[68Ga]Ga-PSMA-11 PET Tumor Volume Predicts Overall Survival of Patients with Metastatic Prostate Cancer Undergoing Taxane-Based Chemotherapy

J Nucl Med. 2025 Nov 3;66(11):1743-1749. doi: 10.2967/jnumed.125.269584.

Abstract

Prostate-specific membrane antigen (PSMA) PET has the potential to monitor the response to taxane-based chemotherapy in patients with prostate cancer and shows promise for predicting outcomes and improving response evaluation. This retrospective study aimed to determine the prognostic value of [68Ga]Ga-PSMA-11 PET (PSMA PET)-derived quantitative tumor burden parameters for overall survival (OS). Methods: Databases from 6 institutions were screened for patients with prostate cancer who underwent PSMA PET and whose serum prostate-specific antigen (PSA) measurements were recorded at baseline and after completing taxane-based chemotherapy. Tumor segmentation was performed using artificial intelligence-based software, and PSMA PET whole-body quantitative parameters were obtained, including PSMA-positive tumor volume (PSMA-VOL), SUVmax, and SUVmean Univariate Cox regression analyses were used to evaluate the association of whole-body quantitative PSMA parameters and PSA levels with OS. The Harrell concordance index (C-index) was used to determine prognostic accuracy. Optimal cutoffs were determined by maximizing the log-rank statistic. Results: In total, 128 patients were included in the study; 62 (48%) had hormone-sensitive prostate cancer, and 66 (52%) had castration-resistant prostate cancer. At baseline, PSMA-VOL had the highest prognostic value for OS compared with serum PSA, SUVmax, and SUVmean (C-index of 0.88, 0.80, 0.69, and 0.29, respectively), whereas the percentage change in PSA levels had the highest prognostic value during treatment compared with percentage change in PSMA-VOL, SUVmax, and SUVmean (C-index of 0.94, 0.85, 0.90, and 0.85, respectively). Conclusion: Baseline and posttherapeutic PSMA PET quantitative parameters are prognostic for OS after taxane-based chemotherapy in patients with metastatic prostate cancer. Baseline PSMA-VOL had the highest prognostic value for OS, whereas changes in PSA levels outperformed changes in quantitative PSMA PET parameters during treatment.

Keywords: PSMA PET; biomarkers; chemotherapy; oncologic imaging; prostate cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Bridged-Ring Compounds* / therapeutic use
  • Dipeptides*
  • Edetic Acid* / analogs & derivatives
  • Gallium Isotopes
  • Gallium Radioisotopes
  • Humans
  • Male
  • Middle Aged
  • Neoplasm Metastasis
  • Oligopeptides*
  • Positron-Emission Tomography*
  • Prognosis
  • Prostatic Neoplasms* / diagnostic imaging
  • Prostatic Neoplasms* / drug therapy
  • Prostatic Neoplasms* / pathology
  • Retrospective Studies
  • Survival Analysis
  • Taxoids* / therapeutic use
  • Tumor Burden* / drug effects

Substances

  • gallium 68 PSMA-11
  • Gallium Radioisotopes
  • Gallium Isotopes
  • Taxoids
  • taxane
  • Bridged-Ring Compounds
  • Oligopeptides
  • Edetic Acid
  • Dipeptides
  • PSMA-11