REGULAR CONTENT
Final ID
449
Type
Original Scientific Research-Oral or Pos
Authors
J Stringam1, B Letzen2, M Lin3, M van der Bom4, J Chapiro5, J Geschwind5
Institutions
1University of Washington School of Medicine, Seattle, WA, 2Yale Radiology and Biomedical Imaging, Orange, CT, 3Phillips Healthcare, Middle River, MD, 4Phillips Healthcare, Andover, MA, 5Yale University School of Medicine, New Haven, CT
Purpose
To evaluate the use of volumetric enhancement of hepatocellular carcinoma (HCC) lesions on dual-phase C-arm cone-beam computed tomography (DP-CBCT) acquired immediately before drug-eluting beads transarterial chemoembolization (DEB-TACE) as a predictor of tumor response.
Materials & Methods
This single-institution retrospective study was HIPAA-compliant and IRB-approved. 16 HCC lesions in 16 patients (10 men, mean age: 66.1 years) were treated with DEB-TACE. Three sets of images were obtained for each patient: Baseline contrast enhanced magnetic resonance imaging (CE-MRI) 4-6 weeks before TACE, intra-procedural DP-CBCT immediately before TACE, and CE-MRI 4-6 weeks post TACE. Volumetric tumor enhancement on arterial phase images was assessed on a voxel-by-voxel basis for all modalities and characterized using qEASL criteria. Findings on follow-up MRI were compared to baseline MRI to assess response and this response was compared to findings on DP-CBCT assessed immediately before therapy using linear regression. The mean enhancement on DP-CBCT was calculated and used as a threshold to separate patients into two groups. Each group was then correlated separately with treatment response.
Results
The relative tumor enhancement (in %) observed immediately before therapy on DP-CBCT demonstrated a strong correlation with therapy-related reduction of MR enhancement (R2 = .835; P < .0001). Patients with greater relative volumetric enhancement of lesions directly before TACE demonstrated substantially higher reduction of volumetric enhancement on follow-up MRI and thus a higher rate of response. 6/16 patients were classified as responders according to qEASL criteria. The mean enhancement calculated on DP-CBCT was 55.3% and separated patients into two groups of 8. Enhancement below the mean on DP-CBCT was correlated with 0% response at follow-up while enhancement above the mean was associated with 75% response.
Conclusions
3D quantitative assessment of HCC lesion enhancement on DP-CBCT immediately before DEB-TACE is strongly coorelated with volumetric reduction of tumor enhancement on follow-up CE-MRI. Greater tumor enhancement on DP-CBCT immediately prior to treatment may be an early predictor of treatment response.
Final ID
449
Type
Original Scientific Research-Oral or Pos
Authors
J Stringam1, B Letzen2, M Lin3, M van der Bom4, J Chapiro5, J Geschwind5
Institutions
1University of Washington School of Medicine, Seattle, WA, 2Yale Radiology and Biomedical Imaging, Orange, CT, 3Phillips Healthcare, Middle River, MD, 4Phillips Healthcare, Andover, MA, 5Yale University School of Medicine, New Haven, CT
Purpose
To evaluate the use of volumetric enhancement of hepatocellular carcinoma (HCC) lesions on dual-phase C-arm cone-beam computed tomography (DP-CBCT) acquired immediately before drug-eluting beads transarterial chemoembolization (DEB-TACE) as a predictor of tumor response.
Materials & Methods
This single-institution retrospective study was HIPAA-compliant and IRB-approved. 16 HCC lesions in 16 patients (10 men, mean age: 66.1 years) were treated with DEB-TACE. Three sets of images were obtained for each patient: Baseline contrast enhanced magnetic resonance imaging (CE-MRI) 4-6 weeks before TACE, intra-procedural DP-CBCT immediately before TACE, and CE-MRI 4-6 weeks post TACE. Volumetric tumor enhancement on arterial phase images was assessed on a voxel-by-voxel basis for all modalities and characterized using qEASL criteria. Findings on follow-up MRI were compared to baseline MRI to assess response and this response was compared to findings on DP-CBCT assessed immediately before therapy using linear regression. The mean enhancement on DP-CBCT was calculated and used as a threshold to separate patients into two groups. Each group was then correlated separately with treatment response.
Results
The relative tumor enhancement (in %) observed immediately before therapy on DP-CBCT demonstrated a strong correlation with therapy-related reduction of MR enhancement (R2 = .835; P < .0001). Patients with greater relative volumetric enhancement of lesions directly before TACE demonstrated substantially higher reduction of volumetric enhancement on follow-up MRI and thus a higher rate of response. 6/16 patients were classified as responders according to qEASL criteria. The mean enhancement calculated on DP-CBCT was 55.3% and separated patients into two groups of 8. Enhancement below the mean on DP-CBCT was correlated with 0% response at follow-up while enhancement above the mean was associated with 75% response.
Conclusions
3D quantitative assessment of HCC lesion enhancement on DP-CBCT immediately before DEB-TACE is strongly coorelated with volumetric reduction of tumor enhancement on follow-up CE-MRI. Greater tumor enhancement on DP-CBCT immediately prior to treatment may be an early predictor of treatment response.