Transarterial radioembolization of intrahepatic cholangiocarcinoma: A dose threshold study.

Monday, March 6, 2023

3:18 PM – 3:27 PM

Location: Phoenix Convention Center, 224AB

Presenting Author(s)

LS

Lucas C. Struycken, MD

Fellow
Banner University Medical Center Tucson

Disclosure(s): No financial relationships to disclose

Author/Co-author(s)

GW

Gregory J. Woodhead, MD, PhD

Assistant Professor, Interventional Radiology
University of Arizona
DG

Daniel Goldberg, MD

Assistant Professo
University of Arizona - Tucson
DS

David Schaub, MD

Medical Student
University of Arizona
JL

Joshua Landavaso, MD

Medical Student
University of Arizona
jR

jacob Ref, MD

Medical Student
University of Arizona
JH

Jack Hannallah, MD, MBA, MPH

Assistant Professor
University of Arizona
Shamar Young, MD

Associate professor and Chief of Interventional Radiology
University of Arizona

Disclosure(s):

Lucas C. Struycken, MD: No financial relationships to disclose

Gregory J. Woodhead, MD, PhD: No relevant disclosure to display

Shamar Young, MD: Boston Scientific: Advisory Committee or Review Panel Member (Ongoing), Consultant (Ongoing), Speaking and Teaching (Ongoing); Galvanize Therapeutics: Consultant (Ongoing); Histosonics Inc: Consultant (Terminated); Mirada: Consultant (Ongoing); Varian: Consultant (Ongoing)

Purpose: To determine dose thresholds for radiologic response in intrahepatic cholangiocarcinoma (IC) patients undergoing transarterial radioembolization (TARE).

Materials and Methods: All patients undergoing TARE for IC at a single academic institution were reviewed. The patients’ charts were reviewed for demographic data and post TARE delivery single proton emission computed tomography (SPECT) computed tomography (CT) scans were analyzed using a dosimetry software (Simplicit90y™, Mirada Medical, Denver, CO) to determine realized dose to tumor. Radiologic response was determined with modified response criteria in solid tumors (mRECIST).

Results:

In total 27 patients with an average age of 66.9 ± 12 years underwent treatment of 28 lesions. The radiologic response was progressive disease (PD), partial response (PR), and complete response (CR) in 12 (12/28, 42.8%), 8 (8/28, 28.6%) and 8 (8/28, 28.6%) lesions respectively. The mean dose to the tumor in those which demonstrated PD, PR, and CR was 90 ± 78.9 Gy, 178.2 ± 134.5 Gy, and 519.2 ± 273 Gy (p< 0.001). Data from the dose volume histograms can be found in table 1. When an ROC analysis of lesion dose was performed based on those who did and did not achieve a CR the AUC was 0.933 (p< 0.001) with a Youden’s index revealing a lesion dose >158.7 Gy provided a sensitivity of 100% and a specificity of 75%. A similar analysis was performed with D25, D50, D75, and D90 with AUCs of 0.933 (p< 0.001), 0.95 (p< 0.001), 0.95 (p< 0.001), and 0.775 (p=0.16) respectively. Youden’s Index analysis demonstrated a cutoff of >190 Gy had a sensitivity of 100% and specificity of 75% in the D25 analysis, for D50 a cutoff of >151 Gy had a sensitivity of 100% and a specificity of 83.3%, for D75 a cutoff of >198 Gy provided a sensitivity of 80% and a specificity of 100%, finally D90 showed a cutoff of >90 Gy provided a sensitivity of 80% and a specificity of 83.3% respectively.

Conclusion:

A relationship between tumor dose and response appears to exist when treating IC with TARE.