Multi-stage automatic and rapid ablation and needle trajectory planning method for CT-guided percutaneous liver tumor ablation

BACKGROUND

Computer-assisted planning methods have increasingly contributed to preoperative ablation planning; however, these methods cannot automatically obtain the final optimal solution within a short time and are rarely validated in practice, greatly limiting their clinical applicability.

PURPOSE

We aimed to propose a full-automatic multi-stage ablation and needle trajectory planning method for CT-guided percutaneous liver ablation to attain the final optimal plans under multiple clinical constraints rapidly.

METHODS

Our proposed method integrates the ablation zone planning fulfilling complete tumor coverage and critical structure avoidance while reaching a trade-off between ablation number and healthy tissue damage, and needle trajectory planning under multiple clinical constraints. Our needle trajectory planning determines feasible skin entry regions based on hard constraints, where the multi-objective optimization (MOO) considering soft constraints is performed using the Pareto Optimality and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) methods for the final optimal solution. The performance of our proposed method was evaluated on 30 tumors of various characteristics from 23 patients and clinically validated in five clinical cases.

RESULTS

Our proposed method achieved 99.8% treatment zone coverage and 40.5% ablation efficiency without involving critical structures, and completely satisfied multiple clinical constraints in all needle trajectory planning results. The average planning time was 23.6 s for tumors of different sizes. All the plans were considered clinically acceptable by the doctors' evaluation. Our method achieved complete tumor coverage without complications in clinical case validation.

CONCLUSION

Our proposed planning method can generate a final optimal plan satisfying multiple clinical constraints within a short time, potentially facilitating preoperative planning for hepatic tumor ablation.

Percutaneous cryoablation of abdominal wall endometriosis: An analysis of 38 patients

PURPOSE

The purpose of this study was to evaluate the efficacy of percutaneous cryoablation in the treatment of abdominal wall endometriosis (AWE) nodules.

MATERIALS AND METHODS

Thirty-eight women treated for symptomatic AWE nodules with percutaneous cryoablation under ultrasound and computed tomography (CT) guidance between May 2020 and July 2023 were retrospectively included. Pain was estimated using visual analog scale (VAS) and assessed at baseline, three months, six months, and 12 months after percutaneous cryoablation. Baseline VAS score, volume of AWE nodule and magnetic resonance imaging (MRI) features of AWE nodules were compared to those obtained after percutaneous cryoablation. Major complications, if any, were noted.

RESULTS

Thirty-eight women with a median age of 35.5 years (interquartile range [IQR]: 32, 39; range: 24-48 years) and a total of 60 AWE nodules were treated. Percutaneous cryoablation was performed under local or regional anesthesia in 30 women (30/38; 79%). Significant decreases between initial median VAS score (7; IQR: 6, 8; range: 3-10) and median VAS score after treatment at three months (0; IQR: 0, 5; range; 0-8) (P < 0.001), six months (0; IQR: 0, 1; range; 0-10) (P < 0.001) and 12 months (0; IQR: 0, 2; range: 0-7) (P < 0.001) were observed. Percutaneous cryoablation resulted in effective pain relief in 31 out of 38 women (82%) at six months and 15 out of 18 women (83%) at 12 months. Contrast-enhanced MRI at six-month follow-up showed a significant decrease in the volume of AWE nodules and the absence of AWE nodule enhancement after treatment by comparison with baseline MRI (P < 0.001). No major complications were reported.

CONCLUSION

Percutaneous cryoablation is an effective, minimally invasive intervention for the treatment of AWE nodules that conveys minimal or no morbidity.

Minimally Invasive Treatment Options for Hepatic Uveal Melanoma Metastases

Uveal melanoma is one of the most common primary intraocular malignancies that accounts for about 85% of all ocular melanomas. The pathophysiology of uveal melanoma is distinct from cutaneous melanoma and has separate tumor profiles. The management of uveal melanoma is largely dependent on the presence of metastases, which confers a poor prognosis with a one-year survival reaching only 15%. Although a better understanding of tumor biology has led to the development of novel pharmacologic agents, there is increasing demand for minimally invasive management of hepatic uveal melanoma metastases. Multiple studies have already summarized the systemic therapeutic options available for metastatic uveal melanoma. This review covers the current research for the most prevalent locoregional treatment options for metastatic uveal melanoma including percutaneous hepatic perfusion, immunoembolization, chemoembolization, thermal ablation, and radioembolization.

Clinical efficacy of systemic chemotherapy combined with radiofrequency ablation and microwave ablation for lung cancer: a comparative study

OBJECTIVE

Local thermal ablation, a minimally invasive technique, has been widely used in clinical treatment of lung cancer. This study aimed to discuss the clinical efficacy of systemic chemotherapy combined with radiofrequency ablation (RFA) versus systemic chemotherapy combined with microwave ablation (MWA) in treating lung cancer.

METHODS

A retrospective analysis involving 124 lung cancer patients, who received RFA (n = 68) and MWA (n = 56) combined with systemic chemotherapy in Cangzhou People's Hospital from August 2017 to December 2019, was conducted. Before comparative analysis for therapeutic efficacy, the two groups of patients were matched with propensity score matching method at a ratio of 1:1. Indicators including progression-free survival (PFS), overall survival (OS), short-term efficacy, tumor marker level, local tumor control rate, and postoperative complications were comparatively analyzed.

RESULTS

There was no statistical difference in disease control rate and objective response rate (90.6% and 78.1% vs 93.8% and 84.4%) between RFA group and MWA group. The incidence of complications was 12.5% in RFA group and 18.8% in MWA group with no statistically significant difference. In addition, the local tumor control rate in MWA group (90.6%) was significantly higher than that in RFA group (78.1%). Regarding survival, a statistically significant difference was observed in median PFS of RFA and MWA groups (9.2 months vs 10.4 months, p < 0.05), while OS in two groups slightly varied.

CONCLUSION

MWA was superior to RFA over local tumor control rate and PFS and showed great potential in lung cancer ablation treatment.

Imaging features of microwave-ablated lesions of the VX2 tumors in rabbit lungs on computed tomography and magnetic resonance images and their correlations with pathological examination

PURPOSE

This study aimed to explore the accuracy of different imaging methods for lesion volume estimation pre- and post-microwave ablation (MWA) as compared with that of pathological examination.

METHODS

We used the VX2 cell line to establish the VX2 lung tumor model in rabbits, followed by MWA of the tumor. The imaging features of the VX2 tumors were documented. The volume of the tumors and the ablated lesions were measured and compared across imaging methods, using the pathological examination as reference.

RESULTS

Tumors were successfully developed in 11 rabbits (age, 13.91 ± 1.38 weeks; weight, 2.15 ± 0.56 kg). The mean volume of the tumors was 2.05 ± 1.88 cm³. CT showed the strongest correlation with the pathologic examination results (r = 0.998, p<.001). MWA created three-layered structures that were delineated on MRI. The mean volume of the post-ablation lesion was 10.39 ± 8.93 cm³, and the measurement of the post-ablation volume on 3D-VIBE-T1WI showed the strongest correlation with the pathologic examination results (r = 0.991, p<.001).

CONCLUSION

Both CT and MRI are capable of depicting lung tumors. In terms of post-ablation evaluation, MR images could provide more versatile information. The 3D-VIBE-T1WI sequence provides more precise lesion volume evaluation after ablation compared with other methods.

Short-Term Outcomes and Safety of Computed Tomography-Guided Percutaneous Microwave Ablation of Solitary Adrenal Metastasis from Lung Cancer: A Multi-Center Retrospective Study

Objective

To retrospectively evaluate the short-term outcomes and safety of computed tomography (CT)-guided percutaneous microwave ablation (MWA) of solitary adrenal metastasis from lung cancer.

Materials and Methods

From May 2010 to April 2014, 31 patients with unilateral adrenal metastasis from lung cancer who were treated with CT-guided percutaneous MWA were enrolled. This study was conducted with approval from local Institutional Review Board. Clinical outcomes and complications of MWA were assessed.

Results

Their tumors ranged from 1.5 to 5.4 cm in diameter. After a median follow-up period of 11.1 months, primary efficacy rate was 90.3% (28/31). Local tumor progression was detected in 7 (22.6%) of 31 cases. Their median overall survival time was 12 months. The 1-year overall survival rate was 44.3%. Median local tumor progression-free survival time was 9 months. Local tumor progression-free survival rate was 77.4%. Of 36 MWA sessions, two (5.6%) had major complications (hypertensive crisis).

Conclusion

CT-guided percutaneous MWA may be fairly safe and effective for treating solitary adrenal metastasis from lung cancer.

Temperature monitoring during radiofrequency ablation of liver: in vivo trials

Radiofrequency ablation (RFA) is a minimally invasive procedure used to treat tumors by means of hyperthermia, mostly through percutaneous approach. The tissue temperature plays a pivotal role in the achievement of the target volume heating, while sparing the surrounding healthy tissue from thermal damage. Several techniques for thermometry during RFA are investigated, most of them based on the use of single-point measurement system (e.g., thermocouples). The measurement of temperature map is crucial for the real-time control and fine adjustment of the treatment settings, to optimize the shape and size of the ablated volume. The recent interest about fiber optic sensors and, among them, fiber Bragg gratings (FBGs) for the monitoring of thermal effects motivated further investigation. In particular, the feature of FBGs to form an array of several elements, thus to be inscribed within the same fiber, allows the use of a single probe for the multi-points monitoring of the tissue temperature during RFA. Hence, the aim of this study is the development and characterization of a needle-like probe embedding an array of three FBGs, which was tested on pig liver during in vivo trials. The needle allows a safe and easy insertion of the fiber optic within the liver. It was inserted by ultrasound guidance into the liver, and monitored the change of tissue temperature during RFA controlled by the roll-off technique. Also the measurement error induced by breathing movements of the liver was assessed (less than 3 °C). Results encourage the use of the probe in clinical settings, as well as the improvement of some features, e.g., a higher number of FBGs for performing quasi-distributed measurement.