SIRT and TomoTherapy for HCC: Asian perspective
Selective internal radiaton therapy (SIRT) in combination with sorafenib has demonstrated encouraging results in a recent study of Asian patients with non-resectable hepatocellular carcinoma (HCC), while data from Korea suggest that TomoTherapy is more effective than 3D conformal RT in locally advanced HCC.
“SIRT with yttrium-90 is indicated for inoperable larger or multifocal HCC, including HCC with portal vein involvement, as well as refractory colorectal cancer liver metastases and neuroendocrine tumor metastases. The disease control rate is approximately 80 percent, compared with 40 percent with transarterial chemoembolization [TACE],” said Professor Pierce Chow of the National University of Singapore and Singapore General Hospital.
The efficacy and safety of SIRT with yttrium-90 was demonstrated in several trials, including a multicenter European trial on HCC across all Barcelona Clinic Liver Cancer (BCLC) stages. In that trial, median survival was 12.8 months (BCLC A, 24.4 months; BCLC B, 16.9 months; BCLC C, 10 months); the majority of patients (93.3 percent) had only one SIRT session. [Hepatology 2011;54: 868-878]
“While yttrium-90 is efficacious in causing complete or partial destruction of the tumor, new lesions can arise from the liver or from metastasis. The Asia-Pacific HCC Trials Group tested yittrium-90 followed by sorafenib, to see if this can prevent or delay the development of new lesions and improve outcomes in advanced HCC,” said Chow.
The phase I/II trial, known as AHCC005, included 34 patients with BCLC B or C HCC. “Tumor response was encouraging, with 12 percent of patients achieving complete regression, 23.5 percent achieving partial regression, and 44 percent achieving stable disease. Tumor response rate was 33.5 percent, while disease control rate was 79.5 percent,” reported Chow. “The median time to progression was 39 weeks. Median survival was 20.6 months for patients with BCLC B disease, and 8.2 months for those with BCLC C disease.”
“As there is currently no established first-line therapy for inoperable HCC without metastasis, the HCC Trials Group has started a phase III randomized controlled trial to compare SIRT with sorafenib in patients with locally advanced HCC,” he continued. “Recruitment is ongoing, and patients previously treated with surgery, TACE or radiofrequency ablation are eligible.”
In another study (n=106), researchers from the Yonsei University, Korea have shown significantly longer overall survival (OS) (1-year, 81.1 vs 52.8 percent; 2-year, 42.2 vs 30.2 percent; 3-year, 31.6 vs 25.9 percent) with TomoTherapy vs 3D conformal RT in patients with locally advanced HCC. “While the two modalities showed similar progression-free survival [PFS] and OS in tumors ≤5 cm, significant benefits in PFS and OS were seen in tumors larger than 5 cm,” said investigator Professor Jinsil Seong. “We therefore strongly suggest TomoTherapy for locally advanced HCC patients with tumors larger than 5 cm.”