Carrie Greene's cancer doctor called her on a Saturday morning a few months ago and said he wanted to change her chemotherapy treatment.

"What do you think about losing your hair?" he asked.

Greene, 41, who has recurring breast cancer, had already been through that. Twice. One of the worst—or funniest—moments came when her 5-year-old daughter yanked off her wig in front of all the kids at day care.

"I decided I wanted to keep it," she said of her short, dishwater blond hair.

And so far she has. Each week when Greene goes in for chemotherapy at Abbott Northwestern Hospital, she dons a gel-filled cap, replaced every 30 minutes, that freezes her scalp. In theory, the caps, which are frozen in a special freezer at 22 degrees below zero, prevent the chemo drugs from killing the cells in her hair follicles.

Now two Twin Cities women, both cancer patients, are raising money so that more women can use the therapy. They call their organization the Rapunzel Project.

Doctors aren't so sure. Hair loss, especially among breast cancer patients, is an extremely painful and emotional issue, they say. They don't want to give patients false hope for a costly therapy that may or may not work.

"It's difficult in the sense that there is no good scientific evidence one way or the other," said Dr. Tom Flynn, an oncologist and president of Minnesota Oncology. "All we can do is advise them on what is known and not known, and they have to make their own choice."

But others say cancer patients can benefit simply from feeling better about the way they look and having a sense of control.

"Cancer patients have a right to know they have an option," said Shirley Billigmeier, one of the founders of the Rapunzel Project.

Billigmeier, 60, credits the cap with saving her head of long, dark blond hair when she had chemo in January for breast cancer. She thinks that, clinically proven or not, patients should know about the Penguin Cold Caps.

Billigmeier and her friend Nancy Marshall, 59, of Edina, Minn., are raising money to buy the $7,000 freezers for hospitals and oncology clinics and to spread the word among patients. So far, they've raised enough to buy two freezers, one at Abbott and the other at the Minnesota Oncology clinic in St. Paul.

WAITING FOR CLINICAL TRIALS

Penguin Cold Caps have been used for about 15 years, primarily in Europe. The maker is Medical Specialities of California, which, despite its name, is a small British company. Frank Fronda, the inventor and company founder, was in the Twin Cities last month to meet with doctors at the invitation of the Rapunzel Project.

Fronda came up with the idea about 20 years ago, when he first heard that scalp freezing could stop hair loss in child patients.

Fronda declined to provide financial or market information about his company, but said the caps are used at hospitals in many countries, including at about 60 in France and 75 in the United Kingdom. So far, he said, about 200 patients have used the caps in the United States.

Fronda said the caps work 90 percent of the time, but he's hoping that researchers in the United States will conduct a clinical trial to prove the claim and provide the data he needs for federal approval. Without it, he agreed, American doctors are unlikely to recommend them.

The few small studies that have been done on scalp cooling show that it can work, but not for all types of cancer or all types of chemotherapy.

Dr. Jeff Margolis, an oncologist at Beaumont Hospital in Royal Oak, Mich., said his clinic has offered it to patients for about eight years. He didn't believe it when he first heard about it from a patient, he said, but depending on the type of chemo, "it does work."