Thermal Therapy Protocols for Benign Prostatic Hyperplasia

2007 ◽  
Author(s):  
Daniel Chinn ◽  
Elvis Nditafon ◽  
Alvin Yew ◽  
Chandrasekhar Thamire
Keyword(s):  
Benign Prostatic Hyperplasia ◽  
Thermal Damage ◽  
Prostatic Hyperplasia ◽  
Operating Conditions ◽  
Thermal Therapy ◽  
Bioheat Transfer ◽  
Surrounding Tissue ◽  
Accurate Estimation ◽  
Transfer Model ◽  
Porous Media Model

Thermal therapy for treatment of benign prostatic hyperplasia (BPH) is becoming increasingly popular due to the minimally invasive nature of the treatment. Successful management of such therapy requires accurate estimation of thermal dosage. The purpose of this study is to provide correlations for the thermal damage caused by ultrasound, microwave, and infrared devices under a range of operating conditions. A boundary-fitting finite difference method is used to examine the heat transfer in the prostate gland and surrounding tissue. The Pennes bioheat transfer model and a porous media model were utilized to calculate temperature histories. Necrosis zones were determined using published necrosis data for prostatic tissue and cells. Thermal damage correlations for the three different hyperthermia sources along with sample temperature contours and necrosis zones are presented. Results indicate that the applicator power level and heating time are the most important parameters in achieving the desired necrosis zones, while coolant parameters strongly affect the temperatures of the sensitive urethra and serve as constraints for protocol parameters. Out of the three sources evaluated, ultrasound modality appears to be the most capable of causing necrosis in the target zones, with least damage to the surrounding healthy tissues.

Treatment Protocols for Managing Transurethral Thermal Therapy for Benign Prostatic Hyperplasia

2005 ◽  
Author(s):  
Lara Paolini ◽  
Chandrasekhar Thamire
Keyword(s):  
Benign Prostatic Hyperplasia ◽  
Power Level ◽  
Heating Time ◽  
Prostatic Hyperplasia ◽  
Thermal Therapy ◽  
Accurate Estimation ◽  
Operating Parameters ◽  
Invasive Treatment ◽  
Treatment Protocols ◽  
Finite Differences Method

Application of thermal therapy using microwave or ultrasound applicators is becoming increasingly popular as a minimally invasive treatment for benign prostatic hyperplasia (BPH). Successful management of the therapy using such methods requires an accurate estimation of the thermal dosage. The purpose of this study is to theoretically evaluate the thermal damage caused by different heating sources for different values of thermal doses and operating parameters. Using a 3-D finite differences method, the Pennes bio-heat transfer equation is solved for selected operating parameters. Necrosis zones are then determined from published necrosis data for prostatic tumor cells. Sample results are presented in terms of the temperature contours and necrosis zones. Results indicate that heating time and power level are the most important parameters in creating the desired necrosis zones, while coolant parameters strongly affect the temperatures of the sensitive urethra and serve as constraints for protocol parameters.

Treatment Planning for Transurethral and Interstitial Thermal Therapy for Benign Prostatic Hyperplasia

2009 ◽  
Author(s):  
Chandrasekhar Thamire ◽  
Rabee Zuberi ◽  
Charlie Choe ◽  
Prabhakar Pandey
Keyword(s):  
Benign Prostatic Hyperplasia ◽  
Treatment Planning ◽  
Thermal Damage ◽  
Treatment Time ◽  
Ex Vivo ◽  
Prostatic Hyperplasia ◽  
Bioheat Transfer ◽  
Temperature History ◽  
Target Tissue ◽  
Thermal Coagulation

The purpose of this study is to develop thermal-damage correlations for transurethral and interstitial thermotherapy to aid treatment planning for benign prostatic hyperplasia (BPH). Using an Alternating-direction implicit method, the Pennes bioheat transfer equation is solved for microwave and ultrasound hyperthermia applicators for a range of parameters, including the applicator power, treatment time, and coolant parameters. Thermal coagulation contours are developed by evaluating the temperature-history data against the thermal-damage data obtained in ex-vivo experiments for prostate tissue slices and cells. Treatment protocols are proposed for treatment planning purposes and developing an optimal hyperthermia applicator that can coagulate the target tissue effectively, without destroying the surrounding healthy tissue.

scholarly journals Microwave thermal therapy in the treatment of benign prostatic hyperplasia and prostatic cancer

2012 ◽  
Vol 30 (0) ◽  
pp. 239-245
Author(s):  
Teruaki Kigure ◽  
Kouki Nakata ◽  
Yasuhiro Yuri ◽  
Tadashi Harada ◽  
Shigeru Miyagata ◽  
...  
Keyword(s):  
Benign Prostatic Hyperplasia ◽  
Prostatic Cancer ◽  
Prostatic Hyperplasia ◽  
Thermal Therapy

Ultrasound Hyperthermia: Dose Estimation and Device Design for Intraluminal and External Delivery

2012 ◽  
Author(s):  
Danica Gordon ◽  
Chandrasekhar Thamire
Keyword(s):  
Thermal Damage ◽  
Treatment Time ◽  
The Body ◽  
Thermal Therapy ◽  
Surrounding Tissue ◽  
Temperature History ◽  
Published Data ◽  
Device Design ◽  
Treatment Protocols ◽  
Thermal Coagulation

Thermal ablation in the context of this study refers to destroying cancer cells by heating them to supraphysiological temperatures for appropriate times. Once the tumor cells and a small layer of surrounding tissue cells are killed, they are absorbed by the body over time. Compared to open surgery, radiation, and chemotherapy, thermal therapy can be less expensive and pose less risk of harmful post-procedural complications, while possessing the potential to be effective [1]. Currently microwave and radiofrequency ablation are in use for local hyperthermia; however, they lack the ability to focus heat into the target zones effectively or treat larger tumors without affecting the surrounding healthy tissue. In the current study, high frequency ultrasound (US) ablation is examined as a treatment modality because of its ability to focus and control heat effectively. Objectives of this study are to 1) develop thermal-damage correlations for US thermal therapy and 2) design delivery devices and associated treatment planning protocols. To achieve these goals, thermal damage information is first evaluated for a variety of cells and tissues from published data or pilot experiments. Required US dose levels are determined next through numerical experiments, followed by device design and estimation of thermal coagulation contours by comparing the temperature-history data against the thermal-damage data. Based on the analysis of the results for a range of parameters, namely, the applicator power, geometry, frequency, coolant parameters, treatment time, and tissue perfusion, treatment protocols are developed. Intraluminal, external, and interstitial modes of delivery are considered for focal sites in a variety of target areas. In the following sections, methods followed and sample results obtained are presented.

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