Dosimetry University VI: Challenging Case Review

The interventional oncologists first outline the types of metastases that they treat, including colorectal, lung, cholangiocarcinoma, breast, gastric, RCC, and melanoma. The doctors then discuss the potential for Y90 to provide palliative relief by reducing tumor-related pain. The conversation also covers key differences between treating liver-dominant and liver-only disease, along with their algorithm for patients not on systemic chemotherapy.

The episode then covers advanced concepts in Y90, such as sub-ablative dosing, the possibility of creating an abscopal effect, and how radiation thresholds change depending on treatment goals. They outline their approach to partition dosimetry, using SPECT/CT to calculate tumor-to-normal ratios, and explain how they modify particle counts and microsphere activity, using flow augmentation based on tumor vascularity. Additional discussion includes the impact of mutation status, prior lines of chemotherapy, and tumor response criteria like RECIST 1.1 and mRECIST.

The experts conclude with a case series that illustrates decision-making around when to consider Y90, thermal ablation, TACE, or alternative approaches—even in complex cases like sphincter of Oddi dysfunction. The session underscores the nuanced nature of advanced dosimetric techniques and the evolving landscape of interventional oncology.