs.0%；p<0.001)。尽管观察到治疗前SUVmax和治疗前SUVmax之间存在中度和正相关，SUV变化与PSA变化无显著相关性.对于接受RT和ADT治疗的患者，有PSA最低点的患者治疗后SUVmax显著降低,SUV变化显著高于无PSA最低点的患者.
结论：我们的初步结果表明，RT，不管有没有ADT,显著降低原发肿瘤SUVmax和血清PSA水平。尽管如此，我们的研究结果表明，使用68Ga-PSMA-PET/CT的早期治疗反应对于那些单独使用RT治疗的患者是不可行的，对于接受RT和ADT的患者，它可能仅有助于更好地区分有和没有PSA最低点的患者。
方法：单用RT治疗的71例IR-PCa患者的临床资料（36例，50.7%)或RT和ADT(35例患者，49.3%)进行回顾性分析。在治疗组之间比较治疗前和治疗后原发性肿瘤PSMA表达和完成治疗后4个月测量的血清PSA值之间的差异。分析原发性肿瘤代谢反应与血清PSA变化的相关性。
结果：整个患者人群的治疗前后68Ga-PSMA-PET/CT的中位持续时间为6.9个月（范围，5.6-8.4个月)，在两个治疗组中都是相似的。在66例患者中观察到原发肿瘤最大标准化摄取值（SUVmax）降低（93.0%），中位数为61.2%，仅接受RT的患者明显低于接受RT和ADT的患者（45.1±30.6％vs.59.1±24.7%；p=0.004）。接受RT和ADT的患者的完全代谢反应率显着高于仅接受RT治疗的患者（40％vs.0%；p<0.001)。尽管观察到治疗前SUVmax和治疗前SUVmax之间存在中度和正相关，SUV变化与PSA变化无显著相关性.对于接受RT和ADT治疗的患者，有PSA最低点的患者治疗后SUVmax显著降低,SUV变化显著高于无PSA最低点的患者.
结论：我们的初步结果表明，RT，不管有没有ADT,显著降低原发肿瘤SUVmax和血清PSA水平。尽管如此，我们的研究结果表明，使用68Ga-PSMA-PET/CT的早期治疗反应对于那些单独使用RT治疗的患者是不可行的，对于接受RT和ADT的患者，它可能仅有助于更好地区分有和没有PSA最低点的患者。
