Dr. Jeffery Wootton Profile

Dr. Jeffery Wootton

at Univ of California San Francisco

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Publications (5)

Proceedings Article | 23 February 2011 Paper

Catheter-based ultrasound hyperthermia with HDR brachytherapy for treatment of locally advanced cancer of the prostate and cervix

Chris Diederich, Jeff Wootton, Punit Prakash, Vasant Salgaonkar, Titania Juang, Serena Scott, Xin Chen, Adam Cunha, Jean Pouliot, I. Hsu

Proceedings Volume 7901, 79010O (2011) https://doi.org/10.1117/12.876401

KEYWORDS: Ultrasonography, High dynamic range imaging, Cervix, Prostate, Transducers, Computing systems, Control systems, Amplifiers, Thermometry, Rectum

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A clinical treatment delivery platform has been developed and is being evaluated in a clinical pilot study for providing 3D controlled hyperthermia with catheter-based ultrasound applicators in conjunction with high dose rate (HDR) brachytherapy. Catheter-based ultrasound applicators are capable of 3D spatial control of heating in both angle and length of the devices, with enhanced radial penetration of heating compared to other hyperthermia technologies. Interstitial and endocavity ultrasound devices have been developed specifically for applying hyperthermia within HDR brachytherapy implants during radiation therapy in the treatment of cervix and prostate. A pilot study of the combination of catheter based ultrasound with HDR brachytherapy for locally advanced prostate and cervical cancer has been initiated, and preliminary results of the performance and heating distributions are reported herein. The treatment delivery platform consists of a 32 channel RF amplifier and a 48 channel thermocouple monitoring system. Controlling software can monitor and regulate frequency and power to each transducer section as required during the procedure. Interstitial applicators consist of multiple transducer sections of 2-4 cm length × 180 deg and 3-4 cm × 360 deg. heating patterns to be inserted in specific placed 13g implant catheters. The endocavity device, designed to be inserted within a 6 mm OD plastic tandem catheter within the cervix, consists of 2-3 transducers × dual 180 or 360 deg sectors. 3D temperature based treatment planning and optimization is dovetailed to the HDR optimization based planning to best configure and position the applicators within the catheters, and to determine optimal base power levels to each transducer section. To date we have treated eight cervix implants and six prostate implants. 100 % of treatments achieved a goal of >60 min duration, with therapeutic temperatures achieved in all cases. Thermal dosimetry within the hyperthermia target volume (HTV) and clinical target volume (CTV) are reported. Catheter-based ultrasound hyperthermia with HDR appears feasible with therapeutic temperature coverage of the target volume within the prostate or cervix while sparing surrounding more sensitive regions.

Proceedings Article | 24 February 2009 Paper

Patient specific optimization-based treatment planning for catheter-based ultrasound hyperthermia and thermal ablation

Punit Prakash, Xin Chen, Jeffery Wootton, Jean Pouliot, I-Chow Hsu, Chris Diederich

Proceedings Volume 7181, 71810E (2009) https://doi.org/10.1117/12.809329

KEYWORDS: Ultrasonography, Tissues, Transducers, 3D modeling, Prostate, High dynamic range imaging, Thermal modeling, Bladder, Rectum, Cervix

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A 3D optimization-based thermal treatment planning platform has been developed for the application of catheter-based ultrasound hyperthermia in conjunction with high dose rate (HDR) brachytherapy for treating advanced pelvic tumors. Optimal selection of applied power levels to each independently controlled transducer segment can be used to conform and maximize therapeutic heating and thermal dose coverage to the target region, providing significant advantages over current hyperthermia technology and improving treatment response. Critical anatomic structures, clinical target outlines, and implant/applicator geometries were acquired from sequential multi-slice 2D images obtained from HDR treatment planning and used to reconstruct patient specific 3D biothermal models. A constrained optimization algorithm was devised and integrated within a finite element thermal solver to determine a priori the optimal applied power levels and the resulting 3D temperature distributions such that therapeutic heating is maximized within the target, while placing constraints on maximum tissue temperature and thermal exposure of surrounding non-targeted tissue. This optimizationbased treatment planning and modeling system was applied on representative cases of clinical implants for HDR treatment of cervix and prostate to evaluate the utility of this planning approach. The planning provided significant improvement in achievable temperature distributions for all cases, with substantial increase in T90 and thermal dose (CEM43T90) coverage to the hyperthermia target volume while decreasing maximum treatment temperature and reducing thermal dose exposure to surrounding non-targeted tissues and thermally sensitive rectum and bladder. This optimization based treatment planning platform with catheter-based ultrasound applicators is a useful tool that has potential to significantly improve the delivery of hyperthermia in conjunction with HDR brachytherapy. The planning platform has been extended to model thermal ablation, including the addition of temperature dependent attenuation, perfusion, and tissue damage. Pilot point control at the target boundaries was implemented to control power delivery to each transducer section, simulating an approach feasible for MR guided procedures. The computer model of thermal ablation was evaluated on representative patient anatomies to demonstrate the feasibility of using catheter-based ultrasound thermal ablation for treatment of benign prostate hyperplasia (BPH) and prostate cancer, and to assist in designing applicators and treatment delivery strategies.

Proceedings Article | 24 February 2009 Paper

Treatment delivery platform for conformal catheter-based ultrasound hyperthermia

Titania Juang, Jeffery Wootton, I-Chow Hsu, Chris Diederich

Proceedings Volume 7181, 718109 (2009) https://doi.org/10.1117/12.808339

KEYWORDS: Francium, Ultrasonography, Thermometry, Amplifiers, Control systems, Transducers, High dynamic range imaging, Computing systems, Temperature metrology, Human-machine interfaces

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A clinical treatment delivery platform has been developed for providing 3D controlled hyperthermia with catheter-based ultrasound applicators in conjunction with high dose rate (HDR) brachytherapy. This integrated system consists of hardware and software components required for thermal therapy delivery, treatment monitoring and control, and realtime and post-treatment analysis; and interstitial and endocavity ultrasound heating applicators. Hardware includes a 32-channel RF amplifier with independent power (0-25 W) and frequency (5-10 MHz) control for ultrasound power delivery and a 48-channel thermometry system compatible with 0.4 mm OD multi-sensor thermocouple probes. Software graphical user interfaces (GUI) are used to monitor and control both the amplifier and the thermometry system. The amplifier GUI controls, monitors, and records individual channel frequency and power values in real-time; the thermometry GUI monitors and records temperature and thermal dose values in real-time, as well as displaying and allowing dynamic control for temperature and thermal dose target thresholds. The thermometry GUI also incorporates registration of thermocouple positions relative to target anatomy and applicator transducers based on HDR planning tools (CT/MRI/US overlays) for improved treatment control and documentation. The interstitial (2.4 mm) and endocavity (6 mm) ultrasound hyperthermia applicators are composed of linear arrays of 1-4 tubular piezoceramic transducers - sectored at 90°, 180°, 270°, and 360° for single or dual directional heating patterns - that are compatible with plastic implant catheters. QA techniques specific to these catheter-based ultrasound applicators have been devised and implemented, and include rotational beam plots and dynamic force balance efficiency measurements, which are critical to establish applicator performance. A quality assurance test matrix has been devised and used to evaluate and characterize all components of this system prior to clinical implementation.

Proceedings Article | 24 February 2009 Paper

An intrauterine ultrasound applicator for targeted delivery of thermal therapy in conjunction with HDR brachytherapy to the cervix

Jeffery Wootton, Titania Juang, Jean Pouliot, I-Chow Joe Hsu, Chris Diederich

Proceedings Volume 7181, 71810T (2009) https://doi.org/10.1117/12.808343

KEYWORDS: Ultrasonography, Tissues, High dynamic range imaging, Transducers, Bladder, Cervix, Acoustics, Rectum, Magnetic resonance imaging, Computed tomography

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Proceedings Article | 9 February 2007 Paper

Prostate thermal therapy with catheter-based ultrasound devices and MR thermal monitoring

Will Nau, Chris Diederich, Adam Kinsey, Tony Ross, Jeff Wootton, Titania Juang, Kim Butts-Pauly, Viola Ricke, Erin Liu, Jing Chen, Donna Bouley, Maurice Van den Bosch, Graham Sommer

Proceedings Volume 6440, 64400D (2007) https://doi.org/10.1117/12.703184

KEYWORDS: Prostate, Ultrasonography, Bone, Transducers, Magnetic resonance imaging, In vivo imaging, Control systems, Tissues, Rectum, HVAC controls

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