2023 - Outcomes of =5 vs. >5 Fraction Hypofractionated Radiation Therapy for Hepatocellular Carcinoma

03:00pm - 04:00pm ET

Poster Hall - Exhibit Hall A

Screen: 28

POSTER

Presenter(s)

Danielle Burner, BS - Duke University, Durham, NC

R. Laoprasert¹, D. Burner¹, J. J. Qazi¹, D. Niedzwiecki², Z. Wan², S. J. Stephens¹, M. Palta¹, and C. Eyler¹; ¹Duke University Medical Center, Department of Radiation Oncology, Durham, NC, ²Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, NC

Purpose/Objective(s):

Hypofractionated radiation therapy (RT) has emerged as an effective local treatment modality for patients with hepatocellular carcinoma (HCC). Comparisons between different fractionation schemes are limited in the literature. In this retrospective cohort study, we compare single-institution outcomes among HCC patients treated with hypofractionated radiation therapy in =5 fractions versus >5 fractions.

Materials/Methods:

Clinical, demographic, treatment, laboratory, and imaging data for patients with HCC treated with an initial course of hypofractionated RT were manually abstracted into a REDCap database. Regimens >5 fractions were chosen by the treating clinicians when there was concern about meeting normal tissue constraints. Time-to-event endpoints were defined from the RT start date. Freedom from in-field liver progression (FFLP) was defined as time to documented in-field progression or last imaging, with censoring at liver transplant when applicable. Time to hepatic function decline was defined as freedom from =2-point increase in Child-Pugh score (CP2). Kaplan–Meier methods were used to estimate survival, and comparisons between fractionation groups were performed using the Log Rank test.

Results:

A total of 124 patients met inclusion criteria. The median age for diagnosis was 67 years (IQR 61–74). The cohort was predominantly male (68.9%), and most patients were White/Caucasian (71.1%) followed by Black or African American (19.8%) and Hispanic (5.0%). The majority had an ECOG performance status of 0–1 (64.5%) and underlying cirrhosis (79.1%). Most presented with a single lesion (73.7%) and the majority were Child-Pugh Class A (62.3%) or B (27.2%) at diagnosis. Additionally, 79.8% were surgery-naïve prior to RT treatment. For subgroup analyses, 111 of 124 patients had sufficient data for fractionation grouping; 73 (65.8%) received =5 fractions and 38 (34.2%) received 6 to 10 fractions. Median dose was 50Gy in both groups (range: 30-55Gy). There were no patients who received >10 fractions. At 12 months, FFLP was 81.6% in the =5 fraction group versus 75.9% in the >5 fraction group (Log Rank p=0.877). Median FFLP was not reached in either group. CP2 at 12 months was 81.2% in the =5 fraction cohort versus 73.9% in the >5 fraction cohort (Log Rank p=0.917). Median CP2 was not reached in either group. Median and 12 month overall survivals were 25.8 months and 78.8% in the group ,and 13.1 months and 52.5% in the >5 fractions group, respectively (Log Rank p=0.032).

Conclusion:

Hypofractionated RT delivered in 6-10 fractions had in-field control and preservation of hepatic function comparable to =5 fraction regimens. Either approach may represent an effective definitive treatment strategy for appropriately selected patients with HCC.