Feasibility of 90Y TOF PET-based dosimetry in liver metastasis therapy using SIR-Spheres

Eur J Nucl Med Mol Imaging. 2010 Aug;37(9):1654-62. doi: 10.1007/s00259-010-1470-9. Epub 2010 Apr 27.


Purpose: (90)Y-labelled compounds used in targeted radiotherapy are usually imaged with SPECT by recording the bremsstrahlung X-rays of the beta decay. The continuous shape of the X-ray spectrum induces the presence of a significant fraction of scatter rays in the acquisition energy window, reducing the accuracy of biodistribution and of dosimetry assessments.

Methods: The aim of this paper is to use instead the low branch of e(-) e(+) pair production in the (90)Y decay. After administration of (90)Y-labelled SIR-Spheres by catheterization of both liver lobes, the activity distribution is obtained by (90)Y time-of-flight (TOF) PET imaging. The activity distribution is convolved with a dose irradiation kernel in order to derive the regional dosimetry distribution.

Results: Evaluation on an anatomical phantom showed that the method provided an accurate dosimetry assessment. Preliminary results on a patient demonstrated a high-resolution absorbed dose distribution with a clear correlation with tumour response.

Conclusion: This supports the implementation of (90)Y PET in selective internal radiation therapy of the liver.

MeSH terms

  • Feasibility Studies
  • Female
  • Humans
  • Linear Models
  • Liver Neoplasms / diagnostic imaging*
  • Liver Neoplasms / metabolism
  • Liver Neoplasms / radiotherapy*
  • Liver Neoplasms / secondary
  • Microspheres
  • Middle Aged
  • Neoplasm Metastasis
  • Phantoms, Imaging
  • Positron-Emission Tomography*
  • Radiometry / methods*
  • Radiotherapy Dosage
  • Reproducibility of Results
  • Time Factors
  • Yttrium Radioisotopes / pharmacokinetics


  • Yttrium Radioisotopes