# Liver injury and recovery following radiation therapy for hepatocellular carcinoma: insights from functional liver imaging

## TL;DR

This study uses functional liver imaging to show how liver function changes after radiation therapy for liver cancer, revealing insights not visible with standard imaging.

## Contribution

The study introduces functional liver imaging with 99mTc-sulfur colloid SPECT/CT to better assess liver injury and recovery after radiation therapy.

## Key findings

- Liver function measured by TLF significantly decreased after RT but showed recovery over time.
- Patients with better pre-treatment liver function (CP-A) had less decline in liver function after RT.
- The decline in liver function correlated with the radiation dose received.

## Abstract

A critical need for hepatocellular carcinoma (HCC) management is understanding how the liver recovers following radiotherapy (RT). We hypothesized that functional liver imaging with 99mTc-sulfur colloid (SC) SPECT/CT provides additional information on liver injury and recovery after RT compared to conventional imaging.

The liver function of patients with HCC was assessed using 99mTc-SC SPECT/CT imaging before and after definitive RT. The anatomical liver volume (ALV) was segmented on CT imaging. Liver function was measured as the total liver function (TLF) encompassing 30% of maximum SC uptake. Changes in ALV and TLF were compared to clinical characteristics.

Of 31 patients with evaluable post-RT SC SPECT/CT scans (total of 32), 23 had pre-treatment Child-Pugh (CP)-A and 9 had CP-B/C scores. The median follow-up post-RT was 57 days. The median change in ALV was −1.7% with no significant difference between CP-A and CP-B/C patients (P = 0.26) or between short- (32-99 days) and long-term (271-1120 days) follow-up imaging groups (P = 0.28). The median change in TLF post-RT was −24% and was significantly different between short- and long-term groups (−39% vs. 2%, P = 0.001) and between CP-A and CP-B/C patients (−19% vs. −57%, P = 0.002). TLF significantly decreased following treatment at all radiation dose levels, with the decline correlating with the dose (P < 0.001).

Functional imaging provides additional information regarding liver injury and recovery following RT that conventional imaging cannot reveal. Patients with CP-A liver status showed less decline following RT and most had liver function near or above pre-treatment levels.