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Zanoli M, Ek E, Dobšíček Trefná H. Antenna Arrangement in UWB Helmet Brain Applicators for Deep Microwave Hyperthermia. Cancers (Basel) 2023; 15:cancers15051447. [PMID: 36900238 PMCID: PMC10000505 DOI: 10.3390/cancers15051447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 02/07/2023] [Accepted: 02/17/2023] [Indexed: 03/02/2023] Open
Abstract
Deep microwave hyperthermia applicators are typically designed as narrow-band conformal antenna arrays with equally spaced elements, arranged in one or more rings. This solution, while adequate for most body regions, might be sub-optimal for brain treatments. The introduction of ultra-wide-band semi-spherical applicators, with elements arranged around the head and not necessarily aligned, has the potential to enhance the selective thermal dose delivery in this challenging anatomical region. However, the additional degrees of freedom in this design make the problem non-trivial. We address this by treating the antenna arrangement as a global SAR-based optimization process aiming at maximizing target coverage and hot-spot suppression in a given patient. To enable the quick evaluation of a certain arrangement, we propose a novel E-field interpolation technique which calculates the field generated by an antenna at any location around the scalp from a limited number of initial simulations. We evaluate the approximation error against full array simulations. We demonstrate the design technique in the optimization of a helmet applicator for the treatment of a medulloblastoma in a paediatric patient. The optimized applicator achieves 0.3 °C higher T90 than a conventional ring applicator with the same number of elements.
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Zanoli M, Dobšíček Trefná H. The hot-to-cold spot quotient for SAR-based treatment planning in deep microwave hyperthermia. Int J Hyperthermia 2022; 39:1421-1439. [DOI: 10.1080/02656736.2022.2136411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Massimiliano Zanoli
- Department of Electrical Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Hana Dobšíček Trefná
- Department of Electrical Engineering, Chalmers University of Technology, Gothenburg, Sweden
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Takeuchi M, Sakai T, Andocs G, Takanaka T, Taka M, Yamashita K, Kawahara M, Nojiri T, Tanaka A, Norishima A, Omoto Y, Omura M, Nagaoka R, Takao K, Hasegawa H. Statistical Analysis of Ultrasonic Scattered Echoes Enables the Non-invasive Measurement of Temperature Elevations inside Tumor Tissue during Oncological Hyperthermia. ULTRASOUND IN MEDICINE & BIOLOGY 2021; 47:3301-3309. [PMID: 34446333 DOI: 10.1016/j.ultrasmedbio.2021.07.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 07/21/2021] [Accepted: 07/25/2021] [Indexed: 06/13/2023]
Abstract
Non-invasive monitoring of temperature elevations inside tumor tissue is imperative for the oncological thermotherapy known as hyperthermia. In the present study, two cancer patients, one with a developing right renal cell carcinoma and the other with pseudomyxoma peritonei, underwent hyperthermia. The two patients were irradiated with radiofrequency current for 40 min during hyperthermia. We report the results of our clinical trial study in which the temperature increases inside the tumor tissues of patients with right renal cell carcinoma and pseudomyxoma peritonei induced by radiofrequency current irradiation for 40 min could be detected by statistical analysis of ultrasonic scattered echoes. The Nakagami shape parameter m varies depending on the temperature of the medium. We calculated the Nakagami shape parameter m by statistical analysis of the ultrasonic echoes scattered from the tumor tissues. The temperature elevations inside the tumor tissues were expressed as increases in brightness on 2-D hot-scale maps of the specific parameter αmod, indicating the absolute values of the percentage changes in m values. In the αmod map for each tumor tissue, the brightness clearly increased with treatment time. In quantitative analysis, the mean values of αmod were calculated. The mean value of αmod for the right renal cell carcinoma increased to 1.35 dB with increasing treatment time, and the mean value of αmod for pseudomyxoma peritonei increased to 1.74 with treatment time. The increase in both αmod brightness and the mean value of αmod implied temperature elevations inside the tumor tissues induced by the radiofrequency current; thus, the acoustic method is promising for monitoring temperature elevations inside tumor tissues during hyperthermia.
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Affiliation(s)
- Michio Takeuchi
- Tateyama Kagaku Co., Ltd., Toyama, Toyama, Japan; Life Science Research Center, University of Toyama, Toyama, Toyama, Japan
| | | | - Gabor Andocs
- Tateyama Machine Co., Ltd., Toyama, Toyama, Japan; Department of Radiology, Faculty of Medicine, University of Toyama, Toyama, Toyama, Japan
| | | | - Masashi Taka
- Kouseiren Takaoka Hospital, Takaoka, Toyama, Japan
| | | | | | | | - Asaka Tanaka
- Kouseiren Takaoka Hospital, Takaoka, Toyama, Japan
| | | | - Yoshitaka Omoto
- Faculty of Engineering, University of Toyama, Toyama, Toyama, Japan
| | - Masaaki Omura
- Faculty of Engineering, University of Toyama, Toyama, Toyama, Japan
| | - Ryo Nagaoka
- Faculty of Engineering, University of Toyama, Toyama, Toyama, Japan
| | - Keizo Takao
- Life Science Research Center, University of Toyama, Toyama, Toyama, Japan; Department of Behavioral Physiology, Faculty of Medicine, University of Toyama, Toyama, Toyama, Japan
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Zanoli M, Trefná HD. Suitability of eigenvalue beam-forming for discrete multi-frequency hyperthermia treatment planning. Med Phys 2021; 48:7410-7426. [PMID: 34529281 DOI: 10.1002/mp.15220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 08/06/2021] [Accepted: 08/06/2021] [Indexed: 11/11/2022] Open
Abstract
PURPOSE Thermal dose delivery in microwave hyperthermia for cancer treatment is expected to benefit from the introduction of ultra-wideband (UWB)-phased array applicators. A full exploitation of the combination of different frequencies to improve the deposition pattern is, however, a nontrivial problem. It is unclear whether the cost functions used for hyperthermia treatment planning (HTP) optimization in the single-frequency setting can be meaningfully extended to the UWB case. METHOD We discuss the ability of the eigenvalue (EV) and a novel implementation of iterative-EV (i-EV) beam-forming methods to fully exploit the available frequency spectrum when a discrete set of simultaneous operating frequencies is available for treatment. We show that the quadratic power deposition ratio solved by the methods can be maximized by only one frequency in the set, therefore rendering EV inadequate for UWB treatment planning. We further investigate whether this represents a limitation in two realistic test cases, comparing the thermal distributions resulting from EV and i-EV to those obtained by optimizing for other nonlinear cost functions that allow for multi-frequency. RESULTS The classical EV-based single-frequency HTP yields systematically lower target SAR deposition and temperature values than nonlinear HTP. In a larynx target, the proposed single-frequency i-EV scheme is able to compensate for this and reach temperatures comparable to those given by global nonlinear optimization. In a meninges target, the multi-frequency setting outperforms the single-frequency one, achieving better target coverage and 0 . 5 ∘ C higher T 90 in the tumor than single-frequency-based HTP. CONCLUSIONS Classical EV performs poorly in terms of resulting target temperatures. The proposed single-frequency i-EV scheme can be a viable option depending on the patient and tumor to be treated, as long as the proper operating frequency can be selected across a UWB range. Multi-frequency HTP can bring a considerable benefit in regions typically difficult to treat such as the brain.
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Affiliation(s)
- Massimiliano Zanoli
- Department of Electrical Engineering, Chalmers University of Technology, Göteborg, Sweden
| | - Hana Dobšíček Trefná
- Department of Electrical Engineering, Chalmers University of Technology, Göteborg, Sweden
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Kok HP, Cressman ENK, Ceelen W, Brace CL, Ivkov R, Grüll H, Ter Haar G, Wust P, Crezee J. Heating technology for malignant tumors: a review. Int J Hyperthermia 2021; 37:711-741. [PMID: 32579419 DOI: 10.1080/02656736.2020.1779357] [Citation(s) in RCA: 147] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The therapeutic application of heat is very effective in cancer treatment. Both hyperthermia, i.e., heating to 39-45 °C to induce sensitization to radiotherapy and chemotherapy, and thermal ablation, where temperatures beyond 50 °C destroy tumor cells directly are frequently applied in the clinic. Achievement of an effective treatment requires high quality heating equipment, precise thermal dosimetry, and adequate quality assurance. Several types of devices, antennas and heating or power delivery systems have been proposed and developed in recent decades. These vary considerably in technique, heating depth, ability to focus, and in the size of the heating focus. Clinically used heating techniques involve electromagnetic and ultrasonic heating, hyperthermic perfusion and conductive heating. Depending on clinical objectives and available technology, thermal therapies can be subdivided into three broad categories: local, locoregional, or whole body heating. Clinically used local heating techniques include interstitial hyperthermia and ablation, high intensity focused ultrasound (HIFU), scanned focused ultrasound (SFUS), electroporation, nanoparticle heating, intraluminal heating and superficial heating. Locoregional heating techniques include phased array systems, capacitive systems and isolated perfusion. Whole body techniques focus on prevention of heat loss supplemented with energy deposition in the body, e.g., by infrared radiation. This review presents an overview of clinical hyperthermia and ablation devices used for local, locoregional, and whole body therapy. Proven and experimental clinical applications of thermal ablation and hyperthermia are listed. Methods for temperature measurement and the role of treatment planning to control treatments are discussed briefly, as well as future perspectives for heating technology for the treatment of tumors.
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Affiliation(s)
- H Petra Kok
- Department of Radiation Oncology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Erik N K Cressman
- Department of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Wim Ceelen
- Department of GI Surgery, Ghent University Hospital, Ghent, Belgium
| | - Christopher L Brace
- Department of Radiology and Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Robert Ivkov
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Mechanical Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, USA.,Department of Materials Science and Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Holger Grüll
- Department of Diagnostic and Interventional Radiology, Faculty of Medicine, University Hospital of Cologne, University of Cologne, Cologne, Germany
| | - Gail Ter Haar
- Department of Physics, The Institute of Cancer Research, London, UK
| | - Peter Wust
- Department of Radiation Oncology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Johannes Crezee
- Department of Radiation Oncology, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
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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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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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Kok HP, Navarro F, Strigari L, Cavagnaro M, Crezee J. Locoregional hyperthermia of deep-seated tumours applied with capacitive and radiative systems: a simulation study. Int J Hyperthermia 2018; 34:714-730. [PMID: 29509043 DOI: 10.1080/02656736.2018.1448119] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Locoregional hyperthermia is applied to deep-seated tumours in the pelvic region. Two very different heating techniques are often applied: capacitive and radiative heating. In this paper, numerical simulations are applied to compare the performance of both techniques in heating of deep-seated tumours. METHODS Phantom simulations were performed for small (30 × 20 × 50 cm3) and large (45 × 30 × 50 cm3), homogeneous fatless and inhomogeneous fat-muscle, tissue-equivalent phantoms with a central or eccentric target region. Radiative heating was simulated with the 70 MHz AMC-4 system and capacitive heating was simulated at 13.56 MHz. Simulations were performed for small fatless, small (i.e. fat layer typically <2 cm) and large (i.e. fat layer typically >3 cm) patients with cervix, prostate, bladder and rectum cancer. Temperature distributions were simulated using constant hyperthermic-level perfusion values with tissue constraints of 44 °C and compared for both heating techniques. RESULTS For the small homogeneous phantom, similar target heating was predicted with radiative and capacitive heating. For the large homogeneous phantom, most effective target heating was predicted with capacitive heating. For inhomogeneous phantoms, hot spots in the fat layer limit adequate capacitive heating, and simulated target temperatures with radiative heating were 2-4 °C higher. Patient simulations predicted therapeutic target temperatures with capacitive heating for fatless patients, but radiative heating was more robust for all tumour sites and patient sizes, yielding target temperatures 1-3 °C higher than those predicted for capacitive heating. CONCLUSION Generally, radiative locoregional heating yields more favourable simulated temperature distributions for deep-seated pelvic tumours, compared with capacitive heating. Therapeutic temperatures are predicted for capacitive heating in patients with (almost) no fat.
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Affiliation(s)
- H P Kok
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
| | - F Navarro
- b Department of Medical Physics , Regional University Hospital of Málaga , Malaga , Spain
| | - L Strigari
- c Laboratory of Medical Physics and Expert Systems , Regina Elena National Cancer Institute , Rome , Italy
| | - M Cavagnaro
- d Department of Information Engineering, Electronics and Telecommunications , Sapienza University of Rome , Rome , Italy
| | - J Crezee
- a Department of Radiation Oncology , Academic Medical Center, University of Amsterdam , Amsterdam , The Netherlands
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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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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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Stauffer PR, van Rhoon GC. Overview of bladder heating technology: matching capabilities with clinical requirements. Int J Hyperthermia 2016; 32:407-16. [PMID: 26939993 DOI: 10.3109/02656736.2016.1141239] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Moderate temperature hyperthermia (40-45°C for 1 h) is emerging as an effective treatment to enhance best available chemotherapy strategies for bladder cancer. A rapidly increasing number of clinical trials have investigated the feasibility and efficacy of treating bladder cancer with combined intravesical chemotherapy and moderate temperature hyperthermia. To date, most studies have concerned treatment of non-muscle-invasive bladder cancer (NMIBC) limited to the interior wall of the bladder. Following the promising results of initial clinical trials, investigators are now considering protocols for treatment of muscle-invasive bladder cancer (MIBC). This paper provides a brief overview of the devices and techniques used for heating bladder cancer. Systems are described for thermal conduction heating of the bladder wall via circulation of hot fluid, intravesical microwave antenna heating, capacitively coupled radio-frequency current heating, and radiofrequency phased array deep regional heating of the pelvis. Relative heating characteristics of the available technologies are compared based on published feasibility studies, and the systems correlated with clinical requirements for effective treatment of MIBC and NMIBC.
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Affiliation(s)
- Paul R Stauffer
- a Department of Radiation Oncology , Thomas Jefferson University , Philadelphia , Pennsylvana , USA and
| | - Gerard C van Rhoon
- b Department of Radiation Oncology , Erasmus Medical Centre Cancer Institute , Rotterdam , The Netherlands
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Kok HP, Wust P, Stauffer PR, Bardati F, van Rhoon GC, Crezee J. Current state of the art of regional hyperthermia treatment planning: a review. Radiat Oncol 2015; 10:196. [PMID: 26383087 PMCID: PMC4574087 DOI: 10.1186/s13014-015-0503-8] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 09/08/2015] [Indexed: 01/15/2023] Open
Abstract
Locoregional hyperthermia, i.e. increasing the tumor temperature to 40–45 °C using an external heating device, is a very effective radio and chemosensitizer, which significantly improves clinical outcome. There is a clear thermal dose-effect relation, but the pursued optimal thermal dose of 43 °C for 1 h can often not be realized due to treatment limiting hot spots in normal tissue. Modern heating devices have a large number of independent antennas, which provides flexible power steering to optimize tumor heating and minimize hot spots, but manual selection of optimal settings is difficult. Treatment planning is a very valuable tool to improve locoregional heating. This paper reviews the developments in treatment planning software for tissue segmentation, electromagnetic field calculations, thermal modeling and optimization techniques. Over the last decade, simulation tools have become more advanced. On-line use has become possible by implementing algorithms on the graphical processing unit, which allows real-time computations. The number of applications using treatment planning is increasing rapidly and moving on from retrospective analyses towards assisting prospective clinical treatment strategies. Some clinically relevant applications will be discussed.
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Affiliation(s)
- H P Kok
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
| | - P Wust
- Department of Radiation Oncology, Charité Universitätsmedizin Berlin, Berlin, Germany.
| | - P R Stauffer
- Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA, USA.
| | - F Bardati
- Department of Civil Engineering and Computer Science, University of Rome Tor Vergata, Rome, Italy.
| | - G C van Rhoon
- Department of Radiation Oncology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands.
| | - J Crezee
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
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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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Benefit of replacing the Sigma-60 by the Sigma-Eye applicator. Strahlenther Onkol 2012; 189:74-80. [DOI: 10.1007/s00066-012-0241-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 09/17/2012] [Indexed: 12/25/2022]
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Abstract
The hyperthermia effect is based on its thermal influence on tumours. Therefore a controlled heating of the tumours must be achieved. In order to guarantee this, two points must be fulfilled at least: First, the hyperthermia equipment must have the necessary power and steering capability. Second, the distribution of the 'hyperthermic drug', the heat, has to be measured and controlled over the whole treatment time. To reach this aim both a sophisticated technique and a staff trained in hyperthermia are required. In treating patients such as those with cervical cancer, the volume to be exposed and the dosage must be clarified. This means that very special technical and medical conditions must be fulfilled in hyperthermia. To reach and maintain a certain level of quality, hyperthermia is embedded in a framework of procedures. These procedures are defined in the modules of quality management. Therefore quality management must contain specific guidelines for each application, i.e. coordinated standards have to be defined. When adapting these standards in hyperthermia, comparable and comprehensible results of the treatment are guaranteed. Furthermore, an analysis of the treatments under a scientific point of view will be possible and finally result in improvements of this method.
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Affiliation(s)
- Gregor Bruggmoser
- Department of Radiotherapy, University Hospital of Freiburg, Freiburg, Germany.
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Canters RAM, Paulides MM, Franckena MF, van der Zee J, van Rhoon GC. Implementation of treatment planning in the routine clinical procedure of regional hyperthermia treatment of cervical cancer: An overview and the Rotterdam experience. Int J Hyperthermia 2012; 28:570-81. [DOI: 10.3109/02656736.2012.675630] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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