Imaging Features of Radiofrequency Ablation with Heat-Deployed Liposomal Doxorubicin in Hepatic Tumors

Abstract

Introduction The imaging features of unresectable hepatic malignancies that underwent radiofrequency ablation (RFA) in combination with lyso-thermosensitive liposomal doxorubicin (LTLD) were determined. Materials and Methods A phase I dose escalation study combining RFA with LTLD was performed with peri- and post- procedural CT and MRI. Imaging features were analyzed and measured in terms of ablative zone size and surrounding penumbra size. The dynamic imaging appearance was described qualitatively immediately following the procedure and at one month follow-up. The control group receiving liver RFA without LTLD was compared to the study group in terms of imaging features and post ablative zone size dynamics at follow-up. Results Post treatment scans of hepatic lesions treated with RFA and LTLD have distinctive imaging characteristics when compared to those treated with RFA alone. The addition of LTLD resulted in a regular or smooth enhancing rim on T1W MRI which often correlated with increased attenuation on CT. The LTLD treated ablation zones were stable or enlarged in the four weeks following ablation in 69% of study subjects as opposed to conventional RFA where the ablation zone underwent involution compared to immediate-post procedure. Conclusion The imaging features following RFA with LTLD were different from those after standard RFA and can mimic residual or recurrent tumor. Knowledge of the subtle findings between the two groups can help avoid misinterpretation and proper identification of treatment failure in this setting. Increased size of the LTLD treated ablation zone after RFA suggests ongoing drug-induced biological effects.

Analysis of iodinated contrast delivered during thermal ablation: is material trapped in the ablation zone?

“…A post-ablation image with good ablation zone sharpness has two characteristics: (1) a high ablation zone shape similarity between radiological and pathological data, and (2) a high level of attenuation contrast across the ablation boundary (Nghiem et al 2002, Hong et al 2015). To compare the shape between radiological and pathological image, the radiological ablation zone was manually segmented slice by slice in each sample.…”