Ep. 511 How to Simplify Dosing: Understanding Y-90 Dosimetry from Simple to Complex

BackTable Vascular & Interventional

Of all the topics covered during interventional radiology training, dosimetry education is often delayed until after IRs enter clinical practice. In this episode, Drs. Tyler Sandow and Sabeen Dhand host a roundtable discussion with experts on the dosimetry fundamentals that all Y90 operators should understand. They are joined by interventional radiologists Drs. Zachary Berman, Kirema Garcia-Reyes, and Siddharth Padia, who provide their expert insights.

Physicians, nurses, nurse practitioners, and physician assistants can follow this link to earn CME / CE credits for completing an accredited learning activity related to this discussion:

https://www.cmeuniversity.com/course/take/125736

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This podcast is supported by an educational grant from:

AstraZeneca

https://www.astrazeneca.com/our-therapy-areas/oncology.html

With additional support from:

Boston Scientific

https://www.bostonscientific.com/en-US/medical-specialties/interventional-radiology/interventional-oncology.html

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SYNPOSIS

The group agrees that dosimetry is not a one-size-fits-all approach. Dosing strategies depend on factors such as tumor size, perfusion territory, underlying liver function, the choice between glass versus resin spheres, and treatment intent. These considerations are illustrated with real-life case examples. The doctors also explore voxel-based dosimetry, a method for calculating the amount of radiation absorbed by different parts of the tumor. They stress the importance of learning how to perform accurate dosage calculations.

Finally, the conversation touches on data from major Y90 trials, current guidelines, and the evolving perspective on Y90 as a potential curative treatment, rather than merely a bridging therapy.

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TIMESTAMPS

00:00 - Introduction

01:59 - Dosimetry Education During Training

05:46 - Benefit of Individualized Dosing

11:01 - Complications from High Doses

15:19 - Dosage Calculation Cases

22:51 - Duration of Response to Y90

25:00 - Dosing Based on Treatment Intent

29:11 - Challenging Case Example

42:31 - Voxel-Based Dosimetry

45:15 - Using Dosimetry Software

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RESOURCES

LEGACY Trial (Salem et al, 2021):

https://pmc.ncbi.nlm.nih.gov/articles/PMC8596669/

Voxel-based tumor dose correlates to complete pathologic necrosis after transarterial radioembolization for hepatocellular carcinoma (Pianka et al, 2024):

https://pubmed.ncbi.nlm.nih.gov/38913189/

RAPY90D Trial (Kappadath et al, 2023):

https://jnm.snmjournals.org/content/64/supplement_1/P268

Clinical, dosimetric, and reporting considerations for Y-90 glass microspheres in hepatocellular carcinoma: updated 2022 recommendations from an international multidisciplinary working group (Salem et al, 2023):

https://pubmed.ncbi.nlm.nih.gov/36114872/

International recommendations for personalised selective internal radiation therapy of primary and metastatic liver diseases with yttrium-90 resin microspheres (Levillain, 2021):

https://link.springer.com/article/10.1007/s00259-020-05163-5)