Funding
National Nature Science Foundation of China
Shanghai Rising-Star Program
Fudan University Shanghai Cancer Center Fund
Shanghai “Rising Stars of Medical Talent” Youth Development
ARTICLE ABSTRACT
Tumor heterogeneity and burden, which impact treatment outcome in prostate cancer, are rarely evaluated using next-generation imaging.
The trial prospectively included 37 patients who had an early PSA progression (≤2 ng/mL) during castration and high-risk (PSA doubling time ≤10 months) nonmetastatic disease by conventional imaging. All patients underwent both 68Ga-PSMA and 18F-FDG PET/CT. Lesions were classified into PSMA+FDG± lesions and PSMA-FDG+ lesions. The primary endpoint was the prevalence of PSMA-FDG+ disease. Tumor burden, predictors for positive imaging, and suitability for oligometastases-directed therapy (OMDT) were also evaluated.
All patients were treated with RP and the median duration of castration was 23 months. The median PSA at imaging was 0.57 ng/mL. Overall, 114 lesions were detected in 29 of the 37 patients. A high prevalence (73%) of N+/M+ disease was observed. Of the 114 lesions, 81 were PSMA+FDG± and 33 were PSMA-FDG+. Per patient level, 9 men (24%; 95% confidence interval: 10%–39%) showed at least one new PSMA-FDG+ lesions. A short PSA doubling time (P = 0.009, OR = 8.000) was associated with PSMA+FDG± disease, while a high Gleason grade group (P = 0.022, OR = 13.091) with PSMA-FDG+ disease. Nineteen patients (51%) with 51 lesions, including 10 PSMA-FDG+ lesions, could be enrolled for OMDT. Among different disease stages, PSMA-FDG+ disease was rarely detected in the hormone-sensitive cohort, but frequently found in the castration-resistant cohort.
Using 68Ga-PSMA and 18F-FDG PET, we observed a high prevalence of N+/M+ disease and a significant proportion of PSMA-FDG+ disease in patients with an early PSA progression during castration (ChiCTR1900022634).
