Researchers investigate new methods for dose quantification following Y-90 using PET/CT

Hepatocellular carcinoma is often managed using a lobar arterial injection of Yttrium-90 radioembolization therapy. This study describes the use of PET-CT to localize and quantify the dose after glass microsphere Y-90 therapy. This retrospective single institution study looked at 64 post-radioembolization “dose maps” created from reconstructed PET-CT images. Contouring of the liver parenchyma and tumors (using pre-procedure imaging if needed) was performed and aligned with these dose maps. A total of 113 tumors were evaluated with an average size of 4.8 cm ±4. The average tumor dose was 173 Gy ±109 and the average non-tumor liver parenchyma dose was 93.4 Gy ±32.6. The calculated average tumor-to-parenchyma dose ratio was 2.2, which suggested a preferential Y-90 uptake within the tumors.

Comments:

The authors were able to characterize the dose deposition of Y-90 in a large cohort of HCC patients being treated using the recommended dose administration algorithms. The study quantifies the well-known, extremely heterogeneous microsphere deposition and highlights the error of applying broad dosing guidelines to all patients. This imaging technique is a valuable tool for any study looking to optimize dosing and clinical response and should be considered for future research studies evaluating the wide discrepancies between dosing and deposition.


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Citation:  Lea WB, Tapp KN, Tann M, et al. Microsphere Localization and Dose Quantification Using Positron Emission Tomography/CT following Hepatic Intraarterial Radioembolization with Yttrium-90 in Patients with Advanced Hepatocellular Carcinoma. J Vasc Interv Radiol (2014)


Post author: Nicholas Hendricks, MD