Percutaneous ablation of lymph node metastases using CT-guided high-dose-rate brachytherapy

Clinical application of 192Ir High-Dose-Rate brachytherapy in metastatic lymph nodes of the neck

OBJECTIVE

The objective of this study was to investigate the safety and effectiveness of high-dose-rate brachytherapy as a treatment modality for recurrent or residual neck metastatic lymph nodes following external radiotherapy.

METHODS

38 patients with 52 metastatic lymph nodes recurring or residual after previous external radiotherapy was completed to metastatic lymph nodes in the neck were collected from January 2019 to February 2022. High-dose-rate brachytherapy with 192Ir was performed with a prescribed dose of 20-30 Gy/1f (effective biological dose of 60-120 Gy), and imaging was performed at 1, 3, and 6 months after treatment to assess the local control rate and adverse effects of treatment.

RESULTS

All 38 patients received completed treatment, and they were followed up for 6 months. 52 patients with neck lymph node metastases had an objective response rate. (Complete response, CR + Partial response, PR) of 76.9%, which comprised 89.5% (34/38) for lymph nodes ≤ 3 cm and 42.9% (4/14) for > 3 cm, P = 0.028. P > 0.05 for CR + PR versus stable disease, SD + progressive disease, PD for lymph nodes between different subdivisions of the neck. Using the Radiation Therapy Oncology Group (RTOG) Acute Toxicity Scoring System, there were 6 cases of acute radioskin injuries of degree I and 4 cases of degree II with a 60% symptomatic relief rate.

CONCLUSIONS

High-dose-rate brachytherapy serves as a safe and effective method in treating recurrent residual neck metastatic lymph nodes in the field after external radiotherapy, exerting tolerable adverse effects.

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.

Image-guided high-dose-rate brachytherapy of malignancies in various inner organs - technique, indications, and perspectives

In the last few years, minimally invasive tumor ablation performed by interventional radiologists has gained increasing relevance in oncologic patient care. Limitations of thermal ablation techniques such as radiofrequency ablation (RFA), microwave ablation (MWA), and laser-induced thermotherapy (LITT), including large tumor size, cooling effects of adjacent vessels, and tumor location near thermosensitive structures, have led to the development of image-guided high-dose-rate (HDR) brachytherapy, especially for the treatment of liver malignancies. This article reviews technical properties of image-guided brachytherapy, indications and its current clinical role in multimodal cancer treatment. Furthermore, perspectives of this novel therapy option will be discussed.

CT-guided high-dose-rate brachytherapy in the interdisciplinary treatment of patients with liver metastases of pancreatic cancer

BACKGROUND

CT-guided high-dose-rate brachytherapy (CT-HDRBT) is an interventional radiologic technique for local ablation of primary and secondary malignomas applying a radiation source through a brachycatheter percutaneously into the targeted lesion. The aim of this study was to assess local tumor control, safety and efficacy of CT-HDRBT in the treatment of liver metastases of pancreatic cancer.

METHODS

Twenty consecutive patients with 49 unresectable liver metastases of pancreatic cancer were included in this retrospective trial and treated with CT-HDRBT, applied as a single fraction high-dose irradiation (15-20 Gy) using a 192Ir-source. Primary endpoint was local tumor control and secondary endpoints were complications, progression-free survival and overall survival.

RESULTS

The mean tumor diameter was 29 mm (range 10-73). The mean irradiation time was 20 minutes (range 7-42). The mean coverage of the clinical target volume was 98% (range 88%-100%). The mean D100 was 18.1 Gy and the median D100 was 19.78 Gy. Three major complications occurred with post-interventional abscesses, three of which were seen in 15 patients with biliodigestive anastomosis (20%) and overall 15%. The mean follow-up time was 13.7 months (range 1.4-55.0). The median progression-free survival was 4.9 months (range 1.4-42.9, mean 9.4). Local recurrence occurred in 5 (10%) of 49 metastases treated. The median overall survival after CT-HDRBT was 8.6 months (range 1.5-55.3). Eleven patients received chemotherapy after ablation with a median progression-free survival of 4.9 months (mean 12.9). Nine patients did not receive chemotherapy after intervention with a median progression-free survival of 3.2 months (mean 5.0). The rate of local tumor control was 91% in both groups after 12 months.

CONCLUSION

CT-HDRBT was safe and effective for the treatment of liver metastases of pancreatic cancer.