Thermal Ablation Shown to Be Safe, Effective Local Treatment in Gynecologic Cancers

Frank Yuan, MD

Thermal ablation was shown to be a safe and effective treatment for patients with localized gynecologic tumors in the lungs, abdomen, and pelvis, according to findings from a retrospective analysis published in the Journal of Vascular and Interventional Radiology.^1,2

Treatment with thermal ablation led to an overall survival (OS) of 37.5 months (95% CI, 27.7-47.3) and a local progression-free survival (PFS) of 16.5 months (95% CI, 9.8-23.2). Regarding safety, only 4.8% of treated patients experienced a major adverse effect.

“In the current study, the safety, feasibility, and efficacy of thermal ablation for treating oligometastatic tumors from ovarian and non-ovarian gynecologic neoplasms were assessed. The findings supported the notion that percutaneous CT and US [ultrasound]-guided thermal ablation were safe and effective for the local control of oligometastatic tumors from ovarian and non-ovarian gynecologic cancers,” Frank Yuan, MD, lead study author and postdoctoral research fellow of interventional radiology at Johns Hopkins School of Medicine, and co-authors wrote in the paper.

Prior studies have shown that treatment with thermal ablation can lead to significant tumor cytoreduction in patients with metastatic ovarian cancers that metastasized to the liver. However, the body of evidence regarding the use of percutaneous thermal ablation for the secondary cytoreduction of metastatic gynecologic cancers is limited.

To that end, the study was designed to evaluate the safety, feasibility, and efficacy of percutaneous thermal ablation in the treatment of patients with metastatic gynecologic tumors.

The study cohort consisted of 42 women with metastatic gynecologic tumors (n = 119). The mean age was 59 years (range, 25-78). Women had been treated with radiofrequency (n = 47), microwave (n = 47), or cryogenic (n = 30) ablation from more than 2800 ablations that had been performed from January 2001 to January 2019.

The primary gynecologic malignancies comprised ovarian (n = 27 patients; 77 tumors; mean tumor diameter [MTD], 2.50 cm), uterine (n = 7; 26 tumors; MTD, 1.89 cm), endometrial (n = 5; 10 tumors; MTD, 2.8 cm), vaginal (n = 2; 5 tumors; MTD, 2.40 cm), and cervical (n = 1; 1 tumor; MTD, 1.90 cm) cancers.

Metastatic tumors treated with thermal ablation were located in the liver or liver capsule (74%), lungs (13%), and peritoneal implants (9%). Single tumors were also treated in the kidneys, rectus muscle, perirectal soft tissue (2.5%), and retroperitoneal lymph nodes (1.6%).

All efficacy parameters of thermal ablation and definitions of major and minor complications were categorized by the latest Society of Interventional Radiology reporting standards.

Additional results demonstrated that the median OS for patients with metastatic ovarian tumors was 37.5 months (95% CI, 23-52) and for patients with metastatic non-ovarian gynecologic tumors was 52.1 months (95% CI, 13.5-90.8). The difference in OS between patients with metastatic ovarian and non-ovarian gynecologic tumors was not statistically significant (Χ2 = 0.13, P = .908).

The median local PFS for patients without local tumor progression after the first ablation was 26.9 months (95% CI, 5.3-48.6) and for patients with local tumor progression was 3.9 months (95% CI, 2-5.7); this difference was statistically significant (Χ2 = 11.5, P = .001).

After the first ablation in patients with metastatic ovarian tumors, local tumor progression resulted in a hazard ratio of 5.3 and was statistically significant (P = .0023). Of 12 patients with local tumor recurrence, the mean local time to progression was 4.1 months (range, 34-497; median, 4.1 months).

At a median follow-up of 10 months in treated patients, 95.6% of patients treated with the initial ablation experienced a complete tumor response confirmed by contrast-enhanced magnetic resonance imaging or computed tomography, translating to an overall efficacy rate of 96.2%.

On surveillance imaging, 8.5% of the ablated tumors developed local progression over a median follow-up of 4.1 months. Five of 8 tumors with local recurrence underwent additional treatment over a mean follow-up of 18 months; 4 of the 5 tumors were completely eradicated after 1 additional treatment session, leading to a secondary efficacy rate of 80%.

Regarding complications, in 2001, 1 patient developed a hepatic abscess after a successful ablation of 2 large hepatic tumors measuring 10 cm and 4 cm and underwent a successful percutaneous drainage. In 2011, another patient was treated for a peritoneal implant between the liver dome and the diaphragm, which was complicated by pleural effusion that required a successful thoracentesis.

Two patients had minor complications, including nonspecific chest pain that was self-limited and a small right apical pneumothorax, both of which were managed without additional interventions.

References

1. Yuan F, Wei SH, Konecny GE, et al. Image-guided percutaneous thermal ablation of oligometastatic ovarian and non-ovarian gynecologic tumors. J Vasc Interv Radiol. 2021;S1051-0443(21)00315-00318. doi:10.1016/j.jvir.2021.01.270
2. Percutaneous image guided thermal ablation safe, effective therapy for metastatic gynecologic cancers. News release. UCLA Health. March 29, 2021. Accessed April 19, 2021. https://bit.ly/3n0uXUV