Method and system for cryoablating tumors
View Patent ↗A cryosurgical system adapted for treatment of fibroadenomas within the breast of a patient. The system includes cryoprobes and a control system which operates the cryoprobes to accomplish freezing in two stages, including a high power freeze and a low power freeze.
1. A method of treating a mass in a body, the method comprising the steps of:
inserting into a mass a cryoprobe adapted to provide cooling at a first power level to a first cryogenic temperature and at a second power level to a second cryogenic temperature that is higher than the first cryogenic temperature;
freezing at least a portion of the mass by operating the cryoprobe at the first power level for a first period and subsequently at the second power level for a second period; and
operating the cryoprobe to allow passive thawing of the portion of the mass for a time generally equal to the sum of the first period and the second period.
2. The method according to claim 1 , wherein the freezing step comprises supplying argon to the cryoprobe.
3. The method according to claim 1 , wherein the freezing step comprises supplying liquid nitrogen to the cryoprobe.
4. The method according to claim 1 , further comprising supplying helium to the cryoprobe to promote thawing of the portion of the mass.
5. The method according to claim 1 , further comprising a second freeze-thaw cycle by providing a second cooling at a first power level to a first cryogenic temperature and at a second power level to a second cryogenic temperature that is higher than the first cryogenic temperature.
6. The method according to claim 1 , wherein the freezing and thawing steps comprise a programmed sequence.
7. The method according to claim 1 , wherein the mass is a benign tumor.
8. The method according to claim 1 , wherein the mass is a fibroadenoma.