Image-guided tumor ablation for the treatment of recurrent non-small cell lung cancer within the radiation field

Treatment strategies for malignant pulmonary nodule: beyond lobectomy. Point-counterpoint

PURPOSE OF REVIEW

Technological advancement in low-dose computed tomography resulted in an increased incidental discovery of early-stage lung cancer and multifocal ground glass opacity. The demand for parenchyma-preserving treatment strategies is greater now than ever. Pulmonary ablative therapy is a groundbreaking technique to offer local ablative treatment in a lung-sparing manner. It has become a promising technique in lung cancer management with its diverse applicability. In this article, we will review the current development of ablative therapy in lung and look into the future of this innovative technique.

RECENT FINDINGS

Current literature suggests that ablative therapy offers comparable local disease control to other local therapies and stereotactic body radiation therapy (SBRT), with a low risk of complications. In particular, bronchoscopic microwave ablation (BMWA) has considerably fewer pleural-based complications due to the avoidance of pleural puncture. BMWA can be considered in the multidisciplinary treatment pathway as it allows re-ablation and allows SBRT after BMWA.

SUMMARY

With the benefits which ablative therapy offers and its ability to incorporate into the multidisciplinary management pathway, we foresee ablative therapy, especially BMWA gaining significance in lung cancer treatment. Future directions on developing novel automated navigation platforms and the latest form of ablative energy would further enhance clinical outcomes for our patients.

Combination of Local Ablative Techniques with Radiotherapy for Primary and Recurrent Lung Cancer: A Systematic Review

In patients with early-stage or recurrent NSCLC who are unable to tolerate surgery, a benefit could derive only from a systemic therapy or another few forms of local therapy. A systematic review was performed to evaluate the feasibility and the effectiveness of radiotherapy combined with local ablative therapies in the treatment of primary and recurrent lung cancer in terms of toxicity profile and local control rate. Six studies featuring a total of 115 patients who met eligibility criteria and 119 lesions were included. Three studies evaluated lung cancer patients with a medically inoperable condition treated with image-guided local ablative therapies followed by radiotherapy: their local control rate (LC) ranged from 75% to 91.7% with only 15 patients (19.4%) reporting local recurrence after combined modality treatment. The other three studies provided a salvage option for patients with locally recurrent NSCLC after RT: the median follow-up period varied from 8.3 to 69.3 months with an LC rate ranging from 50% to 100%. The most common complications were radiation pneumonitis (9.5%) and pneumothorax (29.8%). The proposed intervention appears to be promising in terms of toxicity profile and local control rate. Further prospective studies are need to better delineate combining LTA-RT treatment benefits in this setting.

Feasibility analysis of CT-guided thermal ablation of multiple pulmonary nodules combined with intraoperative biopsy

Purpose

To analyze the safety and feasibility of computed tomography (CT)-guided thermal ablation of multiple pulmonary nodules combined with intraoperative biopsy.

Methods

The data of 431 patients with 540 lung nodules undergoing CT-guided biopsy or ablation were retrospectively analyzed. Biopsy-only group (A): 107 patients (107 lesions) received CT-guided percutaneous lung biopsy only; Ablation-only group (B): 117 cases (117 lesions) only received CT-guided thermal ablation; Single focal ablation combined with biopsy group (C): 103 patients (103 lesions) received CT-guided thermal ablation combined with intraoperative immediate biopsy; Multifocal ablation combined with biopsy group (D): 104 patients (213 lesions) received CT-guided thermal ablation combined with intraoperative biopsy. The success rate of this technique was calculated, the complications were recorded, and the positive rate of pathological diagnosis of the specimens was evaluated (the tissue specimens could be confirmed as positive by pathological diagnosis).

Results

All 431 patients with pulmonary nodules successfully completed the operation, and the technical success rate was 100% (431/431). In group A, hemoptysis occurred in seven cases after operation, while no hemoptysis was observed in the other groups. Pneumothorax occurred in 8 cases in group A, 14 cases in group B, 11 cases in group C, and 13 cases in group D. Hydrothorax occurred in 4 cases in group A, 7 cases in group B, 5 cases in group C and 9 cases in group D, and there were no significant differences between the groups. The positive rate of pathological diagnosis was 84.1% (90/107) in group A, 81.5% (84/103) in group C, and 82.6% (176/213) in group D, and there was no significant difference among the groups (P > 0.05). A total of 15 cases in group C and 23 cases in group D underwent gene testing and analysis, and the biopsy tissue samples all met quality control standards.

Conclusion

CT-guided thermal ablation of multiple pulmonary nodules combined with intraoperative biopsy does not prolong the length of hospital stay or increase the risk of postoperative complications. It can meet the requirements of clinical, pathological and genetic testing, and is safe and reliable.

Current Management of Oligometastatic Lung Cancer and Future Perspectives: Results of Thermal Ablation as a Local Ablative Therapy

A growing body of evidence shows improved overall survival and progression-free survival after thermal ablation in non-small cell lung carcinoma (NSCLC) patients with a limited number of metastases, combined with chemotherapy or tyrosine kinase inhibitors or after local recurrence. Radiofrequency ablation and microwave ablation are the most evaluated modalities, and target tumor size <3 cm (and preferably <2 cm) is a key factor of technical success and efficacy. Although thermal ablation offers some advantages over surgery and radiotherapy in terms of repeatability, safety, and quality of life, optimal management of these patients requires a multidisciplinary approach, and further randomized controlled trials are required to help refine patient selection criteria. In this article, we present a comprehensive review of available thermal ablation modalities and recent results supporting their use in oligometastatic and oligoprogressive NSCLC disease along with their potential future implications in the emerging field of immunotherapy.

Ablation Therapy for Advanced Stage Non-Small Cell Lung Cancer: A National Cancer Database Study

PURPOSE

To compare overall survival (OS) of ablation with no treatment for patients with advanced stage non-small cell lung cancer.

METHODS

Patients with clinical stage IIIB (T_1-4N₃M₀, T₄N₂M₀) and stage IV (T_1-4N_0-3M₁) non-small cell lung cancer, in accordance with the American Joint Committee on Cancer, 7th edition, who did not receive treatment or who received ablation as their sole primary treatment besides chemotherapy from 2004 to 2014, were identified from the National Cancer Data Base. OS was estimated using the Kaplan-Meier method and evaluated by log-rank test, univariate and multivariate Cox proportional hazard regression, and propensity score-matched analysis. Relative survival analyses comparing age- and sex-matched United States populations were performed.

RESULTS

A total of 140,819 patients were included. The 1-, 2-, 3- and 5-year survival rates relative to age- and sex-matched United States population were 28%, 18%, 12%, and 10%, respectively, for ablation (n = 249); and 30%, 15%, 9%, and 5%, respectively for no treatment (n = 140,570). Propensity score matching resulted in 249 patients in the ablation group versus 498 patients in the no-treatment group. After matching, ablation was associated with longer OS than that in the no-treatment group (median, 5.9 vs 4.7 months, respectively; hazard ratio, 0.844; 95% confidence interval, 0.719-0.990; P = .037). These results persisted in patients with an initial tumor size of ≤3 cm.

CONCLUSIONS

Preliminary results suggest ablation may be associated with longer OS in patients with late-stage non-small cell lung cancer than survival in those who received no treatment.

Microwave Ablation in Primary Lung Malignancies

Lung cancer is the leading cause of cancer-related mortality worldwide. Eighty-five percent of cases correspond to non-small cell lung cancer (NSCLC) and pivotal nonsurgical options for early-stage disease include percutaneous ablation and stereotactic body radiation therapy (SBRT). Microwave Ablation (MWA) is a locoregional treatment option that has many advantages over radiofrequency ablation and has been able to overcome the limitations of this technique in the treatment of early-stage NSCLC. In this review article, we highlight the current evidence supporting the use of MWA in patients with early-stage NSCLC and discuss the technical considerations of the procedure, including optimal patient selection and planning strategies, as well as the potential complications and reported outcomes. Finally, we mention future trends involving ablation in NSCLC, including its role in combination with SBRT in central tumors, management of post-SBRT local recurrence, and its potential as an adjuvant treatment option for patients with resistance to systemic therapy or in combination with checkpoint inhibitors.

Clinical experiences with microwave thermal ablation of lung malignancies

Approximately 30% of early stage lung cancer patients are not surgical candidates due to medical co-morbidities, poor cardiopulmonary function and advanced age. These patients are traditionally offered chemotherapy and radiation, which have shown relatively modest improvements in mortality. For over a decade, percutaneous image-guided ablation has emerged as a safe, cost-effective, minimally invasive treatment alternative for patients who would otherwise not qualify for surgery. Although radiofrequency ablation (RFA) is currently the most extensively studied and widely utilised technique in the treatment of lung malignancies, there is a growing body of evidence that microwave ablation (MWA) has several unique benefits over RFA and cryoablation in the lung. This article reviews our institution's clinical experiences in the treatment of lung malignancies with MWA including patient selection, procedural technique, imaging follow-up, treatment outcomes and comparison of ablation techniques.

Stereotactic Radiosurgery/Stereotactic Body Radiotherapy for Recurrent Lung Neoplasm: An Analysis of Outcomes in 100 Patients

BACKGROUND

A significant number of patients have recurrent or persistent lung cancer despite complete resection or treatment with definitive chemoradiation. Stereotactic radiosurgery (SRS)/stereotactic body radiation therapy is emerging as an important modality for the treatment of early-stage lung neoplasm; SRS may also offer an alternative treatment option for patients with recurrent lung disease. We evaluated outcomes after treatment with SRS for recurrent lung neoplasm in a large series of patients.

METHODS

Selected patients with limited recurrent, persistent, or progressive disease after one or more prior treatments for lung cancer were offered SRS. Thoracic surgeons evaluated all patients, placed fiducials when needed, and planned treatment in close collaboration with radiation oncologists and medical physicists. In our early experience, a single fraction of 20 Gy radiation was prescribed and was subsequently increased to 45 to 60 Gy in three to five fractions. The primary endpoint evaluated was overall survival.

RESULTS

We treated 100 patients with recurrent lung cancer (median age 72 years) with SRS. The postprocedure 30-day mortality rate was 0%; median follow-up was 51 months (range, 5 to 123). The median overall survival for the entire group was 23 months (95% confidence interval: 19 to 41). The probability of 2-year and 5-year overall survival was 49% (95% confidence interval: 40% to 60%) and 31% (95% confidence interval: 23% to 43%), respectively.

CONCLUSIONS

Our experience indicates that SRS is safe, and offers an alternative modality for selected patients with recurrent oligometastatic or persistent lung cancer. Thoracic surgeons should actively participate in SRS and continue to evaluate the efficacy of this treatment strategy.

Chinese expert consensus workshop report: Guidelines for thermal ablation of primary and metastatic lung tumors

Although surgical resection is the primary means of curing both primary and metastatic lung cancers, about 80% of lung cancers cannot be removed by surgery. As most patients with unresectable lung cancer receive only limited benefits from traditional radiotherapy and chemotherapy, many new local treatment methods have emerged, including local ablation therapy. The Minimally Invasive and Comprehensive Treatment of Lung Cancer Branch, Professional Committee of Minimally Invasive Treatment of Cancer of the Chinese Anti-Cancer Association has organized multidisciplinary experts to develop guidelines for this treatment modality. These guidelines aim at standardizing thermal ablation procedures and criteria for selecting treatment candidates and assessing outcomes; and for preventing and managing post-ablation complications.