Cryotherapy advances ongoing

Although competing modalities have stolen some of cryotherapy's thunder, technical advances under development could one day restore cryotherapy's luster, an expert says.

"Cryosurgery remains the mainstay of therapy for many skin lesions, particularly tumors, in spite of the fact that so many other physical therapeutic modalities have been introduced in dermatology during the last few years," says William Abramovits, M.D., professor of dermatology, Baylor University Medical Center, Dallas. Such modalities include heat from electrodesiccation, lasers or intense pulsed light (IPL) devices, he says.

"Over the last few years," he adds, "a paucity of technological developments has allowed other treatment modalities to gain some terrain against cryosurgery."

But in the not-too-distant future, instrumentation that's being added to the cryosurgery unit will bring cryosurgery back to the attention of many dermatologists, Dr. Abramovits predicts.

More specifically, he says he's used prototypes featuring temperature gauges that use laser interferometry to allow measurement of target temperature without piercing the skin.

"These will facilitate the interpretation of how long and how deeply the temperature at the target has been sustained," Dr. Abramovits explains.

While cryosurgery remains widely used for lesions such as warts and actinic keratoses, he says, "Cryosurgery has lost the most ground in the treatment of malignancy," due partly to the wide availability of Mohs surgery.

This technique offers a level of certainty that all malignant cells have been removed that cryosurgery does not provide, Dr. Abramovits adds.

"However," he says, "I prognosticate that in the near future, the use of noninvasive imaging techniques such as ultrasound, and, more importantly, confocal microscopy, will allow the cryosurgeon to match the cryodestructive front to the lesion's margin."

Currently, cryosurgery remains useful for treating benign, precancerous and cancerous lesions, says Abramovits says, who estimates he uses this modality at least 20 times daily.

A typical treatment involves spraying the lesion, plus 1 mm to 3 mm of visible margin, with liquid nitrogen or another freezing agent for 30 to 60 seconds, he says. Because of cryotherapy's speed and ease of use, he says, "A dermatologist can treat multiple lesions at one visit at a relatively low cost to the patient or payor."

However, Dr. Abramovits cautions that cryosurgery's effectiveness is operator-sensitive."In the hands of a skilled operator," he explains, "cryosurgery almost always provides excellent outcomes."

But cryosurgery performed by unskilled operators can create morbidities including unduly large blistering or nerve compromise, he says. Therefore, he says he prefers that cryosurgery never be delegated to physician extenders.

Patient selection also impacts cryosurgery's effectiveness. For example, Dr. Abramovits advises against using this modality to treat patients whose immune systems have been compromised.

Regarding lesion size and location, he adds, "We don't want to treat lesions located in areas where a method that is presently less precise than Mohs surgery shouldn't be used."

Examples include lesions in proximity to organs or nerves that could be damaged by cryosurgery, Dr. Abramovits explains. "Also," he says, "don't choose cryosurgery if the lesion is large or histologically aggressive." DT

Disclosure: Dr. Abramovits reports no financial interests relevant to this article.

Dr. Abramovitz presents the "Role for Cryosurgery" in FOC803 from 12:15 to 1:45 p.m. today.