Infrared thermal imaging camera to measure low temperature thermal fields.

To measure low-temperature thermal fields, we have developed a single-element cooled thermal imaging camera for a spectral range of 8-14 µm with an internal shutter for radiometric calibration. To improve the accuracy of measuring the temperature of cold objects, we used a shutter with a combined emissivity as an internal reference source of radiation at the input of the device optical unit. With this aim a small mirror was fixed in the center on its surface covered black, thereby ensuring an efficient reflection of radiation in a wide spectral range of wavelengths. When processing the signal for each pixel of the thermal image, the differential value of the detector response to the shutter blackened and mirror areas was used as a reference. A relative measurement error of 3% was obtained for the studied objects with a temperature of -150 °C. The device was successfully used for remote study of thermal field dynamics during freeze-thawing of biological tissues in vivo.

INFRARED THERMAL IMAGING CONTROL OF RADIATION DERMATITIS DYNAMICS.

BACKGROUND: Radiation-induced dermatitis impairs the quality of life of cancer patients and may lead to the need of interrupting radiotherapy. The grade of dermatitis is subjectively assessed by the visual examination. There is an urgent need for both objective and quantitative methods for assessing the current grade of dermatitis and predicting its severity at an early stage of radiotherapy. AIM: The aim of the study was to evaluate the advantages and limitations of infrared thermography for monitoring the current level of radiation-induced dermatitis and predicting its severity by quantitative analysis of the thermal field dynamics in the irradiated zone. MATERIALS AND METHODS: 30 adult patients were examined by infrared thermography during the course of 2D conventional radiotherapy for malignant tumors of various types and localizations. Our approach for quantifying the thermal field caused by dermatitis alone was applied. A statistical (correlation and ROC) analysis was performed. RESULTS: Dermatitis of varying severity was observed in 100% of the patients studied. The dynamics in the intensity of the anomalous thermal fields in the irradiated zone correlated with the dynamics of dermatitis grades, excluding the case of a radiosensitive tumor (correlation coefficient 0.74÷0.84). It was found that the maximum toxicity (dermatitis grade ≥ 3) develops in patients who how significant hyperthermia in the area of interest (≥ 0.7 °C) at an early stage of radiotherapy. The ROC analysis demonstrated the "good quality" of the prognosis method (AUC = 0.871). CONCLUSIONS: The non-invasive and cheap infrared thermography is a suitable tool for objective quantitative monitoring the current dermatitis grade during radiotherapy as well as predicting its severity for any tumor location.

ASSESSMENT OF DIRECT RESULTS OF CERVICAL CANCER COMBINED TREATMENT.

The aim of the study was to evaluate the immediate results of combined treatment of cervical cancer. This study included 177 patients with cervical cancer. The mean age of patients was 48.0±1.9 years. According to stages the patients were divided as follow: IIA - 56 patients, IIB - 67, III - 54 patients. All patients with cervical cancer are divided into 3 groups: one control and two investigative. Patients of the control group (55 people) received only radiotherapy (RT). The investigative group 1 of 77 patients received RT in combination with ftorafur per os at a dose of 1200 mg in days of EBRT (800 mg in the morning and 400 mg in the evening) No. 23, total dose of 27,600 mg. The investigative group 2 included 45 patients in whom RT was performed in combination with cisplatin at a dose of 40 mg/m2 every 7 days during the entire course of radiation therapy. The effectiveness of combined treatment was assessed according to standard WHO criteria (1978). The combination of radiotherapy with cisplatin allowed to increase the incidence of complete and clinical responses of the cervical tumor by 28.3% compared with only radiation therapy, and also, statistically significant increase in the degree of regression of cervical cancer to 26.7% compared with patients of the control group and to 24.1% compared with patients receiving combination therapy with ftorafur. The most pronounced hematological toxicity was observed in patients with cervical cancer who received SLT with cisplatin, which did not require interruption of radiation treatment and reduction of chemotherapy dosages, the lowest hematological toxicity was in patients receiving radiation therapy alone.

A broadband imaging system for research applications.

We have developed a compact, computer-piloted, high sensitivity broadband imaging system for laboratory research that is compatible with various detectors. Mirror optics allow application from the visible to the far infrared spectral range. A prototype tested in conjunction with a mercury cadmium telluride detector exhibits a peak detectivity of 6.7x10(10) cm Hz(1/2)/W at a wavelength of 11.8 microm. Temperature and spatial resolutions of 0.06 K and 1.6 mrad, respectively, were demonstrated.