Biodistribution and Radiation Dosimetry of the Anti-HER2 Affibody Molecule Ga-68-ABY-025 in Breast Cancer Patients
2016 (English)In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 57, no 6, 867-871 p.Article in journal (Refereed) PublishedText
Ga-68-ABY-025 is a radiolabeled Affibody molecule for in vivo diagnosis of human epidermal growth factor receptor 2 (HER2)-positive breast cancer tumors with PET. The aim of the present work was to measure the biodistribution and estimate the radiation dosimetry of Ga-68-ABY-025 for 2 different peptide mass doses in a single group of patients using dynamic and serial whole-body PET/CT. Methods: Eight patients with metastatic breast cancer were included. Each patient underwent an abdominal 45-min dynamic and 3 whole-body PET/CT scans at 1, 2, and 4 h after injection of a low peptide dose (LD) and a high peptide dose (HD), with approximately the same amount of radioactivity, in separate investigations 1 wk apart. As input to the absorbed dose calculations, volumes of interest were drawn on all clearly identifiable source organs: liver, kidneys, spleen, descending aorta, and upper large intestine. Absorbed doses were calculated using OLINDA/EXM, version 1.1. Results: Of the major organs, the highest radionuclide uptake at 1, 2, and 4 h after injection was observed in the kidneys and liver. The highest absorbed organ doses were seen in the kidneys, followed by the liver for both LD and HD Ga-68-ABY-025. Absorbed doses to liver and kidneys were slightly but significantly higher for LD. Total effective dose was 0.030 +/- 0.003 mSv/MBq for LD and 0.028 +/- 0.002 mSv/MBq for HD. Conclusion: The effective dose for a typical 200-MBq administration of Ga-68-ABY-025 is 6.0 mSv for LD and 5.6 mSv for HD. Therefore, from a radiation dosimetry point of view, HD is preferred for PET/CT evaluation of HER2-expressing breast cancer tumors. These effective doses are somewhat higher than earlier published values for other Ga-68-labeled tracers, such as 0.021 +/- 0.003 mSv/MBq for Ga-68-DOTATATE and Ga-68-DOTATOC, mainly because of higher uptake in liver and kidney.
Place, publisher, year, edition, pages
2016. Vol. 57, no 6, 867-871 p.
Affibody, breast cancer metastases, dosimetry, HER2-receptor, Ga-68-gallium
Radiology, Nuclear Medicine and Medical Imaging
IdentifiersURN: urn:nbn:se:uu:diva-298861DOI: 10.2967/jnumed.115.169342ISI: 000377052400035PubMedID: 26912439OAI: oai:DiVA.org:uu-298861DiVA: diva2:948324
FunderSwedish Cancer Society