Radiation segmentectomy conferred comparable response rates, tumor control and survival outcomes as curative-intent treatments among certain patients with early-stage hepatocellular carcinoma, according to findings published in Radiology.
The novel radiotherapy technique is minimally invasive and delivers high doses of radiation to tumors without affecting the surrounding tissue. It relies on an imaging approach called cone beam CT, which offers a detailed view of the liver, allowing clinicians to focus radiation on the segment of the liver where the tumor is located.
“Cone beam CT has revolutionized our ability to perform segmental injections isolated to very small tumors, sparing the majority of normal tissue,” Riad Salem, MD, chief of vascular interventional radiology at Northwestern University Feinberg School of Medicine, said in a press release. “Before cone beam CT, we had the ability to focus radiation, but not with this level of accuracy.”
Salem and colleagues performed a retrospective study of 70 patients (median age, 71 years; range, 22-96) with solitary hepatocellular carcinoma measuring up to 5 cm that was not amenable to percutaneous ablation. All patients received radiation segmentectomy between 2003 and 2016 at a dose of more than 190 Gy. The study excluded patients who underwent curative liver transplantation.
Ninety percent (n = 63) of patients showed a response as defined by the European Association for the Study of the Liver (EASL). Forty-one (59%) of these patients achieved a complete response.
When researchers used WHO criteria, 50 patients (71%) achieved a response, including 11 (16%) who achieved complete response.
The EASL-defined response rate was 86% at 6 months, compared with the WHO criteria rate of 49%.
The median time to progression was 2.4 years (95% CI, 2.1-5.7). Most patients (72%) had no target lesion progression at 5 years.
Median OS was 6.7 years (95% CI, 3.1-6.7). The probability of survival was 98% at 1 year, 66% at 3 years and 57% at 5 years.
Among patients whose baseline tumors were 3 cm or smaller (n = 45), OS probability was 100% at 1 year, 82% at 3 years and 75% at 5 years. Patients with smaller tumors had significantly longer OS than patients whose tumors were larger than 3 cm (P = .026).
“The results show that we are able to impart curative outcomes to these patients,” Salem said. “Our numbers with radiation segmentectomy match or outperform those of other curative treatments in terms of tumor control, survival rate and recurrence. We want to see these outcomes validated [among] patients over the longer term. We also want to minimize the time from clinic visit to treatment and fine-tune dosimetry so that we can find the optimal dose that will kill the tumor. In the right patient setting, radiation segmentectomy can be considered curative.” – by Andy Polhamus
Disclosures: Salem reports consultant roles with Boston Scientific, BTF and Terumo; as well as travel, accommodations, expenses, and grants to his institution from BTG, all outside of the submitted work. Please see the study for a list of all other authors’ relevant financial disclosures.