Achieving prescribed tumor absorbed dose in radiation segmentectomy with resin microspheres for HCC: Quantitative PET/CT analysis

Monday, March 6, 2023

3:54 PM – 4:03 PM

Location: Phoenix Convention Center, 224AB

Presenting Author(s)

Nhi H. Vo, MD

Resident
BIDMC

Disclosure(s): No financial relationships to disclose

Author/Co-author(s)

Muhammad Saad Malik, MD

Post-doctoral Research Fellow
Beth Israel Deaconess Medical Center | Harvard Medical School
Muhammad Mohid Tahir, MD (he/him/his)

Postdoctoral Research Fellow
Beth Israel Deaconess Medical Center
AP

Anthony J. Parker, MD PhD

Associated Professor Radiology
BIDMC
JW

Jeffrey Weinstein, MD FSIR

Program Director, Interventional Radiology Residency Programs
Beth Israel Deaconess Medical Center/Harvard Medical School
MA

Muneeb Ahmed, MD FSIR

Chief, Division of Interventional Radiology
Beth Israel Deaconess Medical Center/Harvard
Ammar Sarwar, MD FSIR (he/him/his)

Associate Professor of Radiology
Beth Israel Deaconess Medical Center

Disclosure(s):

Nhi H. Vo, MD: No financial relationships to disclose

Muhammad Mohid Tahir, MD: No financial relationships to disclose

Jeffrey Weinstein, MD FSIR: BAIM Institute: Advisory Committee or Review Panel Member (Ongoing); Instylla: Advisory Committee or Review Panel Member (Ongoing)

Muneeb Ahmed, MD FSIR: Agile Devices, Inc.: Advisory Committee or Review Panel Member (Ongoing), Consultant (Ongoing), Ownership Interest (Ongoing); Replimune, Inc.: Consultant (Ongoing); RevOps Health, Inc.: Advisory Committee or Review Panel Member (Ongoing), Consultant (Ongoing), Ownership Interest (Ongoing)

Ammar Sarwar, MD FSIR: Agile Devices, Inc.: Advisory Committee or Review Panel Member (Ongoing)

Purpose:

Quantify PET/CT derived tumor absorbed dose (TAD) with prescribed TAD (pTAD) and compare outcomes using single compartment MIRD model in HCC patients undergoing ⁹⁰Y radiation segmentectomy with resin microspheres.

Materials and Methods:

Consecutive HCC patients from 1/2018 to 7/2022 receiving PET/CT after TARE (108) with resin microspheres in <2 segments (56) & 3-month treatment response (48) were retrospectively reviewed. Prescribed activity & pTAD was determined by ^99mTc MAA prescription dosimetry (PD) using MIRD modeling. Area segmentation on PET/CT was contoured using MIM SurePlan Liver (MIM Software Inc.). Dose delivered to 50, 70, & 95% of tumor (D₅₀, D₇₀, D₉₅) were derived from dose volume histograms. 3-month imaging was used to assess objective response (OR) (complete response) using mRECIST. Median was reported for continuous variables, and unpaired T-test (2 groups) was done on a per tumor per treatment basis.

Results:

Tumors (48 treatments) in 44 patients (71 ± 9 years, 77% male) were analyzed. Most (90%) had cirrhosis with an average MELD of 9 ± 4 (6-22) & tumor size of 3.4 cm (1.9-4.7). pTAD was 250 Gy, and Median D₅₀, D₇₀, & D₉₅ were 202, 145, & 61 Gy. OR was 73% (35/48) at 3 months. 4 patients underwent resection (average pathological necrosis 70%). < 90% of prescribed activity was delivered in 29% (14/48), & ≥90% in 71% (34/48) of treatments. D50 (211 vs 188, p=0.5), D70 (138 vs 145, p=0.3), D95 (50 vs 73, p=0.2) was comparable in < 90% vs ≥90% activity group. < 90% activity group had higher chance of achieving OR compared to ≥90% (93% vs 65%, p=0.046). There was no difference in OR among cases with and without stasis in < 90% activity group (92% vs 100%, p=0.28) vs ≥90% activity group (63% vs 67%, p=0.83). Tumors with a D50 of >200 Gy had higher chance of achieving OR compared to tumors that received < 200 Gy (88% vs 58%, p=0.02) on PET/CT.

Conclusion:

Tumors with < 90% of activity delivered still achieved a high ORR. ORR was comparable in cases with and without stasis following TARE with resin microspheres. Tumors with a D50 of >200 Gy on PET/CT had a higher chance of achieving OR compared to tumors with a D50 of 200 Gy.