A0491 - Patient Survival and Tumor Responses in Patients Undergoing Radiation Segmentectomy: A Large Tertiary Center Experience

Prachi Khanna, ¹, Kyle McCall, ², Mallory Thompson, MS³, Islam Shahin, MD⁴, Parvez Mantry, MD^5
1University of Texas Health Science Center, Dallas, TX; ²Texas A&M Health Science Center College of Medicine, Dallas, TX; ³TCU School of Medicine, Fort Worth, TX; ⁴Methodist Dallas Medical Center, DeSoto, TX; ⁵Methodist Dallas Medical Center, Dallas, TX

Introduction: Unresectable hepatocellular carcinoma (HCC) can be treated with Selective Internal Radiation Therapy (SIRT) with Y-90, using either SIR-Spheres® (SS) or TheraSpheres® (TS). The aim of this study was to report the tumor response, overall survival, and tolerability of SS and TS.

Methods: We retrospectively analyzed charts of 137 patients who underwent SIRT with SS or TS at our center from April 2017 to January 2021, comprising 210 total procedures. Statistical analysis was performed using SAS.

Results: Stratification by therapy type showed 70% of total Y-90 therapy procedures were with SS and 30% with TS. Table 1 contains the demographic breakdown, liver disease etiology, tumor characteristics, MELD score, BCLC stage, pre- and post-SIRT symptoms, and Modified Response Evaluation Criteria in Solid Tumors (mRECIST) for SS and TS.

There was a decrease in size, enhancement, or both size and enhancement in 85% of SS and 88% of TS patients. The median overall survival was 18 months for SS and 20 months for TS. Tumor recurrence occurred in 26% of non-transplanted patients while 3 transplanted patients (out of 15) showed recurrence.

The median injected dose of Y-90 SS (24.9 mCi, range 5.7-81.8 mCi) was significantly lower than that of Y-90 TS (39.6 mCi, range 4.6-90.1 mCi). This is likely due to different dosimetry models for each type of bead, which evolve as imaging modalities allow more accurate representations of absorbed radiation per dose. The procedures were well tolerated.

Discussion: Our findings indicate that intermediate and advanced HCC patients have excellent response to Y-90 therapy with both SS and TS, as depicted by the decrease in size, enhancement, or both in 85% (SS) and 88% (TS) of patients, complete response in 37% (SS) and 49% (TS) of patients, and overall survival that ranges from 18 (SS) to 20 (TS) months, which is very favorable in this group of patients. Therapy is very well tolerated. Differences between SS and TS may possibly be explained by dosimetry; however, further comparative studies may be needed.



Disclosures:


Prachi Khanna, ¹, Kyle McCall, ², Mallory Thompson, MS³, Islam Shahin, MD⁴, Parvez Mantry, MD⁵. A0491 - Patient Survival and Tumor Responses in Patients Undergoing Radiation Segmentectomy: A Large Tertiary Center Experience, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.