Clinical significance of thermal detection of soft-tissue tumors

Upconversion nanoparticles@single-walled carbon nanotubes composites as efficient self-monitored photo-thermal agents

Conventional photothermal therapy (PTT) usually relies on a macroscopic heat source to raise the temperature of tissues to 41-45 °C, which not only kills the pathological cells but causes severe side effects on nearby normal tissues, thus reducing the accuracy of PTT. Here we successfully fabricated nanocomposites of NaYF4:Yb3+,Tm3+@NaYF4:Yb3+@SiO2-SWCNTs, in which the upconversion nanoparticles (UCNPs) serve as real-time temperature-feedback moiety and the single-walled carbon nanotubes (SWCNTs) serve as efficient nano-heaters. The sample displays an excellent photothermal conversion capacity, i.e., the temperature of the aqueous dispersion increases from 23.3 °C up to 60.1 °C under 980 nm excitation due to the intense absorption and highly efficient heat generation of SWCNTs. Meanwhile, the temperature of the nanocomposites is monitored in real time based on the fluorescent intensity ratio of UCNPs. The in-vitro experiments demonstrate that the temperature of the nanocomposites at tissue injection of 1 mm can reach PTT temperature of 42.2 °C with a facile surrounding temperature of 36.2 °C under moderate laser power (980 nm, 2.0 W cm-2). These results provide a novel design for multifunctional nanocomposites that enable safe and controlled PTT.

Soft Biomimetic Fiber-Optic Tactile Sensors Capable of Discriminating Temperature and Pressure

Tactile sensors with high softness and multisensory functions are highly desirable for applications in humanoid robotics, smart prosthetics, and human-machine interfaces. Here, we report a soft biomimetic fiber-optic tactile (SBFT) sensor that offers skin-like tactile sensing abilities to perceive and discriminate temperature and pressure. The SBFT sensor is fabricated by encapsulating a macrobent fiber Bragg grating (FBG) in an elastomeric droplet-shaped structure that results in two optical resonances associated with the FBG and excited whispering gallery modes (WGMs) propagating along the bent region. Benefiting from the different thermo-optic and stress-optic effects of FBG and WGM resonances, the pressure and temperature can be fully decoupled with a high precision of 0.2 °C and 0.8 mN, respectively. To achieve a compact system for signal demodulation, a single-cavity dual-comb fiber laser is developed to interrogate the SBFT sensor based on dual-comb spectroscopy, which enables fast spectral sampling with a single photodiode. We show that the SBFT sensor is capable of perceiving pressure, temperature, and hardness in touching soft tissues and human skins, demonstrating great promise for soft tissue palpation and human-like robotic perception.

Can Adipose Tissue Influence the Evaluation of Thermographic Images in Adolescents?

Infrared thermography (IRT) is a technology easy to use for clinical purposes as a pre-diagnostic tool for many health conditions. However, the analysis process of a thermographic image needs to be meticulous to make an appropriate decision. The adipose tissue is considered a potential influence factor in the skin temperature (Tsk) values obtained by IRT. This study aimed to verify the influence of body fat percentage (%BF) on Tsk measured by IRT in male adolescents. A total of 100 adolescents (16.79 ± 0.97 years old and body mass index of 18.41 ± 2.32 kg/m²) was divided into two groups through the results of a dual-energy X-ray absorptiometry analysis: obese (n = 50, %BF 30.21 ± 3.79) and non-obese (n = 50, %BF 11.33 ± 3.08). Thermograms were obtained by a FLIR T420 infrared camera and analyzed by ThermoHuman^® software version 2.12, subdividing the body into seven regions of interest (ROI). The results showed that obese adolescents presented lower mean Tsk values than the non-obese for all ROIs (p < 0.05), with emphasis on the global Tsk (0.91 °C) and anterior (1.28 °C) and posterior trunk (1.18 °C), with "very large" effect size values. A negative correlation was observed in all the ROI (p < 0.01), mainly in the anterior (r = -0.71, p < 0.001) and posterior trunk (r = -0.65, p < 0.001). Tables of thermal normality were proposed for different ROIs according to the classification of obesity. In conclusion, the %BF affects the registered Tsk values in male Brazilian adolescents assessed by IRT.

Can the body mass index influence the skin temperature of adolescents assessed by infrared thermography?

Infrared thermography (IRT) is a technology that has been used as an auxiliary tool in the diagnostic process of several diseases and in sports monitoring to prevent injuries. However, the evaluation of a thermogram can be influenced by several factors that need to be understood and controlled to avoid a misinterpretation of the thermogram and, consequently, an inappropriate clinical action. Among the possible factors that can affect IRT are anthropometric factors, especially those related to body composition. Based on these, our objective was to verify the influence of Body Mass Index (BMI) on skin temperature (Tsk) in male adolescents. One hundred male adolescents (age: 16.83 ± 1.08 years; body mass: 66.51 ± 13.35 kg; height: 1.75 ± 7.04 m and BMI: 21.57 ± 4.06 kg/m²) were evaluated and divided into three groups, based on the World Health Organization (WHO) proposed classification ranges: underweight (n = 33), normal weight (n = 34) and overweight/obesity (n = 34). Thermograms were obtained using the FLIR T420 thermal imager after a period of acclimatization of the subjects in a controlled environment (temperature: 21.3 ± 0.7 °C and humidity: 55.3 ± 2.2%); they were evaluated using the ThermoHuman® software, integrating the original regions of interest (ROI) into seven larger ROIs. The results showed that underweight individuals had higher Tsk values than normal weight and overweight/obese individuals for all evaluated ROIs, and overweight/obese individuals had lower Tsk values than normal weight individuals for most evaluated ROIs, except for arms region. BMI showed a correlation of -0.68 and -0.64 for the anterior and posterior regions of the trunk, respectively. Thermal normality tables were proposed for various ROIs according to BMI classification. Our study demonstrated that BMI can affect the Tsk values assessed by IRT and needs to be considered to interpret the thermograms.

Tumor Temperature: Friend or Foe of Virus-Based Cancer Immunotherapy

The temperature of a solid tumor is often dissimilar to baseline body temperature and, compared to healthy tissues, may be elevated, reduced, or a mix of both. The temperature of a tumor is dependent on metabolic activity and vascularization and can change due to tumor progression, treatment, or cancer type. Despite the need to function optimally within temperature-variable tumors, oncolytic viruses (OVs) are primarily tested at 37 °C in vitro. Furthermore, animal species utilized to test oncolytic viruses, such as mice, dogs, cats, and non-human primates, poorly recapitulate the temperature profile of humans. In this review, we discuss the importance of temperature as a variable for OV immunotherapy of solid tumors. Accumulating evidence supports that the temperature sensitivity of OVs lies on a spectrum, with some OVs likely hindered but others enhanced by elevated temperatures. We suggest that in vitro temperature sensitivity screening be performed for all OVs destined for the clinic to identify potential hinderances or benefits with regard to elevated temperature. Furthermore, we provide recommendations for the clinical use of temperature and OVs.

Can body mass index influence the skin temperature of adolescents? A preliminary study with the use of infrared thermography

Abstract Infrared thermography (IRT) has been used to assess skin temperature (Tsk), especially during the COVID-19 pandemic, as an important tool in medical screening not only of the general population, but also of young athletes. However, the subcutaneous adipose tissue can act as an insulator when the Tsk is assessed by IRT, modifying the normal Tsk data and leading to their misinterpretation. Considering that the body mass index (BMI) is an important predictor of obesity, the objective of this study was to verify if the Tsk measured by IRT is affected by the BMI in adolescents. A preliminary study was carried out being four participants intentionally selected, all 16 years old, each one classified in a different BMI range according to the criteria of the World Health Organization for the adolescent population: underweight, healthy weight, overweight and obesity. Four thermograms of each participant were recorded and the ThermoHuman® software was used to evaluate 82 regions of interest (ROI), which were integrated into 6 body regions. Using healthy weight subjects as a reference, it was found a progressive reduction in Tsk in all ROI compared to overweight and obese participants, with emphasis on the anterior region of the trunk (3.04% and 6.69% less respectively), and an increase in the Tsk of all body regions for the underweight subject. There are indications that BMI can influence the Tsk value in adolescents and should be taken into account when analyzing thermograms for a correct evaluation of thermal normality.

An analysis of tumor-related skin temperature differences in malignant soft-tissue tumors

Background

Soft tissue tumors are often accompanied with elevated skin temperature; however, studies concerning the relationship between soft-tissue tumors and skin temperature elevation are scarce. We aimed to evaluate the clinical significance of skin temperature elevation in soft-tissue tumors and identify factors related to skin temperature elevation.

Patients and methods

This study comprised 118 patients at our hospital with soft-tissue tumors, excluding lipomatous tumors, whose pathological diagnosis was surgically confirmed between February 2017 and March 2021. Sixty-one and 57 patients had been diagnosed with benign lesions and malignant tumors, respectively (men, 64; women, 54; median age, 61 [range, 20–92] years). The relationship between skin temperature, monitored using a thermography camera, and the presence of soft-tissue malignancy was investigated. We reviewed clinical data to identify factors related to elevated skin temperature.

Results

Temperature differences ≥ 0.2 °C compared to the unaffected side were significantly associated with the presence of malignant tumors (p < 0.001). Logistic regression analysis indicated that intertumoral blood supply was associated with elevated skin temperature (OR 3.22, 95% CI 2.03–5.13; p < 0.001).

Conclusions

Elevated skin temperature, influenced by intertumoral blood supply, may be an important adjunct to physical findings when diagnosing malignant soft-tissue tumors.

Clinical relevance

Intertumoral blood supply influenced elevated skin temperature in malignant soft-tissue tumors. A skin temperature difference ≥ 0.2 °C compared to the unaffected side can help differentiate between benign and malignant tumors. Skin temperature differences may help in diagnosing malignant soft-tissue tumors.

ACUTE EFFECT OF SPEED TEST ON THE SKIN TEMPERATURE OF ELITE SOCCER PLAYERS

ABSTRACT Introduction Infrared thermography has been used in several areas, mainly in sports training, and specifically in soccer. Objectives The objectives of the study were to verify the acute effect of a displacement speed test on the skin temperature of elite female soccer players, to observe pre- and post-test thermal asymmetries, and to compare responses in the anterior and posterior regions of lower limbs. Methods Cross-sectional study that evaluated 17 soccer players of the 2018 Brazilian Championship. They were submitted to thermography before and 10 minutes after performing the displacement speed test. Thermographic images were collected using a FLIR® model 8 thermal imager and changes in skin temperature in the anterior and posterior regions of the lower limbs were analyzed, according to the areas of interest. Descriptive statistics were performed and mean and standard deviation of the temperatures of the areas of interest were analyzed. The normality of the data was verified, and then the Student’s t test for normal paired and independent samples and the Mann-Whitney test for non-normal samples were conducted, with p <0.05 being adopted for significance level. Results It was possible to observe that after the test there was an increase in skin temperature in all the regions analyzed, both on the dominant and non-dominant sides (p <0.05). Regarding the analysis of the anterior region, it was possible to observe a higher temperature (p <0.05) in the region of the tibial muscles than in the region of the quadriceps muscles. Conclusion It is concluded that thermography helps to understand the thermal responses of lower limbs after applying the displacement speed test. The study shows that thermographic evaluation can guide the organization of the training session when motor tests have previously been applied, and in the detection of abnormal overloads, helping to prevent injuries. Level of evidence IV; Therapeutic studies - Investigation of treatment results.