Cryoablation — Extreme cold tumour destruction

Cryoablation, also known as cryosurgery or cryotherapy, is an image-guided thermal ablation procedure. Interventional radiologists insert needle-like applicators called cryoprobes into the centre of a tumour under CT, ultrasound, or MRI guidance. Pressurised gases, typically argon and helium, circulate through the probes based on the Joule-Thomson thermodynamic principle, rapidly dropping local tissue temperatures below minus forty degrees Celsius.

This extreme freezing process induces cell death through two principal mechanisms: immediate physical trauma and progressive vascular shutdown. As ice crystals form within the intracellular and extracellular spaces, they disrupt cell membranes and organelle structures. Subsequent thawing cycles cause osmotic cell swelling, vascular thrombosis, and local tissue ischaemia. Additionally, intracellular antigens released during cell death may stimulate secondary systemic immune responses against residual malignant cells.

Cryoablation offers an effective, tissue-preserving treatment option, particularly for patients who cannot undergo conventional surgery due to advanced age, frailty, or co-existing health conditions. Because the procedure causes minimal tissue disruption and can be performed on an outpatient basis or with a short hospital stay, it provides rapid symptom relief, preserves organ function, and presents low complication rates, allowing individuals to maintain their quality of life.

Suitability for cryoablation depends on high-resolution imaging—such as multiphase contrast CT or MRI scans—to determine the tumour's exact size, number, and location relative to blood vessels. There are no specific molecular biomarkers required; eligibility rests primarily on anatomical tumour boundaries and coagulation blood profiles.

Cryoablation is frequently used to treat small renal cell carcinomas (kidney cancer), early-stage lung tumours, and primary or metastatic liver lesions. It is also an established intervention for focal prostate cancer and serves as an effective palliative option for managing painful metastatic bone lesions.

Cryoablation can serve as an alternative to surgical resection or external radiotherapy, especially for tumours smaller than three to four centimetres. It can be repeated if new lesions appear, and it can be combined safely with systemic treatments, such as immunotherapy, which may benefit from the antigen-releasing effects of cellular freezing.