Related Experiment Video
Updated: May 27, 2026
Radiosynthesis, Quality Control, and Small Animal Positron Emission Tomography Imaging of 68Ga-Labelled Nano Molecules
Published on: October 4, 2024
90Y-PET for the assessment of microsphere biodistribution after selective internal radiotherapy
Oreste Bagni1, Marco D'Arienzo, Paola Chiaramida
1Department of Nuclear Medicine, Santa Maria Goretti Hospital, Latina, Italy.
Objectives:
To demonstrate the feasibility of 90Y-PET imaging for biodistribution assessment after selective internal radiotherapy treatments with 90Y-microspheres, comparing the results with 99mTc-macroaggregated albumin (MAA) images obtained with single-photon emission computed tomography.
Methods:
Preliminary studies were performed with the aim of evaluating the imaging system spatial resolution and scanner sensitivity for detecting annihilation photons. Subsequently, microsphere distribution was evaluated in 10 patients who underwent liver selective internal radiotherapy treatment. 99mTc-MAA and 90Y-microsphere were simultaneously injected for immediate monitoring after treatment. For each patient, the metastases detected with 90Y-PET and 99mTc-MAA were assessed and compared with 18F-fluorodeoxyglucose-PET (18F-FDG-PET) obtained before treatment and used as an imaging benchmark procedure. The correlation between these techniques was thus investigated in terms of matching lesions. Lesions were considered true positive in the case of matching with 18F-FDG-PET. The sensitivity of both techniques was evaluated as the true-positive fraction of detected spots in the treated liver sectors.
Results:
With our experimental setup, a maximum scanner sensitivity of 0.577 and 0.077 cps/MBq was obtained for three-dimensional and two-dimensional acquisitions, respectively. A good correlation was obtained between images obtained before and after treatment, with 90Y-PET being by far the most accurate technique in detecting microsphere distribution and tumor nonhomogeneity areas. A sensitivity as high as 0.91 was obtained with 90Y-PET, whereas 99mTc-MAA imaging showed a SE of 0.75.
Conclusion:
90Y-PET is a promising and reliable technique for microsphere biodistribution evaluation after liver selective internal radiotherapy treatment. Because of the better resolution and the possibility to perform computed tomography fusion, 90Y-PET images are more accurate than 99mTc-MAA single-photon emission computed tomography, which is now considered the gold standard for biodistribution assessment.
Insights
90Y-PET imaging offers a more accurate assessment of 90Y-microsphere biodistribution in liver selective internal radiotherapy compared to 99mTc-MAA SPECT. This improved accuracy aids in better treatment planning and monitoring for liver cancer patients.
Area of Science:
- Nuclear Medicine
- Radiotherapy
- Medical Imaging
Background:
- Selective internal radiotherapy (SIRT) with 90Y-microspheres is a key treatment for liver malignancies.
- Accurate assessment of microsphere biodistribution is crucial for treatment efficacy and minimizing off-target radiation.
- Current methods like 99mTc-macroaggregated albumin (MAA) SPECT have limitations in resolution and accuracy.
Purpose of the Study:
- To evaluate the feasibility and accuracy of 90Y-positron emission tomography (PET) for biodistribution assessment after 90Y-microsphere SIRT.
- To compare the performance of 90Y-PET with conventional 99mTc-MAA SPECT imaging.
- To establish 90Y-PET as a reliable tool for post-treatment evaluation.
Main Methods:
- Preliminary system evaluations for spatial resolution and scanner sensitivity.
- Biodistribution assessment in 10 patients undergoing liver SIRT using simultaneous 99mTc-MAA and 90Y-microsphere injection.
- Comparison of 90Y-PET and 99mTc-MAA images with pre-treatment 18F-fluorodeoxyglucose-PET (18F-FDG-PET) as a benchmark.
- Correlation analysis of detected lesions and calculation of sensitivity for both imaging techniques.
Main Results:
- 90Y-PET demonstrated superior accuracy in detecting microsphere distribution and tumor non-homogeneity compared to 99mTc-MAA SPECT.
- Sensitivity for 90Y-PET was 0.91, significantly higher than the 0.75 sensitivity observed with 99mTc-MAA.
- Good correlation was found between pre- and post-treatment imaging, highlighting 90Y-PET's reliability.
Conclusions:
- 90Y-PET is a highly promising and reliable technique for evaluating microsphere biodistribution following liver SIRT.
- The enhanced resolution and CT-fusion capabilities of 90Y-PET provide more accurate imaging than 99mTc-MAA SPECT.
- 90Y-PET is poised to become the new gold standard for biodistribution assessment in liver SIRT.
More Related Videos
Related Concept Videos
01:25Imaging Studies II: Positron Emission Tomography and Scintigraphy
Fundamental Principles of PET
01:13Radiological Investigation III: Pulmonary Angiogram and PET Scan
Pulmonary Angiogram
A Pulmonary Angiogram is an invasive procedure involving injecting a contrast medium through a catheter threaded into the pulmonary artery or the right side of the heart to visualize the pulmonary vasculature. Computed Tomography (CT) scans have mainly replaced this...
01:29Positron Emission Tomography
One of the main requirements of a PET scan is a positron-emitting radioisotope, which is produced in a cyclotron and then attached to a substance used by the part of the body being...