Diagnostic Value of 68Ga-PSMA PET/CT for Detection of Phosphatase and Tensin Homolog Expression in Prostate Cancer: A Pilot Study

J Nucl Med. 2020 Jun;61(6):873-880. doi: 10.2967/jnumed.119.236059. Epub 2019 Nov 22.

Abstract

Our purpose was to explore the value of 68Ga-prostate-specific membrane antigen (PSMA) PET/CT for detection of phosphatase and tensin homolog (PTEN)-loss prostate cancer. Methods: We retrospectively enrolled 75 patients who underwent multiparametric MRI and 68Ga-PSMA PET/CT before radical prostatectomy. Lesions were outlined on pathologic images, and regions of interest were drawn on matched multiparametric MRI and PET/CT images. Imaging parameters, including average apparent diffusion coefficient and SUVmax, were derived. Immunohistochemical staining was performed to evaluate the PTEN status. The diagnostic performance of imaging parameters was analyzed by receiver-operating-characteristic analysis. Univariate logistic regression analyses were used to evaluate the association between clinical and imaging variables and PTEN status. Results: In total, 103 lesions from 75 patients were analyzed. Of these lesions, 38 of 103 (36.9%) showed PTEN-loss status. Our study showed a strong association between SUVmax and PTEN-loss tumors both in the per-patient analysis (P < 0.01) and in the per-lesion analysis (P < 0.01), yielding sensitivity and specificity of 0.80 and 0.77, respectively, in the per-patient analysis and 0.83 and 0.74, respectively, in the per-lesion analysis. Meanwhile, higher pathologic PSMA expression was found in the PTEN-deficiency tumors. However, there was no significant difference between PTEN-loss tumors and PTEN-intact tumors using parameters such as average apparent diffusion coefficient (P > 0.05) and score on the Prostate Imaging Reporting and Data System, version 2 (P > 0.05). Surprisingly, SUVmax was a significant predictor for detection of PTEN-loss tumors (odds ratio of 7.56 and 95% confidence interval of 2.18-26.24 on per-patient analysis; odds ratio of 13.66 and 95% confidence interval of 4.32-43.24 on per-lesion analysis). Conclusion:68Ga-PSMA PET/CT could effectively detect aggressive PTEN-loss tumors.

Keywords: 68Ga-PSMA-PET/CT; PTEN; SUVmax; prostate cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Gallium Isotopes
  • Gallium Radioisotopes
  • Humans
  • Immunohistochemistry
  • Logistic Models
  • Male
  • Membrane Glycoproteins*
  • Middle Aged
  • Organometallic Compounds*
  • PTEN Phosphohydrolase / analysis*
  • Pilot Projects
  • Positron Emission Tomography Computed Tomography / methods*
  • Prostatic Neoplasms / chemistry
  • Prostatic Neoplasms / diagnostic imaging*
  • Radiopharmaceuticals*

Substances

  • Gallium Isotopes
  • Gallium Radioisotopes
  • Membrane Glycoproteins
  • Organometallic Compounds
  • Radiopharmaceuticals
  • gallium 68 PSMA-11
  • PTEN Phosphohydrolase
  • PTEN protein, human