Image-Guided Percutaneous Thermal Ablation of Oligometastatic Ovarian and Non-Ovarian Gynecologic Tumors

Chemoembolization, Radioembolization, and Percutaneous Ablation: New Opportunities for Treating Ovarian Cancer Liver Metastasis

OPINION STATEMENT

Parenchymal liver metastases from ovarian cancer, occurring in 2-12.5% of cases, significantly worsen prognosis. While surgery and systemic treatments remain primary options, unresectable or chemotherapy-resistant multiple liver metastases pose a significant challenge. Recent advances in liver-directed therapies, including radiofrequency ablation, microwave ablation, cryoablation, transarterial chemoembolization (TACE), and radioembolization, offer potential treatment alternatives. However, the efficacy of these techniques is limited by factors such as tumor size, number, and location. The ideal candidate for tumor ablation is a patient with paucifocal disease, a single tumor up to 5 cm or up to 3 tumors smaller than 3 cm and tumors 1 cm away from major bile ducts and high-flow vessels. Transarterial chemoembolization could be performed in patients with less than 70% tumor load. Differently, radioembolization is available with less limitation on the sites or number of liver cancers. Radioembolization techniques are also able to downsize liver metastases. However, there are limited data regarding the outcomes of loco-regional therapy in patients with hepatic metastases from ovarian cancer. Advancing liver-directed therapies through interventional oncology, combined with robust data on the oncological efficacy of these local treatments, will validate their potential as effective locoregional therapies for liver metastases. This could offer a promising treatment option for patients with ovarian cancer and unresectable hepatic metastases.

Deep learning-based automatic pipeline for 3D needle localization on intra-procedural 3D MRI

PURPOSE

Accurate and rapid needle localization on 3D magnetic resonance imaging (MRI) is critical for MRI-guided percutaneous interventions. The current workflow requires manual needle localization on 3D MRI, which is time-consuming and cumbersome. Automatic methods using 2D deep learning networks for needle segmentation require manual image plane localization, while 3D networks are challenged by the need for sufficient training datasets. This work aimed to develop an automatic deep learning-based pipeline for accurate and rapid 3D needle localization on in vivo intra-procedural 3D MRI using a limited training dataset.

METHODS

The proposed automatic pipeline adopted Shifted Window (Swin) Transformers and employed a coarse-to-fine segmentation strategy: (1) initial 3D needle feature segmentation with 3D Swin UNEt TRansfomer (UNETR); (2) generation of a 2D reformatted image containing the needle feature; (3) fine 2D needle feature segmentation with 2D Swin Transformer and calculation of 3D needle tip position and axis orientation. Pre-training and data augmentation were performed to improve network training. The pipeline was evaluated via cross-validation with 49 in vivo intra-procedural 3D MR images from preclinical pig experiments. The needle tip and axis localization errors were compared with human intra-reader variation using the Wilcoxon signed rank test, with p < 0.05 considered significant.

RESULTS

The average end-to-end computational time for the pipeline was 6 s per 3D volume. The median Dice scores of the 3D Swin UNETR and 2D Swin Transformer in the pipeline were 0.80 and 0.93, respectively. The median 3D needle tip and axis localization errors were 1.48 mm (1.09 pixels) and 0.98°, respectively. Needle tip localization errors were significantly smaller than human intra-reader variation (median 1.70 mm; p < 0.01).

CONCLUSION

The proposed automatic pipeline achieved rapid pixel-level 3D needle localization on intra-procedural 3D MRI without requiring a large 3D training dataset and has the potential to assist MRI-guided percutaneous interventions.

Percutaneous interstitial brachytherapy ablation for targeting oligometastatic gynecologic cancers

INTRODUCTION

Treatment of recurrent oligometastatic gynecologic malignancy may involve targeted surgery, thermal ablation, or CT-guided high-dose-rate interstitial brachytherapy ablation (CT-HDR-IBTA). The purpose of this study was to describe the safety and efficacy of CT-HDR-IBTA for oligometastatic gynecologic malignancies.

METHODS

With institutional review board approval (IRB) approval and compliance with the Health Insurance Portability and Accountability Act of 1996 (HIPAA) compliance, we searched our database to assemble a single-arm study cohort of all patients with oligometastatic gynecologic cancers who underwent CT-HDR-IBTA from 2012-2022 with follow-up. The electronic record was reviewed to determine relevant clinicopathological variables including patient demographics, prior treatments, clinical course, local control, and local and distant recurrence with follow-up imaging.

RESULTS

The study cohort comprised 37 lesions in 34 patients treated with CT-HDR-IBTA for recurrent oligometastatic uterine (n = 17), cervix (n = 1), or ovarian cancer (n = 16) with an average lesion size of 2.5 cm with an average patient age of 61.4 years. Each lesion was treated with an average radiation dose of 23.8 Gy in 1.8 fractions and a median follow-up time of 24.0 months. The primary efficacy of CT HDR ITBA was 73% with a median progression-free survival of 8.0 months (95% CI 3.6-12.8 months) and with 58% of patients still alive at 43 months with median overall survival not reached. The rate of Grade 1 adverse events was 22% without any Grade 2, 3 or 4 events.

CONCLUSIONS

CT HDR IBTA was safe and effective for treating oligometastatic gynecologic cancers in a heavily pretreated cohort.

PARP inhibitors (PARPi) prolongation after local therapy for oligo-metastatic progression in relapsed ovarian cancer patients

BACKGROUND

PARP inhibitors (PARPi) have revolutionized the management of high-grade epithelial ovarian cancer (HGOC) treatment. However, a significant number of patients relapse or progress under PARPi, leading to the introduction of a new line of systemic therapy such as chemotherapy. In patients with a limited number of metastatic sites at progression, -referred to as an oligometastatic progression- a potential indication for local therapy followed by re-introduction or continuation of PARPi treatment rather than initiating a new line of chemotherapy could be proposed. However, the impact of such strategies on progression free survival (PFS) in these patients remains unknown.

METHODS

This international multicenter retrospective study evaluated the efficacy of PARPi continuation or re-introduction in patients with HGOC after local treatment for oligometastatic progression. The main objective was to assess PFS under PARPi after local therapy (PFS post-LT). Secondary objectives included safety and overall survival (OS).

RESULTS

74 patients were identified in 20 centers between April 2020 and November 2021. 65% of patients were BRCA mutated and 92% had received ≥2 lines of prior systemic chemotherapy before the initial introduction of PARPi. Main progression sites were lymph nodes (42%), peritoneum (27%), liver (16%), other visceral (16%) and abdominal wall (4%). Local therapies included radiotherapy (45%), surgery (43%), both (7%), percutaneous thermal ablation (4%) or chemoembolization (1%). Median PFS post-LT was 11.5 months [95% CI 7.4; 17.2]. After a median follow up of 14.8 months, 6 patients (8.1%) discontinued PARPi due to toxicity. The 1-year overall survival rate was 90.7% [95% CI 79.1; 96.0].

CONCLUSIONS

With close to one year without progression or introduction of a new line of systemic therapy, this study reports the feasibility and potential benefit of this original strategy in patients with oligometastatic progression under PARPi.

Percutaneous Radiofrequency Ablation Combined With Chemotherapy Versus Chemotherapy Only for Ovarian Cancer Liver Metastasis

Purpose

To compare the feasibility and efficacy of radiofrequency ablation (RFA) combined with chemotherapy and chemotherapy alone in patients with ovarian cancer liver metastasis (OCLM).

Methods

In this retrospective study, a total of 60 patients diagnosed with OCLM between May 2015 to February 2017 were included. All patients with ovarian cancer received chemotherapy and primary cytoreductive surgery before. Thirty patients underwent RFA and chemotherapy, and thirty patients only took chemotherapy. The overall survival (OS), CA-125 levels, and serum AST and ALT levels were compared between the two groups.

Results

In the RFA group, the 1-,2-, and 3-year OS rates after RFA were 93.3%, 80.0%, and 53.3%, respectively. Serum AST and ALT levels were both elevated after RFA (p=0.0004, p<0.0001). In the chemotherapy group, the 1-,2-, and 3-year OS rates were 79.5%, 60.1%, and 42.1%, respectively. Levels of serum AST and ALT were stable. CA-125 levels for both groups were also available.

Conclusion

Based on our analysis of a single institution’s series of patients with OCLM, RFA could be a feasibly effective option in the management of OCLM.