Effects of Fasting on 18F-DCFPyL Uptake in Prostate Cancer Lesions and Tissues with Known High Physiologic Uptake

J Nucl Med. 2018 Jul;59(7):1081-1084. doi: 10.2967/jnumed.117.207316. Epub 2018 Mar 1.

Abstract

In the literature, a 4- to 6-h fast is recommended before a patient undergoes PET/CT with 2-(3-(1-carboxy-5-[(6-18F-fluoro-pyridine-3-carbonyl)-amino]-pentyl)-ureido)-pentanedioic acid (18F-DCFPyL); however, a scientific underpinning for this recommendation is lacking. Therefore, we performed a study to determine the impact of fasting on 18F-DCFPyL uptake. Methods: The study included 50 patients who fasted at least 6 h before 18F-DCFPyL administration and 50 patients who did not. Activity (SUVmax) was measured in lesions characteristic of prostate cancer and in normal tissues known to express high physiologic uptake. Results: Uptake in suspected lesions did not differ between the cohorts. 18F-DCFPyL uptake in the submandibular gland, liver, and spleen was significantly higher in the fasting than the nonfasting cohort. Conclusion: Our data show that fasting does not significantly affect 18F-DCFPyL uptake in suspected malignant lesions but does result in significantly lower 18F-DCFPyL uptake in tissues with high physiologic uptake. The absolute differences in uptake were relatively small; therefore, the effects of fasting on the diagnostic performance can be considered negligible.

Keywords: 18F-DCFPyL; PET/CT; PSMA; acquisition protocol; genitourinary; prostate cancer.

Publication types

  • Clinical Trial

MeSH terms

  • Aged
  • Aged, 80 and over
  • Biological Transport
  • Fasting*
  • Humans
  • Lysine / analogs & derivatives*
  • Lysine / metabolism
  • Male
  • Middle Aged
  • Neoplasm Metastasis
  • Positron Emission Tomography Computed Tomography / methods*
  • Prostatic Neoplasms / diagnostic imaging
  • Prostatic Neoplasms / metabolism*
  • Prostatic Neoplasms / pathology
  • Prostatic Neoplasms / physiopathology
  • Urea / analogs & derivatives*
  • Urea / metabolism

Substances

  • 2-(3-(1-carboxy-5-((6-fluoropyridine-3-carbonyl)amino)pentyl)ureido)pentanedioic acid
  • Urea
  • Lysine