Brain hyperthermia: I. interstitial microwave antenna array techniques—the Dartmouth experience

Ryan, Thomas P.; Trembly, B. Stuart; Roberts, David W.; Strohbehn, John W.; Coughlin, Christopher T.; Hoopes, P. Jack

doi:10.1016/0360-3016(94)90402-2

Cited by 28 publications

(26 citation statements)

References 25 publications

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“…Accordingly, tissue temperatures achieved were between 42 and 50 C [7]. Interstitial hyperthermia for localised cancer was found to effectively heat tumours and provide local control [7][8][9][10][11][12][13][14] and significantly boost the effectiveness of both radiation therapy and chemotherapy in randomised trials [7,15,16]. No difference was seen in radiation with or without heat for complete response if the hyperthermia treatment did not meet its temperature goals of 42.5 C for 45 to 60 min in the entire tumour [17].…”

Section: Introductionmentioning

confidence: 91%

“…In the early stages of MW therapy, the term hyperthermia included elevated temperatures that exceeded normal body temperatures, including temperatures reaching and exceeding 60 C. As the designs of the MW antennas evolved and input power was increased and combined with imageguided placement, it became possible to treat tumours sufficiently with heat alone as an ablation modality. Recent clinical trials have shown therapeutic MW use over a range of anatomical sites: fibroids [21], lung, kidney [22], bone, pancreas, adrenal glands [23], chest wall [24], liver [25][26][27], brain [7,10], and prostate [12,28]. This paper describes the progression from hyperthermia to ablation (coagulation) with both technology and treatment methods, as well as early clinical results.…”

Section: Introductionmentioning

confidence: 97%

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Interstitial microwave transition from hyperthermia to ablation: Historical perspectives and current trends in thermal therapy

Ryan¹,

Turner

Hamilton

2010

International Journal of Hyperthermia

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This work reviews the transition from hyperthermia to ablation for cancer treatment with interstitial microwave (MW) antennas. Early work utilising MW energy for thermal treatment of cancer tissue began in the late 1970s using single antennas applied interstitially or the use of multiple interstitial antennas driven with the same phase and equal power at 915 or 2450 MHz. The original antenna designs utilised monopole or dipole configurations. Early work in thermal therapy in the hyperthermia field eventually led to utilisation of these antennas and methods for MW ablation of tumours. Efforts to boost the radiated MW power levels while decreasing antenna shaft temperatures led to incorporation of internally cooled antennas for ablation. To address larger tumours, MW treatment utilised arrays that were simultaneously activated by either non-synchronous or synchronous phase operation, benefiting both hyperthermia and ablation strategies. Numerical modelling was used to provide treatment planning guidance for hyperthermia treatments and is expected to provide a similar benefit for ablation therapy. Although this is primarily a review paper, some new data are included. These new data show that three antennas with 2.5 cm spacing at 45 W/channel and 10 min resulted in a volume of 89.8 cm(3) when operated synchronously, but only 53.4 cm(3) non-synchronously. Efficiency was 1.1 (synchronous) versus 0.7 (non-synchronous). MW systems, treatment planning, and image guidance continue to evolve to provide better tools and options for clinicians and patients in order to provide better approach and targeting optimisation with the goal of improved treatment for the patient.

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Section: Introductionmentioning

confidence: 91%

Section: Introductionmentioning

confidence: 97%

Interstitial microwave transition from hyperthermia to ablation: Historical perspectives and current trends in thermal therapy

Ryan¹,

Turner

Hamilton

2010

International Journal of Hyperthermia

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“…Frequency sources of 433, 915, 2450 MHz allow penetration and antenna length to be selected. Various antennas such as dipoles, chokes, helical, hybrid, (17)(18)(19)(20), floating sleeve (39) and dielectric (13,16) allow shaping of the heating pattern as single antennas or as arrays. The choice between phase focusing and using an asynchronous mode,…”

Section: Technologymentioning

confidence: 99%

“…They are operated in phase at 915 MHz, at powers between 1 and 15 watts and have 1-3 temperature sensors in each catheter. These are mostly traditional dipole antennas with a quarter wavelength of 3.7 cm(17)(18)(19)(20).…”

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confidence: 99%

A tutorial on recent advances in thermal therapy systems

Ryan¹

2007

Thermal Treatment of Tissue: Energy Delivery and Assessment IV

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Thermal therapy as a treatment for cancer is a dynamic treatment epicenter, with a variety of technologies available and undergoing continuous improvement. Recent advances in technology and applications for thermal therapy give clinicians more power to affect larger volumes of tissue in less time. New radiofrequency (RF) and microwave (MW) systems have appeared recently, giving powerful tools for cancer therapy. Novel therapeutic ultrasound (US) technologies are being explored, but are presently not commercialized. Thermal therapy applicators that deliver power to the target in the patient will be reviewed for shape, size, and features. The operation and performance of various applicators will be discussed. In the goal of performance increase, several features have been commercialized in the evolution of the technology, including cooling, multiple applicator arrays, power modulation, and applicator deployment and shape change. To place recent progress into perspective, a historical review of some RF and MW applicators will be given. The work will cover modeling and simulations, as well as in-vitro, in-vivo, and clinical results.

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“…A uniform temperature rise in tumour tissue is essential to obtain optimal clinical results, but achieving this is a major problem in clinical hyperthermia [5,[10][11][12][13][14]. The temperature distribution is usually quantified by T 10 , T 50 and T 90 , the temperature at least achieved in 10%, 50% and 90% of the tumour, respectively.…”

Section: Introductionmentioning

confidence: 99%

On estimation of the temperature maximum in intraluminal or intracavitary hyperthermia

Kok

Haaren

Dijk

et al. 2005

International Journal of Hyperthermia

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During intraluminal or intracavitary hyperthermia treatments, limited non-invasive temperature information is available, which may result in sub-optimal treatment control. This article describes a method for estimating temperature maximums and their corresponding locations in tissue heated by a cylindrical applicator with an incorporated cooling system, assuming a hollow cylinder of homogeneous tissue. The main purpose of this study is intraluminal heating of tumours at the oesophagus, but the principle described is generally applicable for cylindrical applicators. When assuming no perfusion and only radial heat flow in the heated tissue, an analytical expression for the temperature profile can be derived such that the complete profile can be reconstructed from the inner wall temperature only. For situations with perfusion, finite difference simulations have been performed and the resulting simulated inner wall temperature was put into the analytical expression to obtain an estimation for the maximum temperature and the corresponding location. This way, an estimation method was developed which does not require a priori knowledge of the perfusion rate or invasive thermometry. For volumetric perfusion rates in the clinically relevant range of 0-10 kg m-3 s-1, the deviations between simulated and estimated temperature maximums were less than 10% and the difference in location was typically a few tenths of a millimetre. These deviations are small enough for treatment control purposes.

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Brain hyperthermia: I. interstitial microwave antenna array techniques—the Dartmouth experience

Cited by 28 publications

References 25 publications

Interstitial microwave transition from hyperthermia to ablation: Historical perspectives and current trends in thermal therapy

Interstitial microwave transition from hyperthermia to ablation: Historical perspectives and current trends in thermal therapy

A tutorial on recent advances in thermal therapy systems

On estimation of the temperature maximum in intraluminal or intracavitary hyperthermia

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