¹⁷⁷Lu-PSMA therapy is an effective treatment in patients with metastatic castration-resistant prostate cancer. SUV_mean is a valuable screening biomarker to assess the suitability for ¹⁷⁷Lu-PSMA therapy but requires quantitative software. This study aims to develop a simple, clinically applicable prostate-specific membrane antigen PET/CT score that encompasses the elements of SUV_mean without requiring additional quantification. Methods: Datasets from ethics-approved trials of patients with metastatic castration-resistant prostate cancer after androgen receptor signaling inhibition and taxane chemotherapy (or unfit for taxane), who were treated with ¹⁷⁷Lu-PSMA-617 and ¹⁷⁷Lu-PSMA I&T with a pretreatment screening with ⁶⁸Ga-PSMA-11 PET/CT, and clinical outcome data, including a prostate-specific antigen (PSA) 50% response rate (PSA50), PSA progression-free survival (PSA-PFS), and overall survival (OS), were included. The screening ⁶⁸Ga-PSMA-11 PET/CT of all participants was analyzed both semiquantitatively and visually. Semiquantitative analysis was used to derive the SUV_mean. Visual analysis of the ⁶⁸Ga-PSMA-11 PET/CT images involved a binary visual heterogeneity assessment (homogeneous or heterogeneous), allocating a tumor SUV_max range (<15, 15–29, 30–49, 50–79, or ≥80). A 4-category score incorporating both heterogeneity and intensity of tumors (HIT) was then developed as a combination of heterogeneity and intensity (SUV_max range). The SUV_max was less than 15 for score 1, 15–79 with heterogeneous intensity for score 2, 15–79 with homogeneous intensity for score 3, and 80 or greater for score 4. This score was evaluated according to clinical outcomes (PSA50, PSA-PFS, and OS) and compared with SUV_mean. Results: Data from 139 participants were analyzed. In total, 75 (54%) patients achieved a PSA50 with a median PSA-PFS of 5.5 mo (95% CI, 4.1–6.0 mo) and an OS of 13.5 mo (95% CI, 11.1–17.9 mo). SUV_mean was associated with PSA50 and survival outcomes when analyzed as a continuous variable or as quartiles. The PSA50 for HIT scores 1–4 was 0%, 39%, 65%, and 76%, respectively. The HIT score was strongly related to PSA-PFS and OS (log-rank test, P < 0.001 and P = 0.002). The median PSA-PFS for HIT scores 1–4 was 1.0, 4.1, 6.0, and 8.5, respectively, and the median OS was 7.6, 12.0, 18.5, and 16.9 mo, respectively. Cohen κ between readers for the HIT score was 0.71. Conclusion: A prostate-specific membrane antigen PET/CT score incorporating HIT derived from tools on a standard PET workstation is comparable with quantitative SUV_mean as a prognostic tool following ¹⁷⁷Lu-PSMA therapy.

¹⁷⁷ Lu-PSMA疗法是转移性去势抵抗性前列腺癌患者的有效治疗方法。 SUV _mean 是一种有价值的筛选生物标志物，可用于评估 ¹⁷⁷ Lu-PSMA 治疗的适用性，但需要定量软件。本研究旨在开发一种简单的、临床适用的前列腺特异性膜抗原 PET/CT 评分，其中包含 SUV _mean 的要素，无需额外量化。方法：数据集来自伦理批准的试验，受试者为雄激素受体信号抑制和紫杉烷化疗（或不适合紫杉烷）的转移性去势抵抗性前列腺癌患者，这些患者接受 ¹⁷⁷ Lu-PSMA-617 和 < b5> Lu-PSMA I&T，使用 ⁶⁸ Ga-PSMA-11 PET/CT 进行预处理筛查，以及临床结果数据，包括前列腺特异性抗原 (PSA) 50% 缓解率（包括 PSA50)、PSA 无进展生存期 (PSA-PFS) 和总生存期 (OS)。对所有参与者的筛选 ⁶⁸ Ga-PSMA-11 PET/CT 进行了半定量和目视分析。使用半定量分析来推导SUV _mean 。 ⁶⁸ Ga-PSMA-11 PET/CT 图像的视觉分析涉及二元视觉异质性评估（同质或异质），分配肿瘤 SUV _max 范围（<15, 15– 29、30–49、50–79 或 ≥80）。然后将异质性和肿瘤强度 (HIT) 结合起来的 4 类评分被开发为异质性和强度的组合（SUV _max 范围）。 1 分的 SUV _max 小于 15，2 分的 SUV _max 为异质强度，15-79，3 分的 SUV _max 为均匀强度，80 或更高。 该评分根据临床结果（PSA50、PSA-PFS 和 OS）进行评估，并与 SUV _mean 进行比较。结果：分析了 139 名参与者的数据。总共有 75 名 (54%) 患者达到了 PSA50，中位 PSA-PFS 为 5.5 个月（95% CI，4.1–6.0 个月），OS 为 13.5 个月（95% CI，11.1–17.9 个月）。当作为连续变量或四分位数进行分析时，SUV _mean 与 PSA50 和生存结果相关。 HIT 分数 1-4 的 PSA50 分别为 0%、39%、65% 和 76%。 HIT 评分与 PSA-PFS 和 OS 密切相关（对数秩检验，P < 0.001 和 P = 0.002）。 HIT 评分 1-4 的中位 PSA-PFS 分别为 1.0、4.1、6.0 和 8.5，中位 OS 分别为 7.6、12.0、18.5 和 16.9 个月。读者之间的 Cohen κ 的 HIT 评分为 0.71。结论：结合源自标准 PET 工作站上工具的 HIT 的前列腺特异性膜抗原 PET/CT 评分与定量 SUV _mean 相当，作为 ¹⁷⁷ Lu-PSMA 治疗后的预后工具。