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Coricciati L, Gabellone M, Donne PD, Fusco I, Zingoni T. Assessment of the efficacy of 595 nm pulsed dye laser in the management of facial flat angiomas. Results of a case series. Skin Res Technol 2023; 29:e13494. [PMID: 37881052 PMCID: PMC10576172 DOI: 10.1111/srt.13494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 09/26/2023] [Indexed: 10/27/2023]
Abstract
BACKGROUND Studies on pulsed dye laser (PDL) have shown the best efficacy and safety data for treating vascular anomalies among the various lasers used and the 595-nm PDL has been used to treat cutaneous vascular anomalies for about 30 years. The purpose of this study was to assess the efficacy of 595 nm Pulsed Dye Laser in the management of facial flat angiomas present in the form of Port-Wine Stain. MATERIALS AND METHODS Seven cases of PWS in Fitzpatrick skin type ranged from I to III and colour ranging from pink to purple, were treated with 595 nm pulse Dye Laser. Patients underwent to 6-8 laser sessions at 20-30 days intervals. Results obtained were judged by dermatologist, by comparing pre-treatment and post-treatment photographs, 6 months after the last session and a quartile scale of lesion clearance (4-point Investigator Global Assessment scale): 1 = no or low results (0%-25% of the lesion area improved), 2 = slight improvement (25%-50% of the lesion area cleared), 3 = moderate-good improvement (50%-75%), and 4 = excellent improvement (75%-100%) was used. Possible side effects such as blisters, hyper/hypopigmentation, and scarring were monitored. RESULTS All patients observed global improvements. 71% of patients achieved excellent clearance and 29% patients achieved good-moderate clearance of their angioma. Patients were asked for a subjective evaluation of the results: 57% of patients were very satisfied, 29% were satisfied, and 14% patients were not very satisfied with the results. No patients were dissatisfied. No significant side effects were noted. CONCLUSION This research confirms the efficacy of the 595 nm PDL for flat angioma management, without considerable side effects.
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Ledezma DK, Balakrishnan PB, Shukla A, Medina JA, Chen J, Oakley E, Bollard CM, Shafirstein G, Miscuglio M, Fernandes R. Interstitial Photothermal Therapy Generates Durable Treatment Responses in Neuroblastoma. Adv Healthc Mater 2022; 11:e2201084. [PMID: 35943173 PMCID: PMC9588730 DOI: 10.1002/adhm.202201084] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 07/23/2022] [Indexed: 01/28/2023]
Abstract
Photothermal therapy (PTT) represents a promising modality for tumor control typically using infrared light-responsive nanoparticles illuminated by a wavelength-matched external laser. However, due to the constraints of light penetration, PTT is generally restricted to superficially accessible tumors. With the goal of extending the benefits of PTT to all tumor settings, interstitial PTT (I-PTT) is evaluated by the photothermal activation of intratumorally administered Prussian blue nanoparticles with a laser fiber positioned interstitially within the tumor. This interstitial fiber, which is fitted with a terminal diffuser, distributes light within the tumor microenvironment from the "inside-out" as compared to from the "outside-in" traditionally observed during superficially administered PTT (S-PTT). I-PTT improves the heating efficiency and heat distribution within a target treatment area compared to S-PTT. Additionally, I-PTT generates increased cytotoxicity and thermal damage at equivalent thermal doses, and elicits immunogenic cell death at lower thermal doses in targeted neuroblastoma tumor cells compared to S-PTT. In vivo, I-PTT induces significantly higher long-term tumor regression, lower rates of tumor recurrence, and improved long-term survival in multiple syngeneic murine models of neuroblastoma. This study highlights the significantly enhanced therapeutic benefit of I-PTT compared to traditional S-PTT as a promising treatment modality for solid tumors.
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Affiliation(s)
- Debbie K Ledezma
- The George Washington Cancer Center, The George Washington University, 800 22nd St NW, 8300 Science and Engineering Hall, Washington, DC, 20052, USA
- The Institute for Biomedical Sciences, The George Washington University, 2300 Eye Street NW, Ross Hall Room 561, Washington, DC, 20037, USA
| | - Preethi B Balakrishnan
- The George Washington Cancer Center, The George Washington University, 800 22nd St NW, 8300 Science and Engineering Hall, Washington, DC, 20052, USA
| | - Anshi Shukla
- The George Washington Cancer Center, The George Washington University, 800 22nd St NW, 8300 Science and Engineering Hall, Washington, DC, 20052, USA
| | - Jacob A Medina
- The George Washington Cancer Center, The George Washington University, 800 22nd St NW, 8300 Science and Engineering Hall, Washington, DC, 20052, USA
- The Institute for Biomedical Sciences, The George Washington University, 2300 Eye Street NW, Ross Hall Room 561, Washington, DC, 20037, USA
| | - Jie Chen
- The George Washington Cancer Center, The George Washington University, 800 22nd St NW, 8300 Science and Engineering Hall, Washington, DC, 20052, USA
| | - Emily Oakley
- Photodynamic Therapy Center, Roswell Park Comprehensive Cancer Center, Department of Cell Stress Biology, Roswell Park, Elm and Carlton Streets, Buffalo, NY, 14263, USA
| | - Catherine M Bollard
- The George Washington Cancer Center, The George Washington University, 800 22nd St NW, 8300 Science and Engineering Hall, Washington, DC, 20052, USA
- Center for Cancer and Immunology Research, Children's National Hospital, 111 Michigan Ave NW, Washington, DC, 20010, USA
| | - Gal Shafirstein
- Photodynamic Therapy Center, Roswell Park Comprehensive Cancer Center, Department of Cell Stress Biology, Roswell Park, Elm and Carlton Streets, Buffalo, NY, 14263, USA
| | - Mario Miscuglio
- Department of Electrical and Computer Engineering, The George Washington University, 800 22nd St NW, 5000 Science and Engineering Hall, Washington, DC, 20052, USA
| | - Rohan Fernandes
- The George Washington Cancer Center, The George Washington University, 800 22nd St NW, 8300 Science and Engineering Hall, Washington, DC, 20052, USA
- Department of Medicine, The George Washington University, 2150 Pennsylvania Avenue, NW, Suite 8-416, Washington, DC, 20037, USA
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Kim MM, Darafsheh A. Light Sources and Dosimetry Techniques for Photodynamic Therapy. Photochem Photobiol 2020; 96:280-294. [PMID: 32003006 DOI: 10.1111/php.13219] [Citation(s) in RCA: 178] [Impact Index Per Article: 44.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 11/29/2019] [Indexed: 12/19/2022]
Abstract
Effective treatment delivery in photodynamic therapy (PDT) requires coordination of the light source, the photosensitizer, and the delivery device appropriate to the target tissue. Lasers, light-emitting diodes (LEDs), and lamps are the main types of light sources utilized for PDT applications. The choice of light source depends on the target location, photosensitizer used, and light dose to be delivered. Geometry of minimally accessible areas also plays a role in deciding light applicator type. Typically, optical fiber-based devices are used to deliver the treatment light close to the target. The optical properties of tissue also affect the distribution of the treatment light. Treatment light undergoes scattering and absorption in tissue. Most tissue will scatter light, but highly pigmented areas will absorb light, especially at short wavelengths. This review will summarize the basic physics of light sources, and describe methods for determining the dose delivered to the patient.
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Affiliation(s)
- Michele M Kim
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA
| | - Arash Darafsheh
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO
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Mohamed EEM, Mohamed Tawfik K, Hassan Ahmad W. Successful treatment of facial vascular skin diseases with a 577-nm pro-yellow laser. J Cosmet Dermatol 2019; 18:1675-1679. [PMID: 31033204 DOI: 10.1111/jocd.12963] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 02/11/2019] [Accepted: 03/20/2019] [Indexed: 11/29/2022]
Abstract
BACKGROUND Treatment of vascular skin diseases is one of the most important indications of the laser. AIMS To evaluate the effectiveness of 577-nm pro-yellow laser in the treatment of some vascular skin diseases. PATIENTS/METHODS Ninety-five patients with vascular skin diseases were included in this prospective monocentric study. They were classified into: port-wine stain birthmarks (n = 37), papulopustular rosacea (n = 20), facial telangiectasia (n = 16), and facial erythema (n = 22). All participants received a monthly session of 577-nm pro-yellow laser. Follow-up was done by comparing the photographs before and at every follow-up visit. RESULTS At the final visit, there was a significant improvement (>50%) occurred in 24/37 (64.82%), 12/20 (60%), 10/16 (62.5%), and 19/22 (86.3%) cases and poor response occurred in 6/37 (16.2%), 2/20 (10%), 2/16 (12.5%), and 0/22 cases after a mean number of sessions 7.76 ± 2.28, 3.1 ± 1.8, 3.63 ± 1.12, and 1.8 ± 0.85 in port-wine stain, rosacea-, facial telangiectasia-, and facial erythema-treated groups, respectively. Transient irritation and erythema during the session were the only complications reported in the study. CONCLUSION Facial port-wine stains, rosacea, telangiectasia, and erythema can be successfully treated with a single pass of 577-nm pro-yellow laser with a minimal side effect. Facial erythema showed the highest degree of success with the least number of sessions, while more sessions needed for the treatment of port-wine stain.
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Treatment of Lower Limbs Telangiectasias with Nd: Yag Laser-Prospective Study on 446 Patients. CURRENT HEALTH SCIENCES JOURNAL 2019; 44:235-242. [PMID: 30647943 PMCID: PMC6311228 DOI: 10.12865/chsj.44.03.06] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 07/10/2018] [Indexed: 11/24/2022]
Abstract
In the last two decades Nd: YAG laser has become a standard of treatment of
telangiectasias of the lower limbs in C1EAP stage of chronic venous
insufficiency. This paper shows the results of a two years study period of
telangiectasias of lower limbs with Nd: YAG laser conducted in a specialised
centre in this type of procedures. The study group consisted of 446 patients
(21 males and 425 females) with telangiectasias (C1EAP) on the lower limbs
between January 2016-December 2017. The patients had to complete a form
in which they noted the initial state on a scale from 1 to 10 but also the
result of the treatment and the intensity of the pain during the laser
treatment. Moreover, the doctor also evaluated the results of the treatment for
each and every patient taking also into account the initial phase of the
disease. We observed a significant improvement of the clinical appearance
(the reduction of telangiectasias) almost in the entire study group, regardless
of the gender and the age, but the intensity of the pain was higher in men and
in persons under the age of 30. Based on these data we can conclude that Nd:
YAG laser represents a minimally invasive therapeutic option with minor side
effects and major aesthetic results and furthermore it can be combined with
several other methods (microsclerotherapy, radiofrequency, complex surgery)
in order to improve peripheral chronic venous insufficiency.
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Bäumler W, Weiß KT. Laser assisted tattoo removal – state of the art and new developments. Photochem Photobiol Sci 2019; 18:349-358. [DOI: 10.1039/c8pp00416a] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Decorative tattoos including permanent make-up are very popular world-wide. As the trend for tattoo acquisition increases, the demand for tattoo removal will similarly rise. This article highlights the state of the art and new developments in laser assisted tattoo removal.
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Affiliation(s)
- W. Bäumler
- Department of Dermatology
- University of Regensburg
- Germany
| | - K. T. Weiß
- Department of Dermatology
- University of Regensburg
- Germany
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Shurrab K, Kochaji N, Bachir W. Development of Temperature Distribution and Light Propagation Model in Biological Tissue Irradiated by 980 nm Laser Diode and Using COMSOL Simulation. J Lasers Med Sci 2017; 8:118-122. [PMID: 29123630 DOI: 10.15171/jlms.2017.21] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Introduction: The purpose of this project is to develop a mathematical model to investigate light distribution and study effective parameters such as laser power and irradiated time to get the optimal laser dosage to control hyperthermia. This study is expected to have a positive impact and a better simulation on laser treatment planning of biological tissues. Moreover, it may enable us to replace animal tests with the results of a COMSOL predictive model. Methods: We used in this work COMSOL5 model to simulate the light diffusion and bio-heat equation of the mouse tissue when irradiated by 980 nm laser diode and the effect of different parameters (laser power, and irradiated time) on the surrounding tissue of the tumor treatment in order to prevent damage from excess heat Results: The model was applied to study light propagation and several parameters (laser power, irradiated time) and their impact on light-heat distribution within the tumor in the mouse back tissue The best result is at laser power 0.5 W and time irradiation 0.5 seconds in order to get the maximum temperature hyperthermia at 52°C. Conclusion: The goal of this study is to simulate a mouse model to control excess heating of tissue and reduce the number of animals in experimental research to get the best laser parameters that was safe for use in living animals and in human subjects.
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Affiliation(s)
- Kawthar Shurrab
- Higher Institute for Laser Research and Applications, Damascus University, Syria
| | - Nabil Kochaji
- Dean of Faculty of Dentistry, Al-Sham University, Damascus, Syria
| | - Wesam Bachir
- Higher Institute for Laser Research and Applications, Damascus University, Syria
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PINHEIRO CLEBERDASILVA. INFLUENCE OF THERMAL-ELECTRICAL PARAMETER COMBINATIONS ON THERMAL LESIONS OF RADIOFREQUENCY TUMOR ABLATION. J BIOL SYST 2017. [DOI: 10.1142/s0218339017500164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Several studies have been conducted on the applicability of hyperthermia radiofrequency in the treatment of liver tumors. Many theoretical studies have reported the relevance of various physical parameters in terms of their efficacy in combating tumors and have analyzed the impact of these physical parameters on the temperature profile in the diseased tissue. Parameters such as thermal and electrical conductivities have been investigated during simulations of thermal ablation. Such parameters play an important role in the process of heat transfer in tissues. The purpose of this study is to predict the lesion volume, considering the inclusion of temperature dependence of thermal-electrical properties. This paper introduces a three-dimensional computational model that includes different comparative combinations of tissue thermal-electrical parameters as a mapping of temperature (such as thermal and electrical conductivities and specific heat). The finite-element method is employed for simulating hepatic radiofrequency ablation through the numerical solutions of the bioheat, Laplace, and Navier–Stokes equations. The results suggest that different combinations of tissue temperature-dependent parameters can significantly affect the computed lesion volume and that the temperature dependence of electrical conductivity has a major impact on the computed lesion volume and temperature distribution.
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Affiliation(s)
- CLEBER DA SILVA PINHEIRO
- Institute of Physics—University of Brasília (UnB), Campus Universitário Darcy Ribeiro, Asa Norte, CEP 70919-970, Brasília/Distrito Federal-DF, Brazil
- Department of Biological Sciences, University Center of Brasilia (UniCEUB), Asa Norte, SEPN 707/907-University Center, CEP 70790-075, Brasília/Distrito Federal-DF, Brazil
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Wang H, Dong XX, Yang JC, Huang H, Li YX, Zhang HX. Finite element method simulating temperature distribution in skin induced by 980-nm pulsed laser based on pain stimulation. Lasers Med Sci 2017; 32:1173-1187. [PMID: 28526914 DOI: 10.1007/s10103-017-2223-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 04/26/2017] [Indexed: 11/29/2022]
Abstract
For predicting the temperature distribution within skin tissue in 980-nm laser-evoked potentials (LEPs) experiments, a five-layer finite element model (FEM-5) was constructed based on Pennes bio-heat conduction equation and the Lambert-Beer law. The prediction results of the FEM-5 model were verified by ex vivo pig skin and in vivo rat experiments. Thirty ex vivo pig skin samples were used to verify the temperature distribution predicted by the model. The output energy of the laser was 1.8, 3, and 4.4 J. The laser spot radius was 1 mm. The experiment time was 30 s. The laser stimulated the surface of the ex vivo pig skin beginning at 10 s and lasted for 40 ms. A thermocouple thermometer was used to measure the temperature of the surface and internal layers of the ex vivo pig skin, and the sampling frequency was set to 60 Hz. For the in vivo experiments, nine adult male Wistar rats weighing 180 ± 10 g were used to verify the prediction results of the model by tail-flick latency. The output energy of the laser was 1.4 and 2.08 J. The pulsed width was 40 ms. The laser spot radius was 1 mm. The Pearson product-moment correlation and Kruskal-Wallis test were used to analyze the correlation and the difference of data. The results of all experiments showed that the measured and predicted data had no significant difference (P > 0.05) and good correlation (r > 0.9). The safe laser output energy range (1.8-3 J) was also predicted. Using the FEM-5 model prediction, the effective pain depth could be accurately controlled, and the nociceptors could be selectively activated. The FEM-5 model can be extended to guide experimental research and clinical applications for humans.
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Affiliation(s)
- Han Wang
- Institute of Biomedical Engineering, Laboratory of Laser Medicine, Chinese Academy of Medical Science & Peking Union Medical College, No.236, Baidi Road, Tianjin, 300192, China
| | - Xiao-Xi Dong
- Institute of Biomedical Engineering, Laboratory of Laser Medicine, Chinese Academy of Medical Science & Peking Union Medical College, No.236, Baidi Road, Tianjin, 300192, China
| | - Ji-Chun Yang
- Institute of Biomedical Engineering, Laboratory of Laser Medicine, Chinese Academy of Medical Science & Peking Union Medical College, No.236, Baidi Road, Tianjin, 300192, China
| | - He Huang
- Institute of Biomedical Engineering, Laboratory of Laser Medicine, Chinese Academy of Medical Science & Peking Union Medical College, No.236, Baidi Road, Tianjin, 300192, China
| | - Ying-Xin Li
- Institute of Biomedical Engineering, Laboratory of Laser Medicine, Chinese Academy of Medical Science & Peking Union Medical College, No.236, Baidi Road, Tianjin, 300192, China. .,Tianjin Key Laboratory of Laser Medicine, Institute of Biomedical Engineering, Chinese Academy of Medical Science & Peking Union Medical College, No.236, Baidi Road, Tianjin, 300192, China.
| | - Hai-Xia Zhang
- Biomedical Engineering and Technology College, Tianjin Medical University, Tianjin, 300070, China
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Hu XM, He L, Zhao Y. Dynamic model of vascular-targeted photodynamic therapy. Comput Methods Biomech Biomed Engin 2017; 20:1056-1065. [PMID: 28521517 DOI: 10.1080/10255842.2017.1331344] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Vascular-targeted photodynamic therapy has shown efficiency in treating port wine stains. A dynamic model that incorporates blood flow, kinetic diffusion, oxygen and photosensitizer consumption and reaction, and light modulation is proposed to reveal the interactions among light, photosensitizer, and oxygen. Simulation results show that pulse light modulation synchronized with heartbeats hold the advantage of increased singlet oxygen accumulation, higher oxygen concentration and lower temperature. Meanwhile, constant light treatment is advantageous in terms of higher temperature, lower total oxygen concentration and singlet oxygen accumulation. Therefore, the optimized treatment protocol may involve a balance among the phototoxicity, hypoxia, and photothermolysis.
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Affiliation(s)
- Xiao-Ming Hu
- a Key Laboratory of Convergence Medical Engineering System and Healthcare Technology, the Ministry of Industry and Information Technology, School of Life Science , Beijing Institute of Technology , Beijing , China
| | - Linhuan He
- a Key Laboratory of Convergence Medical Engineering System and Healthcare Technology, the Ministry of Industry and Information Technology, School of Life Science , Beijing Institute of Technology , Beijing , China
| | - Yi Zhao
- b Department of Dermatology , Beijing Tsinghua Changgung Hospital, Medical Center, Tsinghua University , Beijing , China
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Oakley E, Bellnier DA, Hutson A, Wrazen B, Arshad H, Quon H, Shafirstein G. Surface markers for guiding cylindrical diffuser fiber insertion in interstitial photodynamic therapy of head and neck cancer. Lasers Surg Med 2017; 49:599-608. [PMID: 28185275 DOI: 10.1002/lsm.22644] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2017] [Indexed: 11/09/2022]
Abstract
BACKGROUND AND OBJECTIVES Image-based treatment planning can be used to compute the delivered light dose during interstitial photodynamic therapy (I-PDT) of locally advanced head and neck squamous cell carcinoma (LA-HNSCC). The objectives of this work were to evaluate the use of surface fiducial markers and flexible adhesive grids in guiding interstitial placement of laser fibers, and to quantify the impact of discrepancies in fiber location on the expected light dose volume histograms (DVHs). METHODS Seven gel-based phantoms were made to mimic geometries of LA-HNSCC. Clinical flexible grids and fiducial markers were used to guide the insertion of optically transparent catheters, which are used to place cylindrical diffuser fibers within the phantoms. A computed tomography (CT) was used to image the markers and phantoms before and after catheter insertion and to determine the difference between the planned and actual location of the catheters. A finite element method was utilized to compute the light DVHs. Statistical analysis was employed to evaluate the accuracy of fiber placement and to investigate the correlation between the location of the fibers and the calculated DVHs. RESULTS There was a statistically significant difference (P = 0.018) between all seven phantoms in terms of the mean displacement. There was also statistically significant correlation between DVHs and depth of insertion (P = 0.0027), but not with the lateral displacement (P = 0.3043). The maximum difference between actual and planned DVH was related to the number of fibers (P = 0.0025) and the treatment time. CONCLUSIONS Surface markers and a flexible grid can be used to assist in the administration of a prescribed DVH within 15% of the target dose provided that the treatment fibers are placed within 1.3 cm of the planned depth of insertion in anatomies mimicking LA-HNSCC. The results suggest that the number of cylindrical diffuser fibers and treatment time can impact the delivered DVHs. Lasers Surg. Med. 49:599-608, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Emily Oakley
- Photodynamic Therapy Center, Roswell Park Cancer Institute (RPCI), Buffalo, New York
| | - David A Bellnier
- Photodynamic Therapy Center, Roswell Park Cancer Institute (RPCI), Buffalo, New York.,Department of Cell Stress Biology, Roswell Park Cancer Institute (RPCI), Buffalo, New York
| | - Alan Hutson
- Department of Biostatistics and Bioinformatics, Roswell Park Cancer Institute (RPCI), Buffalo, New York
| | - Brian Wrazen
- Photodynamic Therapy Center, Roswell Park Cancer Institute (RPCI), Buffalo, New York
| | - Hassan Arshad
- Photodynamic Therapy Center, Roswell Park Cancer Institute (RPCI), Buffalo, New York.,Department of Head and Neck Surgery, Roswell Park Cancer Institute (RPCI), Buffalo, New York
| | - Harry Quon
- Department of Radiation Oncology and Molecular Radiation Sciences, Department of Otorhinolaryngology-Head and Neck Surgery, Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland
| | - Gal Shafirstein
- Photodynamic Therapy Center, Roswell Park Cancer Institute (RPCI), Buffalo, New York.,Department of Cell Stress Biology, Roswell Park Cancer Institute (RPCI), Buffalo, New York.,Department of Head and Neck Surgery, Roswell Park Cancer Institute (RPCI), Buffalo, New York
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Shafirstein G, Bellnier D, Oakley E, Hamilton S, Potasek M, Beeson K, Parilov E. Interstitial Photodynamic Therapy-A Focused Review. Cancers (Basel) 2017; 9:cancers9020012. [PMID: 28125024 PMCID: PMC5332935 DOI: 10.3390/cancers9020012] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 01/13/2017] [Accepted: 01/20/2017] [Indexed: 01/07/2023] Open
Abstract
Multiple clinical studies have shown that interstitial photodynamic therapy (I-PDT) is a promising modality in the treatment of locally-advanced cancerous tumors. However, the utilization of I-PDT has been limited to several centers. The objective of this focused review is to highlight the different approaches employed to administer I-PDT with photosensitizers that are either approved or in clinical studies for the treatment of prostate cancer, pancreatic cancer, head and neck cancer, and brain cancer. Our review suggests that I-PDT is a promising treatment in patients with large-volume or thick tumors. Image-based treatment planning and real-time dosimetry are required to optimize and further advance the utilization of I-PDT. In addition, pre- and post-imaging using computed tomography (CT) with contrast may be utilized to assess the response.
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Affiliation(s)
- Gal Shafirstein
- Photodynamic Therapy Center, Department of Cell Stress Biology, Roswell Park Cancer Institute (RPCI), Elm & Carlton Streets, Buffalo, NY 14263, USA.
| | - David Bellnier
- Photodynamic Therapy Center, Department of Cell Stress Biology, Roswell Park Cancer Institute (RPCI), Elm & Carlton Streets, Buffalo, NY 14263, USA.
| | - Emily Oakley
- Photodynamic Therapy Center, Department of Cell Stress Biology, Roswell Park Cancer Institute (RPCI), Elm & Carlton Streets, Buffalo, NY 14263, USA.
| | - Sasheen Hamilton
- Photodynamic Therapy Center, Department of Cell Stress Biology, Roswell Park Cancer Institute (RPCI), Elm & Carlton Streets, Buffalo, NY 14263, USA.
| | - Mary Potasek
- Simphotek, Inc., 211 Warren St, Newark, NJ 07103, USA.
| | - Karl Beeson
- Simphotek, Inc., 211 Warren St, Newark, NJ 07103, USA.
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Choi B, Tan W, Jia W, White SM, Moy WJ, Yang BY, Zhu J, Chen Z, Kelly KM, Nelson JS. The Role of Laser Speckle Imaging in Port-Wine Stain Research: Recent Advances and Opportunities. IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS : A PUBLICATION OF THE IEEE LASERS AND ELECTRO-OPTICS SOCIETY 2016; 2016:6800812. [PMID: 27013846 PMCID: PMC4800318 DOI: 10.1109/jstqe.2015.2493961] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Here, we review our current knowledge on the etiology and treatment of port-wine stain (PWS) birthmarks. Current treatment options have significant limitations in terms of efficacy. With the combination of 1) a suitable preclinical microvascular model, 2) laser speckle imaging (LSI) to evaluate blood-flow dynamics, and 3) a longitudinal experimental design, rapid preclinical assessment of new phototherapies can be translated from the lab to the clinic. The combination of photodynamic therapy (PDT) and pulsed-dye laser (PDL) irradiation achieves a synergistic effect that reduces the required radiant exposures of the individual phototherapies to achieve persistent vascular shutdown. PDL combined with anti-angiogenic agents is a promising strategy to achieve persistent vascular shutdown by preventing reformation and reperfusion of photocoagulated blood vessels. Integration of LSI into the clinical workflow may lead to surgical image guidance that maximizes acute photocoagulation, is expected to improve PWS therapeutic outcome. Continued integration of noninvasive optical imaging technologies and biochemical analysis collectively are expected to lead to more robust treatment strategies.
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Affiliation(s)
- Bernard Choi
- Departments of Biomedical Engineering and Surgery, the Beckman Laser Institute and Medical Clinic, and the Edwards Lifesciences Center for Advanced Cardiovascular Technology, all at University of California, Irvine 92612 USA
| | - Wenbin Tan
- Beckman Laser Institute and Medical Clinic, University of California, Irvine 92612 USA
| | - Wangcun Jia
- Beckman Laser Institute and Medical Clinic, University of California, Irvine 92612 USA
| | - Sean M. White
- Beckman Laser Institute and Medical Clinic, University of California, Irvine 92612 USA
| | - Wesley J. Moy
- Beckman Laser Institute and Medical Clinic, University of California, Irvine 92612 USA
| | - Bruce Y. Yang
- Beckman Laser Institute and Medical Clinic, University of California, Irvine 92612 USA
| | | | | | - Kristen M. Kelly
- Department of Dermatology and the Beckman Laser Institute and Medical Clinic, all at University of California, Irvine 92612 USA
| | - J. Stuart Nelson
- Departments of Biomedical Engineering and Surgery and the Beckman Laser Institute and Medical Clinic, all at University of California, Irvine 92612 USA
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Erkol H, Nouizi F, Luk A, Unlu MB, Gulsen G. Comprehensive analytical model for CW laser induced heat in turbid media. OPTICS EXPRESS 2015; 23:31069-31084. [PMID: 26698736 PMCID: PMC4692257 DOI: 10.1364/oe.23.031069] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 10/07/2015] [Accepted: 10/10/2015] [Indexed: 05/29/2023]
Abstract
In this work, we present a new analytical approach to model continuous wave laser induced temperature in highly homogeneous turbid media. First, the diffusion equation is used to model light transport and a comprehensive solution is derived analytically by obtaining a special Greens' function. Next, the time-dependent bio-heat equation is used to describe the induced heat increase and propagation within the medium. The bio-heat equation is solved analytically utilizing the separation of variables technique. Our theoretical model is successfully validated using numerical simulations and experimental studies with agarose phantoms and ex-vivo chicken breast samples. The encouraging results show that our method can be implemented as a simulation tool to determine important laser parameters that govern the magnitude of temperature rise within homogenous biological tissue or organs.
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Affiliation(s)
- Hakan Erkol
- Center for Functional Onco Imaging, Department of Radiological Sciences, University of California, Irvine, CA,
USA
| | - Farouk Nouizi
- Center for Functional Onco Imaging, Department of Radiological Sciences, University of California, Irvine, CA,
USA
| | - Alex Luk
- Center for Functional Onco Imaging, Department of Radiological Sciences, University of California, Irvine, CA,
USA
| | - Mehmet Burcin Unlu
- Department of Physics, Bogazici University, Bebek, 34342, Istanbul,
Turkey
| | - Gultekin Gulsen
- Center for Functional Onco Imaging, Department of Radiological Sciences, University of California, Irvine, CA,
USA
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15
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Abstract
Port-wine stains are a type of capillary malformation affecting 0.3% to 0.5% of the population. Port-wine stains present at birth as pink to erythematous patches on the skin and/or mucosa. Without treatment, the patches typically darken with age and may eventually develop nodular thickening or associated pyogenic granuloma. Laser and light treatments provide improvement through selective destruction of vasculature. A variety of vascular-selective lasers may be employed, with the pulsed dye laser being the most common and well studied. Early treatment produces more optimal results. Advances in imaging and laser treatment technologies demonstrate potential to further improve clinical outcomes.
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Affiliation(s)
| | - Roy G Geronemus
- Laser and Skin Surgery Center of New York, New York, NY, USA
| | - Kavitha K Reddy
- Department of Dermatology, Boston University School of Medicine, Boston, MA, USA
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16
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Oakley E, Wrazen B, Bellnier DA, Syed Y, Arshad H, Shafirstein G. A new finite element approach for near real-time simulation of light propagation in locally advanced head and neck tumors. Lasers Surg Med 2015; 47:60-7. [PMID: 25559426 PMCID: PMC4304874 DOI: 10.1002/lsm.22313] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/23/2014] [Indexed: 12/21/2022]
Abstract
Background and Objectives Several clinical studies suggest that interstitial photodynamic therapy (I‐PDT) may benefit patients with locally advanced head and neck cancer (LAHNC). For I‐PDT, the therapeutic light is delivered through optical fibers inserted into the target tumor. The complex anatomy of the head and neck requires careful planning of fiber insertions. Often the fibers' location and tumor optical properties may vary from the original plan therefore pretreatment planning needs near real‐time updating to account for any changes. The purpose of this work was to develop a finite element analysis (FEA) approach for near real‐time simulation of light propagation in LAHNC. Methods Our previously developed FEA for modeling light propagation in skin tissue was modified to simulate light propagation from interstitial optical fibers. The modified model was validated by comparing the calculations with measurements in a phantom mimicking tumor optical properties. We investigated the impact of mesh element size and growth rate on the computation time, and defined optimal settings for the FEA. We demonstrated how the optimized FEA can be used for simulating light propagation in two cases of LAHNC amenable to I‐PDT, as proof‐of‐concept. Results The modified FEA was in agreement with the measurements (P = 0.0271). The optimal maximum mesh size and growth rate were 0.005–0.02 m and 2–2.5 m/m, respectively. Using these settings the computation time for simulating light propagation in LAHNC was reduced from 25.9 to 3.7 minutes in one case, and 10.1 to 4 minutes in another case. There were minor differences (1.62%, 1.13%) between the radiant exposures calculated with either mesh in both cases. Conclusions Our FEA approach can be used to model light propagation from diffused optical fibers in complex heterogeneous geometries representing LAHNC. There is a range of maximum element size (MES) and maximum element growth rate (MEGR) that can be used to minimize the computation time of the FEA to 4 minutes. Lasers Surg. Med. 47:60–67, 2015. © 2015 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.
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Affiliation(s)
- Emily Oakley
- Photodynamic Therapy Center, Roswell Park Cancer Institute, Buffalo, New York
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17
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Savas JA, Ledon JA, Franca K, Chacon A, Nouri K. Pulsed dye laser-resistant port-wine stains: mechanisms of resistance and implications for treatment. Br J Dermatol 2013; 168:941-53. [PMID: 23290045 DOI: 10.1111/bjd.12204] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Port-wine stains (PWS) are among the most common congenital vascular malformations. Unlike capillary haemangiomas, these lesions do not involute spontaneously but rather become progressively more disfiguring as the patient ages. While benign in nature, the cosmetic deformity and attendant psychological and emotional distress prompt the majority of those afflicted to seek treatment. The pulsed dye laser (PDL) has long been considered the treatment of choice for these vascular lesions; however, very few patients achieve total clearance with PDL therapy and a significant number of lesions fail to respond at all. In order to address these recalcitrant cases, the mechanisms that contribute to treatment resistance must be understood and novel laser and light therapies must be employed. This review will address what is currently known about lesion-specific characteristics of PDL-resistant PWS as well as discuss current and future treatment options.
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Affiliation(s)
- J A Savas
- Department of Dermatology and Cutaneous Surgery, University of Miami Leonard M. Miller School of Medicine, Miami, FL 33136, USA.
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18
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Estimation of saline-mixed tissue conductivity and ablation lesion size. Comput Biol Med 2013; 43:504-12. [DOI: 10.1016/j.compbiomed.2013.02.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Revised: 12/13/2012] [Accepted: 02/18/2013] [Indexed: 12/27/2022]
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19
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Fuentes D, Elliott A, Weinberg JS, Shetty A, Hazle JD, Stafford RJ. An inverse problem approach to recovery of in vivo nanoparticle concentrations from thermal image monitoring of MR-guided laser induced thermal therapy. Ann Biomed Eng 2012; 41:100-11. [PMID: 22918665 DOI: 10.1007/s10439-012-0638-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 08/04/2012] [Indexed: 12/15/2022]
Abstract
Quantification of local variations in the optical properties of tumor tissue introduced by the presence of gold-silica nanoparticles (NP) presents significant opportunities in monitoring and control of NP-mediated laser induced thermal therapy (LITT) procedures. Finite element methods of inverse parameter recovery constrained by a Pennes bioheat transfer model were applied to estimate the optical parameters. Magnetic resonance temperature imaging (MRTI) acquired during a NP-mediated LITT of a canine transmissible venereal tumor in brain was used in the presented statistical inverse problem formulation. The maximum likelihood (ML) value of the optical parameters illustrated a marked change in the periphery of the tumor corresponding with the expected location of NP and area of selective heating observed on MRTI. Parameter recovery information became increasingly difficult to infer in distal regions of tissue where photon fluence had been significantly attenuated. Finite element temperature predictions using the ML parameter values obtained from the solution of the inverse problem are able to reproduce the NP selective heating within 5 °C of measured MRTI estimations along selected temperature profiles. Results indicate the ML solution found is able to sufficiently reproduce the selectivity of the NP mediated laser induced heating and therefore the ML solution is likely to return useful optical parameters within the region of significant laser fluence.
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Affiliation(s)
- D Fuentes
- Department of Imaging Physics, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA.
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20
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Klein A, Szeimies RM, Bäumler W, Zeman F, Schreml S, Hohenleutner U, Landthaler M, Koller M, Babilas P. Indocyanine green-augmented diode laser treatment of port-wine stains: clinical and histological evidence for a new treatment option from a randomized controlled trial. Br J Dermatol 2012; 167:333-42. [PMID: 22435991 DOI: 10.1111/j.1365-2133.2012.10950.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Complete clearance of port-wine stains (PWS) is difficult to achieve, mainly because of the resistance of small blood vessels to laser irradiation. Indocyanine green (ICG)-augmented diode laser treatment (ICG+DL) may overcome this problem. OBJECTIVES To evaluate the feasibility of ICG+DL therapy of PWS and to compare the safety and efficacy of ICG+DL with the standard treatment, flashlamp-pumped pulsed dye laser (FPDL). METHODS In a prospective randomized controlled clinical study, 31 patients with PWS were treated with FPDL (λ(em)=585 nm, 6 J cm(-2) , 0.45 ms pulse duration) and ICG+DL (λ(em)=810 nm, 20-50 J cm(-2) , 10-25 ms pulse duration, ICG-concentration: 2 mg kg(-1) body weight) in a split-face modus in one single treatment setting that included histological examination (haematoxylin and eosin, CD34). Two blinded investigators and the patients assessed clearance rate, cosmetic appearance and side-effects up to 3 months after treatment. RESULTS ICG+DL therapy induced photocoagulation of medium and large blood vessels (>20 μm diameter) but not of small blood vessels. According to the investigators' assessment, clearance rates and cosmetic appearance were better after ICG+DL therapy than after FPDL treatment (P=0.114, P=0.291, respectively), although not up to a statistically significant level, whereas patients considered these parameters superior (P=0.003, P=0.006, respectively). On a 10-point scale indicating pain during treatment, patients rated ICG+DL to be more painful (5.81 ± 2.12) than FPDL treatment (1.61 ± 1.84). CONCLUSION ICG+DL represents a new and promising treatment modality for PWS, but laser parameters and ICG concentration need to be further optimized.
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Affiliation(s)
- A Klein
- Department of Dermatology, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany
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Milanic M, Majaron B. Three-dimensional Monte Carlo model of pulsed-laser treatment of cutaneous vascular lesions. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:128002. [PMID: 22191938 DOI: 10.1117/1.3659205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We present a three-dimensional Monte Carlo model of optical transport in skin with a novel approach to treatment of side boundaries of the volume of interest. This represents an effective way to overcome the inherent limitations of "escape" and "mirror" boundary conditions and enables high-resolution modeling of skin inclusions with complex geometries and arbitrary irradiation patterns. The optical model correctly reproduces measured values of diffuse reflectance for normal skin. When coupled with a sophisticated model of thermal transport and tissue coagulation kinetics, it also reproduces realistic values of radiant exposure thresholds for epidermal injury and for photocoagulation of port wine stain blood vessels in various skin phototypes, with or without application of cryogen spray cooling.
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Affiliation(s)
- Matija Milanic
- Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia.
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22
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Shafirstein G, Moreno M, Klein A, Siegel E, Babilas P, Landthaler M, Baeumler W. Treatment of leg veins with indocyanine green and lasers investigated with mathematical modelling. Int J Hyperthermia 2011; 27:771-81. [DOI: 10.3109/02656736.2011.602037] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Chang HS, Kim YG, Lee JH. Treatment using a long pulsed nd:yag laser with a pulsed dye laser for four cases of blebbed port wine stains. Ann Dermatol 2011; 23 Suppl 1:S75-8. [PMID: 22028579 PMCID: PMC3199429 DOI: 10.5021/ad.2011.23.s1.s75] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Revised: 10/04/2010] [Accepted: 10/04/2010] [Indexed: 11/26/2022] Open
Abstract
Port wine stains (PWS) are congenital capillary malformations consisting of ectasia of capillaries and venules. At birth,lesions are flat and relatively uniform in color, but evolve with age to become raised, thickened, irregularly surfaced, and deeply colored. Therefore, it is considered optimal to begin treatment of patients at an early age. Conventional treatment modalities, such as electrocautery or excision, require considerable effort and may be cosmetically unsatisfactory. We have performed treatment of blebbed PWS of four patients using a 1,064 nm long pulsed Nd:YAG laser with a contact cooling device. According to their size, most blebs required three or fewer treatment sessions at 8-week intervals. Treatments were well tolerated by all subjects and patients showed moderate to good improvement of blebs. A 1,064 nm long pulsed Nd:YAG laser with contact cooling may be considered as a promising therapeutic option for treatment of blebbed PWS.
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Affiliation(s)
- Hee Sun Chang
- Department of Dermatology, Eulji Hospital, College of Medicine, Eulji University, Seoul, Korea
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Milanič M, Jia W, Nelson JS, Majaron B. Numerical optimization of sequential cryogen spray cooling and laser irradiation for improved therapy of port wine stain. Lasers Surg Med 2011; 43:164-75. [PMID: 21384397 DOI: 10.1002/lsm.21040] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND AND OBJECTIVE Despite application of cryogen spray (CS) precooling, customary treatment of port wine stain (PWS) birthmarks with a single laser pulse does not result in complete lesion blanching for a majority of patients. One obvious reason is nonselective absorption by epidermal melanin, which limits the maximal safe radiant exposure. Another possible reason for treatment failure is screening of laser light within large PWS vessels, which prevents uniform heating of the entire vessel lumen. Our aim is to identify the parameters of sequential CS cooling and laser irradiation that will allow optimal photocoagulation of various PWS blood vessels with minimal risk of epidermal thermal damage. STUDY DESIGN AND METHODS Light and heat transport in laser treatment of PWS are simulated using a custom 3D Monte Carlo model and 2D finite element method, respectively. Protein denaturation in blood and skin are calculated using the Arrhenius kinetic model with tissue-specific coefficients. Simulated PWS vessels with diameters of 30-150 µm are located at depths of 200-600 µm, and shading by nearby vessels is accounted for according to PWS histology data from the literature. For moderately pigmented and dark skin phototypes, PWS blood vessel coagulation and epidermal thermal damage are assessed for various parameters of sequential CS cooling and 532-nm laser irradiation, i.e. the number of pulses in a sequence (1-5), repetition rate (7-30 Hz), and radiant exposure. RESULTS Simulations of PWS treatment in darker skin phototypes indicate specific cooling/irradiation sequences that provide significantly higher efficacy and safety as compared to the customary single-pulse approach across a wide range of PWS blood vessel diameters and depths. The optimal sequences involve three to five laser pulses at repetition rates of 10-15 Hz. CONCLUSIONS Application of the identified cooling/irradiation sequences may offer improved therapeutic outcome for patients with resistant PWS, especially in darker skin phototypes.
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Affiliation(s)
- Matija Milanič
- Jožef Stefan Institute, Jamova 39, SI 1000 Ljubljana, Slovenia.
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25
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A photothermal model of selective photothermolysis with dynamically changing vaporization temperature. Lasers Med Sci 2011; 26:633-40. [DOI: 10.1007/s10103-011-0949-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2010] [Accepted: 06/13/2011] [Indexed: 10/18/2022]
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26
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Klein A, Bäumler W, Landthaler M, Babilas P. Laser and IPL treatment of port-wine stains: therapy options, limitations, and practical aspects. Lasers Med Sci 2011; 26:845-59. [DOI: 10.1007/s10103-011-0903-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Accepted: 02/14/2011] [Indexed: 10/18/2022]
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Shafirstein G, Moros EG. Modelling millimetre wave propagation and absorption in a high resolution skin model: the effect of sweat glands. Phys Med Biol 2011; 56:1329-39. [DOI: 10.1088/0031-9155/56/5/007] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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28
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FUENTES D, WALKER C, ELLIOTT A, SHETTY A, HAZLE J, STAFFORD R. Magnetic resonance temperature imaging validation of a bioheat transfer model for laser-induced thermal therapy. Int J Hyperthermia 2011; 27:453-64. [PMID: 21756043 PMCID: PMC3930085 DOI: 10.3109/02656736.2011.557028] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
PURPOSE Magnetic resonance-guided laser-induced thermal therapy (MRgLITT) is currently undergoing initial safety and feasibility clinical studies for the treatment of intracranial lesions in humans. As studies progress towards evaluation of treatment efficacy, predictive computational models may play an important role for prospective 3D treatment planning. The current work critically evaluates a computational model of laser induced bioheat transfer against retrospective multiplanar MR thermal imaging (MRTI) in a canine model of the MRgLITT procedure in the brain. METHODS A 3D finite element model of the bioheat transfer that couples Pennes equation to a diffusion theory approximation of light transport in tissue is used. The laser source is modelled conformal with the applicator geometry. Dirichlet boundary conditions are used to model the temperature of the actively cooled catheter. The MRgLITT procedure was performed on n = 4 canines using a 1-cm diffusing tip 15-W diode laser (980 nm). A weighted L₂norm is used as the metric of comparison between the spatiotemporal MR-derived temperature estimates and model prediction. RESULTS The normalised error history between the computational models and MRTI was within 1-4 standard deviations of MRTI noise. Active cooling models indicate that the applicator temperature has a strong effect on the maximum temperature reached, but does not significantly decrease the tissue temperature away from the active tip. CONCLUSIONS Results demonstrate the computational model of the bioheat transfer may provide a reasonable approximation of the laser-tissue interaction, which could be useful for treatment planning, but cannot readily replace MR temperature imaging in a complex environment such as the brain.
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Affiliation(s)
- D. FUENTES
- Department of Imaging Physics, M.D. Anderson Cancer Center, University of Texas, Houston
| | - C. WALKER
- Department of Imaging Physics, M.D. Anderson Cancer Center, University of Texas, Houston
| | - A. ELLIOTT
- Department of Imaging Physics, M.D. Anderson Cancer Center, University of Texas, Houston
| | | | - J.D. HAZLE
- Department of Imaging Physics, M.D. Anderson Cancer Center, University of Texas, Houston
| | - R.J. STAFFORD
- Department of Imaging Physics, M.D. Anderson Cancer Center, University of Texas, Houston
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Feng Y, Fuentes D. Model-based planning and real-time predictive control for laser-induced thermal therapy. Int J Hyperthermia 2011; 27:751-61. [PMID: 22098360 PMCID: PMC3930104 DOI: 10.3109/02656736.2011.611962] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In this article, the major idea and mathematical aspects of model-based planning and real-time predictive control for laser-induced thermal therapy (LITT) are presented. In particular, a computational framework and its major components developed by authors in recent years are reviewed. The framework provides the backbone for not only treatment planning but also real-time surgical monitoring and control with a focus on MR thermometry enabled predictive control and applications to image-guided LITT, or MRgLITT. Although this computational framework is designed for LITT in treating prostate cancer, it is further applicable to other thermal therapies in focal lesions induced by radio-frequency (RF), microwave and high-intensity-focused ultrasound (HIFU). Moreover, the model-based dynamic closed-loop predictive control algorithms in the framework, facilitated by the coupling of mathematical modelling and computer simulation with real-time imaging feedback, has great potential to enable a novel methodology in thermal medicine. Such technology could dramatically increase treatment efficacy and reduce morbidity.
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Affiliation(s)
- Yusheng Feng
- Computational Bioengineering and Control Lab, The University of Texas at San Antonio, USA.
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30
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Shafirstein G, Kaufmann Y, Hennings L, Siegel E, Griffin RJ, Novák P, Ferguson S, Moros EG. Conductive interstitial thermal therapy (CITT) inhibits recurrence and metastasis in rabbit VX2 carcinoma model. Int J Hyperthermia 2010; 25:446-54. [PMID: 19657851 DOI: 10.1080/02656730903013618] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
PURPOSE To investigate the potential of conductive interstitial thermal therapy (CITT) to inhibit recurrence and metastasis in a partially resected tumour model. METHOD Fifteen New Zealand white rabbits were implanted with VX2 tumour intramuscularly in the rear thigh. Once the tumour size reached 20-25 mm in diameter, three animals were randomly selected to serve as controls, while the remaining animals were designated as the study group and treated with CITT. In the CITT group, the partially resected tumour and margins were thermally ablated. In the control group the tumour was partially resected to simulate positive margins. The animals were monitored for up to 12 weeks. At the endpoint, the animals were sacrificed, and whole-body diagnostic necropsy was conducted immediately. RESULTS Recurrences and metastatic lesions were observed in iliac and popliteal lymph nodes and abdomens of all control animals. In contrast, the observed rate of recurrence and metastatic lesion was 0% among CITT-treated animals, significantly less than the >or=50% null-hypothesis rate expected upon treatment failure (exact binomial P = 0.0002). Complete histopathological healing was obtained in 2 of 12 rabbits, and residual inflammation remained at the ablation site up to 12 weeks post-ablation in 10 of 12 rabbits. This pattern of necrosis and inflammatory response was not observed in any of the control rabbits. CONCLUSIONS The CITT device effectively ablated partially resected VX2 carcinoma in a rabbit model, and inhibited recurrence and metastasis in this model. CITT evoked an inflammatory response that may be linked to the mechanism involved in reduced metastatic spread.
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Affiliation(s)
- Gal Shafirstein
- Department of Otolaryngology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA.
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31
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Abstract
Thermal tissue ablation is an interventional procedure increasingly being used for treatment of diverse medical conditions. Microwave ablation is emerging as an attractive modality for thermal therapy of large soft tissue targets in short periods of time, making it particularly suitable for ablation of hepatic and other tumors. Theoretical models of the ablation process are a powerful tool for predicting the temperature profile in tissue and resultant tissue damage created by ablation devices. These models play an important role in the design and optimization of devices for microwave tissue ablation. Furthermore, they are a useful tool for exploring and planning treatment delivery strategies. This review describes the status of theoretical models developed for microwave tissue ablation. It also reviews current challenges, research trends and progress towards development of accurate models for high temperature microwave tissue ablation.
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Prakash P. Theoretical modeling for hepatic microwave ablation. Open Biomed Eng J 2010; 4:27-38. [PMID: 20309393 PMCID: PMC2840585 DOI: 10.2174/1874120701004020027] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Revised: 11/29/2009] [Accepted: 12/30/2009] [Indexed: 01/08/2023] Open
Abstract
Thermal tissue ablation is an interventional procedure increasingly being used for treatment of diverse medical conditions. Microwave ablation is emerging as an attractive modality for thermal therapy of large soft tissue targets in short periods of time, making it particularly suitable for ablation of hepatic and other tumors. Theoretical models of the ablation process are a powerful tool for predicting the temperature profile in tissue and resultant tissue damage created by ablation devices. These models play an important role in the design and optimization of devices for microwave tissue ablation. Furthermore, they are a useful tool for exploring and planning treatment delivery strategies. This review describes the status of theoretical models developed for microwave tissue ablation. It also reviews current challenges, research trends and progress towards development of accurate models for high temperature microwave tissue ablation.
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Affiliation(s)
- Punit Prakash
- Department of Radiation Oncology, University of California, San Francisco, USA
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Cell-level temperature distributions in skeletal muscle post spinal cord injury as related to deep tissue injury. Med Biol Eng Comput 2009; 48:113-22. [PMID: 20039142 DOI: 10.1007/s11517-009-0566-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Accepted: 12/05/2009] [Indexed: 10/20/2022]
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34
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Shafirstein G, Novák P, Moros EG, Siegel E, Hennings L, Kaufmann Y, Ferguson S, Myhill J, Swaney M, Spring P. Conductive interstitial thermal therapy device for surgical margin ablation:In vivoverification of a theoretical model. Int J Hyperthermia 2009; 23:477-92. [PMID: 17852514 DOI: 10.1080/02656730701591476] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
PURPOSE To demonstrate the efficacy and predictability of a new conductive interstitial thermal therapy (CITT) device to ablate surgical margins. METHOD The temperature distributions during thermal ablation of CITT were calculated with finite element modelling in a geometrical representation of perfused tissue. The depth of ablation was derived using the Arrhenius and the Sapareto and Dewey (S&D) models for the temperature range of 90 to 150 degrees C. The female pig animal model was used to test the validity of the mathematical model. Breast tissues were ablated to temperatures in the range of 79-170 degrees C, in vivo. Triphenyltetrazolium chloride viability stain was used to delineate viable tissue from ablated regions and the ablation depths were measured using digital imaging. RESULTS The calculations suggest that the CITT can be used to ablate perfused tissues to a 10-15 mm width within 20 minutes. The measured and calculated depths of ablation were statistically equivalent (99% confidence intervals) within +/- 1mm at 170 degrees C. At lower temperatures the equivalence between the model and the observations was within +/- 2 mm. CONCLUSION The CITT device can reliably and uniformly ablate a 10-15 mm wide region of soft tissue. Thus, it can be used to secure negative margins following the resection of a primary tumor, which could impede local recurrences in the treatment of local diseases such as early staged, non-metastatic, breast cancer.
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Affiliation(s)
- Gal Shafirstein
- Department of Otolaryngology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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ALSTER TINAS, TANZI ELIZABETHL. Combined 595-nm and 1,064-nm Laser Irradiation of Recalcitrant and Hypertrophic Port-Wine Stains in Children and Adults. Dermatol Surg 2009; 35:914-8; discussion 918-9. [DOI: 10.1111/j.1524-4725.2009.01155.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Eivazi B, Ardelean M, Bäumler W, Berlien HP, Cremer H, Elluru R, Koltai P, Olofsson J, Richter G, Schick B, Werner JA. Update on hemangiomas and vascular malformations of the head and neck. Eur Arch Otorhinolaryngol 2008; 266:187-97. [PMID: 19052764 DOI: 10.1007/s00405-008-0875-6] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Accepted: 11/10/2008] [Indexed: 12/19/2022]
Abstract
Although the current classification systems of vascular malformations and hemangiomas are increasingly accepted, there are nonetheless several aspects that show us how special and at the same time difficult it is to diagnose, evaluate, and treat some of those diseases. Close interdisciplinary cooperation of all involved disciplines is essential; the discussion of the adequate individual procedure must be performed in angioma boards, as it is already well established in the context of tumor boards. The interface of angioma therapy and tumor therapy seems to be very close, which is certainly true for the aspect of angiogenesis and of course for the inhibited proliferation as promising therapeutic approach of complex vascular malformations. This leads to another obvious necessity of intensifying experimental scientific research on vascular malformations and hemangiomas, which is a precondition for optimizing or elimination of different current problems and deficits in the mentioned field.
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Affiliation(s)
- Behfar Eivazi
- Department of Otolaryngology, Head and Neck Surgery, Philipps University of Marburg, Deutschhausstr. 3, 35037 Marburg, Germany
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Elliott A, Schwartz J, Wang J, Shetty A, Hazle J, Stafford JR. Analytical solution to heat equation with magnetic resonance experimental verification for nanoshell enhanced thermal therapy. Lasers Surg Med 2008; 40:660-5. [DOI: 10.1002/lsm.20682] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Bernstein EF. Treatment of a resistant port-wine stain with a new variable pulse-duration pulsed-dye laser. J Cosmet Dermatol 2008; 7:139-42. [PMID: 18482019 DOI: 10.1111/j.1473-2165.2008.00378.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND OBJECTIVES Because of the heterogeneity in port-wine stains, a number of them prove resistant to treatment with the pulsed-dye laser (PDL). A new variable pulse-duration PDL improves a refractory port-wine stain. STUDY DESIGN/MATERIALS AND METHODS A 26-year-old man with a congenital port-wine stain underwent eight treatments with the 1.5-ms pulse-duration PDL resulting in minimal improvement. A single treatment was then administered with the 3-ms pulse-duration PDL. RESULTS Initial results of treatment with the 3-ms pulse-duration PDL on this patient's port-wine stain show dramatic clearance in areas previously treated with significantly higher fluences, an identical spot size, but with a pulse duration half as long. CONCLUSION Vessel heterogeneity may require changing pulse durations once a port-wine stain or a portion of a port-wine stain becomes refractory to given pulse-duration.
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Affiliation(s)
- Eric F Bernstein
- Laser Surgery and Cosmetic Dermatology Centers, Bryn Mawr, PA, USA.
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Werner A, Bäumler W, Zietz S, Kühnel T, Hohenleutner U, Landthaler M. Hereditary haemorrhagic telangiectasia treated by pulsed neodymium:yttrium-aluminium-garnet (Nd:YAG) laser (1,064 nm). Lasers Med Sci 2007; 23:385-91. [DOI: 10.1007/s10103-007-0512-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Accepted: 10/02/2007] [Indexed: 10/22/2022]
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Shafirstein G, Hennings L, Kaufmann Y, Novak P, Moros EG, Ferguson S, Siegel E, Klimberg SV, Waner M, Spring P. Conductive interstitial thermal therapy (CITT) device evaluation in VX2 rabbit model. Technol Cancer Res Treat 2007; 6:235-46. [PMID: 17535032 DOI: 10.1177/153303460700600311] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
We have developed a conductive interstitial thermal therapy (CITT) device to precisely and reliably deliver controlled thermal doses to the surgical margins at the cavity site following tumor resection, intraoperatively. The temperature field created by CITT ablation of a perfused tissue was modeled with a finite element package Femlab. The modeling suggested that a maximum probe temperature of 120 degrees C and an ablation time of 20 minutes were required to ablate highly perfused tissue such as the VX2 carcinoma. Deployable pins enable faster and more reliable thermal ablation. The model predictions were tested by thermal ablation of VX2 carcinoma tumors implanted in adult New Zealand rabbits. The size of the ablated region was confirmed with a viability stain, triphenyltetrazolium chloride (TTC). Histopathological examination revealed 3 regions in the ablated area: a carbonized region (1-3 mm); a region that contained thermally fixed cells; and an area of coagulated necrosis cells. Cells in the thermally fixed region stained for PCNA (proliferating cell nuclear antigen) and were bounded by the carbonized layer at the cavity wall, and by necrotic cells that exhibit nuclear fragmentation and cell dissociation, 5 to 10 mm away from the CITT probe. Adjacent tissue outside the target region was spared with a clear demarcation between ablated and normal viable tissue. It is suggested that the CITT device can be used, clinically, to inhibit local recurrence by creating negative surgical margins following the resection of a primary tumor in non-metastatic early staged tumors.
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Affiliation(s)
- Gal Shafirstein
- Dept. of Otolaryngology, Univ. of Arkansas, Medical Sciences, 4301 West Markham, Little Rock, AR, USA.
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41
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Vural E, Winfield HL, Shingleton AW, Horn TD, Shafirstein G. The effects of laser irradiation on Trichophyton rubrum growth. Lasers Med Sci 2007; 23:349-53. [PMID: 17902014 DOI: 10.1007/s10103-007-0492-4] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2007] [Accepted: 08/08/2007] [Indexed: 10/22/2022]
Abstract
The effects of various laser wavelengths and fluences on the fungal isolate, Trichophyton rubrum, were examined in vitro. Standard-size isolates of T. rubrum were irradiated by using various laser systems. Colony areas were compared for growth inhibition on days 1, 3, and 6 after laser irradiation. Statistically significant growth inhibition of T. rubrum was detected in colonies treated with the 1,064-nm Q-switched Nd:YAG laser at 4 and 8 J/cm(2) and 532-nm Q-switched Nd:YAG laser at 8 J/cm(2). Q-switched Nd:YAG laser at 532- and 1,064-nm wavelengths produced significant inhibitory effect upon the fungal isolate T. rubrum in this in vitro study. However, more in vitro and in vivo studies are necessary to investigate if lasers would have a potential use in the treatment of fungal infections of skin and its adnexa.
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Affiliation(s)
- Emre Vural
- Department of Otolaryngology-Head and Neck Surgery, University of Arkansas for Medical Sciences, 4301 West Markham, Slot 543, Little Rock, AR 72205, USA.
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Jasim ZF, Handley JM. Treatment of pulsed dye laser-resistant port wine stain birthmarks. J Am Acad Dermatol 2007; 57:677-82. [PMID: 17658196 DOI: 10.1016/j.jaad.2007.01.019] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2006] [Revised: 12/17/2006] [Accepted: 01/09/2007] [Indexed: 12/12/2022]
Abstract
The concept of selective photothermolysis with the 577-/585-nm pulsed dye laser (PDL) revolutionized treatment of relatively common port wine stain (PWS) birthmarks. The majority of PWS can be significantly lightened with the PDL. However, few PWS are lightened completely with PDL and up to 20% hardly lighten at all. PDL-resistant PWS exist in any large cutaneous laser practice and constitute a difficult management problem. This article discusses the proposed cause, and currently available and emerging options for PDL-resistant PWS. These include higher power, longer wavelength, variable pulse width lasers with selective epidermal cooling such as 595-nm PDL, 755-nm alexandrite, 810-nm diode, 1064-nm neodymium:yttrium-aluminum-garnet, and intense pulse light systems. Other promising modalities include topical and systemic photodynamic therapy, electrical optical synergy technology, pulse stacking of similar or differing wavelengths, use of optical clearing agents in conjunction with laser, and erbium laser epidermal stripping before laser treatment.
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Affiliation(s)
- Zaid F Jasim
- Royal Victoria Hospitals, Belfast, United Kingdom.
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Babilas P, Shafirstein G, Baier J, Schacht V, Szeimies RM, Landthaler M, Bäumler W, Abels C. Photothermolysis of blood vessels using indocyanine green and pulsed diode laser irradiation in the dorsal skinfold chamber model. Lasers Surg Med 2007; 39:341-52. [PMID: 17457841 DOI: 10.1002/lsm.20483] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND AND OBJECTIVE For the treatment of vascular lesions, the use of laser light absorbed by the endogenous chromophore hemoglobin may still be improved. MATERIALS AND METHODS Laser treatment (lambda(em) = 805 nm; fluence rate: 106 kW/cm2; fluence: 3.2 J/cm2 (3 milliseconds)), of blood vessels directly after i.v. application of indocyanine green (ICG) (ICG-concentration: 0, 2, or 4 mg/kg body weight (b.w.)) (n = 14,117) was investigated in the skinfold chamber model. Vessel diameters (1-351 microm) were measured using intravital fluorescence microscopy up to 24 hours following irradiation. Histology was taken 1 or 24 hours after irradiation. Results were compared to a mathematical model based on the finite element method. RESULTS The reduction of blood vessel perfusion was proportional to ICG-concentration and pulse duration; only a 30 milliseconds pulse duration (2 or 4 mg/kg b.w. ICG-concentration) induced a loss of perfusion even of blood vessels with a diameter <30 microm. Histology revealed photocoagulation of blood vessels up to 24 hours. Results were in agreement with mathematical calculations. CONCLUSION ICG-mediated laser irradiation induces irreversible photocoagulation of blood vessels of all diameters in this model.
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Affiliation(s)
- Philipp Babilas
- Department of Dermatology, Regensburg University Medical Center, 93042 Regensburg, Germany.
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Mordon SR, Wassmer B, Zemmouri J. Mathematical modeling of 980-nm and 1320-nm endovenous laser treatment. Lasers Surg Med 2007; 39:256-65. [PMID: 17252577 DOI: 10.1002/lsm.20476] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND AND OBJECTIVES Endovenous laser treatment (ELT) has been proposed as an alternative in the treatment of reflux of the great saphenous vein (GSV) and small saphenous vein (SSV). Numerous studies have since demonstrated that this technique is both safe and efficacious. ELT was presented initially using diode lasers of 810 nm, 940 nm, and 980 nm. Recently, a 1,320-nm Nd:YAG laser was introduced for ELT. This study aims to provide mathematical modeling of ELT in order to compare 980 nm and 1,320 nm laser-induced damage of saphenous veins. STUDY DESIGN/MATERIALS AND METHODS The model is based on calculations describing light distribution using the diffusion approximation of the transport theory, the temperature rise using the bioheat equation, and the laser-induced injury using the Arrhenius damage model. The geometry to simulate ELT was based on a 2D model consisting of a cylindrically symmetric blood vessel including a vessel wall and surrounded by an infinite homogenous tissue. The mathematical model was implemented using the Macsyma-Pdease2D software (Macsyma, Inc., Arlington, MA). Calculations were performed so as to determine the damage induced in the intima tunica, the externa tunica and inside the peri-venous tissue for 3 mm and 5 mm vessels (considered after tumescent anesthesia) and different linear endovenous energy densities (LEED) usually reported in the literature. RESULTS Calculations were performed for two different vein diameters: 3 mm and 5 mm and with LEED typically reported in the literature. For 980 nm, LEED: 50 to 160 J/cm (CW mode, 2 mm/second pullback speed, power: 10 W to 32 W) and for 1,320 nm, LEED: 50 to 80 J/cm (pulsed mode, pulse duration 1.2 milliseconds, peak power: 135 W, repetition rate 30 Hz to 50 Hz). DISCUSSION AND CONCLUSION Numerical simulations are in agreement with LEED reported in clinical studies. Mathematical modeling shows clearly that 1,320 nm, with a better absorption by the vessel wall, requires less energy to achieve wall damage. In the 810-1,320-nm range, blood plays only a minor role. Consequently, the classification of these lasers into hemoglobin-specific laser wavelengths (810, 940, 980 nm) and water-specific laser wavelengths (1,320 nm) is inappropriate. In terms of closure rate, 980 nm and 1,320 nm can lead to similar results and, as reported by the literature, to similar side effects. This model should serve as a useful tool to simulate and better understand the mechanism of action of the ELT.
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Affiliation(s)
- Serge R Mordon
- INSERM (French National Institute of Health and Medical Research), Lille University Hospital, Lille, France.
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Bäumler W, Vural E, Landthaler M, Muzzi F, Shafirstein G. The effects of intense pulsed light (IPL) on blood vessels investigated by mathematical modeling. Lasers Surg Med 2007; 39:132-9. [PMID: 17066482 DOI: 10.1002/lsm.20408] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND AND OBJECTIVES Intense pulsed light (IPL) sources have been successfully used for coagulation of blood vessels in clinical practice. However, the broadband emission of IPL hampers the clinical evaluation of optimal light parameters. We describe a mathematical model in order to visualize the thermal effects of IPL on skin vessels, which was not available, so far. STUDY DESIGN/MATERIALS AND METHODS One IPL spectrum was shifted towards the near infrared range (near IR shifted spectrum: NIRSS) and the other was heavily shifted toward the visible range (visible shifted spectrum: VSS). The broadband emission was separated in distinct wavelengths with the respective relative light intensity. For each wavelength, the light and heat diffusion equations were simultaneously solved with the finite element method. The thermal effects of all wavelengths at the given radiant exposure (15 or 30 J/cm2) were added and the temperature in the vessels of varying diameters (60, 150, 300, 500 microm) was calculated for the entire pulse duration of 30 milliseconds. RESULTS VSS and NIRSS both provided homogeneous heating in the entire vessel. With the exception of the small vessels (60 microm), which showed only a moderate temperature increase, all vessels exhibited a temperature raise within the vessel sufficient for coagulation with each IPL parameter. The time interval for effective temperature raise in larger vessels (diameter >60 microm) was clearly shorter than the pulse duration. In most instances, the vessel temperature was higher for VSS when compared to NIRSS. CONCLUSIONS We presented a mathematical model capable of calculating the photon distribution and the thermal effects of the broadband IPL emission within cutaneous blood vessels.
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Affiliation(s)
- Wolfgang Bäumler
- Department of Dermatology, University of Regensburg, Regensburg, Germany.
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Franco W, Childers M, Nelson JS, Aguilar G. Laser surgery of port wine stains using local vacuum [corrected] pressure: changes in calculated energy deposition (Part II). Lasers Surg Med 2007; 39:118-27. [PMID: 17311275 DOI: 10.1002/lsm.20464] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND AND OBJECTIVES Application of local vacuum pressure to human skin during laser irradiation results in less absorption in the epidermis and more light delivered to targeted vessels with an increased blood volume. The objective of the present numerical study is to assess the effect of applying local vacuum pressure on the temperatures of the epidermis and small vessels during port wine stain (PWS) laser treatment. STUDY DESIGN/ MATERIALS AND METHODS: Mathematical models of light deposition and heat diffusion are used to compute absorbed energy and temperature distributions of skin and blood vessels with different diameters (10-60 microm) at various depths (200-800 microm) exposed to laser irradiation under atmospheric and vacuum pressures. RESULTS Under 50 kPa (15 in Hg) vacuum pressure, peak temperatures at the inner walls of small diameter vessels (10-30 microm) located 200-300 microm below the skin surface are approximately 10 degrees C higher than those under atmospheric pressure, and peak temperatures in the epidermis of patients with skin phototype II are approximately 5 degrees C lower. In patients with darker skin phototype (IV), the peak temperature at the inner wall of a 10 microm diameter vessel located 200 microm below the skin surface is approximately 5 degrees C higher than that under atmospheric pressure, and the peak temperature in the epidermis is approximately 10 degrees C lower. CONCLUSIONS Additional energy deposition in a larger blood volume permits higher temperatures to be achieved at vessel walls in response to laser irradiation. While more energy is deposited in every vessel, temperature gains in small diameter vessels (10-30 microm) are greater, increasing the likelihood of irreversible thermal damage to such vessels. In addition, temperatures in the epidermis decrease because less energy is absorbed therein due to reduced epidermal thickness and concentration of melanin per unit area.
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Affiliation(s)
- Walfre Franco
- Beckman Laser Institute, University of California, Irvine, California 92612, USA.
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Wassmer B, Zemmouri J, Mordon SR. Modélisation mathématique du traitement par laser endoveineux (LEV). Ing Rech Biomed 2007. [DOI: 10.1016/j.rbmret.2007.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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McGill DJ, Mackay IR. Capillary Vascular Malformation Response to Increased Ambient Temperature Is Dependent Upon Anatomical Location. Ann Plast Surg 2007; 58:193-9. [PMID: 17245148 DOI: 10.1097/01.sap.0000237616.86277.0d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND It has been documented that capillary malformations (CMs) located on the limbs tend to respond less well to laser treatment than those sited on the head and neck. However, there is little evidence available to explain this observation. OBJECTIVES To investigate potential differences between CMs located on the head and neck with those on the limbs, by comparing their response to increasing ambient temperature. METHODS Fifteen previously untreated subjects with CMs were compared as the ambient temperature was increased from 20 degrees C to 28 degrees C. These included 10 with head and neck CMs and 5 with limb CMs. The following measurements were taken at 2 degrees C intervals: cutaneous blood flow, capillary diameter, density and depth, CM color, skin and core temperatures. RESULTS There were no statistically significant differences in mean capillary depth, diameter, density, or CM color between groups. Cutaneous blood flow increased with ambient temperature in the head and neck CMs (P = 0.009) and was significantly higher than that in the limb CMs at all temperatures (P < 0.001), while the limb CMs did not demonstrate any increase in cutaneous blood flow with temperature. CONCLUSIONS These results suggest a possible reason for the poorer response to laser treatment seen in limb CMs: since cutaneous blood flow is a product of the blood flow velocity and hemoglobin concentration, malformations with lower blood perfusion would have less chromophore available and therefore be less suitable for laser destruction.
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Affiliation(s)
- David J McGill
- Laser Suite, Canniesburn Plastic Surgery Unit, Glasgow Royal Infirmary, Glasgow, UK.
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Abstract
BACKGROUND Following pulsed dye laser (PDL) treatment of capillary vascular malformations (CMs), the capillaries left behind tend to be smaller and deeper. The PDL is most effective against capillaries over 50 microm, suggesting that clearance of CM could be improved by inducing capillary vasodilation of the smaller remaining capillaries. However, there are reduced perivascular nerves within CMs, implying that autonomic innervation to these capillaries may be abnormal. OBJECTIVES To investigate whether CM capillaries will vasodilate in response to autonomic stimulation by raising ambient temperature. METHODS Ten patients with untreated CMs and nine with previously laser-treated CMs were studied as ambient temperature was increased from 20 degrees C to 28 degrees C. The following measurements were taken at 2 degrees C intervals: skin blood flow (SBF); capillary diameter and depth; CM colour; and skin and core temperatures. RESULTS All the subjects studied demonstrated superficial capillary vasodilation and increased SBF as the ambient temperature was raised from 20 degrees C to 28 degrees C. Mean+/-SEM capillary diameter increased from 66+/-7 microm to 110+/-13 microm (P<0.001) in the untreated group, compared with an increase from 28+/-5 microm to 70+/-14 microm (P<0.001) in the treated group. Mean+/-SEM SBF increased from 427.2+/-98.2 perfusion units (PU) to 580.9+/-92.7 PU (P<0.01) in the untreated group, compared with an increase from 201.3+/-28.4 PU to 458.1+/-53.7 PU (P<0.05) in the treated group. CONCLUSIONS Superficial capillary vasodilation within CM is achievable by raising ambient temperature, including in those patients resistant to PDL treatment, potentially allowing further clearance of these lesions.
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Affiliation(s)
- D J McGill
- Laser Suite, Canniesburn Plastic Surgery Unit, Glasgow Royal Infirmary, Glasgow G4 0SF, UK.
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Kono T, Groff WF, Sakurai H, Takeuchi M, Yamaki T, Soejima K, Nozaki M. Evaluation of fluence and pulse-duration on purpuric threshold using an extended pulse pulsed-dye laser in the treatment of port wine stains. J Dermatol 2006; 33:473-6. [PMID: 16848819 DOI: 10.1111/j.1346-8138.2006.00111.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Laser therapy of port-wine stains (PWS) using the extended pulse pulsed-dye laser (EPPDL) is accepted as the optimal approach because the thermal relaxation time for the vessels in PWS is actually 1-10 msec. The purpose of this study is to elucidate the purpuric threshold using the EPPDL for treatment of PWS. One hundred and seventy-seven Japanese patients with PWS were recruited for this study. All the patients were dark-skinned with skin phototype III (n = 103) and IV (n = 74). PWS were treated with the EPPDL with a pulse duration ranging 1.5-10 msec, fluence ranging 9-15 J/cm(2), and a spot size of 7 mm. Cryogen spray cooling (CSC) was fixed to 30 msec of delay and 30 msec of spray duration. Patients returned to our clinic within 1 week after their initial laser therapy and the treatment sites were examined for the evidence of purpura formation. Of the 177 patients, 108 developed purpura. The lowest fluences that caused purpura and were seen in more than 50% of patients were 10 J/cm(2) with a pulse duration of 1.5 msec, 12 J/cm(2) with a pulse duration of 3 msec, 13 J/cm(2) with a pulse duration of 6 msec, and 13 J/cm(2) with a pulse duration of 10 msec. The fluence and pulse duration thresholds were 12.5 J/cm(2) and 1.65 msec, respectively. Because purpura is one of the treatment endpoints when using a pulsed-dye laser for PWS, higher fluences are necessary when using a long pulse duration.
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Affiliation(s)
- Taro Kono
- Department of Plastic and Reconstructive Surgery, Tokyo Women's Medical University, Tokyo, Japan.
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