Radiation dosimetry of [68Ga]PSMA-11 in low-risk prostate cancer patients

Research output: Contribution to journalArticle

Abstract

Background: 68Ga-labeled Glu-NH-CO-NH-Lys(Ahx)-HBED-CC ([68Ga]PSMA-11) has been increasingly used to image prostate cancer using positron emission tomography (PET)/computed tomography (CT) both during diagnosis and treatment planning. It has been shown to be of clinical value for patients both in the primary and secondary stages of prostate cancer. The aim of this study was to determine the effective dose and organ doses from injection of [68Ga]PSMA-11 in a cohort of low-risk prostate cancer patients. Methods: Six low-risk prostate cancer patients were injected with 133–178 MBq [68Ga]PSMA-11 and examined with four PET/CT acquisitions from injection to 255 min post-injection. Urine was collected up to 4 h post-injection, and venous blood samples were drawn at 45 min, 85 min, 175 min, and 245 min post-injection. Kidneys, liver, lungs, spleen, salivary and lacrimal glands, and total body where delineated, and cumulated activities and absorbed organ doses calculated. The software IDAC-Dose 2.1 was used to calculate absorbed organ doses according to the International Commission on Radiological Protection (ICRP) publication 107 using specific absorbed fractions published in ICRP 133 and effective dose according to ICRP Publication 103. We also estimated the absorbed dose to the eye lenses using Monte Carlo methods. Results: [68Ga]PSMA-11 was rapidly cleared from the blood and accumulated preferentially in the kidneys and the liver. The substance has a biological half-life in blood of 6.5 min (91%) and 4.4 h (9%). The effective dose was calculated to 0.022 mSv/MBq. The kidneys received approximately 40 mGy after an injection with 160 MBq [68Ga]PSMA-11 while the lacrimal glands obtained an absorbed dose of 0.12 mGy per administered MBq. Regarding the eye lenses, the absorbed dose was low (0.0051 mGy/MBq). Conclusion: The effective dose for [68Ga]PSMA-11 is 0.022 mSv/MBq, where the kidneys and lacrimal glands receiving the highest organ dose.

Details

Authors
  • Kristina Sandgren
  • Lennart Johansson
  • Jan Axelsson
  • Joakim Jonsson
  • Mattias Ögren
  • Margareta Ögren
  • Martin Andersson
  • Sara Strandberg
  • Tufve Nyholm
  • Katrine Riklund
  • Anders Widmark
Organisations
External organisations
  • Umeå University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Cancer and Oncology
  • Radiology, Nuclear Medicine and Medical Imaging

Keywords

  • Absorbed dose and effective dose, Glu-NH-CO-NH-Lys(Ahx)-HBED-CC, PET-tracer, Prostate cancer, PSMA, Radiation dosimetry, [Ga]PSMA-11
Original languageEnglish
Article number2
JournalEJNMMI Physics
Volume6
Issue number1
StatePublished - 2019 Dec 1
Publication categoryResearch
Peer-reviewedYes