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PubMed1982

Local microwave hyperthermia in cancer therapy. Preliminary report.

From February 1981 to September 1981, 16 patients (19 fields) with histologically proven malignancy (10 squamous carcinoma, 4 melanoma, 1 adenocarcinoma, 1 chordoma) were treated with hyperthermia combined with radiotherapy or chemotherapy (1 patient). There were 5 females and 11 males; average age was 65 years, range 45 to 94 years; 15 patients had a Karnofsky index greater than 50%. Hyperthermia (42.5 44.0 degrees C) was induced by 250 MHz to 1 GHz microwaves (BSD - 1000 Unit). Thermometry was performed by means of non-perturbing probes placed in intratumorally inserted catheters and by measurement of skin temperatures. After hyperthermia plus radiotherapy (18 fields), 9 patients showed 100% response, 5 a volume regression of more than 50%, 3 less than 50% and 1 no change. After chemotherapy plus hyperthermia, 1 patient showed no change. No significant side effects were observed (3 skin burns in 147 hyperthermia treatment sessions).

Aged↗
PubMed1992

Hyperthermia in clinical practice: preliminary results and current problems in the treatment of 21 patients.

From February 1988 through February 1991, 21 patients were managed by superficial hyperthermia and radiotherapy. Nineteen patients had received previous treatment; the most common histology was breast carcinoma. Twenty-six cycles of combined hyperthermia and radiotherapy were delivered: 4 complete responses (15.4%), 17 partial responses (65.4%), 1 minimal partial response (3.8%), 3 stable diseases (11.6%) and 1 disease progression (3.8%) were obtained. The median duration of response was 7 months (range 1-16) for responding and 4 months (range 2.5-4) for non-responding patients. The toxicity encountered (confined mostly to epithelitis--7/21 patients) was completely reversible. In our experience, hyperthermia combined with radiotherapy proved to be an effective treatment. However, some problem that emerged during treatment planning and delivery showed the need for further development and research into hyperthermic devices and thermometry systems.

Adult↗
PubMed1993

Radio-hyperthermia in post-surgical recurrence of melanoma.

AIMS AND BACKGROUND: Malignant melanoma is one of the most radioresistant tumors. It can be treated with combinated hyperthermia and radiation therapy. METHODS: From January 1991 through June 1992, 7 patients, 1 male and 6 female, aged 40-88 years (mean 75), with skin and nodal post-surgical recurrences of melanoma, were treated with a combination of radiation therapy and hyperthermia. Two patients presented systemic disease when they reached our observation, but all of them were without symptoms. None of them underwent surgical excision of the recurrence before or during thermoradiotherapy. None received chemotherapy for these recurrences or had received radiotherapy in the past. They were irradiated with electron beams, with electron energies selected according to the depth of the lesions. The total dose was 40 Gy in 10 fractions in 5 weeks. Hyperthermia was administered for 10 minutes to 1 hour after irradiation. An inductive method of radiofrequency heating at 434 of 915 MHz was used depending on the depth of the lesions. In all of these treatments a ionized water bolus was used. The prescribed hyperthermic dose was 42 degrees C for half a hour. The treatments were carried out twice a week for 5 weeks. A fiberoptic multichannel thermometer was used for thermometry. RESULTS: Four patients (57%) achieved a complete response, 2 patients (29%) a partial response, and 1 patient (14%) stabilization. We found no correlation between tumor volume and response rate. Site effects and complications of the treatment were minimal (moderate erythema). CONCLUSIONS: Our results are in the wide range of values reported in the literature.

Adult↗
PubMed1988

Effect of continuously warmed irrigating solution during transurethral resection.

The effects of a continuously warmed irrigating solution on body temperature during transurethral resection of the prostate and of bladder tumours were studied in forty patients. Anaesthesia was spinal and deep body temperatures of the forehead and lower abdomen were measured, using a deep body thermometry system. Both forehead and lower abdominal deep body temperatures decreased significantly in the patients who underwent transurethral resection of the prostate with an irrigating solution at operating room temperature, but did not decrease in the patients who received a continuously warmed irrigating solution. The same results were obtained for the patients who underwent transurethral resection of bladder tumour. Our results indicate that a continuously warmed irrigating solution could prevent the fall in body temperature during transurethral resection, especially prostate resection, under spinal anaesthesia.

Aged↗
PubMedDate not supplied

Radiofrequency energy-induced heating of bovine articular cartilage using a bipolar radiofrequency electrode.

Radiofrequency energy is used for thermal-assisted chondroplasty to treat grade II and III chondromalacia with the lowest possible energy setting that achieves the desired result. The purpose of this in vitro study was to determine the temperature changes associated with the use of radiofrequency energy delivered at different settings to bovine articular cartilage using a bipolar electrode. Cartilage samples were placed in a temperature-controlled (37 degrees C) saline bath for the delivery of radiofrequency energy. A fluoroptic thermometry probe was positioned to record the temperatures at the electrode-tissue interface. The electrode was activated for 2 seconds at settings of V2-120, V2-60, V2-40, and V2-20 in two modes: ablation and desiccation. Additionally, the cartilage samples were visually inspected to determine changes in appearance. The highest average temperatures were as follows: ablation mode, 78.5 degrees C (V2-120), 62.6 degrees C (V2-60), 58.1 degrees C (V2-40), and 54.1 degrees C (V2-20); desiccation mode, 71.8 degrees C (V2-120), 61.4 degrees C (V2-60), 57.7 degrees C (V2-40), and 53.3 degrees C (V2-20). There were statistically significant increases in temperatures associated with each of the respective settings. There were no substantial visual changes produced by the V2-20 settings, while the other settings produced a gradation of effects. These data provide information to help guide the use of a bipolar radiofrequency electrode and electrosurgical system for thermal-assisted chondroplasty.

Animals↗
PubMed1986

Abdominal regional hyperthermia with an annular phased array.

Twenty-eight patients with advanced upper-abdominal malignancy were treated at the University of Utah on a pilot protocol involving regional hyperthermia (HT) produced by the BSD-1000 HT system and the annular phased array applicator (AA), usually driven at 60 MHz. Eighty-two percent of the patients had widespread metastatic disease, and the mean tumor burden was 2,900 cc. Seventy-nine percent of the patients received concurrent radiotherapy. Acute toxicity consisted primarily of pain within the AA aperture (43%), systemic stress (43%), and nausea or vomiting (29%). Systemic stress was the most frequent power-limiting factor (46%). There were two treatment-related complications: sciatic neuritis from intramuscular injection (one) and pleural effusion from thermometry probe placement (one). Detailed thermal mapping and thermal dosimetry were performed on 26 patients. The mean thermal dosimetry parameters were quite low. Concurrent radiation doses were also quite low (mean, 1,500 rad) to avoid toxicity of sensitive organ systems within the abdomen. The objective response rate was only 18%, all partial, but 43% of the patients achieved effective symptomatic palliation. The five objective responders did survive significantly (P = .02) longer than the 23 nonresponders.

Abdominal Neoplasms↗
PubMed1990

Ifosfamide plus etoposide combined with regional hyperthermia in patients with locally advanced sarcomas: a phase II study.

From July 1986 to July 1989, 40 patients (92% pretreated) with deep-seated, advanced soft tissue sarcomas (STS, 25 patients), Ewing's sarcomas (ES, eight patients), osteosarcomas (OS, three patients) and chondrosarcomas (ChS, four patients) were treated at the University of Munich in a protocol involving regional hyperthermia (RHT) combined with ifosfamide plus etoposide. A total of 265 RHT treatments (mean, 6.6 RHT per patient) were applied including 33 pelvic, four extremity, and three abdominal sites. The mean tumor volume was 537 cc (range, 50 to 2,980 cc). For systemic chemotherapy, all patients received ifosfamide (1.5 g/m2, days 1 to 5), etoposide (100 mg/m2, days 1, 3, and 5), and mesna (300 mg/m2 x 4, days 1 to 5) with RHT given only on days 1 and 5 in repeated cycles every 4 weeks. Acute toxicity consisted primarily of pain (57%) combined with local discomfort within the annular phased array applicator (AA) of the BSD hyperthermia system (BSD Medical Corp, Salt Lake City, UT). The average maximum systemic temperature was 37.4 +/- 0.5 degrees C, and there was no indication of enhanced bone marrow toxicity due to the addition of RHT to the systemic chemotherapy. Detailed thermal mapping by invasive thermometry was performed in all patients. In 38 assessable patients, the overall objective response rate was 37%: six complete responses (CRs), four partial responses (PRs), and four favorable histologic responses (FHRs) (95% confidence limits, 22% to 54%). Complete responders are alive and disease-free at 40, 35, 23, 19, 19, and 8 months. Of patients with PR and FHR, two died from metastatic disease after 4 and 17 months and one died from other disease after 27 months. The remaining five patients are stable at 37, 25, 21, 13, and 8 months. Eleven patients showed no change (NC), and 13 patients showed local tumor progression (PD). The mean observation time for all patients was 11.6 months. The time-averaged temperatures (Ts) of all RHT treatments calculated as 20% (T20), 50% (T50), or 90% (T90) of measured tumor sites differed significantly between responders and nonresponders (T20, P = .003; T50, P = .006; and T90, P = .004; respectively). These data support activity for ifosfamide-etoposide combined with RHT in pretreated patients with advanced sarcomas.

Adolescent↗
PubMed1999

Effect of sympathetic activity on capsaicin-evoked pain, hyperalgesia, and vasodilatation.

BACKGROUND: Painful nerve and tissue injuries can be exacerbated by activity in sympathetic neurons. The mechanisms of sympathetically maintained pain (SMP) are unclear. OBJECTIVE: To determine the effect of cutaneous sympathetic activity on pain induced by primary afferent C-nociceptor sensitization with capsaicin in humans. METHODS: In healthy volunteers capsaicin was applied topically (n = 12) or injected into the forearm skin (n = 10) to induce spontaneous pain, dynamic and punctate mechanical hyperalgesia, and antidromic (axon reflex) vasodilatation (flare). Intensity of pain and hyperalgesia, axon reflex vasodilatation (laser Doppler), and flare size and area of hyperalgesia (planimetry) were assessed. The local skin temperature at the application and measurement sites was kept constant at 35 degrees C. In each individual the analyses were performed during the presence of high and low sympathetic skin activity induced by whole-body cooling and warming with a thermal suit. By this method sympathetic vasoconstrictor activity is modulated in the widest range that can be achieved physiologically. The degree of vasoconstrictor discharge was monitored by measuring skin blood flow (laser Doppler) and temperature (infrared thermometry) at the index finger. RESULTS: The intensity and spatial distribution of capsaicin-evoked spontaneous pain and dynamic and punctate mechanical hyperalgesia were identical during the presence of high and low sympathetic discharge. Antidromic vasodilatation and flare size were significantly diminished when sympathetic vasoconstrictor neurons were excited. CONCLUSIONS: Cutaneous sympathetic vasoconstrictor activity does not influence spontaneous pain and mechanical hyperalgesia after capsaicin-induced C-nociceptor sensitization. When using physiologic stimulation of sympathetic activity, the capsaicin model is not useful for elucidating mechanisms of SMP. In neuropathic pain states with SMP, different mechanisms may be present.

Adult↗
PubMed2005

Reduction of magnetic resonance imaging-related heating in deep brain stimulation leads using a lead management device.

OBJECTIVE: To evaluate the ability of a lead management device to reduce magnetic resonance imaging (MRI)-related heating of deep brain stimulation (DBS) leads and thereby to decrease the risks of exposing patients with these implants to MRI procedures. METHODS: Experiments were performed using the Activa series (Medtronic, Inc., Minneapolis, MN) DBS systems in an in vitro, gelled-saline head and torso phantom. Temperature change was recorded using fluoroptic thermometry during MRI performed using a transmit-and-receive radiofrequency body coil at 1.5 T and a transmit-and-receive radiofrequency head coil at 3 T. A cranial model placed in the phantom was used to test a custom-designed burr hole device that permitted the placement of small-diameter, concentric loops around the burr hole at the DBS lead as it exited the cranium. RESULTS: A total of 41 scans were performed, with absolute temperature changes ranging from 0.8 to 10.3 degrees C. Depending on the MRI system tested and the side of the phantom on which the hardware was placed, loop placement resulted in reductions in temperature rise of 41 to 74%. The effect was linearly related to the number of loops formed (P < 0.01) over the range tested (0-2.75 loops). CONCLUSION: Small, concentric loops placed around the burr hole seem to reduce MRI-related heating for these implants. Although the mechanism is still not fully understood, a device such as that used in the present study could permit a wider range of clinical scanning sequences to be used at 1.5 and 3 T in patients with DBS implants, in addition to increasing the margin of safety for the patient.

Deep Brain Stimulation↗
PubMed1985

A clinical microwave hyperthermia system with multipoint real-time thermal dosimetry.

A clinical hyperthermia system using a 915 MHz microwave generator and incorporating multipoint thermocouple thermometry is described. Temperatures can be monitored simultaneously at 16 points and measurements displayed on a visual display unit and a plotter. The power output of the generator is adjusted under computer control to maintain a constant predetermined temperature in a chosen control channel. A clinically useful feature of the system is the ability to determine the effective cumulative thermal dose delivered to the tissue at points monitored in real time. The basis for the thermal dose calculation is discussed in detail. The calculated dose parameter is displayed for each of the 16 channels during the treatment and updated every 30 s. This real-time display of a thermal dose parameter has made possible a more homogeneous heating of tumours.

Animals↗
PubMedDate not supplied

Design and development of an automated and non-contact sensing system for continuous monitoring of plant health and growth.

An automated system was designed and built to continuously monitor plant health and growth in a controlled environment using a distributed system approach for operational control and data collection. The computer-controlled system consisted of a motorized turntable to present the plants to the stationary sensors and reduce microclimate variability among the plants. Major sensing capabilities of the system included machine vision, infrared thermometry, time domain reflectometry, and micro-lysimeters. The system also maintained precise growth-medium moisture levels through a computer-controlled drip irrigation system. The system was capable of collecting required data continuously to monitor and to evaluate the plant health and growth.

Automation↗
PubMed2003

Analysis of transient-grating signals for reacting-flow applications.

Single-shot transient-grating measurements for thermometry in pressurized reacting flows are examined in the context of rapid digital signal processing. Simple approaches are discussed for temperature determination and rejection of unwanted signals in real-time measurement applications. Examples of temperature data in pressurized postflame gases are presented in the form of probability-density functions (PDFs). Three contributions to the PDF half-widths are discussed. Analysis of phase-matching requirements indicates that beam steering as a result of density fluctuations affects the signal amplitude but not the grating period. Therefore, such stochastic beam deviations have little effect on the derived temperatures. Mode noise on the cw probe beam as well as linear light scattering are found to be insignificant in the frequency range of the observed transient-grating acoustic signature. Use of a single-mode laser for the pump beams is shown to enhance the signal intensity.

Journal Article↗
PubMed2003

Temperature field measurements of small, nonpremixed flames with use of an Abel inversion of holographic interferograms.

Interferometry has been used for many years as a semi-quantitative image-based diagnostic for combustion research. In this paper, we use image-plane, double-pulse holographic interferograms of axisymmetric flames to infer their radial temperature distribution. An Abel inversion is performed on the fringe data to account for line-of-sight integration through the flame. The sensitivity of nonresonant refractive diagnostics decreases inversely with temperature, and the accuracy of the technique is discussed in this context. A small, nonpremixed capillary flame is investigated, and the temperatures inferred from interferometry are compared with those obtained with N2 coherent anti-Stokes Raman spectroscopy thermometry. Additionally, the thermal field of a burning monodisperse methanol droplet stream is investigated interferometrically. Because of their small size, both of these flames challenge the performance limit of temperature interferometery.

Journal Article↗
PubMed2003

Emissivity modeling of metals during the growth of oxide film and comparison of the model with experimental results.

Emissivity modeling of metals has been developed to elucidate behavior during the growth of oxide film, and the modeling results have been compared with experimental results. To express emissivities, pseudo-optical constants of a bare metal and of an oxide film obtained by an elipsometer are substituted into the model equations. Emissivity behavior during the growth of an oxide film upon the surface of a specimen is shown in terms of spectral, directional, and polarized characteristics, and it coincides with the experimental results, both quantitatively and qualitatively. The modeling is simple and provides useful guidance for the development of emissivity-compensated radiation thermometry.

Journal Article↗
PubMed2004

Multiband fiber optic radiometry for measuring the temperature and emissivity of gray bodies of low or high emissivity.

Infrared fiber optic radiometry was used for noncontact thermometry of gray bodies whose temperature was close to room temperature (40-70 degrees C). We selected three gray bodies, one with high emissivity (epsilon = 0.97), one with medium emissivity (epsilon = 0.71), and one with low emissivity (epsilon = 0.025). We carried out optimization calculations and measurements for a multiband fiber optic radiometer that consisted of a silver halide (AgClBr) infrared-transmitting fiber, a dual-band cooled infrared detector, and a set of 18 narrowband infrared filters that covered the 2-14-microm spectral range. We determined the optimal spectral range, the optimal number of filters to be used, and the optimal chopping scheme. Using these optimal conditions, we performed measurements of the three gray bodies and obtained an accuracy of better than 1 degrees C for body temperature and for room temperature. An accuracy of 0.03 was obtained for body emissivity.

Journal Article↗
PubMed2005

Simultaneous and time-resolved temperature and relative CO2-N2 and O2-CO2-N2 concentration measurements with pure rotational coherent anti-Stokes Raman scattering for pressures as great as 5 MPa.

Pure rotational coherent anti-Stokes Raman-scattering (CARS) measurements have been performed in binary CO2-N2 and ternary CO2-O2-N2 mixtures in a temperature range between 300 and 773 K and pressures from 0.1 to 5 MPa to prove its potential for simultaneous single-shot thermometry and multispecies concentration measurements. In pressurized systems the CO2 component has a strong spectral influence on the pure rotational CARS spectra. Because of this dominance, pure rotational CARS proves to be a sensitive tool to measure in high-pressure combustion systems and the relative CO2-N2 concentration in the lower temperature range simultaneously with the temperature and the relative O2-N2 concentration. The evaluation of the spectra utilized a least-sum-squared differences fit of the spectral shape, weighted either constantly or inversely with respect to the normalized signal intensity. The results of the simultaneous temperature and relative CO2-N2 and O2-CO2-N2 concentration measurements provided a good accuracy and precision both in temperature and in concentrations. Because of the strong increase in the relative spectral contribution of CO2 with rising pressure, the precision of the CO2 concentration determination is in general significantly improved toward higher pressures, thus also clearly enhancing the CO2 detectability. The influence of temperature, O2 and CO2 concentration, pressure, and the evaluation techniques employed on both the accuracy and the precision is explained as well as their cross dependencies. The influence and limitations of the approximations used to model the CO2 molecule are discussed.

Journal Article↗
PubMed2005

Near-infrared diode laser absorption diagnostic for temperature and water vapor in a scramjet combustor.

Tunable diode laser absorption measurements of gas temperature and water concentration were made at the exit of a model scramjet combustor fueled on JP-7. Multiplexed, fiber-coupled, near-infrared distributed feedback lasers were used to probe three water vapor absorption features in the 1.34-1.47 microm spectral region (2v1 and vl + v3 overtone bands). Ratio thermometry was performed using direct-absorption wavelength scans of isolated features at a 4-kHz repetition rate, as well as 2f wavelength modulation scans at a 2-kHz scan rate. Large signal-to-noise ratios demonstrate the ability of the optimally engineered optical hardware to reject beam steering and vibration noise. Successful measurements were made at full combustion conditions for a variety of fuel/air equivalence ratios and at eight vertical positions in the duct to investigate spatial uniformity. The use of three water vapor absorption features allowed for preliminary estimates of temperature distributions along the line of sight. The improved signal quality afforded by 2f measurements, in the case of weak absorption, demonstrates the utility of a scanned wavelength modulation strategy in such situations.

Journal Article↗
PubMed2006

Improved temperature precision in rotational coherent anti-stokes raman spectroscopy with a modeless dye laser.

Single-shot thermometry with dual-broadband rotational coherent anti-Stokes Raman spectroscopy that employs amplified spontaneous emission from a broadband modeless dye laser has been examined. Evaluation of single-shot spectra of air, N2, and O2 showed an improved temperature precision at room temperature compared with the precision obtained with a conventional dye laser. A comparison was also made between the use of single-mode and multimode Nd:YAG lasers as sources for narrowband radiation, and in all cases the single-mode Nd:YAG laser resulted in higher precision. The experimental results are compared with theoretical predictions.

Journal Article↗