Value of post-therapy 177Lu-PSMA images for accurate interpretation of therapy response with 68Ga-PSMA PET/CT

Rev Esp Med Nucl Imagen Mol (Engl Ed). 2018 Mar-Apr;37(2):114-117. doi: 10.1016/j.remn.2017.05.004. Epub 2017 Jul 24.
[Article in English, Spanish]

Abstract

A 54-year-old man with progressive prostate cancer underwent a 68Ga-PSMA PET/CT, which showed lymph node and bone metastases. After 2-cycles of 177Lu-PSMA therapy, the repeated 68Ga-PSMA PET/CT showed decreased radiotracer uptake in lymph node and bones metastases, but there were new lesions which may be compatible with progression or tumour sink-effect. A review of 177Lu-PSMA-therapy images revealed that new lesions in the second PET/CT were the metastatic lesions that progressed after the first PET/CT, and subsequently showed a good response. The patient received additional cycles of 177Lu-PSMA therapy, and the disease regressed further, with a PSA of 0.06ng/ml. Response evaluation of new therapeutic diagnostics (theranostic) agents needs a review of not only diagnostic PET/CT images, but also post-therapy images and laboratory results.

Keywords: (177)Lu- PSMA; (68)Ga-PSMA; Regresión tumoral; Respuesta a la terapia; Therapeutic response; Tumor sink effect.

Publication types

  • Case Reports

MeSH terms

  • Adenocarcinoma / blood
  • Adenocarcinoma / diagnostic imaging*
  • Adenocarcinoma / radiotherapy
  • Adenocarcinoma / secondary*
  • Bone Neoplasms / blood
  • Bone Neoplasms / diagnostic imaging*
  • Bone Neoplasms / radiotherapy
  • Bone Neoplasms / secondary*
  • Dipeptides / analysis
  • Dipeptides / therapeutic use*
  • Drug Monitoring
  • Edetic Acid / analogs & derivatives
  • Edetic Acid / analysis
  • Gallium Isotopes
  • Gallium Radioisotopes / analysis
  • Heterocyclic Compounds, 1-Ring / analysis
  • Heterocyclic Compounds, 1-Ring / therapeutic use*
  • Humans
  • Lutetium / analysis
  • Lutetium / therapeutic use*
  • Lymphatic Metastasis / diagnostic imaging*
  • Lymphatic Metastasis / radiotherapy
  • Male
  • Middle Aged
  • Oligopeptides / analysis
  • Positron Emission Tomography Computed Tomography*
  • Prostate-Specific Antigen / blood
  • Prostatic Neoplasms / blood
  • Prostatic Neoplasms / diagnostic imaging*
  • Prostatic Neoplasms / radiotherapy
  • Radioisotopes / analysis
  • Radioisotopes / therapeutic use*
  • Radiopharmaceuticals / analysis
  • Radiopharmaceuticals / therapeutic use*
  • Sensitivity and Specificity

Substances

  • 177Lu-PSMA-617
  • Dipeptides
  • Gallium Isotopes
  • Gallium Radioisotopes
  • Heterocyclic Compounds, 1-Ring
  • Oligopeptides
  • Radioisotopes
  • Radiopharmaceuticals
  • gallium 68 PSMA-11
  • Lutetium
  • Gallium-68
  • Edetic Acid
  • Lutetium-177
  • Prostate-Specific Antigen