Bern University Hospital Surgery
Bern University Hospital
Surgery

Author of 2 Presentations

SS 7.1 - Stereotactic image-guided microwave ablation for malignant liver tumours: a multivariable accuracy and efficacy analysis

Presentation Number
SS 7.1
Channel
On-demand channel 6

Abstract

Purpose

Therapeutic success of microwave ablation for liver lesions depends on precise placement of ablation probes and complete tumor destruction. We investigated factors influencing targeting accuracy and efficacy of percutaneous stereotactic image-guided microwave ablation (SMWA) for malignant liver tumors.

Material and methods

All malignant liver tumors treated with SMWA over 3 years were analyzed in this observational study. A computed tomography-based navigation system was used for ablation probe trajectory planning, stereotactic probe positioning and validation of probe positions and ablation zones. Factors potentially influencing target positioning errors (TPE) of ablation probes, and local tumor progression (LTP) within 6 months, were analyzed using a multivariable regression model including challenging lesion locations (liver segments I, VII and VIII; subphrenic location).

Results

301 lesions (174 HCC, 87 CRLM, 17 NET, 23 other) were targeted in 191 interventions in 153 patients. Median TPE per ablation probe was 2.9 millimeters (0.2 - 14.1 mm) (n=384). Factors significantly influencing TPE were cirrhosis (R 0.668, CI 0.218 - 1.119) and targeting trajectory length in centimeters (R 0.205, CI 0.118 - 0.291). Overall technique efficacy was 96% and LTP within 6 months 22%. Factors significantly influencing early LTP were lesion size >30 mm (OR 5.221, CI 2.435 - 11.192) and TPE >5 mm (OR 2.480, CI 1.064 – 5.784). Challenging intrahepatic lesion locations had no significant influence on TPE or early LTP.

Conclusion

SMWA allows precise and effective treatment of malignant liver tumors, with targeting accuracy independently predicting efficacy, while unaffected by challenging lesion locations. This might broaden treatment eligibility for otherwise difficult-to-target liver tumors.

Collapse

SS 7.9 - Stereotactic microwave ablation of malignant liver lesions using MRI/CT fusion for targeting of “invisible” lesions

Presentation Number
SS 7.9
Channel
On-demand channel 6

Abstract

Purpose

In thermal ablation for treating primary or metastatic liver neoplasms, advanced stereotactic navigation technology not only improves precise tumor targeting and antenna guidance but also allows approaching lesions that are not detectable on CT planning scans by fusion with a prior MRI. The purpose of our study was to assess the technical feasibility of MRI/CT fusion for lesions invisible on CT planning scans and its outcome in patients treated with stereotactic microwave ablation (SMWA).

Material and methods

Patients who underwent SMWA between January 2015 and December 2018 were retrospectively analyzed. All liver lesions for which MRI/CT fusion was performed due to invisibility on pre-interventional CT planning scans were included and reassessed. The endpoint was successful ablation of the lesion at first follow-up imaging.

Results

During the study period, 236 patients underwent 312 SMWAs with ablation of 496 lesions. Twenty-four lesions in 15 patients (mean age 62 years; range 43 - 80 years) were included. Following MRI/CT image fusion, all 24 lesions were sufficiently visible to perform SMWA. The first follow-up imaging showed complete ablation of 22 lesions. Two initially incompletely ablated lesions were HCCs, and were successfully re-ablated afterwards.

Conclusion

SMWA with MRI/CT image fusion is an efficient and safe treatment option for patients with liver lesions not detectable on contrast-enhanced CT planning scans. Using MRI/CT image fusion may allow more patients with malignant liver lesions to benefit from locally ablative therapies even if their lesions are not visible on CT planning examinations.

Collapse

Author of 2 Presentations

SS 7.1 - Stereotactic image-guided microwave ablation for malignant liver tumours: a multivariable accuracy and efficacy analysis (ID 912)

Abstract

Purpose

Therapeutic success of microwave ablation for liver lesions depends on precise placement of ablation probes and complete tumor destruction. We investigated factors influencing targeting accuracy and efficacy of percutaneous stereotactic image-guided microwave ablation (SMWA) for malignant liver tumors.

Material and methods

All malignant liver tumors treated with SMWA over 3 years were analyzed in this observational study. A computed tomography-based navigation system was used for ablation probe trajectory planning, stereotactic probe positioning and validation of probe positions and ablation zones. Factors potentially influencing target positioning errors (TPE) of ablation probes, and local tumor progression (LTP) within 6 months, were analyzed using a multivariable regression model including challenging lesion locations (liver segments I, VII and VIII; subphrenic location).

Results

301 lesions (174 HCC, 87 CRLM, 17 NET, 23 other) were targeted in 191 interventions in 153 patients. Median TPE per ablation probe was 2.9 millimeters (0.2 - 14.1 mm) (n=384). Factors significantly influencing TPE were cirrhosis (R 0.668, CI 0.218 - 1.119) and targeting trajectory length in centimeters (R 0.205, CI 0.118 - 0.291). Overall technique efficacy was 96% and LTP within 6 months 22%. Factors significantly influencing early LTP were lesion size >30 mm (OR 5.221, CI 2.435 - 11.192) and TPE >5 mm (OR 2.480, CI 1.064 – 5.784). Challenging intrahepatic lesion locations had no significant influence on TPE or early LTP.

Conclusion

SMWA allows precise and effective treatment of malignant liver tumors, with targeting accuracy independently predicting efficacy, while unaffected by challenging lesion locations. This might broaden treatment eligibility for otherwise difficult-to-target liver tumors.

Collapse

SS 7.9 - Stereotactic microwave ablation of malignant liver lesions using MRI/CT fusion for targeting of “invisible” lesions (ID 502)

Abstract

Purpose

In thermal ablation for treating primary or metastatic liver neoplasms, advanced stereotactic navigation technology not only improves precise tumor targeting and antenna guidance but also allows approaching lesions that are not detectable on CT planning scans by fusion with a prior MRI. The purpose of our study was to assess the technical feasibility of MRI/CT fusion for lesions invisible on CT planning scans and its outcome in patients treated with stereotactic microwave ablation (SMWA).

Material and methods

Patients who underwent SMWA between January 2015 and December 2018 were retrospectively analyzed. All liver lesions for which MRI/CT fusion was performed due to invisibility on pre-interventional CT planning scans were included and reassessed. The endpoint was successful ablation of the lesion at first follow-up imaging.

Results

During the study period, 236 patients underwent 312 SMWAs with ablation of 496 lesions. Twenty-four lesions in 15 patients (mean age 62 years; range 43 - 80 years) were included. Following MRI/CT image fusion, all 24 lesions were sufficiently visible to perform SMWA. The first follow-up imaging showed complete ablation of 22 lesions. Two initially incompletely ablated lesions were HCCs, and were successfully re-ablated afterwards.

Conclusion

SMWA with MRI/CT image fusion is an efficient and safe treatment option for patients with liver lesions not detectable on contrast-enhanced CT planning scans. Using MRI/CT image fusion may allow more patients with malignant liver lesions to benefit from locally ablative therapies even if their lesions are not visible on CT planning examinations.

Collapse