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VilasBoas-Ribeiro I, Sumser K, Nouwens S, Feddersen T, Heemels W, van Rhoon GC, Paulides MM. Adapting Temperature Predictions to MR Imaging in Treatment Position to Improve Simulation-Guided Hyperthermia for Cervical Cancer. IEEE OPEN JOURNAL OF ENGINEERING IN MEDICINE AND BIOLOGY 2023; 5:99-106. [PMID: 38445240 PMCID: PMC10914156 DOI: 10.1109/ojemb.2023.3321990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 04/13/2023] [Accepted: 09/21/2023] [Indexed: 03/07/2024] Open
Abstract
Hyperthermia treatment consists of elevating the temperature of the tumor to increase the effectiveness of radiotherapy and chemotherapy. Hyperthermia treatment planning (HTP) is an important tool to optimize treatment quality using pre-treatment temperature predictions. The accuracy of these predictions depends on modeling uncertainties such as tissue properties and positioning. In this study, we evaluated if HTP accuracy improves when the patient is imaged inside the applicator at the start of treatment. Because perfusion is a major uncertainty source, the importance of accurate treatment position and anatomy was evaluated using different perfusion values. Volunteers were scanned using MR imaging without ("planning setup") and with the MR-compatible hyperthermia device ("treatment setup"). Temperature-based quality indicators were used to assess the differences between the standard, apparent and the optimized hyperthermia dose. We conclude that pre-treatment imaging can improve HTP predictions accuracy but also, that tissue perfusion modelling is crucial if temperature-based optimization is applied.
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Affiliation(s)
- Iva VilasBoas-Ribeiro
- Department of Radiotherapy, Erasmus MC Cancer InstituteUniversity Medical Center Rotterdam3015GDRotterdamThe Netherlands
| | - Kemal Sumser
- Care and Cure research lab (EM-4C&C) of the Electromagnetics Group, Department of Electrical EngineeringEindhoven University of Technology5600 MBEindhovenThe Netherlands
| | - Sven Nouwens
- Control System Technology Group, Department of Mechanical EngineeringEindhoven University of Technology5600 MBEindhovenThe Netherlands
| | - Theresa Feddersen
- Department of Radiology & Nuclear Medicine, Erasmus MCUniversity Medical Center Rotterdam3015GDRotterdamThe Netherlands
| | - W.P.M.H. Heemels
- Control System Technology Group, Department of Mechanical EngineeringEindhoven University of Technology5600 MBEindhovenThe Netherlands
| | - Gerard C. van Rhoon
- Department of Radiotherapy, Erasmus MC Cancer InstituteUniversity Medical Center Rotterdam3015GDRotterdamThe Netherlands
- Department of Applied Radiation and Isotopes, Reactor Institute DelftDelft University of Technology2629JBDelftThe Netherlands
| | - Margarethus M. Paulides
- Care and Cure research lab (EM-4C&C) of the Electromagnetics Group, Department of Electrical EngineeringEindhoven University of Technology5600 MBEindhovenThe Netherlands
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Kok HP, Herrera TD, Crezee J. The Relevance of High Temperatures and Short Time Intervals Between Radiation Therapy and Hyperthermia: Insights in Terms of Predicted Equivalent Enhanced Radiation Dose. Int J Radiat Oncol Biol Phys 2023; 115:994-1003. [PMID: 36288756 DOI: 10.1016/j.ijrobp.2022.10.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 09/27/2022] [Accepted: 10/13/2022] [Indexed: 11/07/2022]
Abstract
PURPOSE The radiosensitization effect of hyperthermia can be considered and quantified as an enhanced equivalent radiation dose (EQDRT), that is, the dose needed to achieve the same effect without hyperthermia. EQDRT can be predicted using an extended linear quadratic model, with temperature-dependent parameters. Clinical data show that both the achieved temperature and time interval between radiation therapy and hyperthermia correlate with clinical outcome, but their effect on expected EQDRT is unknown and was therefore evaluated in this study. METHODS AND MATERIALS Biological modeling was performed using our in-house developed software (X-Term), considering a 23- × 2-Gy external beam radiation scheme, as applied for patients with locally advanced cervical cancer. First, the EQDRT was calculated for homogeneous temperature levels, evaluating time intervals between 0 and 4 hours. Next, realistic heterogeneous hyperthermia treatment plans were combined with radiation therapy plans and the EQDRT was calculated for 10 patients. Furthermore, the effect of achieving 0.5°C to 1°C lower or higher temperatures was evaluated. RESULTS EQDRT increases substantially with both increasing temperature and decreasing time interval. The effect of the time interval is most pronounced at higher temperatures (>41°C). At a typical hyperthermic temperature level of 41.5°C, an enhancement of ∼10 Gy can be realized with a 0-hour time interval, which is decreased to only ∼4 Gy enhancement with a 4-hour time interval. Most enhancement is already lost after 1 hour. Evaluation in patients predicted an average additional EQDRT (D95%) of 2.2 and 6.3 Gy for 4- and 0-hour time intervals, respectively. The effect of 0.5°C to 1°C lower or higher temperatures is most pronounced at high temperature levels and short time intervals. The additional EQDRT (D95%) ranged between 1.5 and 3.3 Gy and between 4.5 and 8.5 Gy for 4- and 0-hour time intervals, respectively. CONCLUSIONS Biological modeling provides relevant insight into the relationship between treatment parameters and expected EQDRT. Both high temperatures and short time intervals are essential to maximize EQDRT.
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Affiliation(s)
- H Petra Kok
- Amsterdam UMC Location University of Amsterdam, Department of Radiation Oncology, Amsterdam, The Netherlands; Cancer Center Amsterdam, Treatment and Quality of Life, Cancer Biology and Immunology, Amsterdam, The Netherlands.
| | - Timoteo D Herrera
- Amsterdam UMC Location University of Amsterdam, Department of Radiation Oncology, Amsterdam, The Netherlands; Cancer Center Amsterdam, Treatment and Quality of Life, Cancer Biology and Immunology, Amsterdam, The Netherlands
| | - Johannes Crezee
- Amsterdam UMC Location University of Amsterdam, Department of Radiation Oncology, Amsterdam, The Netherlands; Cancer Center Amsterdam, Treatment and Quality of Life, Cancer Biology and Immunology, Amsterdam, The Netherlands
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3
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Poni R, Neufeld E, Capstick M, Bodis S, Kuster N. Rapid SAR optimization for hyperthermic oncology: combining multi-goal optimization and time-multiplexed steering for hotspot suppression. Int J Hyperthermia 2022; 39:758-771. [PMID: 35654473 DOI: 10.1080/02656736.2022.2080284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
PURPOSE Healthy tissue hotspots are a main limiting factor in administering deep hyperthermia cancer therapy. We propose an optimization scheme that uses time-multiplexed steering (TMPS) among minimally correlated (nearly) Pareto-optimal solutions to suppress hotspots without reducing tumor heating. Furthermore, tumor heating homogeneity is maximized, thus reducing toxicity and avoiding underexposed tumor regions, which in turn may reduce recurrence. MATERIALS AND METHODS The novel optimization scheme combines random generation of steering parameters with local optimization to efficiently identify the set of (Pareto-) optimal solutions of conflicting optimization goals. To achieve simultaneous suppression of hotspots, multiple steering parameter configurations with minimally correlated hotspots are selected near the Pareto front and combined in TMPS. The performance of the novel scheme was compared with that of a multi-goal Genetic Algorithm for a range of simulated treatment configurations involving a modular applicator heating a generic tumor situated in the bladder, cervix, or pelvic bone. SAR cumulative histograms in tumor and healthy tissue, as well as hotspot volumes are used as metrics. RESULTS Compared to the non-TMPS optimization, the proposed scheme was able to reduce the peak temperature in healthy tissue by 0.2 °C-1.0 °C (a thermal dose reduction by at least 26%) and, importantly, the hotspot volume above 42 °C in healthy tissue by 41%-86%. At the same time, tumor heating homogeneity was maintained or improved. CONCLUSIONS The extremely rapid optimization (5 s for TMPS part, on a standard PC) permits closed-loop treatment reoptimization during treatment administration, and empowers physicians with a selection of optimal treatment scenarios reflecting different weighting of conflicting treatment goals.
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Affiliation(s)
- Redi Poni
- Department of Information Technology and Electrical Engineering, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland.,Foundation for Research on Information Technologies in Society (IT'IS), Zurich, Switzerland
| | - Esra Neufeld
- Department of Information Technology and Electrical Engineering, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland.,Foundation for Research on Information Technologies in Society (IT'IS), Zurich, Switzerland
| | - Myles Capstick
- Foundation for Research on Information Technologies in Society (IT'IS), Zurich, Switzerland
| | - Stephan Bodis
- Kantonsspital Aarau Radio-Onkologie, Aarau, Switzerland
| | - Niels Kuster
- Department of Information Technology and Electrical Engineering, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland.,Foundation for Research on Information Technologies in Society (IT'IS), Zurich, Switzerland
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Kok HP, Crezee J. Adapt2Heat: treatment planning-assisted locoregional hyperthermia by on-line visualization, optimization and re-optimization of SAR and temperature distributions. Int J Hyperthermia 2022; 39:265-277. [PMID: 35109742 DOI: 10.1080/02656736.2022.2032845] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
BACKGROUND Hyperthermia treatment planning is increasingly used in clinical applications and recommended in quality assurance guidelines. Assistance in phase-amplitude steering during treatment requires dedicated software for on-line visualization of SAR/temperature distributions and fast re-optimization in response to hot spots. As such software tools are not yet commercially available, we developed Adapt2Heat for on-line adaptive hyperthermia treatment planning and illustrate possible application by different relevant real patient examples. METHODS Adapt2Heat was developed as a separate module of the treatment planning software Plan2Heat. Adapt2Heat runs on a Linux operating system and was developed in C++, using the open source Qt, Qwt and VTK libraries. A graphical user interface allows interactive and flexible on-line use of hyperthermia treatment planning. Predicted SAR/temperature distributions and statistics for selected phase-amplitude settings can be visualized instantly and settings can be re-optimized manually or automatically in response to hot spots. RESULTS Pretreatment planning E-Field, SAR and temperature calculations are performed with Plan2Heat and imported in Adapt2Heat. Examples show that Adapt2Heat can be helpful in assisting with phase-amplitude steering, e.g., by suppressing indicated hot spots. The effects of phase-amplitude adjustments on the tumor and potential hot spot locations are comprehensively visualized, allowing intuitive and flexible assistance by treatment planning during locoregional hyperthermia treatments. CONCLUSION Adapt2Heat provides an intuitive and flexible treatment planning tool for on-line treatment planning-assisted hyperthermia. Extensive features for visualization and (re-)optimization during treatment allow practical use in many locoregional hyperthermia applications. This type of tools are indispensable for enhancing the quality of hyperthermia treatment delivery.
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Affiliation(s)
- H Petra Kok
- Department Radiation Oncology, Cancer Center Amsterdam, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Johannes Crezee
- Department Radiation Oncology, Cancer Center Amsterdam, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
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IJff M, Crezee J, Oei AL, Stalpers LJA, Westerveld H. The role of hyperthermia in the treatment of locally advanced cervical cancer: a comprehensive review. Int J Gynecol Cancer 2022; 32:288-296. [PMID: 35046082 PMCID: PMC8921566 DOI: 10.1136/ijgc-2021-002473] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 12/14/2021] [Indexed: 01/02/2023] Open
Abstract
Radiotherapy with cisplatin (chemoradiation) is the standard treatment for women with locally advanced cervical cancer. Radiotherapy with deep hyperthermia (thermoradiation) is a well established alternative, but is rarely offered as an alternative to chemoradiation, particularly for patients in whom cisplatin is contraindicated. The scope of this review is to provide an overview of the biological rationale of hyperthermia treatment delivery, including patient workflow, and the clinical effectiveness of hyperthermia as a radiosensitizer in the treatment of cervical cancer. Hyperthermia is especially effective in hypoxic and nutrient deprived areas of the tumor where radiotherapy is less effective. Its radiosensitizing effectiveness depends on the temperature level, duration of treatment, and the time interval between radiotherapy and hyperthermia. High quality hyperthermia treatment requires an experienced team, adequate online adaptive treatment planning, and is preferably performed using a phased array radiative locoregional hyperthermia device to achieve the optimal thermal dose effect. Hyperthermia is well tolerated and generally leads to only mild toxicity, such as patient discomfort. Patients in whom cisplatin is contraindicated should therefore be referred to a hyperthermia center for thermoradiation.
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Affiliation(s)
- Marloes IJff
- Department of Radiation Oncology, Amsterdam University Medical Centers, Cancer Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands.,Laboratory for Experimental Oncology and Radiobiology (LEXOR), Cancer Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Johannes Crezee
- Department of Radiation Oncology, Amsterdam University Medical Centers, Cancer Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Arlene L Oei
- Department of Radiation Oncology, Amsterdam University Medical Centers, Cancer Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands.,Laboratory for Experimental Oncology and Radiobiology (LEXOR), Cancer Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Lukas J A Stalpers
- Department of Radiation Oncology, Amsterdam University Medical Centers, Cancer Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands.,Laboratory for Experimental Oncology and Radiobiology (LEXOR), Cancer Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Henrike Westerveld
- Department of Radiation Oncology, Amsterdam University Medical Centers, Cancer Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
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Kok HP, Crezee J. Fast Adaptive Temperature-Based Re-Optimization Strategies for On-Line Hot Spot Suppression during Locoregional Hyperthermia. Cancers (Basel) 2021; 14:cancers14010133. [PMID: 35008300 PMCID: PMC8749938 DOI: 10.3390/cancers14010133] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/21/2021] [Accepted: 12/23/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary When treatment limiting hot spots occur during locoregional hyperthermia (i.e., heating tumors to 40–44 °C for ~1 h), system settings are adjusted based on experience. In this study, we developed and evaluated treatment planning with temperature-based re-optimization and compared the predicted effectiveness to clinically applied protocol/experience-based steering. Re-optimization times were typically ~10 s; sufficiently fast for on-line use. Effective hot spot suppression was predicted, while maintaining adequate tumor heating. Inducing new hot spots was avoided. Temperature-based re-optimization to suppress treatment limiting hot spots seemed feasible to match the effectiveness of long-term clinical experience and will be further evaluated in a clinical setting. When numerical algorithms are proven to match long-term experience, the overall treatment quality within hyperthermia centers can significantly improve. Implementing these strategies would then imply that treatments become less dependent on the experience of the center/operator. Abstract Background: Experience-based adjustments in phase-amplitude settings are applied to suppress treatment limiting hot spots that occur during locoregional hyperthermia for pelvic tumors. Treatment planning could help to further optimize treatments. The aim of this research was to develop temperature-based re-optimization strategies and compare the predicted effectiveness with clinically applied protocol/experience-based steering. Methods: This study evaluated 22 hot spot suppressions in 16 cervical cancer patients (mean age 67 ± 13 year). As a first step, all potential hot spot locations were represented by a spherical region, with a user-specified diameter. For fast and robust calculations, the hot spot temperature was represented by a user-specified percentage of the voxels with the largest heating potential (HPP). Re-optimization maximized tumor T90, with constraints to suppress the hot spot and avoid any significant increase in other regions. Potential hot spot region diameter and HPP were varied and objective functions with and without penalty terms to prevent and minimize temperature increase at other potential hot spot locations were evaluated. Predicted effectiveness was compared with clinically applied steering results. Results: All strategies showed effective hot spot suppression, without affecting tumor temperatures, similar to clinical steering. To avoid the risk of inducing new hot spots, HPP should not exceed 10%. Adding a penalty term to the objective function to minimize the temperature increase at other potential hot spot locations was most effective. Re-optimization times were typically ~10 s. Conclusion: Fast on-line re-optimization to suppress treatment limiting hot spots seems feasible to match effectiveness of ~30 years clinical experience and will be further evaluated in a clinical setting.
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Sumser K, Drizdal T, Bellizzi GG, Hernandez-Tamames JA, van Rhoon GC, Paulides MM. Experimental Validation of the MRcollar: An MR Compatible Applicator for Deep Heating in the Head and Neck Region. Cancers (Basel) 2021; 13:5617. [PMID: 34830773 PMCID: PMC8615935 DOI: 10.3390/cancers13225617] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/29/2021] [Accepted: 11/08/2021] [Indexed: 12/13/2022] Open
Abstract
Clinical effectiveness of hyperthermia treatments, in which tumor tissue is artificially heated to 40-44 °C for 60-90 min, can be hampered by a lack of accurate temperature monitoring. The need for noninvasive temperature monitoring in the head and neck region (H&N) and the potential of MR thermometry prompt us to design an MR compatible hyperthermia applicator: the MRcollar. In this work, we validate the design, numerical model, and MR performance of the MRcollar. The MRcollar antennas have low reflection coefficients (<-15 dB) and the intended low interaction between the individual antenna modules (<-32 dB). A 10 °C increase in 3 min was reached in a muscle-equivalent phantom, such that the specifications from the European Society for Hyperthermic Oncology were easily reached. The MRcollar had a minimal effect on MR image quality and a five-fold improvement in SNR was achieved using the integrated coils of the MRcollar, compared to the body coil. The feasibility of using the MRcollar in an MR environment was shown by a synchronous heating experiment. The match between the predicted SAR and measured SAR using MR thermometry satisfied the gamma criteria [distance-to-agreement = 5 mm, dose-difference = 7%]. All experiments combined show that the MRcollar delivers on the needs for MR-hyperthermia in the H&N and is ready for in vivo investigation.
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Affiliation(s)
- Kemal Sumser
- Department of Radiotherapy, Erasmus Medical Center Cancer Institute, 3015 GD Rotterdam, The Netherlands; (T.D.); (G.G.B.); (G.C.v.R.); (M.M.P.)
| | - Tomas Drizdal
- Department of Radiotherapy, Erasmus Medical Center Cancer Institute, 3015 GD Rotterdam, The Netherlands; (T.D.); (G.G.B.); (G.C.v.R.); (M.M.P.)
- Department of Biomedical Technology, Czech Technical University in Prague, nam. Sítna 3105, 272 01 Kladno, Czech Republic
| | - Gennaro G. Bellizzi
- Department of Radiotherapy, Erasmus Medical Center Cancer Institute, 3015 GD Rotterdam, The Netherlands; (T.D.); (G.G.B.); (G.C.v.R.); (M.M.P.)
| | - Juan A. Hernandez-Tamames
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center Cancer Institute, 3015 GD Rotterdam, The Netherlands;
| | - Gerard C. van Rhoon
- Department of Radiotherapy, Erasmus Medical Center Cancer Institute, 3015 GD Rotterdam, The Netherlands; (T.D.); (G.G.B.); (G.C.v.R.); (M.M.P.)
| | - Margarethus Marius Paulides
- Department of Radiotherapy, Erasmus Medical Center Cancer Institute, 3015 GD Rotterdam, The Netherlands; (T.D.); (G.G.B.); (G.C.v.R.); (M.M.P.)
- Department of Electrical Engineering, Eindhoven University of Technology, 5612 AZ Eindhoven, The Netherlands
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Paulides MM, Rodrigues DB, Bellizzi GG, Sumser K, Curto S, Neufeld E, Montanaro H, Kok HP, Dobsicek Trefna H. ESHO benchmarks for computational modeling and optimization in hyperthermia therapy. Int J Hyperthermia 2021; 38:1425-1442. [PMID: 34581246 DOI: 10.1080/02656736.2021.1979254] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND The success of cancer hyperthermia (HT) treatments is strongly dependent on the temperatures achieved in the tumor and healthy tissues as it correlates with treatment efficacy and safety, respectively. Hyperthermia treatment planning (HTP) simulations have become pivotal for treatment optimization due to the possibility for pretreatment planning, optimization and decision making, as well as real-time treatment guidance. MATERIALS AND METHODS The same computational methods deployed in HTP are also used for in silico studies. These are of great relevance for the development of new HT devices and treatment approaches. To aid this work, 3 D patient models have been recently developed and made available for the HT community. Unfortunately, there is no consensus regarding tissue properties, simulation settings, and benchmark applicators, which significantly influence the clinical relevance of computational outcomes. RESULTS AND DISCUSSION Herein, we propose a comprehensive set of applicator benchmarks, efficacy and safety optimization algorithms, simulation settings and clinical parameters, to establish benchmarks for method comparison and code verification, to provide guidance, and in view of the 2021 ESHO Grand Challenge (Details on the ESHO grand challenge on HTP will be provided at https://www.esho.info/). CONCLUSION We aim to establish guidelines to promote standardization within the hyperthermia community such that novel approaches can quickly prove their benefit as quickly as possible in clinically relevant simulation scenarios. This paper is primarily focused on radiofrequency and microwave hyperthermia but, since 3 D simulation studies on heating with ultrasound are now a reality, guidance as well as a benchmark for ultrasound-based hyperthermia are also included.
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Affiliation(s)
- Margarethus M Paulides
- Electromagnetics for Care & Cure Laboratory (EM4C&C), Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.,Department of Radiotherapy, Erasmus University Medical Center Cancer Institute, Rotterdam, The Netherlands
| | - Dario B Rodrigues
- Hyperthermia Therapy Program, Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, USA
| | - Gennaro G Bellizzi
- Department of Radiotherapy, Erasmus University Medical Center Cancer Institute, Rotterdam, The Netherlands
| | - Kemal Sumser
- Department of Radiotherapy, Erasmus University Medical Center Cancer Institute, Rotterdam, The Netherlands
| | - Sergio Curto
- Department of Radiotherapy, Erasmus University Medical Center Cancer Institute, Rotterdam, The Netherlands
| | - Esra Neufeld
- Foundation for Research on Information Technologies in Society (IT'IS), Zurich, Switzerland
| | - Hazael Montanaro
- Foundation for Research on Information Technologies in Society (IT'IS), Zurich, Switzerland.,Laboratory for Acoustics/Noise control, Swiss Federal Laboratories for Materials Science and Technology (EMPA), Dubendorf, Switzerland
| | - H Petra Kok
- Department of Radiation Oncology, Amsterdam University Medical Centers, University of Amsterdam, Cancer Center Amsterdam, Amsterdam, The Netherlands
| | - Hana Dobsicek Trefna
- Biomedical Electromagnetics Group, Department of Electrical Engineering, Chalmers University of Technology, Göteborg, Sweden
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Nadobny J, Lim A, Seifert G, Sullivan D, Chrzon B, Weihrauch M, Zschaeck S, Herz E, Moczynska A, Pellicer-Guridi R, Wust P, Beck M, Ghadjar P. Improved patient-specific hyperthermia planning based on parametrized electromagnetic and thermal models for the SIGMA-30 applicator. Int J Hyperthermia 2021; 38:663-678. [PMID: 33899658 DOI: 10.1080/02656736.2021.1909757] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
OBJECTIVE To create an improved planning method for pediatric regional hyperthermia (RHT) using the SIGMA-30 applicator (SIGMA-30). MATERIALS AND METHODS An electromagnetic model of SIGMA-30 was generated for use with the finite-difference time-domain (FDTD) method. Applying special MATLAB-based algorithms, voxel models of a pediatric patient with pelvic rhabdomyosarcoma were created from Computed-Tomography (CT) contours for use with the FDTD method and the finite-difference (FD) method capable of using either temperature-independent or temperature-dependent perfusion models for solving the Bioheat Transfer Equation (BHTE). Patient models were parametrized regarding, first, the positioning in the applicator, second, the absorbed power range and, third, different perfusion models, resulting in the so-called Parametrized Treatment Models (PTMs). A novel dedicated optimization procedure was developed based on quantitative comparison of numerical calculations against temperature and power measurements from two RHT therapies. RESULTS Using measured data, a realistic absorbed power range in the patient model was estimated. Within this range, several FDTD and BHTE runs were performed and, applying the aforementioned optimization scheme, the best PTMs and perfusion models were identified for each therapy via a retrospective comparison with measurements in 14 temperature sensor positions: 5 in the tumor, 8 in rectum and one in bladder. CONCLUSION A novel dedicated optimization procedure for identification of suitable patient-specific electromagnetic and thermal models, which can be used for improved patient planning, was developed and evaluated by comparison with treatment-derived measurements using SIGMA-30. The optimization procedure can be extended to other hyperthermia applicators and to other patient types, including adults.
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Affiliation(s)
- Jacek Nadobny
- Department of Radiation Oncology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Amanda Lim
- Department of Radiation Oncology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Georg Seifert
- Department of Paediatric Oncology/Haematology, Otto-Heubner Centre for Paediatric and Adolescent Medicine (OHC), Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Dennis Sullivan
- Department of Electrical and Computer Engineering, University of Idaho, Moscow, ID, USA
| | - Benjamin Chrzon
- Department of Radiation Oncology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Mirko Weihrauch
- Department of Radiation Oncology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Sebastian Zschaeck
- Department of Radiation Oncology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Berlin Institute of Health, Berlin, Germany
| | - Enrico Herz
- Department of Radiation Oncology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Aleksandra Moczynska
- Department of Radiation Oncology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Ruben Pellicer-Guridi
- Department of Radiation Oncology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Peter Wust
- Department of Radiation Oncology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Marcus Beck
- Department of Radiation Oncology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Pirus Ghadjar
- Department of Radiation Oncology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
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11
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Gavazzi S, van Lier ALHMW, Zachiu C, Jansen E, Lagendijk JJW, Stalpers LJA, Crezee H, Kok HP. Advanced patient-specific hyperthermia treatment planning. Int J Hyperthermia 2021; 37:992-1007. [PMID: 32806979 DOI: 10.1080/02656736.2020.1806361] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Hyperthermia treatment planning (HTP) is valuable to optimize tumor heating during thermal therapy delivery. Yet, clinical hyperthermia treatment plans lack quantitative accuracy due to uncertainties in tissue properties and modeling, and report tumor absorbed power and temperature distributions which cannot be linked directly to treatment outcome. Over the last decade, considerable progress has been made to address these inaccuracies and therefore improve the reliability of hyperthermia treatment planning. Patient-specific electrical tissue conductivity derived from MR measurements has been introduced to accurately model the power deposition in the patient. Thermodynamic fluid modeling has been developed to account for the convective heat transport in fluids such as urine in the bladder. Moreover, discrete vasculature trees have been included in thermal models to account for the impact of thermally significant large blood vessels. Computationally efficient optimization strategies based on SAR and temperature distributions have been established to calculate the phase-amplitude settings that provide the best tumor thermal dose while avoiding hot spots in normal tissue. Finally, biological modeling has been developed to quantify the hyperthermic radiosensitization effect in terms of equivalent radiation dose of the combined radiotherapy and hyperthermia treatment. In this paper, we review the present status of these developments and illustrate the most relevant advanced elements within a single treatment planning example of a cervical cancer patient. The resulting advanced HTP workflow paves the way for a clinically feasible and more reliable patient-specific hyperthermia treatment planning.
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Affiliation(s)
- Soraya Gavazzi
- Department of Radiotherapy, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Cornel Zachiu
- Department of Radiotherapy, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Eric Jansen
- Amsterdam UMC, Department of Radiation Oncology, Cancer Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Jan J W Lagendijk
- Department of Radiotherapy, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Lukas J A Stalpers
- Amsterdam UMC, Department of Radiation Oncology, Cancer Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Hans Crezee
- Amsterdam UMC, Department of Radiation Oncology, Cancer Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - H Petra Kok
- Amsterdam UMC, Department of Radiation Oncology, Cancer Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
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Lifante J, Shen Y, Zabala Gutierrez I, Rubia‐Rodríguez I, Ortega D, Fernandez N, Melle S, Granado M, Rubio‐Retama J, Jaque D, Ximendes E. Reaching Deeper: Absolute In Vivo Thermal Reading of Liver by Combining Superbright Ag 2S Nanothermometers and In Silico Simulations. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2003838. [PMID: 33977056 PMCID: PMC8097345 DOI: 10.1002/advs.202003838] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/23/2020] [Indexed: 05/19/2023]
Abstract
Luminescent nano-thermometry is a fast-developing technique with great potential for in vivo sensing, diagnosis, and therapy. Unfortunately, it presents serious limitations. The luminescence generated by nanothermometers, from which thermal readout is obtained, is strongly distorted by the attenuation induced by tissues. Such distortions lead to low signal levels and entangle absolute and reliable thermal monitoring of internal organs. Overcoming both limitations requires the use of high-brightness luminescent nanothermometers and adopting more complex approaches for temperature estimation. In this work, it is demonstrated how superbright Ag2S nanothermometers can provide in vivo, reliable, and absolute thermal reading of the liver during laser-induced hyperthermia. For that, a new procedure is designed in which thermal readout is obtained from the combination of in vivo transient thermometry measurements and in silico simulations. The synergy between in vivo and in silico measurements has made it possible to assess relevant numbers such as the efficiency of hyperthermia processes, the total heat energy deposited in the liver, and the relative contribution of Ag2S nanoparticles to liver heating. This work provides a new way for absolute thermal sensing of internal organs with potential application not only to hyperthermia processes but also to advanced diagnosis and therapy.
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Affiliation(s)
- José Lifante
- Nanomaterials for Bioimaging Group (NanoBIG)Departamento de Fisiología ‐ Facultad de MedicinaUniversidad Autónoma de MadridArzobispo Morcillo 2Madrid28029Spain
- Nanomaterials for Bioimaging Group (NanoBIG)Instituto Ramón y Cajal de Investigación SanitariaIRYCISCtra. Colmenar km. 9.100Madrid28034Spain
| | - Yingli Shen
- Nanomaterials for Bioimaging Group (NanoBIG)Instituto Ramón y Cajal de Investigación SanitariaIRYCISCtra. Colmenar km. 9.100Madrid28034Spain
- Nanomaterials for Bioimaging Group (NanoBIG)Departamento de Física de Materiales ‐ Facultad de CienciasUniversidad Autónoma de MadridC/Francisco Tomás y Valiente 7Madrid28049Spain
| | - Irene Zabala Gutierrez
- Departamento de Química en Ciencias Farmacéuticas ‐ Facultad de FarmaciaUniversidad Complutense de MadridPlaza Ramón y Cajal S/NMadrid28040Spain
| | | | - Daniel Ortega
- IMDEA NanocienciaCiudad Universitaria de CantoblancoFaraday 9Madrid28049Spain
- Department of Condensed Matter PhysicsFaculty of SciencesUniversity of CádizPuerto Real (Cádiz)11510Spain
- Biomedical Research and Innovation Institute of Cádiz (INiBICA)Cádiz11009Spain
| | - Nuria Fernandez
- Nanomaterials for Bioimaging Group (NanoBIG)Departamento de Fisiología ‐ Facultad de MedicinaUniversidad Autónoma de MadridArzobispo Morcillo 2Madrid28029Spain
- Nanomaterials for Bioimaging Group (NanoBIG)Instituto Ramón y Cajal de Investigación SanitariaIRYCISCtra. Colmenar km. 9.100Madrid28034Spain
| | - Sonia Melle
- Departamento de Óptica, Facultad de Óptica y OptometríaUniversidad Complutense de MadridArcos de Jalon 118Madrid28037Spain
| | - Miriam Granado
- Nanomaterials for Bioimaging Group (NanoBIG)Departamento de Fisiología ‐ Facultad de MedicinaUniversidad Autónoma de MadridArzobispo Morcillo 2Madrid28029Spain
- Nanomaterials for Bioimaging Group (NanoBIG)Instituto Ramón y Cajal de Investigación SanitariaIRYCISCtra. Colmenar km. 9.100Madrid28034Spain
| | - Jorge Rubio‐Retama
- Departamento de Química en Ciencias Farmacéuticas ‐ Facultad de FarmaciaUniversidad Complutense de MadridPlaza Ramón y Cajal S/NMadrid28040Spain
| | - Daniel Jaque
- Nanomaterials for Bioimaging Group (NanoBIG)Instituto Ramón y Cajal de Investigación SanitariaIRYCISCtra. Colmenar km. 9.100Madrid28034Spain
- Nanomaterials for Bioimaging Group (NanoBIG)Departamento de Física de Materiales ‐ Facultad de CienciasUniversidad Autónoma de MadridC/Francisco Tomás y Valiente 7Madrid28049Spain
| | - Erving Ximendes
- Nanomaterials for Bioimaging Group (NanoBIG)Instituto Ramón y Cajal de Investigación SanitariaIRYCISCtra. Colmenar km. 9.100Madrid28034Spain
- Nanomaterials for Bioimaging Group (NanoBIG)Departamento de Física de Materiales ‐ Facultad de CienciasUniversidad Autónoma de MadridC/Francisco Tomás y Valiente 7Madrid28049Spain
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13
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van der Horst A, Kok HP, Crezee J. Effect of gastrointestinal gas on the temperature distribution in pancreatic cancer hyperthermia treatment planning. Int J Hyperthermia 2021; 38:229-240. [PMID: 33602033 DOI: 10.1080/02656736.2021.1882709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
PURPOSE In pancreatic cancer treatment, hyperthermia can be added to increase efficacy of chemo- and/or radiotherapy. Gas in stomach, intestines and colon is often in close proximity to the target volume. We investigated the impact of variations in gastrointestinal gas (GG) on temperature distributions during simulated hyperthermia treatment (HT). METHODS We used sets of one CT and eight cone-beam CT (CBCT) scans obtained prior to/during fractionated image-guided radiotherapy in four pancreatic cancer patients. In Plan2Heat, we simulated locoregional heating by an ALBA-4D phased array radiofrequency system and calculated temperature distributions for (i) the segmented CT (sCT), (ii) sCT with GG replaced by muscle (sCT0), (iii) sCT0 with eight different GG distributions as visible on CBCT inserted (sCTCBCT). We calculated cumulative temperature-volume histograms for the clinical target volume (CTV) for all ten temperature distributions for each patient and investigated the relationship between GG volume and change in ΔT50 (temperature increase at 50% of CTV volume). We determined location and volume of normal tissue receiving a high thermal dose. RESULTS GG volume on CBCT varied greatly (9-991 cm3). ΔT50 increased for increasing GG volume; maximum ΔT50 difference per patient was 0.4-0.6 °C. The risk for GG-associated treatment-limiting hot spots appeared low. Normal tissue high-temperature regions mostly occurred anteriorly; their volume and maximum temperature showed moderate positive correlations with GG volume, while fat-muscle interfaces were associated with higher risks for hot spots. CONCLUSIONS Considerable changes in volume and position of gastrointestinal gas can occur and are associated with clinically relevant tumor temperature differences.
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Affiliation(s)
- Astrid van der Horst
- Department of Radiation Oncology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - H Petra Kok
- Department of Radiation Oncology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Johannes Crezee
- Department of Radiation Oncology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
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14
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Datta NR, Kok HP, Crezee H, Gaipl US, Bodis S. Integrating Loco-Regional Hyperthermia Into the Current Oncology Practice: SWOT and TOWS Analyses. Front Oncol 2020; 10:819. [PMID: 32596144 PMCID: PMC7303270 DOI: 10.3389/fonc.2020.00819] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 04/27/2020] [Indexed: 12/14/2022] Open
Abstract
Moderate hyperthermia at temperatures between 40 and 44°C is a multifaceted therapeutic modality. It is a potent radiosensitizer, interacts favorably with a host of chemotherapeutic agents, and, in combination with radiotherapy, enforces immunomodulation akin to “in situ tumor vaccination.” By sensitizing hypoxic tumor cells and inhibiting repair of radiotherapy-induced DNA damage, the properties of hyperthermia delivered together with photons might provide a tumor-selective therapeutic advantage analogous to high linear energy transfer (LET) neutrons, but with less normal tissue toxicity. Furthermore, the high LET attributes of hyperthermia thermoradiobiologically are likely to enhance low LET protons; thus, proton thermoradiotherapy would mimic 12C ion therapy. Hyperthermia with radiotherapy and/or chemotherapy substantially improves therapeutic outcomes without enhancing normal tissue morbidities, yielding level I evidence reported in several randomized clinical trials, systematic reviews, and meta-analyses for various tumor sites. Technological advancements in hyperthermia delivery, advancements in hyperthermia treatment planning, online invasive and non-invasive MR-guided thermometry, and adherence to quality assurance guidelines have ensured safe and effective delivery of hyperthermia to the target region. Novel biological modeling permits integration of hyperthermia and radiotherapy treatment plans. Further, hyperthermia along with immune checkpoint inhibitors and DNA damage repair inhibitors could further augment the therapeutic efficacy resulting in synthetic lethality. Additionally, hyperthermia induced by magnetic nanoparticles coupled to selective payloads, namely, tumor-specific radiotheranostics (for both tumor imaging and radionuclide therapy), chemotherapeutic drugs, immunotherapeutic agents, and gene silencing, could provide a comprehensive tumor-specific theranostic modality akin to “magic (nano)bullets.” To get a realistic overview of the strength (S), weakness (W), opportunities (O), and threats (T) of hyperthermia, a SWOT analysis has been undertaken. Additionally, a TOWS analysis categorizes future strategies to facilitate further integration of hyperthermia with the current treatment modalities. These could gainfully accomplish a safe, versatile, and cost-effective enhancement of the existing therapeutic armamentarium to improve outcomes in clinical oncology.
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Affiliation(s)
- Niloy R Datta
- Centre for Radiation Oncology KSA-KSB, Kantonsspital Aarau, Aarau, Switzerland
| | - H Petra Kok
- Department of Radiation Oncology, Cancer Center Amsterdam, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Hans Crezee
- Department of Radiation Oncology, Cancer Center Amsterdam, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Udo S Gaipl
- Department of Radiation Oncology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Stephan Bodis
- Centre for Radiation Oncology KSA-KSB, Kantonsspital Aarau, Aarau, Switzerland
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15
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Role of Simulations in the Treatment Planning of Radiofrequency Hyperthermia Therapy in Clinics. JOURNAL OF ONCOLOGY 2019; 2019:9685476. [PMID: 31558904 PMCID: PMC6735211 DOI: 10.1155/2019/9685476] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 07/20/2019] [Accepted: 07/28/2019] [Indexed: 12/26/2022]
Abstract
Hyperthermia therapy is a treatment modality in which tumor temperatures are elevated to higher temperatures to cause damage to cancerous tissues. Numerical simulations are integral in the development of hyperthermia treatment systems and in clinical treatment planning. In this study, simulations in radiofrequency hyperthermia therapy are reviewed in terms of their technical development and clinical aspects for effective clinical use. This review offers an overview of mathematical models and the importance of tissue properties; locoregional mild hyperthermia therapy, including phantom and realistic human anatomy models; phase array systems; tissue damage; thermal dose analysis; and thermoradiotherapy planning. This review details the improvements in numerical approaches in treatment planning and their application for effective clinical use. Furthermore, the modeling of thermoradiotherapy planning, which can be integrated with radiotherapy to provide combined hyperthermia and radiotherapy treatment planning strategies, are also discussed. This review may contribute to the effective development of thermoradiotherapy planning in clinics.
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16
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Aklan B, Zilles B, Paprottka P, Manz K, Pfirrmann M, Santl M, Abdel-Rahman S, Lindner LH. Regional deep hyperthermia: quantitative evaluation of predicted and direct measured temperature distributions in patients with high-risk extremity soft-tissue sarcoma. Int J Hyperthermia 2019; 36:170-185. [PMID: 30777497 DOI: 10.1080/02656736.2018.1545098] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
BACKGROUND Temperature distributions resulting from hyperthermia treatment of patients with high-risk soft-tissue sarcoma (STS) were quantitatively evaluated and globally compared with thermal simulations performed by a treatment planning system. The aim was to test whether the treatment planning system was able to predict correct temperature distributions. METHODS Five patients underwent computed tomography (CT) fluoroscopy-guided placement of tumor catheters used for the interstitial temperature measurements. For the simulations, five 3 D patient models were reconstructed by segmenting the patient CT datasets into different tissues. The measured and simulated data were evaluated by calculating the temperature change ( ΔT ), T90, T50, T20, Tmean, Tmin and Tmax, as well as the 90th percentile thermal dose (CEM43T90). In order to measure the agreement between both methods quantitatively, the Bland-Altman analysis was applied. RESULTS The absolute difference between measured and simulated temperatures were found to be 2°, 6°, 1°, 4°, 5° and 4 °C on average for Tmin, Tmax, T90, T50, T20 and Tmean, respectively. Furthermore, the thermal simulations exhibited relatively higher thermal dose compared to those that were measured. Finally, the results of the Bland-Altman analysis showed that the mean difference between both methods was above 2 °C which is considered to be clinically unacceptable. CONCLUSION Given the current practical limitations on resolution of calculation grid, tissue properties, and perfusion information, the software SigmaHyperPlan™ is incapable to produce thermal simulations with sufficient correlation to typically heterogeneous tissue temperatures to be useful for clinical treatment planning.
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Affiliation(s)
- B Aklan
- a Department of Internal Medicine III , Ludwig Maximilians University Hospital , Munich , Germany
| | - B Zilles
- a Department of Internal Medicine III , Ludwig Maximilians University Hospital , Munich , Germany
| | - P Paprottka
- b Institute for Clinical Radiology, Ludwig Maximilians University Hospital , Munich, Germany
| | - K Manz
- c Institute for Medical Information Processing, Biometry, and Epidemiology (IBE), Ludwig-Maximilians-University Munich , Munich , Germany
| | - M Pfirrmann
- c Institute for Medical Information Processing, Biometry, and Epidemiology (IBE), Ludwig-Maximilians-University Munich , Munich , Germany
| | - M Santl
- a Department of Internal Medicine III , Ludwig Maximilians University Hospital , Munich , Germany
| | - S Abdel-Rahman
- a Department of Internal Medicine III , Ludwig Maximilians University Hospital , Munich , Germany
| | - L H Lindner
- a Department of Internal Medicine III , Ludwig Maximilians University Hospital , Munich , Germany
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17
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Bellizzi GG, Drizdal T, van Rhoon GC, Crocco L, Isernia T, Paulides MM. The potential of constrained SAR focusing for hyperthermia treatment planning: analysis for the head & neck region. Phys Med Biol 2018; 64:015013. [PMID: 30523869 DOI: 10.1088/1361-6560/aaf0c4] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Clinical trials have shown that hyperthermia is a potent adjuvant to conventional cancer treatments, but the temperatures currently achieved in the clinic are still suboptimal. Hyperthermia treatment planning simulations have potential to improve the heating profile of phased-array applicators. An important open challenge is the development of an effective optimization procedure that enables uniform heating of the target region while keeping temperature below a threshold in healthy tissues. In this work, we analyzed the effectiveness and efficiency of a recently proposed optimization approach, i.e. focusing via constrained power optimization (FOCO), using 3D simulations of twelve clinical patient specific models. FOCO performance was compared against a clinically used particle swarm based optimization approach. Evaluation metrics were target coverage at the 25% iso-SAR level, target hotspot quotient, median target temperature (T50) and computational requirements. Our results show that, on average, constrained power focusing performs slightly better than the clinical benchmark ([Formula: see text]T50 [Formula: see text] °C), but outperforms this clinical benchmark for large target volumes ([Formula: see text]40 cm[Formula: see text], [Formula: see text]T50 [Formula: see text] °C). In addition, the results are achieved in a shorter time ([Formula: see text]%) and are repeatable because the approach is formulated as a convex optimization problem.
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Affiliation(s)
- G G Bellizzi
- Universitá Mediterranea di Reggio Calabria, DIIES, Reggio di Calabria, Italy. Erasmus Medical Center, Radiation Oncology Department, Hyperthermia Unit, Rotterdam, The Netherlands. IREA-CNR, Institute for Electromagnetic Sensing of the Environment, National Research Council of Italy, Napoli, Italy. Author to whom any correspondence should be addressed
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18
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Kok HP, Schooneveldt G, Bakker A, de Kroon-Oldenhof R, Korshuize-van Straten L, de Jong CE, Steggerda-Carvalho E, Geijsen ED, Stalpers LJA, Crezee J. Predictive value of simulated SAR and temperature for changes in measured temperature after phase-amplitude steering during locoregional hyperthermia treatments. Int J Hyperthermia 2018; 35:330-339. [DOI: 10.1080/02656736.2018.1500720] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Affiliation(s)
- H. P. Kok
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - G. Schooneveldt
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - A. Bakker
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - R. de Kroon-Oldenhof
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - L. Korshuize-van Straten
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - C. E. de Jong
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - E. Steggerda-Carvalho
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - E. D. Geijsen
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - L. J. A. Stalpers
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - J. Crezee
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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19
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Guérin B, Villena JF, Polimeridis AG, Adalsteinsson E, Daniel L, White JK, Rosen BR, Wald LL. Computation of ultimate SAR amplification factors for radiofrequency hyperthermia in non-uniform body models: impact of frequency and tumour location. Int J Hyperthermia 2018; 34:87-100. [PMID: 28540815 PMCID: PMC5681886 DOI: 10.1080/02656736.2017.1319077] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 04/10/2017] [Accepted: 04/10/2017] [Indexed: 10/19/2022] Open
Abstract
PURPOSE We introduce a method for calculation of the ultimate specific absorption rate (SAR) amplification factors (uSAF) in non-uniform body models. The uSAF is the greatest possible SAF achievable by any hyperthermia (HT) phased array for a given frequency, body model and target heating volume. METHODS First, we generate a basis-set of solutions to Maxwell's equations inside the body model. We place a large number of electric and magnetic dipoles around the body model and excite them with random amplitudes and phases. We then compute the electric fields created in the body model by these excitations using an ultra-fast volume integral solver called MARIE. We express the field pattern that maximises the SAF in the target tumour as a linear combination of these basis fields and optimise the combination weights so as to maximise SAF (concave problem). We compute the uSAFs in the Duke body models at 10 frequencies in the 20-900 MHz range and for twelve 3 cm-diameter tumours located at various depths in the head and neck. RESULTS For both shallow and deep tumours, the frequency yielding the greatest uSAF was ∼900 MHz. Since this is the greatest frequency that we simulated, we hypothesise that the globally optimal frequency is actually greater. CONCLUSIONS The uSAFs computed in this work are very large (40-100 for shallow tumours and 4-17 for deep tumours), indicating that there is a large room for improvement of the current state-of-the-art head and neck HT devices.
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Affiliation(s)
- Bastien Guérin
- a Martinos Center for Biomedical Imaging, Department of Radiology , Massachusetts General Hospital , Charlestown , MA , USA
- b Harvard Medical School , Boston , MA , USA
| | | | | | - Elfar Adalsteinsson
- e Research Laboratory of Electronics , Massachusetts Institute of Technology , Cambridge , MA , USA
- f Harvard-MIT Division of Health Sciences Technology , Cambridge , MA , USA
| | - Luca Daniel
- e Research Laboratory of Electronics , Massachusetts Institute of Technology , Cambridge , MA , USA
| | - Jacob K White
- e Research Laboratory of Electronics , Massachusetts Institute of Technology , Cambridge , MA , USA
| | - Bruce R Rosen
- a Martinos Center for Biomedical Imaging, Department of Radiology , Massachusetts General Hospital , Charlestown , MA , USA
- b Harvard Medical School , Boston , MA , USA
- f Harvard-MIT Division of Health Sciences Technology , Cambridge , MA , USA
| | - Lawrence L Wald
- a Martinos Center for Biomedical Imaging, Department of Radiology , Massachusetts General Hospital , Charlestown , MA , USA
- b Harvard Medical School , Boston , MA , USA
- f Harvard-MIT Division of Health Sciences Technology , Cambridge , MA , USA
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20
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Kok HP, Korshuize-van Straten L, Bakker A, de Kroon – Oldenhof R, Westerveld GH, Versteijne E, Stalpers LJA, Crezee J. Feasibility of on-line temperature-based hyperthermia treatment planning to improve tumour temperatures during locoregional hyperthermia. Int J Hyperthermia 2017; 34:1082-1091. [DOI: 10.1080/02656736.2017.1400120] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Affiliation(s)
- H. P. Kok
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - L. Korshuize-van Straten
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - A. Bakker
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - R. de Kroon – Oldenhof
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - G. H. Westerveld
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - E. Versteijne
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - L. J. A. Stalpers
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - J. Crezee
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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21
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Online Adaptive Hyperthermia Treatment Planning During Locoregional Heating to Suppress Treatment-Limiting Hot Spots. Int J Radiat Oncol Biol Phys 2017; 99:1039-1047. [PMID: 28870786 DOI: 10.1016/j.ijrobp.2017.07.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 07/05/2017] [Accepted: 07/10/2017] [Indexed: 01/20/2023]
Abstract
BACKGROUND Adequate tumor temperatures during hyperthermia are essential for good clinical response, but excessive heating of normal tissue should be avoided. This makes locoregional heating using phased array systems technically challenging. Online application of hyperthermia treatment planning could help to improve the heating quality. The aim of this study was to evaluate the clinical benefit of online treatment planning during treatment of pelvic tumors heated with the AMC-8 locoregional hyperthermia system. METHODS For online adaptive hyperthermia treatment planning, a graphical user interface was developed. Electric fields were calculated in a preprocessing step using our in-house-developed finite-difference-based treatment planning system. This allows instant calculation of the temperature distribution for user-selected phase-amplitude settings during treatment and projection onto the patient's computed tomographic scan for online visualization. Online treatment planning was used for 14 treatment sessions in 8 patients to reduce the patients' reports of hot spots while maintaining the same level of tumor heating. The predicted decrease in hot spot temperature should be at least 0.5°C, and the tumor temperature should decrease less than 0.2°C. These predictions were compared with clinical data: patient feedback about the hot spot and temperature measurements in the tumor region. RESULTS In total, 17 hot spot reports occurred during the 14 sessions, and the alternative settings predicted the hot spot temperature to decrease by at least 0.5°C, which was confirmed by the disappearance of all 17 hot spot reports. At the same time, the average tumor temperature was predicted to change on average -0.01°C (range, -0.19°C to 0.34°C). The measured tumor temperature change was on average only -0.02°C (range, -0.26°C to 0.31°C). In only 2 cases the temperature decrease was slightly larger than 0.2°C, but at most it was 0.26°C. CONCLUSIONS Online application of hyperthermia treatment planning is reliable and very useful to reduce hot spots without affecting tumor temperatures.
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22
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van Leeuwen CM, Oei AL, Ten Cate R, Franken NAP, Bel A, Stalpers LJA, Crezee J, Kok HP. Measurement and analysis of the impact of time-interval, temperature and radiation dose on tumour cell survival and its application in thermoradiotherapy plan evaluation. Int J Hyperthermia 2017; 34:30-38. [PMID: 28540813 DOI: 10.1080/02656736.2017.1320812] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
PURPOSE Biological modelling of thermoradiotherapy may further improve patient selection and treatment plan optimisation, but requires a model that describes the biological effect as a function of variables that affect treatment outcome (e.g. temperature, radiation dose). This study aimed to establish such a model and its parameters. Additionally, a clinical example was presented to illustrate the application. METHODS Cell survival assays were performed at various combinations of radiation dose (0-8 Gy), temperature (37-42 °C), time interval (0-4 h) and treatment sequence (radiotherapy before/after hyperthermia) for two cervical cancer cell lines (SiHa and HeLa). An extended linear-quadratic model was fitted to the data using maximum likelihood estimation. As an example application, a thermoradiotherapy plan (23 × 2 Gy + weekly hyperthermia) was compared with a radiotherapy-only plan (23 × 2 Gy) for a cervical cancer patient. The equivalent uniform radiation dose (EUD) in the tumour, including confidence intervals, was estimated using the SiHa parameters. Additionally, the difference in tumour control probability (TCP) was estimated. RESULTS Our model described the dependency of cell survival on dose, temperature and time interval well for both SiHa and HeLa data (R2=0.90 and R2=0.91, respectively), making it suitable for biological modelling. In the patient example, the thermoradiotherapy plan showed an increase in EUD of 9.8 Gy that was robust (95% CI: 7.7-14.3 Gy) against propagation of the uncertainty in radiobiological parameters. This corresponded to a 20% (95% CI: 15-29%) increase in TCP. CONCLUSIONS This study presents a model that describes the cell survival as a function of radiation dose, temperature and time interval, which is essential for biological modelling of thermoradiotherapy treatments.
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Affiliation(s)
- C M van Leeuwen
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
| | - A L Oei
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands.,b Laboratory for Experimental Oncology and Radiobiology (LEXOR)/Center for Experimental Molecular Medicine , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
| | - R Ten Cate
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands.,b Laboratory for Experimental Oncology and Radiobiology (LEXOR)/Center for Experimental Molecular Medicine , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
| | - N A P Franken
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands.,b Laboratory for Experimental Oncology and Radiobiology (LEXOR)/Center for Experimental Molecular Medicine , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
| | - A Bel
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
| | - L J A Stalpers
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
| | - J Crezee
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
| | - H P Kok
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
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Kok HP, Kotte ANTJ, Crezee J. Planning, optimisation and evaluation of hyperthermia treatments. Int J Hyperthermia 2017; 33:593-607. [PMID: 28540779 DOI: 10.1080/02656736.2017.1295323] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Hyperthermia treatment planning using dedicated simulations of power and temperature distributions is very useful to assist in hyperthermia applications. This paper describes an advanced treatment planning software package for a wide variety of applications. METHODS The in-house developed C++ software package Plan2Heat runs on a Linux operating system. Modules are available to perform electric field and temperature calculations for many heating techniques. The package also contains optimisation routines, post-treatment evaluation tools and a sophisticated thermal model enabling to account for 3D vasculature based on an angiogram or generated artificially using a vessel generation algorithm. The use of the software is illustrated by a simulation of a locoregional hyperthermia treatment for a pancreatic cancer patient and a spherical tumour model heated by interstitial hyperthermia, with detailed 3D vasculature included. RESULTS The module-based set-up makes the software flexible and easy to use. The first example demonstrates that treatment planning can help to focus the heating to the tumour. After optimisation, the simulated absorbed power in the tumour increased with 50%. The second example demonstrates the impact of accurately modelling discrete vasculature. Blood at body core temperature entering the heated volume causes relatively cold tracks in the heated volume, where the temperature remains below 40 °C. CONCLUSIONS A flexible software package for hyperthermia treatment planning has been developed, which can be very useful in many hyperthermia applications. The object-oriented structure of the source code allows relatively easy extension of the software package with additional tools when necessary for future applications.
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Affiliation(s)
- H P Kok
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
| | - A N T J Kotte
- b Department of Radiotherapy , University Medical Center Utrecht , Utrecht , The Netherlands
| | - J Crezee
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
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van Leeuwen CM, Crezee J, Oei AL, Franken NAP, Stalpers LJA, Bel A, Kok HP. 3D radiobiological evaluation of combined radiotherapy and hyperthermia treatments. Int J Hyperthermia 2016; 33:160-169. [PMID: 27744728 DOI: 10.1080/02656736.2016.1241431] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
PURPOSE Currently, clinical decisions regarding thermoradiotherapy treatments are based on clinical experience. Quantification of the radiosensitising effect of hyperthermia allows comparison of different treatment strategies, and can support clinical decision-making regarding the optimal treatment. The software presented here enables biological evaluation of thermoradiotherapy plans through calculation of equivalent 3D dose distributions. METHODS Our in-house developed software (X-Term) uses an extended version of the linear-quadratic model to calculate equivalent radiation dose, i.e. the radiation dose yielding the same effect as the thermoradiotherapy treatment. Separate sets of model parameters can be assigned to each delineated structure, allowing tissue specific modelling of hyperthermic radiosensitisation. After calculation, the equivalent radiation dose can be evaluated according to conventional radiotherapy planning criteria. The procedure is illustrated using two realistic examples. First, for a previously irradiated patient, normal tissue dose for a radiotherapy and thermoradiotherapy plan (with equal predicted tumour control) is compared. Second, tumour control probability (TCP) is assessed for two (otherwise identical) thermoradiotherapy schedules with different time intervals between radiotherapy and hyperthermia. RESULTS The examples demonstrate that our software can be used for individualised treatment decisions (first example) and treatment optimisation (second example) in thermoradiotherapy. In the first example, clinically acceptable doses to the bowel were exceeded for the conventional plan, and a substantial reduction of this excess was predicted for the thermoradiotherapy plan. In the second example, the thermoradiotherapy schedule with long time interval was shown to result in a substantially lower TCP. CONCLUSIONS Using biological modelling, our software can facilitate the evaluation of thermoradiotherapy plans and support individualised treatment decisions.
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Affiliation(s)
- C M van Leeuwen
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
| | - J Crezee
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
| | - A L Oei
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands.,b Laboratory for Experimental Oncology and Radiobiology (LEXOR)/Center for Experimental Molecular Medicine , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
| | - N A P Franken
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands.,b Laboratory for Experimental Oncology and Radiobiology (LEXOR)/Center for Experimental Molecular Medicine , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
| | - L J A Stalpers
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
| | - A Bel
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
| | - H P Kok
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
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Schooneveldt G, Kok HP, Balidemaj E, Geijsen ED, van Ommen F, Sijbrands J, Bakker A, de la Rosette JJMCH, Hulshof MCCM, de Reijke TM, Crezee J. Improving hyperthermia treatment planning for the pelvis by accurate fluid modeling. Med Phys 2016; 43:5442. [DOI: 10.1118/1.4961741] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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Schooneveldt G, Bakker A, Balidemaj E, Chopra R, Crezee J, Geijsen ED, Hartmann J, Hulshof MC, Kok HP, Paulides MM, Sousa-Escandon A, Stauffer PR, Maccarini PF. Thermal dosimetry for bladder hyperthermia treatment. An overview. Int J Hyperthermia 2016; 32:417-33. [DOI: 10.3109/02656736.2016.1156170] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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Balidemaj E, Kok HP, Schooneveldt G, van Lier ALHMW, Remis RF, Stalpers LJA, Westerveld H, Nederveen AJ, van den Berg CAT, Crezee J. Hyperthermia treatment planning for cervical cancer patients based on electrical conductivity tissue properties acquired in vivo with EPT at 3 T MRI. Int J Hyperthermia 2016; 32:558-68. [PMID: 26982889 DOI: 10.3109/02656736.2015.1129440] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Introduction The reliability of hyperthermia treatment planning (HTP) is strongly dependent on the accuracy of the electric properties of each tissue. The values currently used are mostly based on ex vivo measurements. In this study, in vivo conductivity of human muscle, bladder content and cervical tumours, acquired with magnetic resonance-based electric properties tomography (MR-EPT), are exploited to investigate the effect on HTP for cervical cancer patients. Methods Temperature-based optimisation of five different patients was performed using literature-based conductivity values yielding certain antenna settings, which are then used to compute the temperature distribution of the patient models with EPT-based conductivity values. Furthermore, the effects of altered bladder and muscle conductivity were studied separately. Finally, the temperature-based optimisation was performed with patient models based on EPT conductivity values. Results The tumour temperatures for all EPT-based dielectric patient models were lower compared to the optimal tumour temperatures based on literature values. The largest deviation was observed for patient 1 with ΔT90 = -1.37 °C. A negative impact was also observed when the treatment was optimised based on the EPT values. For four patients ΔT90 was less than 0.6 °C; for one patient it was 1.5 °C. Conclusions Electric conductivity values acquired by EPT are higher than commonly used from literature. This difference has a substantial impact on cervical tumour temperatures achieved during hyperthermia. A higher conductivity in the bladder and in the muscle tissue surrounding the tumour leads to higher power dissipation in the bladder and muscle, and therefore to lower tumour temperatures.
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Affiliation(s)
- Edmond Balidemaj
- a Department of Radiation Oncology , Academic Medical Centre , Meibergdreef 9 , Amsterdam , 1105 AZ Netherlands
| | - Henny Petra Kok
- a Department of Radiation Oncology , Academic Medical Centre , Meibergdreef 9 , Amsterdam , 1105 AZ Netherlands
| | - Gerben Schooneveldt
- a Department of Radiation Oncology , Academic Medical Centre , Meibergdreef 9 , Amsterdam , 1105 AZ Netherlands
| | | | - Rob F Remis
- c Circuits and Systems Group, Delft Technical University Technical University , Delft , Netherlands
| | - Lukas J A Stalpers
- a Department of Radiation Oncology , Academic Medical Centre , Meibergdreef 9 , Amsterdam , 1105 AZ Netherlands
| | - Henrike Westerveld
- a Department of Radiation Oncology , Academic Medical Centre , Meibergdreef 9 , Amsterdam , 1105 AZ Netherlands
| | - Aart J Nederveen
- a Department of Radiation Oncology , Academic Medical Centre , Meibergdreef 9 , Amsterdam , 1105 AZ Netherlands
| | | | - Johannes Crezee
- a Department of Radiation Oncology , Academic Medical Centre , Meibergdreef 9 , Amsterdam , 1105 AZ Netherlands
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Cordeiro ER, Geijsen DE, Zum Vörde Sive Vörding PJ, Schooneveldt G, Sijbrands J, Hulshof MC, de la Rosette J, de Reijke TM, Crezee H. Novel multisensor probe for monitoring bladder temperature during locoregional chemohyperthermia for nonmuscle-invasive bladder cancer: technical feasibility study. J Endourol 2013; 27:1504-9. [PMID: 24112045 DOI: 10.1089/end.2013.0179] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND AND PURPOSE The effectiveness of locoregional hyperthermia combined with intravesical instillation of mitomycin C to reduce the risk of recurrence and progression of intermediate- and high-risk nonmuscle-invasive bladder cancer is currently investigated in clinical trials. Clinically effective locoregional hyperthermia delivery necessitates adequate thermal dosimetry; thus, optimal thermometry methods are needed to monitor accurately the temperature distribution throughout the bladder wall. The aim of the study was to evaluate the technical feasibility of a novel intravesical device (multi-sensor probe) developed to monitor the local bladder wall temperatures during loco-regional C-HT. MATERIALS AND METHODS A multisensor thermocouple probe was designed for deployment in the human bladder, using special sensors to cover the bladder wall in different directions. The deployment of the thermocouples against the bladder wall was evaluated with visual, endoscopic, and CT imaging in bladder phantoms, porcine models, and human bladders obtained from obduction for bladder volumes and different deployment sizes of the probe. Finally, porcine bladders were embedded in a phantom and subjected to locoregional heating to compare probe temperatures with additional thermometry inside and outside the bladder wall. RESULTS The 7.5 cm thermocouple probe yielded optimal bladder wall contact, adapting to different bladder volumes. Temperature monitoring was shown to be accurate and representative for the actual bladder wall temperature. CONCLUSIONS Use of this novel multisensor probe could yield a more accurate monitoring of the bladder wall temperature during locoregional chemohyperthermia.
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Affiliation(s)
- Ernesto R Cordeiro
- 1 Department of Urology, Academic Medical Center , Amsterdam, The Netherlands
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Kok HP, van den Berg CAT, Bel A, Crezee J. Fast thermal simulations and temperature optimization for hyperthermia treatment planning, including realistic 3D vessel networks. Med Phys 2013; 40:103303. [DOI: 10.1118/1.4821544] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Cordeiro Feijoo ER, Geijsen DE, Zum Vörde Sive Vörding PJ, Schooneveldt G, Sijbrands J, Hulshof MC, De La Rosette J, de Reijke TM, Crezee H. Novel multi-sensor probe for monitoring bladder temperature during loco-regional chemo-hyperthermia for non-muscle invasive bladder cancer: technical feasibility study. J Endourol 2013. [DOI: 10.1089/end.2013-0179.ecb13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Paulides MM, Stauffer PR, Neufeld E, Maccarini PF, Kyriakou A, Canters RAM, Diederich CJ, Bakker JF, Van Rhoon GC. Simulation techniques in hyperthermia treatment planning. Int J Hyperthermia 2013; 29:346-57. [PMID: 23672453 PMCID: PMC3711016 DOI: 10.3109/02656736.2013.790092] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract Clinical trials have shown that hyperthermia (HT), i.e. an increase of tissue temperature to 39-44 °C, significantly enhance radiotherapy and chemotherapy effectiveness [1]. Driven by the developments in computational techniques and computing power, personalised hyperthermia treatment planning (HTP) has matured and has become a powerful tool for optimising treatment quality. Electromagnetic, ultrasound, and thermal simulations using realistic clinical set-ups are now being performed to achieve patient-specific treatment optimisation. In addition, extensive studies aimed to properly implement novel HT tools and techniques, and to assess the quality of HT, are becoming more common. In this paper, we review the simulation tools and techniques developed for clinical hyperthermia, and evaluate their current status on the path from 'model' to 'clinic'. In addition, we illustrate the major techniques employed for validation and optimisation. HTP has become an essential tool for improvement, control, and assessment of HT treatment quality. As such, it plays a pivotal role in the quest to establish HT as an efficacious addition to multi-modality treatment of cancer.
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Affiliation(s)
- Margarethus M Paulides
- Hyperthermia Unit, Department of Radiation Oncology, Daniel den Hoed Cancer Centre, Erasmus Medical Centre, Rotterdam, The Netherlands.
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Bardati F, Tognolatti P. Figures of merit and their bounds in radiofrequency heating by phased arrays. Int J Hyperthermia 2013; 29:169-80. [PMID: 23590360 DOI: 10.3109/02656736.2013.784813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
PURPOSE The problem of effective power delivery to a semi-deep target by a phased array has been addressed for application to hyperthermia treatment of some tumours in the thorax. METHODS Three efficiencies have been introduced, which estimate system ability in power transfer from generators to body, from body to tumour, and from generators to tumour. They are formulated in terms of a dissipation matrix and an interference matrix. Bounds to achievable efficiencies are obtained. Further figures of merit have also been introduced. The necessary mathematics has been developed. RESULTS A numerical analysis has been carried out for a partially interdigitated planar array of resonant dipoles. Results show how the new parameters can be exploited for optimal selection of the array's degrees of freedom. CONCLUSION The figures of merit and their bounds allow comparisons between RF heating devices and provide guidelines to phased array design.
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Affiliation(s)
- Fernando Bardati
- Department of Civil Engineering and Computer Science, University of Rome Tor Vergata, Rome, Italy.
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Bruggmoser G, Bauchowitz S, Canters R, Crezee H, Ehmann M, Gellermann J, Lamprecht U, Lomax N, Messmer M, Ott O, Abdel-Rahman S, Schmidt M, Sauer R, Thomsen A, Wessalowski R, van Rhoon G. Guideline for the clinical application, documentation and analysis of clinical studies for regional deep hyperthermia. Strahlenther Onkol 2012; 188 Suppl 2:198-211. [DOI: 10.1007/s00066-012-0176-2] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Salgaonkar VA, Prakash P, Diederich CJ. Temperature superposition for fast computation of 3D temperature distributions during optimization and planning of interstitial ultrasound hyperthermia treatments. Int J Hyperthermia 2012; 28:235-49. [PMID: 22515345 DOI: 10.3109/02656736.2012.662666] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
PURPOSE A temperature superposition method has been developed for fast optimisation and planning of interstitial hyperthermia treatments with convectively cooled multi-transducer ultrasound applicators integrated within high dose rate (HDR) brachytherapy catheters. METHODS Steady-state temperature distributions produced by individual tubular transducers capable of directional heating were pre-computed using finite element models (FEM) methods. The composite temperature distributions generated by multi-applicator implants were approximated as superposition sums of the pre-computed temperature profiles. Composite temperature distributions produced by the multi-applicator implants were also computed using accurate but computationally expensive FEM methods (considered here as the validation standard). Both methods were used for temperature calculation on a range of test implant geometries and representative patient cases (HDR implants in prostate (n = 13) and cervix (n = 2)), with optimised treatment plans created for the latter. RESULTS Difference between temperatures calculated by the superposition and FEM methods was below 0.37°C (95% confidence interval) in test implants at clinically relevant acoustic intensities (0.3-2.0 W/cm²) and blood perfusion (2 kg/m³/s). Difference in 41°C isothermal volumes was below 8.3%. Superposition-based optimisations followed by FEM forward calculations (hybrid plans) were completed 4-7 times faster than FEM-only plans (FEM optimisation + FEM forward). Mean T₉₀, T₅₀ and T₁₀ values from both plans were within 0.3°C, 0.4°C and 0.45°C respectively, and the mean acoustic intensities were within 0.23 W/cm². CONCLUSIONS Temperature superposition provides a fast technique for forward or optimised planning of interstitial ultrasound hyperthermia treatments with calculations comparable to more accurate but time consuming FEM methods.
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Affiliation(s)
- Vasant A Salgaonkar
- Department of Radiation Oncology, University of California, San Francisco, California, USA
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De Greef M, Kok HP, Bel A, Crezee J. 3D versus 2D steering in patient anatomies: A comparison using hyperthermia treatment planning. Int J Hyperthermia 2011; 27:74-85. [DOI: 10.3109/02656736.2010.531882] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Kayal S, Bandyopadhyay D, Mandal TK, Ramanujan RV. The flow of magnetic nanoparticles in magnetic drug targeting. RSC Adv 2011. [DOI: 10.1039/c1ra00023c] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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van Haaren PMA, Kok HP, Zum Vörde Sive Vörding PJ, van Dijk JDP, Hulshof MCCM, Fockens P, van Lanschot JJB, Crezee J. Reliability of temperature and SAR measurements at oesophageal tumour locations. Int J Hyperthermia 2010; 22:545-61. [PMID: 17079213 DOI: 10.1080/02656730600931765] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
INTRODUCTION For treatment of oesophageal cancer, neo-adjuvant locoregional hyperthermia (HT) has been applied in combination with chemotherapy (ChT) +/- radiotherapy (RT) at the institute. Until now, 26 patients were treated within a completed phase I study combining HT with ChT and 29 patients within an ongoing phase II study combining HT with ChT + RT. METHODS HT was given with the 70 MHz AMC-4 waveguide system. Initially, oesophageal temperatures were measured using multi-sensor thermocouple probes (TCs) inside a nasogastric tube (NT), but the question arose whether these measurements were reliable enough to quantify the achieved tumour temperatures accurately. Presently, TCs are mounted on the outside of an inflatable balloon catheter (BC) for better intra-luminal fixation and better contact with the tumour. During 14 treatment sessions in four patients TCs inside a NT and mounted on a BC were used simultaneously. Data from these 14 treatment sessions were used to compare temperature and Specific Absorption Rate (SAR) measurements ('DeltaT-measurements') using NTs or BCs. To determine the predictive value of the local SAR for the tumour temperatures achieved during treatment, the relation between the initial DeltaT and steady state temperature (SST) was evaluated. RESULTS There was a strong correlation between the temperature measured in the NT (Ttube) and the temperature measured with a BC (Tballoon): R = 0.88 +/- 0.13. However, Ttube was on average approximately 1 degrees C higher than Tballoon and there was a large variation between the different treatments in the relation between both measurements, rendering Ttube a probably unreliable measure for tumour temperatures. The correlation between the DeltaT measured in the NT (DeltaTtube) and with a BC (DeltaTballoon) was rather weak: R = 0.46 +/- 0.25. The correlation between the initial DeltaT and the SST was much stronger for the BC measurements, R = 0.78 +/- 0.19, than for the NT measurements, R = 0.61 +/- 0.23. Thus, DeltaTballoon has a higher predictive value for the achieved tumour temperatures than DeltaTtube. Both DeltaT and SST were generally higher for the NT measurements than for the BC measurements, suggesting an over-estimation of tumour temperatures. Averaged over all treatments in the phase I trial using a NT (20 treatments) or a BC (45 treatments), T90 was significantly higher when measured with a NT. CONCLUSION Oesophageal temperature and SAR (DeltaT) measurements inside a NT are less reliable than BC measurements. These artefacts are due to bad thermal contact with the tumour tissue and are, therefore, not specific for thermocouple thermometry. For reliable temperature or SAR measurements inside lumina or cavities good thermal contact must be assured, e.g. by using a balloon catheter.
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Affiliation(s)
- P M A van Haaren
- Department of Radiation Oncology, Academic Medical Centre, University of Amsterdam, The Netherlands.
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Trefná HD, Vrba J, Persson M. Time-reversal focusing in microwave hyperthermia for deep-seated tumors. Phys Med Biol 2010; 55:2167-85. [PMID: 20348605 DOI: 10.1088/0031-9155/55/8/004] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A fast beam-forming method for hyperthermia treatment of deep-seated tumors is described and verified. The approach is based on the time-reversal characteristics of Maxwell equations. The basic principle of the method is coupling of the electromagnetic modeling of the system with the actual application. In this modeling the wavefront of the source is propagated through a patient-specific model from a virtual antenna placed in the tumor of the model. The simulated radiated field is then captured using a computer model of the surrounding antenna system. The acquired amplitudes and phases are then used in the real antenna system. The effectiveness of this procedure is demonstrated by calculating the power absorption distribution using FDTD electromagnetic simulations of a realistic 2D breast model as well as a 2D neck model. Several design parameters, i.e. number of antennas, operating frequency and dimensions, have been evaluated by performance indicators. The promising results suggest that the development of this technique is pursued further.
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Kok HP, De Greef M, Correia D, Vörding PJZVS, Van Stam G, Gelvich EA, Bel A, Crezee J. FDTD simulations to assess the performance of CFMA-434 applicators for superficial hyperthermia. Int J Hyperthermia 2010; 25:462-76. [PMID: 19657850 DOI: 10.1080/02656730903008493] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
INTRODUCTION Contact flexible microstrip applicators (CFMA), operating at 434 MHz, are applied at the Academic Medical Center (AMC) for superficial hyperthermia (e.g. chest wall recurrences and melanoma). This paper investigates the performance of CFMA, evaluating the stability of the specific absorption rate (SAR) distribution, effective heating depth (EHD) and effective field size (EFS) under different conditions. METHODS Simulations were performed using finite differences and were compared to existing measurement data, performed using a rectangular phantom with a superficial fat-equivalent layer of 1 cm and filled with saline solution. The electrode plates of the applicators measure approximately 7 x 20, 29 x 21 and 20 x 29 cm(2). Bolus thickness varied between 1 and 2 cm. The impact of the presence of possible air layers between the rubber frame and the electrodes on the SAR distribution was investigated. RESULTS The EHD was approximately 1.4 cm and the EFS ranged between approximately 60 and approximately 300 cm(2), depending on the applicator type. Both measurements and simulations showed a split-up of the SAR focus with a 2 cm water bolus. The extent and location of air layers has a strong influence on the shape and size of the iso-SAR contours with a value higher than 50%, but the impact on EFS and EHD is limited. CONCLUSION Simulations, confirmed by measurements, showed that the presence of air between the rubber and the electrodes changes the iso-SAR contours, but the impact on the EFS and EHD is limited.
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Affiliation(s)
- H Petra Kok
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
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Chen X, Diederich CJ, Wootton JH, Pouliot J, Hsu IC. Optimisation-based thermal treatment planning for catheter-based ultrasound hyperthermia. Int J Hyperthermia 2010; 26:39-55. [DOI: 10.3109/02656730903341332] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Crezee J, Van Haaren P, Westendorp H, De Greef M, Kok H, Wiersma J, Van Stam G, Sijbrands J, Zum Vörde Sive Vörding P, Van Dijk J, Hulshof M, Bel A. Improving locoregional hyperthermia delivery using the 3-D controlled AMC-8 phased array hyperthermia system: A preclinical study. Int J Hyperthermia 2009; 25:581-92. [DOI: 10.3109/02656730903213374] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Kok HP, de Greef M, Bel A, Crezee J. Acceleration of high resolution temperature based optimization for hyperthermia treatment planning using element grouping. Med Phys 2009; 36:3795-805. [DOI: 10.1118/1.3168973] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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van Haaren PMA, Hulshof MCCM, Kok HP, Oldenborg S, Geijsen ED, Van Lanschot JJB, Crezee J. Relation between body size and temperatures during locoregional hyperthermia of oesophageal cancer patients. Int J Hyperthermia 2009; 24:663-74. [DOI: 10.1080/02656730802210448] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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van Haaren PMA, Kok HP, van den Berg CAT, Zum Vörde Sive Vörding PJ, Oldenborg S, Stalpers LJA, Schilthuis MS, de Leeuw AAC, Crezee J. On verification of hyperthermia treatment planning for cervical carcinoma patients. Int J Hyperthermia 2009; 23:303-14. [PMID: 17523022 DOI: 10.1080/02656730701297538] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
PURPOSE The aim of this study was to verify hyperthermia treatment planning calculations by means of measurements performed during hyperthermia treatments. The calculated specific absorption rate (SAR(calc)) was compared with clinically measured SAR values, during 11 treatments in seven cervical carcinoma patients. METHODS Hyperthermia treatments were performed using the 70 MHz AMC-4 waveguide system. Temperatures were measured using multisensor thermocouple probes. One invasive thermometry catheter in the cervical tumour and two non-invasive catheters in the vagina were used. For optimal tissue contact and fixation of the catheters, a gynaecological tampon was inserted, moisturized with distilled water (4 treatments), or saline (6 treatments) for better thermal contact. During one treatment no tampon was used. At the start of treatment the temperature rise (DeltaT(meas)) after a short power pulse was measured, which is proportional to SAR(meas). The SAR(calc) along the catheter tracks was extracted from the calculated SAR distribution and compared with the DeltaT(meas)-profiles. RESULTS The correlation between DeltaT(meas) and SAR(calc) was on average R = 0.56 +/- 0.28, but appeared highly dependent on the wetness of the tampon (preferably with saline) and the tissue contact of the catheters. Correlations were strong (R approximately 0.85-0.93) when thermal contact was good, but much weaker (R approximately 0.14-0.48) for cases with poor thermal contact. CONCLUSION Good correlations between measurements and calculations were found when tissue contact of the catheters was good. The main difficulties for accurate verification were of clinical nature, arising from improper use of the gynaecological tampon. Poor thermal contact between thermocouples and tissue caused measurement artefacts that were difficult to correlate with calculations.
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Affiliation(s)
- P M A van Haaren
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, The Netherlands.
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Prakash P, Converse MC, Webster JG, Mahvi DM. An optimal sliding choke antenna for hepatic microwave ablation. IEEE Trans Biomed Eng 2009; 56:2470-6. [PMID: 19535312 DOI: 10.1109/tbme.2009.2025264] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Microwave ablation (MWA) is a minimally invasive technique increasingly used for thermal therapy of liver tumors. Effective MWA requires efficient interstitial antennas that destroy tumors and a margin of healthy tissue, in situ, while minimizing damage to the rest of the organ. Previously, we presented a method for optimizing MWA antenna designs by coupling finite element method models of antennas with a real-coded, multiobjective genetic algorithm. We utilized this procedure to optimize the design of a minimally invasive choke antenna that can be used to create near-spherical ablation zones of adjustable size (radius 1-2 cm) by adjusting treatment durations and a sliding structure of the antenna. Computational results were validated with experiments in ex vivo bovine liver. The optimization procedure yielded antennas with reflection coefficients below -30 dB, which were capable of creating spherical ablation zones up to 2 cm in radius using 100 W input power at 2.45 GHz with treatment durations under 2 min.
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Affiliation(s)
- Punit Prakash
- Department of Radiation Oncology, University of California, San Francisco, CA 94143, USA.
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Cheng KS, Stakhursky V, Stauffer P, Dewhirst M, Das SK. Online feedback focusing algorithm for hyperthermia cancer treatment. Int J Hyperthermia 2008; 23:539-54. [PMID: 17943551 DOI: 10.1080/02656730701678877] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
PURPOSE Magnetic resonance (MR) imaging is increasingly being utilized to visualize the 3D temperature distribution in patients during treatment with hyperthermia or thermal ablation therapy. The goal of this work is to lay the foundation for improving the localization of heat in tumors with an online focusing algorithm that uses MR images as feedback to iteratively steer and focus heat into the target. METHODS The algorithm iteratively updates the model that quantifies the relationship between the source (antenna) settings and resulting tissue temperature distribution. At each step in the iterative process, optimal settings of power and relative phase of each antenna are computed to maximize averaged tumor temperature in the model. The MR-measured thermal distribution is then used to update/correct the model. This iterative procedure is repeated until convergence, i.e. until the model prediction and MR thermal image are in agreement. A human thigh tumor model heated in a 140 MHz four-antenna cylindrical mini-annular phased array is used for numerical validation of the proposed algorithm. Numerically simulated temperatures are used during the iterative process as surrogates for MR thermal images. Gaussian white noise with a standard deviation of 0.3 degrees C and zero mean is added to simulate MRI measurement uncertainty. The algorithm is validated for cases where the source settings for the first iteration are based on erroneous models: (1) tissue property variability, (2) patient position mismatch, (3) a simple idealized patient model built from CT-based actual geometry, and (4) antenna excitation uncertainty due to load dependent impedance mismatch and antenna cross-coupling. Choices of starting heating vector are also validated. RESULTS The algorithm successfully steers and focuses a tumor when there is no antenna excitation uncertainty. Temperature is raised to > or = 43 degrees C for more than about 90% of tumor volume, accompanied by less than about 20% of normal tissue volume being raised to a temperature > or = 41 degrees C. However, when there is antenna excitation uncertainty, about 40% to 80% of normal tissue volume is raised to a temperature > or = 41 degrees C. No significant tumor heating improvement is observed in all simulations after about 25 iteration steps. CONCLUSIONS A feedback control algorithm is presented and shown to be successful in iteratively improving the focus of tissue heating within a four-antenna cylindrical phased array hyperthermia applicator. This algorithm appears to be robust in the presence of errors in assumed tissue properties, including realistic deviations of tissue properties and patient position in applicator. Only moderate robustness was achieved in the presence of misaligned applicator/tumor positioning and antenna excitation errors resulting from load mismatch or antenna cross coupling.
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Affiliation(s)
- Kung-Shan Cheng
- Division of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
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Nadobny J, Szimtenings M, Diehl D, Stetter E, Brinker G, Wust P. Evaluation of MR-Induced Hot Spots for Different Temporal SAR Modes Using a Time-Dependent Finite Difference Method With Explicit Temperature Gradient Treatment. IEEE Trans Biomed Eng 2007; 54:1837-50. [DOI: 10.1109/tbme.2007.893499] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Kok HP, van Haaren PMA, van de Kamer JB, Zum Vörde Sive Vörding PJ, Wiersma J, Hulshof MCCM, Geijsen ED, van Lanschot JJB, Crezee J. Prospective treatment planning to improve locoregional hyperthermia for oesophageal cancer. Int J Hyperthermia 2006; 22:375-89. [PMID: 16891240 DOI: 10.1080/02656730600760149] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
BACKGROUND In the Academic Medical Center (AMC) Amsterdam, locoregional hyperthermia for oesophageal tumours is applied using the 70 MHz AMC-4 phased array system. Due to the occurrence of treatment-limiting hot spots in normal tissue and systemic stress at high power, the thermal dose achieved in the tumour can be sub-optimal. The large number of degrees of freedom of the heating device, i.e. the amplitudes and phases of the antennae, makes it difficult to avoid treatment-limiting hot spots by intuitive amplitude/phase steering. AIM Prospective hyperthermia treatment planning combined with high resolution temperature-based optimization was applied to improve hyperthermia treatment of patients with oesophageal cancer. METHODS All hyperthermia treatments were performed with 'standard' clinical settings. Temperatures were measured systemically, at the location of the tumour and near the spinal cord, which is an organ at risk. For 16 patients numerically optimized settings were obtained from treatment planning with temperature-based optimization. Steady state tumour temperatures were maximized, subject to constraints to normal tissue temperatures. At the start of 48 hyperthermia treatments in these 16 patients temperature rise (DeltaT) measurements were performed by applying a short power pulse with the numerically optimized amplitude/phase settings, with the clinical settings and with mixed settings, i.e. numerically optimized amplitudes combined with clinical phases. The heating efficiency of the three settings was determined by the measured DeltaT values and the DeltaT-ratio between the DeltaT in the tumour (DeltaToes) and near the spinal cord (DeltaTcord). For a single patient the steady state temperature distribution was computed retrospectively for all three settings, since the temperature distributions may be quite different. To illustrate that the choice of the optimization strategy is decisive for the obtained settings, a numerical optimization on DeltaT-ratio was performed for this patient and the steady state temperature distribution for the obtained settings was computed. RESULTS A higher DeltaToes was measured with the mixed settings compared to the calculated and clinical settings; DeltaTcord was higher with the mixed settings compared to the clinical settings. The DeltaT-ratio was approximately 1.5 for all three settings. These results indicate that the most effective tumour heating can be achieved with the mixed settings. DeltaT is proportional to the Specific Absorption Rate (SAR) and a higher SAR results in a higher steady state temperature, which implies that mixed settings are likely to provide the most effective heating at steady state as well. The steady state temperature distributions for the clinical and mixed settings, computed for the single patient, showed some locations where temperatures exceeded the normal tissue constraints used in the optimization. This demonstrates that the numerical optimization did not prescribe the mixed settings, because it had to comply with the constraints set to the normal tissue temperatures. However, the predicted hot spots are not necessarily clinically relevant. Numerical optimization on DeltaT-ratio for this patient yielded a very high DeltaT-ratio ( approximately 380), albeit at the cost of excessive heating of normal tissue and lower steady state tumour temperatures compared to the conventional optimization. CONCLUSION Treatment planning can be valuable to improve hyperthermia treatments. A thorough discussion on clinically relevant objectives and constraints is essential.
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Affiliation(s)
- H P Kok
- Department of Radiation Oncology, University of Amsterdam, Amsterdam, The Netherlands.
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Van den Berg CAT, Van de Kamer JB, De Leeuw AAC, Jeukens CRLPN, Raaymakers BW, van Vulpen M, Lagendijk JJW. Towards patient specific thermal modelling of the prostate. Phys Med Biol 2006; 51:809-25. [PMID: 16467580 DOI: 10.1088/0031-9155/51/4/004] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The application of thermal modelling for hyperthermia and thermal ablation is severely hampered by lack of information about perfusion and vasculature. However, recently, with the advent of sophisticated angiography and dynamic contrast enhanced (DCE) imaging techniques, it has become possible to image small vessels and blood perfusion bringing the ultimate goal of patient specific thermal modelling closer within reach. In this study dynamic contrast enhanced multi-slice CT imaging techniques are employed to investigate the feasibility of this concept for regional hyperthermia treatment of the prostate. The results are retrospectively compared with clinical thermometry data of a patient group from an earlier trial. Furthermore, the role of the prostate vasculature in the establishment of the prostate temperature distribution is studied. Quantitative 3D perfusion maps of the prostate were constructed for five patients using a distributed-parameter tracer kinetics model to analyse dynamic CT data. CT angiography was applied to construct a discrete vessel model of the pelvis. Additionally, a discrete vessel model of the prostate vasculature was constructed of a prostate taken from a human corpse. Three thermal modelling schemes with increasing inclusion of the patient specific physiological information were used to simulate the temperature distribution of the prostate during regional hyperthermia. Prostate perfusion was found to be heterogeneous and T3 prostate carcinomas are often characterized by a strongly elevated tumour perfusion (up to 70-80 ml 100 g(-1) min(-1)). This elevated tumour perfusion leads to 1-2 degrees C lower tumour temperatures than thermal simulations based on a homogeneous prostate perfusion. Furthermore, the comparison has shown that the simulations with the measured perfusion maps result in consistently lower prostate temperatures than clinically achieved. The simulations with the discrete vessel model indicate that significant pre-heating takes place in the prostate capsule vasculature which forms a possible explanation for the discrepancy. Pre-heating in the larger pelvic vessels is very moderate, approximately 0.1-0.3 degrees C. In conclusion, perfusion imaging provides important input for thermal modelling and can be used to obtain a lower limit on the prostate and tumour temperature in regional hyperthermia. However, it is not sufficient to calculate in detail the prostate temperature distribution in individual patients. The prostate vasculature plays such a crucial role that a patient specific discrete vessel model of the prostate vasculature is required.
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Affiliation(s)
- Cornelis A T Van den Berg
- Department of Radiotherapy, University Medical Center Utrecht, PO Box 85500, HP Q.00.118 3508 GA Utrecht, The Netherlands.
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