Abstract
Purpose: To evaluate a patient-specific single photon emission computed tomography (SPECT)-based method of dose calculation for treatment planning of yttrium-90 (90Y) microsphere selective internal radiotherapy (SIRT). Methods and Materials: Fourteen consecutive 90Y 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 90Y SIRT.
Original language | English (US) |
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Pages (from-to) | 313-320 |
Number of pages | 8 |
Journal | International Journal of Radiation Oncology Biology Physics |
Volume | 74 |
Issue number | 1 |
DOIs | |
State | Published - May 1 2009 |
Externally published | Yes |
Keywords
- Dose response
- Liver cancer
- PET
- SPECT
- Yttrium-90 microsphere
ASJC Scopus subject areas
- Radiation
- Oncology
- Radiology Nuclear Medicine and imaging
- Cancer Research