68Ga-PSMA Ligand PET/CT-based Radiotherapy for Lymph Node Relapse of Prostate Cancer After Primary Therapy Delays Initiation of Systemic Therapy

Anticancer Res. 2017 Mar;37(3):1273-1279. doi: 10.21873/anticanres.11444.

Abstract

Aim: To evaluate 68Ga-PSMA ligand positron-emission tomography-computed tomography (PET/CT)-based radiotherapy for lymph node metastases of prostate cancer after primary therapy.

Patients and methods: Twenty-three patients received radiotherapy for PSMA ligand-positive lymph node metastases.

Results: The median follow-up time was 12.4 (range=6.0-28.5) months. The median pre-treatment prostate-specific antigen (PSA) decreased from 2.75 (range=0.52-8.92) ng/ml to a nadir of 1.37 (range=0.11-8.00) ng/ml (p=0.001) following radiotherapy. Except for one patient (4.4%), PSA level decreased in 22 patients (95.6%). The biochemical failure-free survival and time to initiation of systemic therapy at the median follow-up were 95.6% and 100%, respectively. Three patients (12.9%) presented with recurrent disease outside the initial radiation field. No grade III acute toxicities or late grade II toxicities were observed.

Conclusion: 68Ga-PSMA ligand PET/CT-based radiotherapy is a promising local treatment option for isolated lymph node metastases of prostate cancer.

Keywords: PSMA-PET/CT; lymph node metastases; radiotherapy; recurrent prostate cancer; systemic therapy.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Antigens, Surface / chemistry
  • Gallium Radioisotopes / chemistry*
  • Glutamate Carboxypeptidase II / chemistry
  • Humans
  • Ligands
  • Lymphatic Metastasis
  • Male
  • Middle Aged
  • Neoplasm Recurrence, Local / pathology
  • Neoplasm Staging
  • Positron Emission Tomography Computed Tomography*
  • Prostate-Specific Antigen / blood
  • Prostatic Neoplasms / diagnostic imaging*
  • Prostatic Neoplasms / pathology
  • Prostatic Neoplasms / therapy*
  • Recurrence
  • Time-to-Treatment
  • Treatment Outcome

Substances

  • Antigens, Surface
  • Gallium Radioisotopes
  • Ligands
  • FOLH1 protein, human
  • Glutamate Carboxypeptidase II
  • Prostate-Specific Antigen