e15654 Background: The radiation dose is the key factor to improve survival of patients with hepatocellular carcinoma (HCC). The optimal way to increase radiation dose is to reduce uncertainties of target mainly due to respiratory motion and setup error in radiotherapy. Our previous study demonstrated that lipiodol can be a reliable surrogate of direct tumor targeting in Kv- cone beam CT(CBCT) for patients with good lipiodol embolization. Relying on lipiodol,the daily on-line CBCT guidance with ABC is feasible. By reducing geometric position uncertainty, as well as liver movement, the technique of ABC combined with on-line CBCT guidance can permit CTV(clinical target volume)-PTV(planning target volume) margin reduction and dose escalation. The purpose of the study is to apply the new technique for clinical application and investigate the dose escalation, toxicities and response of liver tumors with the technique combined with chemoembolization(TACE). Methods: 20 HCC patients with Child-Pugh A liver function score were treated by daily on-line CBCT guided radiotherapy relying on lipiodol combined with ABC after TACE. After current doses of 45Gy/ 9 fractions,3 fractions/weeks were delivered,the scheduled dose escalation ranged from 5 to 20Gy. Each mean liver dose not reached 23G y, V30 ( the percentage of normal liver volume with radiation dose≥30 Gy) less than 28%. Results: The planned dose escalation was finished in all subgroups. None of these patients developed Grade 2 or greater liver toxicity except two patients developed Grade 2 gastrointestinal complications and one had grade 1 acute liver toxicity.The overall immediate tumor response rate was 76.3%. 1-year overall survival rate was 80.5%. Conclusions: The technique of daily on-line CBCT guided radiotherapy combined with ABC after TACE is a safe and effective treatment which can reduce CTV-PTV margin significantly and increase target precision greatly. With the technique combined with TACE, the total irradiation dose above 65Gy is feasible in daily fraction of 5Gy. No significant financial relationships to disclose.
Clinical Application of Transcatheter Arterial Chemoembolization Combined with Synchronous C-arm Cone-Beam CT Guided Radiofrequency Ablation in treatment of Large Hepatocellular Carcinoma