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Updated: Mar 28, 2026
Y-90 Radioembolization and PD-1 Inhibitor as Neoadjuvant Treatment in Hepatocellular Carcinoma
Published on: May 24, 2024
PET/MRI of Hepatic 90Y Microsphere Deposition Determines Individual Tumor Response
Kathryn J Fowler1, Nichole M Maughan2, Richard Laforest3
1Department of Radiology, Washington University, Campus Box 8131, 510 S. Kingshighway Blvd, St. Louis, MO, 63110, USA.
Purpose:
The purpose of our study is to determine if there is a relationship between dose deposition measured by PET/MRI and individual lesion response to yttrium-90 ((90)Y) microsphere radioembolization.
Materials And Methods:
26 patients undergoing lobar treatment with (90)Y microspheres underwent PET/MRI within 66 h of treatment and had follow-up imaging available. Adequate visualization of tumor was available in 24 patients, and contours were drawn on simultaneously acquired PET/MRI data. Dose volume histograms (DVHs) were extracted from dose maps, which were generated using a voxelized dose kernel. Similar contours to capture dimensional and volumetric change of tumors were drawn on follow-up imaging. Response was analyzed using both RECIST and volumetric RECIST (vRECIST) criteria.
Results:
A total of 8 hepatocellular carcinoma (HCC), 4 neuroendocrine tumor (NET), 9 colorectal metastases (CRC) patients, and 3 patients with other metastatic disease met inclusion criteria. Average dose was useful in predicting response between responders and non-responders for all lesion types and for CRC lesions alone using both response criteria (p < 0.05). D70 (minimum dose to 70 % of volume) was also useful in predicting response when using vRECIST. No significant trend was seen in the other tumor types. For CRC lesions, an average dose of 29.8 Gy offered 76.9 % sensitivity and 75.9 % specificity for response.
Conclusions:
PET/MRI of (90)Y microsphere distribution showed significantly higher DVH values for responders than non-responders in patients with CRC. DVH analysis of (90)Y microsphere distribution following treatment may be an important predictor of response and could be used to guide future adaptive therapy trials.
Insights
PET/MRI accurately measures dose deposition for yttrium-90 microsphere radioembolization. Higher dose volumes in PET/MRI predict treatment response, especially for colorectal metastases, guiding future therapies.
Area of Science:
- Nuclear Medicine
- Radiology
- Oncology
Background:
- Radioembolization with yttrium-90 ((90)Y) microspheres is a treatment for liver tumors.
- Accurate assessment of dose delivered to tumors is crucial for treatment efficacy.
- Positron Emission Tomography/Magnetic Resonance Imaging (PET/MRI) offers advanced imaging capabilities.
Purpose of the Study:
- To investigate the relationship between PET/MRI-measured dose deposition and tumor response.
- To evaluate the predictive value of dose metrics for (90)Y microsphere radioembolization outcomes.
Main Methods:
- 26 patients with liver tumors treated with (90)Y microspheres underwent PET/MRI post-treatment.
- Dose volume histograms (DVHs) were generated from PET/MRI data.
- Tumor response was assessed using RECIST and volumetric RECIST (vRECIST) criteria.
Main Results:
- Average dose predicted treatment response for all lesion types and specifically for colorectal metastases (CRC).
- D70 (minimum dose to 70% of tumor volume) was predictive of response with vRECIST.
- Higher DVH values were observed in responders compared to non-responders for CRC lesions.
Conclusions:
- PET/MRI-based DVH analysis of (90)Y microsphere distribution is a significant predictor of treatment response in CRC.
- These findings suggest DVH analysis can guide adaptive therapy strategies in radioembolization.
- Further trials can leverage PET/MRI for personalized dose assessment in radioembolization.
