BackTable Vascular & Interventional

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

Jan 24, 2025

Zachary Berman and Kirema Garcia-Reyes, interventional radiologists, share their expertise on Y-90 dosimetry, stressing that it's not a one-size-fits-all approach. They discuss factors influencing dosing, such as tumor size and underlying liver function. The guests reflect on gaps in training and the evolution of dosimetry education in interventional radiology. Real-life case examples illustrate the complexities of individualized treatment plans. They also critique planning software and underscore the importance of empirical approaches to achieve optimal dosages.

54:16

Episode guests

Kirema Garcia-Reyes

Zachary Berman

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Episode notes

Podcast summary created with Snipd AI

Quick takeaways

The podcast emphasizes that dosimetry is a customized process influenced by tumor characteristics, liver function, and treatment goals.

Challenges in dosimetry training highlight the need for improved educational strategies for newly graduated interventional radiologists in clinical practice.

Integrating systemic therapy with localized treatments is essential for effective management and improved outcomes in liver cancer patients.

Deep dives

Selective Treatment for Multifocal Tumors

Selective treatment for multifocal tumors is emphasized as a strategy to preserve healthy liver tissue during radiotherapy. Instead of delivering a single dose to the entire liver lobe, interventional radiologists can perform multiple radioembolization sessions targeting individual tumors. This approach aims to deliver concentrated doses to each tumor while minimizing exposure to surrounding healthy liver tissue. The use of selective dosing is suggested to improve treatment outcomes for conditions like hepatocellular carcinoma (HCC) and metastatic liver diseases.

Intro

2min

From Walkout Songs to Dosimetry Insights: A Physician's Journey

2min

Reflections on the Evolution of Dosimetry Training in Radioembolization

2min

Navigating Y-90 Dosimetry Challenges

16min

Optimizing Dosing in Radiation Segmentectomy

9min

Navigating Liver Cancer Treatment Decisions

12min

Understanding Tumor Dosimetry

8min

Exploring Diverse Approaches in Dosimetry

3min

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 Pharmaceuticals and Boston Scientific.

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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)

CME Accreditation Information:

https://f7cae4ec-b69e-490d-9e0f-19b16a6f146d.usrfiles.com/ugd/f7cae4_a7c37ea3cd1b4d3fa53d5edf8dfe255b.pdf

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BackTable Vascular & Interventional

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

Episode guests

Podcast summary created with Snipd AI

Quick takeaways

Deep dives

Selective Treatment for Multifocal Tumors

Challenges in Dosimetry Training

The Importance of Treatment Intent

Voxel-Based Dosimetry and Tumor Heterogeneity

Integration of Systemic Therapy with Localized Treatments

Remember Everything You Learn from Podcasts