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The Novel Concept and Treatments for Cancer

Cryosurgery with "Argon- helium knife"

Cryosurgery With “Argon-Helium Knife”

Cryosurgery is a novel technique for treatment of cancer which is approved by FDA,USA, 1998 and SFDA, China, 1999. Our Hospital has used the technique since 2000, has the experience of about 4000 patients with a variety of malignant tumors (more 34 kinds of cancers), stands first on the list in China and over world.

Principle

Cryosurgery is an important ablation technique for tumor. It destroys tumors by freezing and thawing them. Cryosurgery destructive effects on tumors are due to two major mechanisms, one immediate, the other delayed. The immediate mechanism is the damaging effect of freezing and thawing the cells. The delayed mechanism is the progressive failure of microcirculation; ultimately, vascular stasis becomes operative as an important cause of tumor tissue destruction. Once the temperature falls below -40?C, ice crystals may form within the cells. Once it occurs, cell death is almost certain.

During cryosurgery, progressive failure of microcirculation occurs due to a cascade of events: endothelial layer destruction causing vessel walls to become porous, interstitial edema, platelet aggregation, microthrombii, and ultimately vascular congestion and obliteration.

It was theorized that during cryosurgery, the immune system of the host became sensitized to the tumor being destroyed by the cryosurgery. Any primary tumor tissue undamaged by the cryosurgery and the metastases were destroyed by the immune system after cryosurgery. This response was termed the “cryoimmunological response.”

Procedure Of Cryosurgery

Cryosurgery is performed through intraoperative, endoscopic or percutaneous routes depending upon the location and size of tumor.
Cryoablation was performed by using argon-helium system (Endocare, CA, USA). Two to three cycles of the freezing/thawing were performed. The freezing continued until the iceball was large enough to cover tumor. A 5-10 mm margin of normal tissue was included in the freezing process. For larger tumors, multiple cryoprobes were used. In some cases, it became necessary to perform at least 2-3 sessions of the cryoablation procedure.

Advantages

Cryosurgery is a localized medical procedure. It can be used as the sole means of cancer treatment or it can be combined with other conventional treatment techniques such as surgical operation, chemotherapy, radiotherapy.
Combining cryosurgery with excision can be advantageous since freezing the tumor before excision minimizes the risk of spreading the cancerous cells during excision
In addition to sparing healthy tissue, cryosurgery is advantageous because it is not dose-limited? can be repeated as necessary in order to destroy all cancerous tissue
In situations where the tumor is not removed after freezing, especially percutaneous cryosurgery, operative blood loss is small and post-surgical discomfort is minimized
Cryoprobes are relatively small (generally in the range of 24 mm in diameter) and therefore they may be used in minimally in-vasive surgical procedures
There are no major side effects which are commonly found in chemotherapy or radiotherapy
Cryosurgery is adaptable for treatment of tumor close to large vessel which cannot be removed by operation
Cryosurgery can treat small as well as large tumors, and solitary as well as multiple tumors
Cryosurgery per se aims at a local effect, namely, destruction in situ of neoplasms resistant to conventional treatments, but it also elicits an immunologic reaction (cryoimmunologic reaction) against cancer for eradication of residual or metastatic tumors
There is evidence that the recurrence rate of cancer after cryosurgery is lower than that of operation

Indication

Nearly all parenchymal cancers can be given cryoablation. These malignancies include:

Liver cancer
Lung cancer
Kidney cancer
Ovary cancer
Pharyngeal cancer
Testicular cancer
Uterine tumors
Vaginal cancer
Pancreatic cancer
Breast cancer
Sarcoma and other benign or malignant
lesions of bone
Prostate cancer
Skin cancer and melanoma
Head and neck cancer
Malignant or benign tumors of soft tissues

In addition, cryosurgery can be an effective treatment for the following:

Retinoblastoma (a childhood cancer that affects the retina of the eye)

Early-stage skin cancers (both basal cell and squamous cell carcinomas)
Precancerous skin growths known as actinic keratosis
recancerous conditions of the cervix known as cervical intraepithelial neoplasia (abnormal cell changes in the cervix that can develop into cervical cancer)

Dr. Niu is performing cryosurgery

(Left) A lung cancer patient's CT scan before cryosurgery( Right) CT scan shows an ice-ball comes into being during cryosurgery

An ice-ball is being formed during cryosurgery

Argon-helium Knife