One in nine men will be diagnosed with prostate cancer in their lifetime, making it the most common nonskin cancer in the United States. Traditionally, therapies to treat prostate cancer have not been as specific as they could be, often leading to unwanted side effects and damage to the sensitive surrounding tissue. Now, a new study from investigators at Mt. Sinai’s Icahn School of Medicine provides new data that biocompatible gold nanoparticles, designed to convert near-infrared light to heat have been shown to safely and effectively ablate low- to intermediate-grade tumors within the prostate.
Findings from the new study were published recently in PNAS through an article titled “Gold nanoshell-localized photothermal ablation of prostate tumors in a clinical pilot device study.” This treatment could offer patients a targeted therapy option that would preserve critical structures within the prostate, thus avoiding side effects associated with whole-gland treatment such as prostatectomies.
Removal or other whole-gland treatment of the prostate carries risks of urinary incontinence and erectile dysfunction. However, technological advances have provided clinicians with options for focal therapies with fewer complications.
In the current study, researchers tested the effectiveness of AuroLase® Therapy, a treatment from medical device company Nanospectra Biosciences that is based on technology invented at Rice University. The technique was used in the clinical trial to target and treat the prostate cancer cells using a custom-built MR US fusion guided platform in collaboration with Philips Healthcare. AuroLase uses gold-silica nanoshells (GSN), particles invented that is composed of a silica core and a gold shell with a diameter of 150 nm. AuroShells are designed to absorb energy from near-infrared light and convert it to heat, resulting in selective hyperthermic cell death, without affecting adjacent non-tumorous tissue. The treatment was effectively demonstrated in previous cell studies and animal models. Following treatment, the particles are cleared through the liver, while some remain sequestered in the liver and spleen. There are no known side effects.
“Gold-silica nanoshells infusion allows for a focused therapy that treats the cancer, while sparing the rest of the prostate, thus preserving a patient’s quality of life by reducing unwanted side effects, which could include erectile dysfunction and/or the leakage of urine,” explained lead study investigator Ardeshir Rastinehad, DO, associate professor of urology, and radiology, at the Icahn School of Medicine at Mount Sinai.
Sixteen men aged 58 to 79 with low- to intermediate-grade prostate cancer (Gleason score of 4+3) received GSN infusion. All were diagnosed and treated at using a targeted biopsy technique called magnetic resonance-ultrasound fusion imaging, which uses MRI technology to extract a tissue sample directly from the tumor. Patients underwent GSN infusion and high-precision laser ablation and received an MRI of the prostate 48–72 hours after the procedure, MRI-targeted fusion biopsies at 3 and 12 months, and a standard biopsy at 12 months. Patients were discharged on the same day as the procedure after several hours of monitoring.
Amazingly, GSN-mediated focal laser ablation was successful in 87.5% of lesions treated at one year of follow-up. The goal of researchers was to find an eradication of cancer cells during a biopsy.
“Mount Sinai’s interventional urology program is research-driven and offers patients minimally invasive treatment therapies that improve quality of life,” said Ash Tewari, MD, chair of the department of urology at the Mount Sinai Health System and professor of urology at the Icahn School of Medicine at Mount Sinai. “Dr. Rastinehad’s gold nanoparticle research shows that patients are not only benefiting from this treatment but also experiencing minimal side effects.”