Chemoembolization versus Radiotherapy for Single Hepatocellular Carcinomas of ≤3 cm Unsuitable for Image-Guided Tumor Ablation.

Background/Aims: Local ablation therapy (LAT) is primarily recommended for solitary inoperable hepatocellular carcinomas (HCCs) of ≤3 cm in diameter. However, only two-thirds of uninodular small HCCs are suitable for LAT, and the second-best treatment option for managing these nodules is unclear. We aimed to compare the therapeutic outcomes of chemoembolization and radiotherapy in small HCCs unsuitable for LAT. Methods: The study included 651 patients from a tertiary referral center who underwent planning sonography for LAT. These patients had 801 solitary HCCs of ≤3 cm in diameter and were treated with LAT, chemoembolization, or radiotherapy. Local tumor progression (LTP)-free survival and overall survival (OS) were measured according to the type of treatment of the index nodule. Results: LAT, chemoembolization, and radiotherapy were used to treat 561, 185, and 55 nodules in 467, 148, and 36 patients, respectively. LTP-free survival was significantly shorter in patients treated with chemoembolization than for those treated with LAT (multivariate hazard ratio [HR], 2.36; 95% confidence interval [CI], 1.61 to 3.47) but not for those treated with radiotherapy (HR, 0.83; 95% CI, 0.38 to 1.83). However, OS was not affected by treatment modality. Matching and weighting analyses confirmed that radiotherapy gave comparable results to chemoembolization in terms of OS despite better LTP-free survival (HR, 2.91; 95% CI, 1.13 to 7.47 and HR, 3.07; 95% CI, 1.11 to 8.48, respectively). Conclusions: Our data suggest that chemoembolization and radiotherapy are equally effective options for single small HCCs found to be unsuitable for LAT after sonographic planning. Betterfit indications for each procedure should be established by specifically designed studies.