Magnetic Resonance Imaging–Guided Transurethral Ultrasound Ablation of Prostate Tissue in Patients with Localized Prostate Cancer: A Prospective Phase 1 Clinical Trial

Chin, Joseph L.; Billia, Michele; Relle, James; Roethke, Matthias; Popeneciu, Ionel Valentin; Kuru, Timur H.; Hatiboglu, Gencay; Mueller-Wolf, Maya; Motsch, J.; Romagnoli, Cesare; Kassam, Zahra; Harle, Christopher; Hafron, Jason; Nandalur, Kiran R.; Chronik, Blaine A.; Burtnyk, Mathieu; Schlemmer, Heinz Peter; Pahernik, Sascha

doi:10.1016/j.eururo.2015.12.029

Cited by 76 publications

(106 citation statements)

References 27 publications

Supporting

Mentioning

100

Contrasting

Order By: Relevance

“…Averaged over all sector angles, slices and subjects, the temperature control accuracy was −1.6 ± 4.8 °C, while the spatial targeting accuracy achieved was −1.5 ± 2.8 mm. This agrees with observations from recent clinical trials with similar technology 17 . The key requirements for this technology to achieve this performance include: 1) the ability to plan treatment sectors efficiently on a slice by slice basis, 2) independent control over power and frequency across the multi-element transducer 16,23 , and 3) the capability to perform 3D MR thermometry with sufficient temporal and spatial resolution to monitor the tissue temperature evolution during treatment 16,19,24,25 .…”

Section: Discussionsupporting

confidence: 93%

“…The treatments in this preliminary study, however, did not extend to the periphery of the prostate, and only a single plane of tissue was treated. More recently, a phase 1 study using a commercial transurethral system to coagulate the whole prostate gland was reported by Chin et al 17 demonstrating an acceptable safety profile and encouraging quality of life outcomes at 12 months. A three millimeter safety margin between the ablation boundary and prostate capsule was mandated in this study, which left up to 10% of the prostate volume untreated.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Evaluation of Focal Ablation of Magnetic Resonance Imaging Defined Prostate Cancer Using Magnetic Resonance Imaging Controlled Transurethral Ultrasound Therapy with Prostatectomy as the Reference Standard

et al. 2017

View full text Add to dashboard Cite

Section: Discussionsupporting

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Evaluation of Focal Ablation of Magnetic Resonance Imaging Defined Prostate Cancer Using Magnetic Resonance Imaging Controlled Transurethral Ultrasound Therapy with Prostatectomy as the Reference Standard

et al. 2017

View full text Add to dashboard Cite

“…They all deliver the treatment using a probe with an integrated HIFU and imaging transducer, which is used transrectally under US guidance to induce ablation of the targeted region . On the other hand, the TULSA‐PRO (PROFOUND MEDICAL Corp., Toronto, Canada) delivers transurethral ultrasound ablation of prostate cancer under magnetic resonance imaging (MRI) guidance …”

Section: Methodsmentioning

confidence: 99%

“…24 On the other hand, the TULSA-PRO (PRO-FOUND MEDICAL Corp., Toronto, Canada) delivers transurethral ultrasound ablation of prostate cancer under magnetic resonance imaging (MRI) guidance. 46 The transducer model used in this work nominally followed the specifications of the Sonablate 500 (SonaCare Medical). This system is currently in use at University College London Hospital (UCLH).…”

Section: A Clinical Hifu Systems For Prostate Cancermentioning

confidence: 99%

Beam distortion due to gold fiducial markers during salvage high‐intensity focused ultrasound in the prostate

et al. 2017

View full text Add to dashboard Cite

The copyright line for this article was changed on March 17, 2017, after original online publication.Purpose: High intensity focused ultrasound (HIFU) provides a non-invasive salvage treatment option for patients with recurrence after external beam radiation therapy (EBRT). As part of EBRT the prostate is frequently implanted with permanent fiducial markers. To date, the impact of these markers on subsequent HIFU treatment is unknown. The objective of this work was to systematically investigate, using computational simulations, how these fiducial markers affect the delivery of HIFU treatment. Methods: A series of simulations was performed modelling the propagation of ultrasound pressure waves in the prostate with a single spherical or cylindrical gold marker at different positions and orientations. For each marker configuration, a set of metrics (spatial-peak temporal-average intensity, focus shift, focal volume) was evaluated to quantify the distortion introduced at the focus. An analytical model was also developed describing the marker effect on the intensity at the focus. The model was used to examine the marker's impact in a clinical setting through case studies. Results: The simulations show that the presence of the marker in the pre-focal region causes reflections which induce a decrease in the focal intensity and focal volume, and a shift of the maximum pressure point away from the transducer's focus. These effects depend on the shape and orientation of the marker and become more pronounced as its distance from the transducer's focus decreases, with the distortion introduced by the marker greatly increasing when placed within 5 mm of the focus. The analytical model approximates the marker's effect and can be used as an alternative method to the computationally intensive and time consuming simulations for quickly estimating the intensity at the focus. A retrospective review of a small patient cohort selected for focal HIFU after failed EBRT indicates that the presence of the marker may affect HIFU treatment delivery. Conclusions: The distortion introduced by the marker to the HIFU beam when positioned close to the focus may result in an undertreated region beyond the marker due to less energy arriving at the focus, and an overtreated region due to reflections. Further work is necessary to investigate whether the results presented here justify the revision of the patient selection criteria or the markers' placement protocol.

show abstract

“…Transurethral ultrasound ablation (TULSA) administers acoustic energy directly into the prostate without having to traverse intervening tissue. MR imaging (MRI) enables real‐time temperature monitoring to assess the treatment progress . TULSA sources utilize an unfocused transducer, which enables bulk heating of prostate tissue.…”

Section: Introductionmentioning

confidence: 99%

MRI‐guided transurethral insonation of silica‐shell phase‐shift emulsions in the prostate with an advanced navigation platform

et al. 2018

View full text Add to dashboard Cite

Purpose In this study, the efficacy of transurethral prostate ablation in the presence of silica‐shell ultrasound‐triggered phase‐shift emulsions (sUPEs) doped with MR contrast was evaluated. The influence of sUPEs on MR imaging assessment of the ablation zone was also investigated. Methods sUPEs were doped with a magnetic resonance (MR) contrast agent, Gd2O3, to assess ultrasound transition. Injections of saline (sham), saline and sUPEs alone, and saline and sUPEs with Optison microbubbles were performed under guidance of a prototype interventional MRI navigation platform in a healthy canine prostate. Treatment arms were evaluated for differences in lesion size, T1 contrast, and temperature. In addition, non‐perfused areas (NPAs) on dynamic contrast‐enhanced (DCE) MRI, 55°C isotherms, and areas of 240 cumulative equivalent minutes at 43°C (CEM43) dose or greater computed from MR thermometry were measured and correlated with ablated areas indicated by histology. Results For treatment arms including sUPEs, the computed correlation coefficients between the histological ablation zone and the NPA, 55°C isotherm, and 240 CEM43 area ranged from 0.96–0.99, 0.98–0.99, and 0.91–0.99, respectively. In the absence of sUPEs, the computed correlation coefficients between the histological ablation zone and the NPA, 55°C isotherm, and 240 CEM43 area were 0.69, 0.54, and 0.50, respectively. Across all treatment arms, the areas of thermal tissue damage and NPAs were not significantly different (P = 0.47). Areas denoted by 55°C isotherms and 240 CEM43 dose boundaries were significantly larger than the areas of thermal damage, again for all treatment arms (P = 0.009 and 0.003, respectively). No significant differences in lesion size, T1 contrast, or temperature were observed between any of the treatment arms (P > 0.0167). Lesions exhibiting thermal fixation on histological analysis were present in six of nine insonations involving sUPE injections and one of five insonations involving saline sham injections. Significantly larger areas (P = 0.002), higher temperatures (P = 0.004), and more frequent ring patterns of restricted diffusion on ex vivo diffusion‐weighted imaging (P = 0.005) were apparent in lesions with thermal fixation. Conclusions T1 contrast suggesting sUPE transition was not evident in sUPE treatment arms. The use of MR imaging metrics to predict prostate ablation was not diminished by the presence of sUPEs. Lesions generated in the presence of sUPEs exhibited more frequent thermal fixation, though there were no significant changes in the ablation areas when comparing arms with and without sUPEs. Thermal fixation corresponded to some qualitative imaging features.

show abstract

Magnetic Resonance Imaging–Guided Transurethral Ultrasound Ablation of Prostate Tissue in Patients with Localized Prostate Cancer: A Prospective Phase 1 Clinical Trial

Cited by 76 publications

References 27 publications

Evaluation of Focal Ablation of Magnetic Resonance Imaging Defined Prostate Cancer Using Magnetic Resonance Imaging Controlled Transurethral Ultrasound Therapy with Prostatectomy as the Reference Standard

Evaluation of Focal Ablation of Magnetic Resonance Imaging Defined Prostate Cancer Using Magnetic Resonance Imaging Controlled Transurethral Ultrasound Therapy with Prostatectomy as the Reference Standard

Beam distortion due to gold fiducial markers during salvage high‐intensity focused ultrasound in the prostate

MRI‐guided transurethral insonation of silica‐shell phase‐shift emulsions in the prostate with an advanced navigation platform

Contact Info

Product

Resources

About