Correlation analysis of PSMA PET/CT-derived parameters and circulating tumor DNA features in patients with hormone-sensitive prostate cancer

Background and purpose: Both prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) and circulating tumor DNA (ctDNA) sequencing outcomes serve as references for therapeutic decision-making in hormone-sensitive prostate cancer (HSPC) treatment. This study aimed to analyze the association between PSMA PET/CT-derived parameters and ctDNA characteristics in patients with HSPC. Methods: HSPC patients who received PSMA PET/CT and ctDNA sequencing at an interval of less than 2 weeks and with complete medical records were retrospectively included in Fudan University Shanghai Cancer Center. Patients with active malignancies other than prostate cancer and those with histological features supporting a diagnosis of pure neuroendocrine carcinoma or small cell carcinoma were excluded. This study was approved by the Ethics Committee of Fudan University Shanghai Cancer Center (Ethics number: 1909207-12). The correlation between PSMA PET/CT-derived parameters, including the maximum standardized uptake value (SUVmax), total tumor volume (TTV), total lesion uptake (TLU) and ctDNA fraction (ctDNA%) was evaluated using the Spearman correlation coefficient. Results: A total of 60 HSPC patients were included, with TP53 (3.3%), BRCA2 (3.3%) and ATM (3.3%) being the most common mutated genes. In the correlation analysis, a significant correlation was observed between ctDNA% and SUVmax levels (Spearman’s rho=0.272, P=0.036); however, no significant correlation was found between ctDNA% and TLU (Spearman’s rho=0.160, P=0.222) or TTV (Spearman’s rho=0.162, P=0.215). Conclusion: There was a significant correlation between SUVmax and ctDNA%, suggesting that patients with high PSMA uptake lesions were more likely to receive combined targeted therapy than patients with no PSMA positive lesions and patients with low PSMA uptake lesions, which provided a certain reference for the formulation of individualized treatment plans.