Unterrainer Lena M, Hope Thomas A, Fendler Wolfgang P, Grogan Tristan, Ndlovu Honest, Armstrong Wesley, Barbato Francesco, Benz Matthias R, Rettig Matthew B, Kishan Amar U, Sathekge Mike, Herrmann Ken, Czernin Johannes, Calais Jeremie
Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, California;
Department of Nuclear Medicine, LMU Munich, Munich, Germany.
J Nucl Med. 2025 Jan 3;66(1):54-60. doi: 10.2967/jnumed.124.268441.
High-volume disease (HVD) and low-volume disease (LVD) definitions in metastatic hormone-sensitive prostate cancer (mHSPC) patients are based on conventional imaging (CI) (CT/MRI with bone scan [BS]) according to CHAARTED criteria. HVD and LVD definitions are associated with overall survival and are used for treatment decisions. It remains unknown how these definitions transfer to prostate-specific membrane antigen (PSMA) PET imaging. The aim of this retrospective multicenter study was to compare the CI-based disease volume criteria to PSMA PET-based volume definitions in a CHAARTED-like cohort. mHSPC patients from 5 international sites who underwent PSMA PET/CT or PSMA PET/MRI and BS within a time interval of 100 d and without initiation of a new therapy between the 2 scans were retrospectively included in the analysis. CHAARTED HVD and LVD criteria were applied to BS, CT, MRI, and PSMA PET. HVD was defined by the presence of visceral metastases or at least 4 bone metastases (with ≥1 beyond the spine or pelvis). Whole-body (WB) tumor burden was estimated with the automated bone scan index (aBSI, EXINI v2.0) on BS and with the WB PSMA PET-positive tumor volume (PSMA-TV) on PSMA PET, respectively. Sixty-seven patients with paired PSMA PET and BS were included. The median prostate-specific antigen level was 54.9 ng/mL (interquartile range [IQR], 10.4-191.0 ng/mL). On the basis of CI, it was determined that 17 of 67 patients had HVD-CI (25.4%) and 50 of 67 patients had LVD-CI (74.6%). On the basis of PSMA PET, it was determined that 27 of 67 patients had HVD-PET (40.3%) and 24 of 67 patients had LVD-PET (35.8%). In total, 16 of 67 patients (22.4%) had no visible lesion or only locoregional pelvic disease (M0) with PSMA PET (M0-PET). Stage migration between CI and PSMA PET occurred in 27 of 67 patients (40.3%) by both upstaging and downstaging: 11 of 50 (22%) LVD-CI patients were HVD-PET, whereas 1 of 17 (5.9%) HVD-CI and 15 of 50 (30%) of LVD-CI patients were M0-PET. The median WB PSMA-TV and automated BS index were 248.0 mL (IQR, 54.6-1,427.0 mL) and 3.4% (IQR, 1,0-7.2%) for HVD-CI, 25.1 mL (IQR, 6.6-74.6 mL) and 0.1% (IQR, 0.0-0.2%) for LVD-CI, 141.0 mL (IQR, 47.5-458.0 mL) and 0.9% (IQR, 0.04-4.1%) for HVD-PET, and 31.5 mL (IQR, 10.1-67.9 mL) and 0% (IQR, 0-0.1%) for LVD-PET, respectively. The optimal WB PSMA-TV to stratify CI-based CHAARTED LVD-CI versus HVD-CI was 107 mL with a misclassification of 21.9%. Compared with CI, addition of PSMA PET leads to M0 downstaging in every third and LVD to HVD upstaging in every fifth mHSPC patient. Future HVD and LVD definitions based on PSMA PET/CT should be adjusted based on patient outcome.
转移性激素敏感性前列腺癌（mHSPC）患者的高肿瘤负荷疾病（HVD）和低肿瘤负荷疾病（LVD）定义是根据CHAARTED标准基于传统影像学（CI）（CT/MRI联合骨扫描[BS]）制定的。HVD和LVD定义与总生存期相关，并用于治疗决策。目前尚不清楚这些定义如何转换到前列腺特异性膜抗原（PSMA）PET成像中。这项回顾性多中心研究的目的是在一个类似CHAARTED的队列中，将基于CI的疾病体积标准与基于PSMA PET的体积定义进行比较。对来自5个国际研究点的mHSPC患者进行回顾性分析，这些患者在100天的时间间隔内接受了PSMA PET/CT或PSMA PET/MRI及BS检查，且在两次扫描之间未开始新的治疗。将CHAARTED的HVD和LVD标准应用于BS、CT、MRI和PSMA PET。HVD的定义为存在内脏转移或至少4处骨转移（其中≥1处位于脊柱或骨盆以外）。分别使用BS上的自动骨扫描指数（aBSI，EXINI v2.0）和PSMA PET上的全身（WB）PSMA PET阳性肿瘤体积（PSMA-TV）来估计全身肿瘤负荷。纳入了67例有配对PSMA PET和BS检查结果的患者。前列腺特异性抗原水平的中位数为54.9 ng/mL（四分位间距[IQR]，10.4 - 191.0 ng/mL）。基于CI，确定67例患者中有17例为HVD-CI（25.4%），50例为LVD-CI（74.6%）。基于PSMA PET，确定67例患者中有27例为HVD-PET（40.3%），24例为LVD-PET（35.8%）。67例患者中共有16例（22.4%）在PSMA PET检查时无可见病变或仅存在局部盆腔疾病（M0）（M0-PET）。CI和PSMA PET之间的分期迁移发生在67例患者中的27例（40.3%），包括分期上调和下调：50例LVD-CI患者中有11例（22%）为HVD-PET，而17例HVD-CI患者中有1例（5.9%）以及50例LVD-CI患者中有15例（30%）为M0-PET。HVD-CI的WB PSMA-TV中位数和自动BS指数分别为248.0 mL（IQR，54.6 - 1427.0 mL）和3.4%（IQR，1.0 - 7.2%），LVD-CI分别为25.1 mL（IQR，6.6 - 74.6 mL）和0.1%（IQR，0.0 - 0.2%），HVD-PET分别为141.0 mL（IQR，47.5 - 458.0 mL）和0.9%（IQR，0.04 - 4.1%），LVD-PET分别为31.5 mL（IQR，10.1 - 67.9 mL）和0%（IQR，0 - 0.1%）。用于区分基于CI的CHAARTED LVD-CI与HVD-CI的最佳WB PSMA-TV为107 mL，错误分类率为21.9%。与CI相比，添加PSMA PET会使每三分之一的mHSPC患者出现M0分期下调，每五分之一的LVD患者出现LVD到HVD分期上调。基于PSMA PET/CT的未来HVD和LVD定义应根据患者预后进行调整。
