Thirteen of the 15 prostate cancer patients treated with a Rice University-developed therapy were cancer-free after one year, a new study shows.

The study, published Monday in the journal Proceedings of the National Academy of Sciences, is the most recent step in a 20-year quest to get Food and Drug Administration approval for AuroLase Therapy, a treatment method that involves nanoparticles. Nanoparticles can be 500 to 10,0000 times thinner than a human hair.

“We’re so excited about this,” said Naomi Halas, Rice University engineer and nanoscientist. “This cancer touches every single family in some way. This is going to be a really good thing.”

Halas invented the particles — which are called nanoshells and are coated with a thin layer of gold — in 1997. Three years later, Halas met Rice colleague Jennifer West, and together they found a way to use these particles to attack cancer cells.

They quickly founded a company, Nanospectra Biosciences, to develop the technology for commercial use.

With this treatment technique, particles are injected into the bloodstream and automatically gravitate toward the tumor. Then, they are heated from outside the body with a low-power, near-infrared laser that destroys the cells.

It worked in 13 of the 15 patients who received treatment — leaving them cancer-free after one year. Sixteen patients were part of the study, but only 15 received the treatment.

Prostate cancer is the second leading cause of cancer death for men in the United States, just behind lung cancer. One in nine men will be diagnosed with it in their lifetime, and one in 41 will die from it, according to the American Cancer Society.

The patients selected were 58 to 79 years old and had low- to intermediate-risk localized prostate cancer, according to Rice. They underwent two days of treatment and were tested for cancer after three months, six months and one year.

Frank Billingsley, KPRC chief meteorologist, underwent this treatment, but he wasn’t included in the study. He is part of the larger clinical trial that involves 44 patients from across the U.S.

All 16 patients included in this study were treated at Mount Sinai in New York, but some of the treatments, including Billingsley’s, were conducted at the University of Texas Health Science Center at Houston. The results of the other patients will be published later.

Billingsley was diagnosed a year ago, and was declared cancer-free last December after undergoing this new cancer therapy.

In December, Billingsley shared the good news on Facebook, saying “Last Friday’s MRI following my gold nanoparticle procedure for prostate cancer came back this evening as Cancer Free!”

He’d have more follow up tests, but said that the doctors were “‘very confident that I’ve had a successful procedure. It’s been a long few months. Thank you, everyone, for the support!”

Halas believes the therapy could be used for many types of cancers, but she said prostate cancer was the focus first because of the negative side effects of traditional forms of treatment, such as radiation and chemotherapy.

Those side effects can include erectile dysfunction and incontinence — and Halas knows about them first-hand.

Her father was diagnosed at 85 in the early 2000s but didn’t begin experiencing side effects —in his case, the inability to urinate — until two years after undergoing radiation treatment.

“It was terrible,” Halas said. “He was in and out of the hospital weekly. The doctor would catheterize him. He’d go home. Things would be fine for a few days, and then he’d have to go to the emergency room.”

Studies have shown that the nanoshells are safe and nontoxic.

The results in this study are promising, Halas said, and she thinks the treatment could be approved by the FDA for commercial application in a year.

“It’s really just so satisfying to a start a project so long ago and envision this as something that could be used for widespread human use,” Halas said. “It took longer than we thought but we’re all just so thrilled and excited that we found an application that impacts a lot of people’s lives positively.”

Alex Stuckey writes about NASA and the environment for the Houston Chronicle. You can reach her at alex.stuckey@chron.com or Twitter.com/alexdstuckey.