Percutaneous laser ablation: a new contribution to unresectable high-risk metastatic retroperitoneal lesions?

Transarterial Embolization and Percutaneous Ablation of Primary and Metastatic Soft Tissue Tumors

Soft tissue tumors (STTs) include a range of benign and malignant tumors originating from soft tissues. Transarterial and percutaneous therapies are image-guided and minimally invasive approaches for managing primary and metastatic STTs. The objective of this review is to discuss transarterial and percutaneous therapies by examining the current literature, including indications, patient selection, safety, and effectiveness. Transarterial therapies (e.g., transarterial bland embolization and transarterial chemoembolization) involve the delivery of either embolic or chemotherapeutic particles using a catheter into arteries feeding the tumor, resulting in localized tumor destruction. Percutaneous therapies (e.g., radiofrequency ablation, cryoablation, irreversible electroporation, laser ablation, and magnetic resonance-guided high-intensity focused ultrasound) involve the delivery of either hot or cold temperatures, electrical current, laser, or ultrasound to specifically target tumor cells. Both therapies have been shown to be safe and effective for reducing morbidity and local control of STTs, specifically in patients who are surgically inoperable or who are unresponsive to conventional therapies. Accurate diagnosis, staging, and histological subtype identification are crucial for treatment selection. A multidisciplinary approach, a thorough understanding of tissue anatomy and surrounding structures, as well as individualized strategies based on assessment are essential for optimal patient care.

Safety and Local Efficacy of Laser Ablation for the Extrahepatic Metastasis of Hepatocellular Carcinoma: An Available Treatment Strategy

Thermal ablation plays an important role in the treatment of extrahepatic metastasis of hepatocellular carcinoma (HCC). Yet laser ablation (LA), as a safe thermal ablative modality, is less investigated in this field. In this study, the safety and local effectiveness of LA in the treatment for the extrahepatic metastasis of HCC were evaluated. From May 2012 to May 2019, 17 patients (13 males and 4 females; mean age, 54.1 ± 14.6 years; age range, 34–80 years), who underwent LA for treatment of extrahepatic metastasis of HCC at the First Affiliated Hospital of Sun Yat-sen University, were retrospectively enrolled in this study. Local effectiveness, complications, local tumor progression (LTP), and overall survival (OS) were evaluated. Finally, a total of 28 LA treated extrahepatic metastatic lesions of HCC were reviewed. Neither LA-related mortality nor major complication occurred. Complete ablation (CA) was achieved in 20 out of 28 lesions (71.4%). During the follow-up (mean, 19.5 ± 12.8 months; range, 5–42.7 months), LTP developed in 4 out of 20 lesions with CA (20%). Four patients died of tumor progression or multiple organ dysfunction syndrome. The accumulative one- and three-year OS rates were 79.0% and 65.8%, respectively. In conclusion, LA is a safe and effective therapeutic option in the treatment of extrahepatic metastasis of HCC. Further studies are necessary to evaluate the benefit of LA.

Efficacy and safety of percutaneous computed tomography-guided high-dose-rate interstitial brachytherapy in treatment of oligometastatic lymph node metastases of retroperitoneal space

Purpose

To assess efficacy, safety, and outcome of computed tomography (CT)-guided high-dose-rate (HDR) interstitial brachytherapy in patients with oligometastatic lymph node metastases of the retroperitoneal space.

Material and methods

24 patients with a total of 47 retroperitoneal lymph node metastases from different primary tumors were treated with CT-guided interstitial brachytherapy using an ¹⁹²Ir source (single fraction irradiation). Every three months after treatment, clinical and imaging follow-up were conducted to evaluate local control and safety.

Results

Median follow-up was 9.6 months (range, 2.9-39.0 months). Local tumor control rate was 95.7%. The median diameter of the gross tumor volume was 2.2 cm (range, 1-8.6 cm), treated with a median D₁₀₀ (minimal enclosing tumor dose) of 14.9 Gy (range, 4.5-20.6 Gy). One severe adverse event (grade three) was recorded.

Cumulative median progression-free survival was 4.2 months (range, 1.4-23.7 months), and cumulative median overall survival after interstitial brachytherapy was 15.9 months (range, 3.8-39.0 months).

Conclusions

CT-guided HDR interstitial brachytherapy is a safe and feasible method for local ablation of oligometastatic lymph node metastases of the retroperitoneal space, and might provide a well-tolerated additional therapeutic option in the multidisciplinary management of selected patients.

Ultrasound-guided percutaneous laser ablation for papillary thyroid microcarcinoma: a retrospective analysis of 37 patients

BACKGROUND

Over the past ten years, more papillary thyroid microcarcinoma (PTMC) has been diagnosed more frequently due to the development of imaging technology, and the incidence of PTMC has increased significantly. Ultrasound-guided percutaneous laser ablation (PLA) is mainly used for benign thyroid nodules, and few studies have been published on the use of PLA for PTMC. In the present study, a retrospective analysis was performed to explore the efficacy of PLA for PTMC.

METHODS

A total of 37 patients with PTMC who underwent PLA were included in this study. Measurement of the lesion volume and serum thyroid hormone levels and clinical evaluation were performed at 1, 3, 6, and 12 months and every 6 months thereafter.

RESULTS

We found that all patients were successfully treated with PLA without serious complications. At the last follow-up visit, 12/37 (32.4%) primary lesions had disappeared, and 24/37 (64.9%) remained as cicatricial hyperplasia. One patient (2.7%) had cervical lymph node metastasis at 24 months post-operatively and underwent open surgery.

CONCLUSION

Our initial studies suggest that ultrasound-guided PLA is a safe and effective treatment for PTMC.

The efficacy and safety of microwave ablation in patients with retroperitoneal metastases

BACKGROUND

Retroperitoneal metastases are common, and most present with symptoms; however, treatments for this condition are limited. This retrospective study verified the efficacy and safety of microwave ablation (MWA) in retroperitoneal metastases patients.

METHODS

Patients with pathologically confirmed malignant carcinoma and imaging showing retroperitoneal metastases were enrolled and underwent MWA. The end-points included objective response rate, time to local progression (TTLP), overall survival, visual analogue scale (VAS) score, dose of morphine pre- and post-ablation and complications.

RESULTS

Twenty-three patients were enrolled. The mean tumour diameter was 3.6 cm. Altogether, 29 tumour sites in 23 patients were ablated during 23 procedures; technical success was achieved in all 23 patients. The objective response and disease control rates were 95.7% and 100.0%, respectively. The mean TTLP and median OS were 22.8 months (95% CI: 16.1-29.6 months) and 10.6 months (95% CI: 7.4-13.8 months), respectively. In 13 patients with symptoms, the VAS values before ablation and 48 h, 1 month, 2 months, 3 months and 6 months after ablation were 5.38, 2.77 (p = 0.015), 2.15 (p = 0.001), 2.17 (p = 0.001), 1.40 (p = 0.000) and 1.71 (p = 0.006), respectively. The corresponding morphine doses were 76.9 mg, 70.7 mg (p = 0.584), 50.7 mg (p = 0.031), 55.0 mg (p = 0.097), 46.0 mg (p = 0.057) and 40.0 mg (p = 0.363), respectively. No ablation-associated mortality was observed. Major complications, minor complications and adverse events were observed in eight (34.8%), five (21.7%) and four (17.4%) patients, respectively.

CONCLUSION

MWA for the treatment of retroperitoneal metastases was effective and the complications were common.

Enhanced killing of HepG2 during cryosurgery with Fe3O4-nanoparticle improved intracellular ice formation and cell dehydration

Cryosurgery is a minimally invasive treatment that utilize extreme low temperatures to destroy abnormal tissues. The clinical monitoring methods for cryosurgery are almost based on the visualization of the iceball. However, for a normal cryosurgery process, the effective killing region is always smaller than the iceball. As a result, the end of the cryosurgery process can only be judged by the surgeons according to their experience. The subjective judgement is one of the main reasons for poor estimation of tumor ablation, and it sparks high probability of recurrence and metastasis associate with cryosurgery. Being different from the previous optimization studies, we develop a novel approach with the aid of nanoparticles to enlarge the effective killing region of entire iceball, and thus it greatly decrease the difficulty of precise judgement of the cryosurgery only by applying the common clinical imaging methods. To verify this approach, both the experiments on a tissue-scale phantom with embedded living HepG2 cells in agarose and on a cell-scale cryo-microscopic freeze-thaw stage are performed. The results indicate that the introduction of the self-synthesized Fe3O4 nanoparticles significantly improved cell killing in the cryosurgery and the range of killing is extended to the entire iceball. The potential mechanism is further revealed by the cryo-microscopic experiments, which verifies the presence of Fe3O4 nanoparticles can significantly enhance the probability of intracellular ice formation and the cell dehydration during freezing hence it promote precise killing of the cells. These findings may further promote the widespread clinical application of modern cryosurgery.