The
Sigma Eye can achieve a central focus of approximately
9 cm (approximately a third of the wavelength
of the diseased tissue). This focusing ability
enables deep tumors to be non-invasively treated
by the Sigma Eye Applicator.
The 3D electronic steering capability of the Sigma Eye can position and shape the energy focus in the long body axis as well as the axial cross-section. A phase shift of 80 degrees between the end dipole rings will shift the heating pattern
The Sigma Eye applicator is a revolutionary annular phased array design invented and patented by BSD Medical. Its 3D array of 24 dipole antennae combined with its elliptical shape produce the unique 3D pattern-shaping capabilities. The novel application of this phased array technology to clinical hyperthermia provides unparalleled ability to control and focus energy inside the body. center. |
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CAUTION: Investigational device or investigation device exemption pending.
Limited by United States law to investigational use.
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What is the Advantage of 3d Hyperthermia?
3d hyperthermia allows for optimum results, since the heating zone is targeted specifically at the tumor region. This is achieved by focusing the electromagnetic power onto the target volume. The focus is not fixed at the center of the applicator but may be targeted at any specific area, providing the system operator with significantly more freedom in positioning the applicator. The BSD 2000.3d hyperthermia system is designed particularly for treating tumors in hard-to-reach locations.
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How is 3d Hyperthermia Applied?
To begin with, part of the patient's body is enclosed by an eye-shaped applicator. Phase and amplitude steering can be used to create the heating focus within the applicator. The 3d technology makes use of 24 dipole antennas driven by 12 RF power channels. These dipoles are arranged in three rings of eight antennas each. By varying the phase and amplitude of each of the 12 input channels, the operator creates a constructive interference at the tumor zone. The dedicated treatment-planning software, HyperPlan, calculates the best possible settings for each channel. |
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Hyperthermia and Radiotherapy
Clinical studies have revealed that the addition of hyperthermia to radiotherapy can double the efficacy of the treatment.
This is because the temperatures attained through hyperthermia increase blood flow to the tumor, accentuating the formation of the oxygen radicals required to attack cancer cell DNA through radiotherapy. Heat shock through hyperthermia is also an effective agent in inhibiting DNA repair in cancer cells after double-strand breaks occur from ionizing radiation. Further, hyperthermia kills radiation-resistant hypoxic cancer cells by forcing a rise in their anaerobic metabolism, causing them to weaken as they deplete their energy supply and become toxically acidic as their consumption exceeds their ability to expel waste. |
Hyperthermia and Radiotherapy
Hyperthermia used in combination with chemotherapy increases the drug concentration in the tumor region due to increased blood flow, thus raising the effectiveness of cytostatic drugs. In addition, hyperthermia has been proven to enhance drug toxicity in cells resistant to many drugs.
Hyperthermia can, therefore, be employed synergistically with chemotherapy in strategies to treat high-risk tumors with a view towards total tumor eradication.
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Soft Tissue Sarcomas
Click to enlarge.
Response to neoadjuvant chemotherapy combined with regional hyperthermia is predictive for an improved local tumor
control resulting in a long-term survival benefit for patients with high-risk soft tissue sarcomas at unfavorable
retroperitoneal or visceral sites.
International Journal Radiation Oncology Biol. Phys. 2000, Vol. 48: 381 - 391
Prostate Cancer
... patients with symptomatic, locally advanced, previously irradiated hormone refractory
prostate cancer were treated with further radiation and external hyperthermia. All patients had complete
resolution of symptoms lasting for 12 - 24 month. At most recent follow-up, no patient has experienced
significant treatment-related side effects. In these patients with no other therapeutic alternatives,
re-irradiation and hyperthermia can provide durable tumor response for more than a year, resulting in
significant improvement in quality of life.
The British Journal of Radiology 2001, Vol. 74: 745 - 751
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Let clinical studies speak for themselves
Pelvic Tumors (Cervix/Rectum/Bladder)
Click to enlarge
Complete-response rates were 39% after radiotherapy and 55% after radiotherapy plus hyperthermia. The duration of local control was significantly longer with radiotherapy plus hyperthermia than with radiotherapy alone. 3-year overall survival was 27% in the radiotherapy group and 51% in the radiotherapy plus hyperthermia group.
The Lancet 2000, Vol. 355: 1119 - 1125
Cervical Carcinoma
. was well tolerated and did not significantly add to either the relevant clinical acute or long-term toxicity over radiation alone. A complete response was achieved in 50% in the radiotherapy group versus 80% in the thermoradiotherapy group. The 3-year local relapse-free survival of the patients who were treated with thermoradiotherapy (79.7%) was significantly better than that of the patients treated with radiotherapy (48.5%).
The Lancet 2000, Vol. 355: 1119 - 1125
Rectum Carcinoma
Preoperative radiochemotherapy is a widely used means of treatment for patients suffering from primary, locally advanced,
or recurrent rectal cancer. We evaluated the efficacy of treatment due to additional application of regional hyperthermia
... The rate of resectability (89%) and response (59%) were high... there exists a positive interrelationship between
thermal parameters (...) and clinical parameters concerning effectiveness.
International Journal Radiation Oncology Biol. Phys. 2000, Vol. 48: 381 - 391
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Sigma Treatment Base Unit
The Sigma Treatment Base Unit includes both patient and applicator support systems.
The patient support system consists of two fiberglass rods that support a mesh sling, which is connected
in turn to the hydraulic lift assembly, located at both ends of the patient support system. The patient
is placed on the sling in preparation for the therapy, then the applicator is positioned over the tumor
area and the water bolus filled. A large water reservoir mounted in the base unit maintains the bolus
water at the desired temperature throughout the treatment.
The low-down on the high-tech
Thermal Mapping
Thermal mapping is an advanced automated thermometry system that periodically shifts
temperature probes to multiple locations within the implanted catheters during treatment. The thermal
mapping system is integrated into both the hardware and software systems to provide a comprehensive
set of parameters, thermal dose calculation, data display, and printout capabilities. Temperatures
are automatically recorded throughout this process to provide temperature scans along the entire
catheter length. The probes are automatically repositioned after the scans and the temperature scan
plots (temperature profiles) are stored by the computer and displayed on the system monitor.
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Dodek Amplifier
The system is powered by a solid-state Dodek amplifier with 12-channel independent amplifier
phase and amplitude adjustment. The amplifier operates over a frequency of 75 to 140 MHz and delivers up to
1,800 watts of radio frequency power to the applicator. Each channel is monitored and controlled by computer
and can be individually tailored to the requirements of each treatment session. This low maintenance amplifier
is located separately from the patient and operator room, and is housed in a 24" mounting rack.
Thermometry
Sophisticated temperature monitoring is carried out by a ceiling-mounted interface box
that supports up to eight temperature probes. These each have a diameter of 1.1 mm and an accuracy
of ± 0.1 °C and are non-perturbing to radio-frequency fields, which ensures precise, continuous
temperature monitoring during treatment without the need to switch off power.
Computer System
The entire BSD 2000.3d hyperthermia system is controlled by a PC, running under
Windows® 2000 Professional, interfaced to all system modules. A large, user-friendly LCD color monitor,
cordless keyboard and cordless mouse create an ergonomic operating environment. The system also includes
a high-resolution color inkjet printer for instant hardcopy treatment reports. The system software
incorporates a color Graphic User Interface, automatically guiding the operator through the set-up
and treatment procedures and featuring menu-driven selection of treatment parameters.
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Sigma Eye - Adults
The Sigma Eye applicator is the standard for 3d conformal treatments.
It is based on the latest, well-proven phased-array technology and includes an integrated water bolus for
energy coupling, surface cooling as well as fast and easy patient setup.
It takes its name from the eye-shaped water bolus surface that minimizes the bolus pressure on the patient.
The 24 paired antenna arrays are mounted in three rings of 8 dipoles each and are driven by the 12-channel
generator. By adjusting the amplitude and phase of each channel, the electromagnetic energy can be focused
three-dimensionally onto the tumor region. |
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Sigma 60 - Large Adults
The cylindrical Sigma 60 is the applicator of choice for patients too large to fit inside
the Sigma Eye applicator. With its opening diameter of 60 cm, it allows for the treatment of patients with
severe adiposis. The integrated water bolus provides both coupling for the electromagnetic energy and surface
cooling for the patient. With a four channel power input, the applicator creates a two dimensionally focused
heating field adapted to the tumor region. |
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Sigma 40 - Adolescents, Children
The Sigma 40 cylindrical applicator is designed specifically for the treatment of children, youths, and
smaller-sized adults - its 40 cm opening is ideally suited for smaller patients. The integrated water bolus
provides both coupling for the electromagnetic energy and surface cooling for the patient. The Sigma 40
features twelve generator channels driving the 24-paired antenna array. The antennas are mounted in three
rings of 8 dipoles each, and an adjustment of the amplitude and phase of each channel focuses the electromagnetic
energy three-dimensionally onto the tumor region. |
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Sigma 30 - Adult extremities, Children
The Sigma 30 applicator is designed for the treatment of limbs. While it shares the same technical features as
the Sigma 60, it differs in its aperture opening of only 30 cm. |
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Enhanced Software Integration
HyperPlan, an optional software program, has been developed to provide customized
pretreatment planning to optimize the procedures for each patient and individual tumor type.
HyperPlan was developed by the Konrad-Zuse-Institute and the Charité University Hospital in Berlin.
The software, designed especially for 3d hyperthermia treatment planning, uses patient CT and/or MRI data
to determine the optimum settings for each specific patient. These data are divided according to tissue
type - bones, muscle, fat, tumor - and once the appropriate applicator for treatment has been selected,
the electrical field distribution is calculated using Maxwell's equations. The optimization module allows
field maximums that conform precisely to the tumor region. The system determines the most suitable settings
for both amplitudes and phases. The temperature distribution can also be predicted using preset perfusion
factors for each tissue type. |
Individual patient treatment optimization
Treatment Planning - Step by Step
1. Patient Models are Created from CT-Data ...
2. ... and from MRI Data
3. Segmentation of Different Tissue Types
4. Creation of the Tetrahedral Grid
5. Generated SAR Distribution
6. Optimized Temperature Distribution |
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| A standard hyperthermia suite consists of the treatment room, the operator room
plus a small technical room. For convenient patient handling, the treatment room is equipped with electromagnetic
shielding and requires floor space of around 24 - 35 m2. The adjoining operator room requires floor space of 12
to 16 m2 and an observation window looking into the treatment room. A small technical room of 8 to 10 m2 is
required for installation of the Dodek amplifier.
Our site-planning specialists will be happy to assist you in finding the ideal layout for your given
environment. The installation manual includes specification parameters for building services, electricity,
air conditioning, and other relevant factors. |
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| We offer complete site planning assistance to ensure proper
installation and efficient clinical design of the clinical facility. |
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View a 3D Site Planning Movie, simply click on the 3D View icon.
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BSD
2000/3D
