Clinical implementation and patient-specific quality assurance solutions for real-time target tracking and dynamic delivery in Radixact synchrony.

BACKGROUND: The installation and testing of the first Radixact with Synchrony system in Colombia marked a significant milestone in Latin America's medical landscape. There was a need to devise a robust quality assurance protocol to comprehensively evaluate both dose delivery and motion tracking accuracy. However, testing experiences under clinical conditions have not been extensively reported. Additionally, there are limited recommended measuring devices for Synchrony evaluation. PURPOSE: To validate and implement an alternative setup for dynamic-PSQA while testing Synchrony's functionality under clinical scenarios, including real-patient motion traces, and to provide guidance to new centers undergoing clinical implementation of Helical Synchrony. METHODS: This approach involves using the Iba miniPhantomR with strategically placed fiducial markers for configuring Gafchromic-films and array-based setups. When paired with the CIRS Dynamic Platform, this enables an innovative dynamic setup with trackable features for Synchrony delivery testing. Assessment scenarios, including compensation (M1S1) and no-motion compensation (M1S0), were evaluated using 2D-gamma pass rate analysis with multiple clinical gamma criteria. The Synchrony-Simulation feature was used to assess pre-treatment performance and capture the patient's target motion pattern. Synchrony for common clinical cases with patient's motion-traces was validated. RESULTS: The results for M1S0 and M1S1 demonstrated consistency with previous studies evaluating Synchrony functionality. Analysis using different gamma criteria unveiled dosimetric differences and impacts across various motion ranges. The application of effective kV-dose subtraction for array-based methods is of upmost importance when evaluating dynamic-PSQA with stringent gamma-criteria. However, no significant kV-dose impact on EBT3-Film was detectable. CONCLUSION: Two implemented configurations for dynamic-PSQA setups were validated and successfully integrated into our clinic. We addressed both the benefits and limitations of array-based and film-based methods. The functionality and limitations of Synchrony were evaluated using the proposed setups. The potential utility of Synchrony-Simulation, along with the proposed patient-case classification table, can offer valuable support for new users during the clinical implementation of Synchrony treatments.

An application based on the analysis of thermograms to calculate the thermographic index for pain and swelling assessment.

As the world's population ages, the prevalence of rheumatic diseases is increasing. These diseases are often diagnosed and monitored using imaging techniques such as infrared thermography. In this study, we developed an application to calculate the thermographic index (TI) in a series of thermograms. Such index is used in rheumatology as a complementary diagnostic tool to assess pain and swelling. We designed the application in MATLAB App Designer; an environment for creating applications with a graphical user interface. To evaluate the performance of the developed application, we calculated the TI of ten trigger points (anterior shoulder, sternum, posterior shoulder, upper back, lower back, elbow, lateral shoulder, elbow pit, knee, and back of the knee) in a series of thermal images from 37 healthy participants. Results of the average temperature varied between 31.35 (knee for women) and 33.92 (lateral shoulder for men) in °C and TIs were lower than 2 and the results in the knee region are consistent with those reported in previous studies due to only the TI in the knee is known. This study contributes to the literature with reference values for nine trigger points other than the knee. This app is easy to use and may be useful in future applications for disease detection or monitoring of its progression.

Assessing Muscle Fatigue in Multiple Sclerosis using the Sample Entropy of Electromyographic Signals: A Proof of Concept.

Background: Multiple sclerosis (MS) is a progressive and neurodegenerative disease of the central nervous system. Its symptoms vary greatly, which makes its diagnosis complex, expensive, and time-consuming. One of its most prevalent symptoms is muscle fatigue. It occurs in about 92% of patients with MS (PwMS) and is defined as a decrease in maximal strength or energy production in response to contractile activity. This article aims to compare the behavior of a healthy control (HC) with that of a patient with MS before and after muscle fatigue. Methods: For this purpose, a static baropodometric test and a dynamic electromyographic analysis are performed to calculate the area of the stabilometric ellipse, the remitting MS (RMS) value, and the sample entropy (SampEn) of the signals, as a proof of concept to explore the feasibility of this test in the muscle fatigue quantitative analysis; in addition, the statistical analysis was realized to verify the results. Results: According to the results, the ellipse area increased in the presence of muscle fatigue, indicating a decrease in postural stability. Likewise, the RMS value increased in the MS patient and decreased in the HC subject and the opposite behavior in the SampEn was observed in the presence of muscle fatigue. Conclusion: Thus, this study demonstrates that SampEn is a viable parameter to estimate muscle fatigue in PwMS and other neuromuscular diseases.

Facial thermal and blood perfusion patterns of human emotions: Proof-of-Concept.

In this work, a preliminary study of proof-of-concept was conducted to evaluate the performance of the thermographic and blood perfusion data when emotions of positive and negative valence are applied, where the blood perfusion data are obtained from the thermographic data. The images were obtained for baseline, positive, and negative valence according to the protocol of the Geneva Affective Picture Database. Absolute and percentage differences of average values of the data between the valences and the baseline were calculated for different regions of interest (forehead, periorbital eyes, cheeks, nose and upper lips). For negative valence, a decrease in temperature and blood perfusion was observed in the regions of interest, and the effect was greater on the left side than on the right side. In positive valence, the temperature and blood perfusion increased in some cases, showing a complex pattern. The temperature and perfusion of the nose was reduced for both valences, which is indicative of the arousal dimension. The blood perfusion images were found to be greater contrast; the percentage differences in the blood perfusion images are greater than those obtained in thermographic images. Moreover, the blood perfusion images, and vasomotor answer are consistent, therefore, they can be a better biomarker than thermographic analysis in identifying emotions.

Estimation of blood and bone marrow doses of thyroid carcinoma patients treated with 131I through gamma spectrometry.

131I therapy is the treatment for patients with differentiated thyroid carcinoma (DTC) to ablate remnant thyroid tissue after surgery. The aim of this study was to estimate the absorbed doses to the blood and bone marrow of patients with DTC using gamma spectrometry. The evaluation of the absorbed dose in blood and bone marrow is a good indicator of a patient's response and its radiological protection. The average of low activities administered (AAAL) to ten patients was 3.20 GBq and the average of high activities administered (AAAH) to eight patients was 4.95 GBq. The blood and bone marrow doses were determined according to Lassmann et al 2008, performing successive measurements of activity in blood samples and whole body. Blood samples of 2 ml were taken during the first 48 h; the first one was extracted 2 h after the administration of the capsule and the following ones were taken every 12 h. The whole-body measurements were made at regular intervals of time throughout the patient's isolation period using a mobile gamma spectrometry system located inside the isolation room of the Dr Hernán Henríquez Aravena Hospital. The average residence times in blood and whole-body were (6.9 ± 1.7) × 10-4 h ml-1 and (23.2 ± 4.5) h, respectively. The average doses in blood and bone marrow of patients with AAAL were (0.33 ± 0.09) Gy and (0.63 ± 0.18) Gy, respectively, and with AAAH were (0.48 ± 0.06) Gy and (0.87 ± 0.19) Gy, respectively. In all studied patients, the bone marrow doses were less than 2 Gy. The results were compared with the previously published values, finding some differences between the residence times and significant differences in the doses, which show the need to compare the different methodologies.

Design and implementation of a mobile gamma spectrometry system to in vivo measure the accumulated activity of 131I in patients with thyroid diseases.

The design and implementation of a mobile gamma spectrometry system to in vivo measure the accumulated activity of 131I in whole body and thyroid of patients with thyroid diseases are presented in this work. This system may be used for both pre-therapeutic and post-therapeutic dosimetry calculations. It consists of a detector and a movable support that allows its movement from one place to another.