ParticipantsDavid Bonekamp, MD, PhD, Heidelberg, Germany (Presenter) Speaker, Profound Medical Inc
Sandeep S. Arora, MBBS, Nashville, TN (Abstract Co-Author) Speaker, Profound Medical Inc; Researcher, Profound Medical Inc
Masoom A. Haider, MD, Toronto, ON (Abstract Co-Author) Consultant, Bayer AG; Advisory Board, Siemens AG; ;
Zahra Kassam, MD, London, ON (Abstract Co-Author) Nothing to Disclose
Gary L. Brahm, BMedSc, MD, London, ON (Abstract Co-Author) Nothing to Disclose
Jurgen J. Futterer, MD, PhD, Nijmegen, Netherlands (Abstract Co-Author) Research Grant, Siemens AG
Maya B. Mueller-Wolf, MD, Heidelberg, Germany (Abstract Co-Author) Nothing to Disclose
Kiran R. Nandalur, MD, Bloomfield Hills , MI (Abstract Co-Author) Nothing to Disclose
Robert Staruch, Mississauga, ON (Abstract Co-Author) Employee, Profound Medical Inc
Mathieu Burtnyk, DIPLPHYS, Toronto, ON (Abstract Co-Author) Employee, Profound Medical Inc
Joseph Chin, MD, London, ON (Abstract Co-Author) Nothing to Disclose
Gencay Hatiboglu, Heidelberg, Germany (Abstract Co-Author) Nothing to Disclose
Markus Hohenfellner, MD, PhD, Heidelberg, Germany (Abstract Co-Author) Nothing to Disclose
Heinz-Peter W. Schlemmer, MD, Heidelberg, Germany (Abstract Co-Author) Nothing to Disclose
MRI-guided transurethral ultrasound ablation (TULSA) is a novel minimally-invasive technology for ablation of malignant and benign prostate tissue, aiming to provide control of localized prostate cancer (PCa) with low morbidity. A prospective Phase I clinical study investigated safety and feasibility of TULSA; 12-month data have been published, and 30-month follow-up is presented here. Additionally, initial results are described from a larger Pivotal study (TACT) which is currently underway to evaluate the safety and efficacy of TULSA whole-gland ablation.
METHOD AND MATERIALSThirty PCa patients were enrolled in the Phase I trial: age>=65y, T1c/T2a, PSA<=10ng/ml, Gleason<=3+3 (3+4 in Canada only). Under general anaesthesia and 3T MRI guidance, the ultrasound device (TULSA-PRO, Profound Medical Inc.) was positioned in the prostatic urethra. Treatment planning was performed with 3mm margins at the gland periphery, and 10% residual viable prostate expected around the capsule. Treatment was delivered under continuous MRI thermometry feedback control. In the Pivotal trial, treatment planning has been adjusted to reduce residual viable prostate to <1%. To-date, 20 PCa patients have been enrolled in the TACT study: age 45-80y, <=T2b, PSA<=15ng/ml, Gleason<=3+4.
RESULTSIn Phase I, median (IQR) age was 69 (67-71) years and PSA 5.8 (3.8-8.0) ng/ml. Median PSA decreased 87% at 1 month, stable to 0.8 (0.6-1.1) ng/ml at 12 months (n=30), and to 0.7 (0.5-1.1) ng/ml at 30 months (n=15). MRI at 12 months shows diminutive prostates with median volume reduction of 88% (83-95%). In the first 16 TACT study patients, age was 64 (60-66) years and PSA 6.2 (5.4-7.1 ng/ml), with 53% low-risk and 47% intermediate-risk cancers (D'Amico). Spatial control of ablation was ±1.5mm on MRI thermometry, and correlated well with the non-perfused volume confirmed on CE-MRI immediately after treatment.
CONCLUSIONMRI-guidance enables accurate treatment planning, real-time dosimetry and control of the thermal ablation volume. Phase I data demonstrate safety and tissue ablation performance of TULSA. A larger TULSA trial with reduced safety margins is currently enrolling patients.
CLINICAL RELEVANCE/APPLICATIONWhole-gland ablation can be safely and accurately achieved using MRI-guided TULSA, which represents a minimally-invasive treatment option for organ-confined prostate cancer.