Gold nanoshell-localized photothermal ablation of prostate tumors in a clinical pilot device study

Published: Department of Urology, Icahn School of Medicine at Mount Sinai, New York, NY 10029; Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, Clinical Research, Nanospectra Biosciences, Inc., Houston, TX 77054; Department of Urology, McGovern Medical School at the University of Texas Health Science Center at Houston, Houston, TX 77030; Department of Urology, Michigan Medicine University of Michigan, Ann Arbor, MI 48109; Department of Biomedical Engineering, Duke University, Durham, NC 27708; and Laboratory for Nanophotonics, Rice University, Houston, TX 77005

Keyword: MRI-ultrasound, fusion photothermal therapy, focal therapy, gold nanoshell, prostate cancer

Author(s): Ardeshir R. Rastinehada,b,1, Harry Anastosa, Ethan Wajswola, Jared S. Winokera, John P. Sfakianosa, Sai K. Doppalapudia, Michael R. Carrickb, Cynthia J. Knauera, Bachir Taoulib, Sara C. Lewisb, Ashutosh K. Tewaria, Jon A. Schwartzc, Steven E. Canfieldd, Arvin K. Georgee, Jennifer L. Westf, and Naomi J. Halasg

Overview:  This pilot device study reports feasibility and safety data from 16 cases of human patients diagnosed with low- or intermediate-risk localized prostate cancer.  Participants underwent Gold-Silica Nanoshell (GSN) infusion and high-precision photothermal ablation via laser of the prostate.  This treatment protocol appears to be feasible and safe in men with low- or intermediate-risk localized prostate cancer without serious complications or deleterious changes in genitourinary function.

Materials/Methods:

• Sixteen men aged 58 to 79 years with clinical stage T2a or less prostate cancer, Gleason score of 4+3 or less, and a minimum post-ablation follow-up of 12-mo endpoints were analyzed.
• 15 of the initial 16 patients successfully completed the treatment protocol.
• During each procedure, a median of 11 (from a range of 4 to 21) interstitial catheters with laser fibers were inserted into the prostate, which correlated to the cross-sectional area of the tumor in the axial plane.
• The median number of laser excitations was 25 (from a range of 5 to 52). The laser power used increased from 4.5 W up to 6.5 W.

Results: 

• Median prostate volume observed on MRI decreased from 49 cm³ at baseline to 42 cm³ at 3 mo (Wilcoxon signed-rank test P = 0.23). Median prostate-specific antigen (PSA) at baseline decreased from 6.7 ng/mL at baseline to 3.9 ng/mL at 3 months
• All 15 treated patients with 16 total lesions underwent mpMRI and targeted biopsy at 3 months, as well as a mpMRI, targeted biopsy, and systematic 12 core standard biopsy at 12 months post-treatment.
• All patients had evidence of coagulative necrosis on repeat biopsy. The ablation zones were negative for tumors in 62.5% (10/16) of lesions at 3 months. At 12 months, 87.5% (14/16) of lesions were negative for tumor in the ablation zones.

Conclusions:  This current pilot device study demonstrates that GSN-directed laser excitation and photothermal ablation is a safe and technically feasible procedure for the targeted destruction of prostate tumors.