Overview

Lung cancer is the leading cause of cancer-related mortality worldwide, making early diagnosis and intervention critical. With the widespread adoption of low-dose computed tomography (LDCT) screening, the detection rate of pulmonary ground-glass nodules (GGNs) has increased significantly. Although video-assisted thoracoscopic surgery (VATS) remains the standard treatment for early-stage lung cancer, a considerable proportion of patients are ineligible for surgery due to advanced age, impaired cardiopulmonary function, or multiple nodules. Cryoablation, a minimally invasive ablation technique, uses ultra-low temperatures to induce tumor cell death. It offers distinct advantages, including well-defined ablation margins, reduced procedural pain, preservation of adjacent healthy structures, and potential immune activation, providing an important alternative for this patient population. However, the safety and long-term efficacy of cryoablation for GGNs require further high-quality clinical evidence.

This study aims to conduct a prospective, single-center, open-label clinical trial to systematically evaluate the feasibility and outcomes of cryoablation (percutaneous or electromagnetic navigation bronchoscopy \[ENB\]-guided) for treating pulmonary GGNs. We plan to enroll 90 patients who meet the following criteria: pathologically or multidisciplinary team (MDT)-confirmed malignancy, GGN size ranging from 6-30 mm, solid component ratio \<25%, unsuitability for or refusal of surgery/radiotherapy, and an Eastern Cooperative Oncology Group (ECOG) performance status of 0-1. The primary endpoint is the 2-year local recurrence rate after ablation. Secondary endpoints include the 5-year local recurrence rate, 3- and 5-year disease-free survival (DFS) rates, technical success rate (ablation completion), perioperative complications (e.g., pneumothorax, hemorrhage, infection), postoperative pulmonary function, pain scores, length of hospital stay, and treatment-related costs. The results of this study will provide critical clinical evidence to support the use of cryoablation for GGNs, optimize patient selection criteria, and promote the advancement of this minimally invasive technique.

Eligibility

Inclusion Criteria:

• Age ≥ 18 years.
• Malignancy confirmed by histopathology or multidisciplinary team (MDT) discussion.

For a solitary GGN: size between 6-30 mm. For multiple GGNs: each measuring 6-30 mm, with no more than 3 nodules deemed to require treatment upon MDT consensus.

• Patient is ineligible for or unwilling to undergo video-assisted thoracoscopic surgery (VATS).
• Patient is ineligible for or declines radiotherapy or stereotactic body radiotherapy (SBRT).
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
• The subject demonstrates good compliance and has voluntarily provided written informed consent to participate.

Exclusion Criteria:

• Presence of severe cardiac, pulmonary, hepatic, or renal dysfunction, rendering the patient ineligible for general anesthesia.
• Contraindication to either bronchoscopy or computed tomography (CT)-guided percutaneous puncture.
• High risk associated with percutaneous puncture for at least one target lesion, or absence of a feasible access route as determined by pre-procedural bronchoscopic path planning.
• Platelet count \< 50 × 10⁹/L, or presence of an uncorrectable bleeding diathesis or coagulation disorder (prothrombin time \> 18 seconds, or prothrombin activity \< 40%).
• Concurrent participation in another interventional clinical trial, or anticipation of requiring additional antitumor therapy outside the scope of this study during the trial period.
• Any other condition deemed by the investigator to render the patient unsuitable for study participation.