NIH Research Festival
External beam radiation therapy (XRT) and thermal ablation have complementary risk profiles and synergistic mechanisms. Our clinical trial employs fusion software guidance to combine XRT with ablation for potentially synergistic treatment of large (up to 10 cm in diameter) and/or multiple (up to 5) liver tumors. Patients were treated with 5 total fractions (50 Gy total) of XRT over 2 weeks, and ablation was done between fractions 3 and 4. A custom navigation system for ablation was developed to fuse radiation dose map, multiple imaging modalities, ablation probe trajectories, and expected ablation zones for any planned treatment volume. Thus far, 3 patients have been enrolled and treated. Two patients received spatially synergistic treatment, using XRT and ablation to achieve an overall larger lesion coverage compared to what each modality could achieve alone. One patient received temporally synergistic treatment (XRT and ablation to same volume), which resulted in an ablation volume of 58.69 cc (nearly 3 times greater than the expected volume derived from in vitro porcine studies). On subsequent follow-up, no definite local tumor recurrence was seen in any patient, although one patient had suspected marginal recurrence one year after treatment of an almost 10 cm lesion. Fusion navigation guided by radiation dose map input may combine the complementary therapies of XRT and ablation, thus potentially enhancing coverage and increasing indications for treatment. Both spatial and temporal synergy appear to be feasible, with possibly different effects to target tissue, warranting additional investigation into the interaction of the two treatment modalities.
Scientific Focus Area: Cancer Biology
This page was last updated on Friday, March 26, 2021