Cryoablation is a common minimally-invasive and effective procedure now adopted to treat a wide variety of benign and malignant tumors. In recent years, cryoablation is being adopted as the treatment of small lung tumors that are medically inoperable.
How common is lung cancer in 2022?
Lung cancer (both small cell and non-small cell) is the second most common cancer. It is by far the leading cause of cancer death, making up almost 25% of all cancer deaths – more than colon, breast, and prostate cancers combined as stated on cancer.org.
According to the American Cancer Society, there are about 240K new cases of lung cancer and 130K deaths from lung cancer in 2022. Lung cancer mainly occurs in older people with most people diagnosed with lung cancer 65 or older.
In general, about 84% of all lung cancers are non-small cell lung cancer (NSCLC) and 13% are small cell lung cancer (SCLC).
How do you treat lung cancer?
People with SCLC are usually treated with radiation therapy and chemotherapy. People with NSCLC can be treated with surgery (the current gold standard), chemotherapy, radiation therapy, as well as other ablation methods.
Tumor ablation is a popular non-surgical alternative, in use since the 1990s in Europe and the U.S., to destroy cancer cells by heat or extreme cold (lung cryoablation). Tumor ablation can be divided into three main types: radiofrequency ablation (RFA), microwave ablation (MWA) and cryoablation. These minimally invasive procedures are done percutaneously through a very small incision.
For patients with stage IA NSCLC, image-guided thermal ablation, such as cryoablation, is a safe and effective treatment with minimal complications and acceptable long-term oncological and survival outcomes. These are comparable to stereotactic body radiation therapy (SBRT) and sublobar resection (removing smaller sections of the lung).
Image-guided thermal ablation is a safe and effective treatment option for patients with recurrent NSCLC.
What is lung cancer cryoablation?
Lung cancer cryoablation uses extreme cold to destroy cancerous tumors by freezing. It is considered safe and effective (1) and provides a curable treatment for medically inoperable early-stage lung cancer (stage I non-small-cell lung carcinoma (NSCLC)) (2,3).
Providing high local lesion control (2), lung cancer cryoablation is associated with good overall long-term survival and minimally significant complications (3).
Lung cancer cryoablation is recommended for patients with NSCLC lesions less than 3cm in size.
How does lung cancer cryoablation work?
A thin cryoprobe is directly inserted into the tumor. A freezing coolant material, liquid nitrogen or argon gas, is pumped into the cryoprobe which grows an iceball engulfing the tumor and killing the cancerous tissue in the lung.
Interventional radiologists or oncologists perform the minimally-invasive procedure using imaging to navigate to the tumor and confirm the cryoprobe is in the correct location for treatment. The physicians will also ensure that the targeted tissue is completely engulfed in an iceball with adequate margins for complete cell destruction.
A triple freeze protocol of 3 freeze/thaw cycles is recommended for the cryoablation of lung cancers with low recurrence and complication rates (4). In some cases, a 4th cycle will be necessary. The time of procedures should last 1 ½ to 2 hours.
As the lung consists mostly of air spaces, the first freeze cycle is important to create an optimal environment for heat conduction. It is thought that blood leakage from the frozen area into the lung parenchyma optimizes the environment for heat conduction by pushing out the air. This makes the second cycle of freezing more successful in forming a larger iceball and a third cycle is necessary for more tumor destruction.
Clinical advantages versus other treatment modalities
Lung cryoablation compared to RFA showed improved local tumor control as well as a lower risk of metastatic progression (1). While in comparison to MWA it was associated with better preservation of the collagenous architecture (1).
SBRT is most often used to treat early-stage lung cancers when surgery isn’t an option due to a person’s health or in people who don’t want surgery. However, when tumors are resistant to radiation, cryoablation may be used instead. Cryoablation may also be conducted as many times as necessary, unlike SBRT. Furthermore, pulmonary function does not decrease after cryoablation treatment and interstitial pneumonia does not occur.
How successful is lung cancer cryoablation?
Clinical studies have demonstrated that lung ablation can be an effective treatment for local control of early-stage lung cancer or limited metastatic disease to the lung.
A recent retrospective observational study conducted by Professor Nomori treating metastatic lung tumors was conducted including 68 patients with 121 metastatic lung tumors between 2013 and 2019. Highly promising results showed 96% of patients treated with cryoablation using liquid nitrogen (the ProSense™ Cryoablation System) in tumors <2cm showed recurrence free survival at 3 years follow-up. Furthermore, 75% of patients were without the adverse effect of pneumothorax, a common complication from heat-based ablation techniques.
An earlier clinical study followed 101 patients on average for 35 months with stage T1N0M0 non-small cell lung cancer treated with the ProSense™ Cryoablation System. Investigators found cryoablation using liquid nitrogen to be a promising treatment with local control and recurrence-free survival of cryoablation satisfactory for tumors <1.8 cm (5). Three-year follow-up on ~30 T1mi +T1a +T1b cancer patients with <2cm tumor mass in an early evaluation showed an overall survival rate of 100% after ProSense™ therapy compared to ~78% after radiation therapy.
Cryoablation for NSCLC shows good long-term survival. Left: pre-cryoablation. Right: Immediately post cryoablation: Lung cavitation. (3)
Future of cryoablation for lung cancer
Cryoablation offers a promising safe, effective and minimally invasive option for treating small NSCLC lung tumors, with good overall long-term survival and minimally significant complications.
As focus is shifting to earlier lung cancer detection and screening with even better diagnostic tools to support physicians, it is envisaged that patient care will be improved. While lung cancer ablation is curative for medically inoperable early-stage lung cancer (2) (stage I non-small-cell lung carcinoma (NSCLC))(3), ablation of non-small cell lung cancer (NSCLC) lesions >3 cm is associated with higher rates of recurrence and complications. The safe, effective and repeatable nature of cryoablation for treating small tumors has the potential to offer massive clinical benefits for long-term treatment as well as life-prolonging treatment of larger lesions and chronic cases of lung cancer.
To dive deeper into the understanding of cryoablation for lung cancer get our latest webinar with Dr. Frandon.
- Zhany Y. et al. Percutaneous imaging-guided cryoablation for lung cancer. J Thorac Dis. 2016 Oct;8(Suppl 9):S705-S709. 7
- Palussière J., Catena V. & Buy X. Percutaneous thermal ablation of lung tumors – Radiofrequency, microwave and cryotherapy: Where are we going? Diagn Interv Imaging. 2017 Sep;98(9):619-625
- Moore W. et al. Five-year survival after cryoablation of stage I non-small cell lung cancer in medically inoperable patients. J Vasc Interv Radiol. 2015 Mar;26(3):312-9.
- Nomori, H. et al, 2020. Cryoablation for T1N0M0 non-small cell lung cancer using liquid nitrogen. European Journal of Radiology: 133 (2020) 109334