Take-Away Points
■ Major Focus: Evaluation of prognostic value of posttreatment prostate-specific membrane antigen (PSMA) and fluorodeoxyglucose (FDG) PET following lutetium 177 (177Lu) PSMA-617 therapy and NOX66 for metastatic castrate-resistant prostate cancer.
■ Key Results: Increased posttreatment total tumor volume at PSMA PET relative to baseline was a significant predictor of overall survival.
■ Impact: Quantitative assessment of PSMA PET response to 177Lu-PSMA-617 therapy may be a useful prognostic biomarker.
The LuPIN clinical trial prospectively assessed 177Lu-PSMA-617 radionuclide therapy combined with the radiation sensitizer NOX66 in a dose-escalation protocol to treat metastatic castration-resistant prostate cancer in participants previously treated with taxane chemotherapy and an androgen inhibitor.
This substudy by Pathmanandavel et al evaluated 37 participants from the LuPIN trial who underwent baseline and posttreatment 68Ga-PSMA-11 PET and 18F-FDG PET over a median follow-up duration of 24 months. Increased PSMA total tumor volume (TTV) was the only quantitative imaging variable that remained independently predictive of overall survival using multivariable regression (hazard ratio = 5.1; 95% CI: 1.5, 17.1). Compared with baseline, progression of posttreatment serum prostate-specific antigen (PSA) concentration also predicted overall survival (hazard ratio = 3.5; 95% CI: 1.1, 10.9). FDG PET–based quantitative parameters were statistically significant predictors of overall survival, suggesting the limited prognostic value of these measurements. Posttherapy increases in PSMA TTV, FDG TTV, FDG maximum standardized uptake value, and PSA were associated with shorter PSA progression-free survival.
This study suggests that quantitative analysis and posttherapy imaging with PSMA PET may provide valuable prognostic information following 177Lu-PSMA treatment with NOX66, warranting further evaluation in a larger number of patients.
Highlighted Article
Pathmanandavel S, Crumbaker M, Nguyen A, et al. The prognostic value of post-treatment PSMA and FDG PET/CT in metastatic, castration-resistant prostate cancer treated with 177LuPSMA-617 and NOX66 in a phase I/II trial (LuPIN). J Nucl Med 2022. jnumed.122.264104. doi: https://doi.org/10.2967/jnumed.122.264104
Highlighted Article
- Pathmanandavel S , Crumbaker M , Nguyen A , et al . The prognostic value of post-treatment PSMA and FDG PET/CT in metastatic, castration-resistant prostate cancer treated with 177LuPSMA-617 and NOX66 in a phase I/II trial (LuPIN) . J Nucl Med 2022. . jnumed.122.264104. doi: 10.2967/jnumed.122.264104 [DOI] [PMC free article] [PubMed] [Google Scholar]