Selection of kilovolt based on body mass index reduced radiation dose for computed tomography-guided radiofrequency ablation of liver tumors

To explore the effect of kilovolt (kV) selection based on body mass index (BMI) on reducing the radiation dose of radiofrequency ablation (RFA) in liver tumours under computed tomography (CT) guidance.

This study retrospectively reviewed CT-guided RFA of liver tumours performed between 1 January 2019 and 31 December 2019. The radiation dose received by the patients was recorded after the planning, execution and surgery. The RFA protocol for liver tumours was subsequently modified according to the patients’ BMI. Changes in tube voltage and tube current were recorded for the RFA protocol based on BMI. The image quality and overall operator satisfaction were recorded for each case based on the BMI-modified protocol. The radiation dose received by the patients was also recorded, and the degree of dose reduction adjusted based on BMI was calculated.

The results showed that the mean (± SD) overall CT dose index (CTDI) of CT-guided RFA was 12.83 ± 3.78 mGy. Following protocol modification, the mean CTDI decreased to 3.84 ± 2.24 mGy, a 70.07% reduction overall. The image quality was slightly lower compared with before the modification, but the image quality in both stages met the needs of CT-guided RFA for liver tumours. Electrode needle display and operator confidence satisfaction showed no significant difference between the groups (P > 0.05).

Modification of the BMI-based kV protocol could significantly reduce the radiation dose received by patients during CT-guided ablation of liver tumours. Furthermore, the image quality was not significantly compromised.