[Percutaneous lung cancer cryotherapy guided by computer tomography].

Objective: To document the feasibility, safety and efficacy of percutaneous lung cancer cryotherapy (PLC) guided by Computer Tomography (CT).

Methods: Two hundred and thirty seven patients with lung cancer underwent CT-guided PLC from August, 2001 to April, 2003. CT-visualized immediate ice formation beyond tumor margins was compared to tumor size and location. PLC feasibility and safety were evaluated. CT scan, lung tissue biopsy and survival rate were observed at different stages postcryoablation.

Results: All the patients underwent PLC using local anesthesia with minimal or no sedation. Iceball formation was well seen as negative Hounsfield units within soft tissue masses. Tumor size and location were independent determinants of ice coverage which was 97% (n = 124) for masses < 4 cm in diameter, and 80% (n = 183) for masses > 4 cm in diameter (P < 0.01). Only 59 patients had transient mild hypertension, and no death occurred during cryotherapy. Most of the slight side-effects were self-limited. No major bleeding or bronchial sequelae were identified. CT scan showed that necrotic cavitation larger than the original mass developed in 78% of the cases within one week, and mostly resolved by 6 months (4%). Partial resolution + complete resolution was noted by 1 - 6 months, which demonstrated reduced or stable tumor size. Necrotic coagulation could be found within 1 month and fibrin scarring 3 months postcryoablation. The survival rate in 18 months was 86% for patients at an early stage of lung cancer, and 21% for patients at stage III, while the one year survival rate for patients at stage IV was 9%.

Conclusion: CT-guided PLC, with minimal procedure associated morbidity or sequelae, is a promising treatment for lung neoplasm of any stage in nearly any location.