Enhancing Tumor Response Prediction with Yttrium-90 Radioembolization: Advanced Imaging Techniques

Predicting tumor response remains challenging across oncology, and Y-90 radioembolization is being explored as a potential aid through improved mapping of treatment distribution and dose.

Yttrium-90 radioembolization research includes bremsstrahlung SPECT-based mapping of Y-90 distribution, with early studies exploring its utility; however, spatial resolution is lower than PET and the predictive value remains under investigation.

Voxel-based dosimetry captures intra-tumoral dose heterogeneity and can provide lesion-level metrics that, in some studies, correlate with response better than population-based models (e.g., partition/MIRD), potentially informing patient-specific planning.

Node-RADS proposes a structured five-point scale integrating CT/MRI features for nodal assessment and has shown promising diagnostic performance in initial evaluations for specified tumor sites; broader validation is ongoing in early studies.

Advanced modalities such as PET/CT and MRI (including diffusion-weighted sequences) can improve staging in selected tumor types, though impact varies by disease and protocol.

Together, Y-90 distribution imaging, voxel-level dosimetry, and standardized nodal assessment frameworks like Node-RADS help address the persistent challenge of predicting response by supporting more informed staging and treatment planning.

Key Takeaways:

• Emerging work is using Y-90 imaging to map intraprocedural and post-procedural distribution, which may support response assessment.
• Voxel-based dosimetry can capture lesion-level dose heterogeneity and, in early studies, may assist individualized planning.
• Node-RADS offers a structured approach to nodal evaluation under ongoing validation rather than broad adoption.
• Contributions of PET/CT and MRI vary by disease and protocol, with potential to improve staging in selected contexts.