Early dose response to yttrium-90 microsphere treatment of metastatic liver cancer by a patient-specific method using single photon emission computed tomography and positron emission tomography

Int J Radiat Oncol Biol Phys. 2009 May 1;74(1):313-20. doi: 10.1016/j.ijrobp.2008.12.058.


Purpose: To evaluate a patient-specific single photon emission computed tomography (SPECT)-based method of dose calculation for treatment planning of yttrium-90 ((90)Y) microsphere selective internal radiotherapy (SIRT).

Methods and materials: Fourteen consecutive (90)Y SIRTs for colorectal liver metastasis were retrospectively analyzed. Absorbed dose to tumor and normal liver tissue was calculated by partition methods with two different tumor/normal liver vascularity ratios: an average 3:1 and a patient-specific ratio derived from pretreatment technetium-99m macroaggregated albumin SPECT. Tumor response was quantitatively evaluated from fluorine-18 fluoro-2-deoxy-D-glucose positron emission tomography scans.

Results: Positron emission tomography showed a significant decrease in total tumor standardized uptake value (average, 52%). There was a significant difference in the tumor absorbed dose between the average and specific methods (p = 0.009). Response vs. dose curves fit by linear and linear-quadratic modeling showed similar results. Linear fit r values increased for all tumor response parameters with the specific method (+0.20 for mean standardized uptake value).

Conclusion: Tumor dose calculated with the patient-specific method was more predictive of response in liver-directed (90)Y SIRT.

MeSH terms

  • Adult
  • Aged
  • Colorectal Neoplasms*
  • Dose-Response Relationship, Radiation
  • Female
  • Humans
  • Liver / diagnostic imaging
  • Liver / radiation effects
  • Liver Neoplasms / diagnostic imaging*
  • Liver Neoplasms / radiotherapy*
  • Liver Neoplasms / secondary
  • Lung / diagnostic imaging
  • Lung / radiation effects
  • Male
  • Microspheres
  • Middle Aged
  • Phantoms, Imaging
  • Positron-Emission Tomography / methods*
  • Radiography
  • Radiopharmaceuticals
  • Retrospective Studies
  • Technetium Tc 99m Aggregated Albumin
  • Tomography, Emission-Computed, Single-Photon / methods*
  • Yttrium Radioisotopes / pharmacokinetics
  • Yttrium Radioisotopes / therapeutic use*


  • Radiopharmaceuticals
  • Technetium Tc 99m Aggregated Albumin
  • Yttrium Radioisotopes