ABSTRACT
PURPOSE: To determine the accuracy of AlignRT surface deformation module in detecting and quantifying oedema in breast cancer radiotherapy. MATERIALS AND METHODS: A female torso phantom and water-equivalent boluses of different thicknesses (0.5-1.5 cm) were used. The variation of surface displacement and the percentage of surface within tolerance, as a function of bolus thickness and Region of Interest (ROI) size, were investigated. Additionally, a dynamic phantom was used to study the impact of patient breathing on the swelling estimation. Lastly, a flowchart was derived to alert physicians in the case of breast swelling. RESULTS: Average displacement value proved to be inversely correlated with ROI size (R2 > 0.9). As such, for a ROI smaller than the bolus size (2.5x2.5 cm2), the average displacement (1.05 cm) provides an accurate estimate of the oedema thickness (within 5%). In opposition, with a clinical ROI, the 1 cm-thick bolus was largely underestimated with an average displacement value of 0.28 cm only. To limit the impact of patient breathing on surface deformation, dynamic surface captures and the use of the corrected patient position should be privileged. Using AlignRT, a clinical workflow for breast swelling follow-up was developed to help in the decision for repeat simulation and dosimetry. CONCLUSION: The surface deformation module provides an accurate, simple, and radiation-free approach to detect and quantify breast oedema during the course of radiotherapy.
ABSTRACT
Ivabradine is a drug used for the treatment of angina and chronic heart failure in cases of intolerance or insufficiency of response to beta-blocker treatment. A 47-year-old man was admitted to the emergency department of the hospital for a voluntary intoxication with 280 mg of ivabradine: he presented drowsiness and a mild sinusal bradycardia (50 bpm) associated with a well-tolerated low blood pressure at 100/50 mmHg. No complication was noted and he was discharged from the hospital on Day 3. A method for ivabradine assay in serum was obtained using liquid chromatography coupled with a mass spectrometry detection method. After a deproteinization step using QuECHERS salts and acetonitrile, a chromatographic separation was performed using a 5-µm 50 × 2.1 mm Xterra® column (Waters, France). Detection was performed using an LTQ linear ion-trap mass spectrometer equipped with an electrospray ionization source used in a positive ionization mode (ThermoFisher Scientific, San Jose CA, USA) and a detection in full MS(2) scan. The limit of quantification of ivabradine was 10 µg/L, and the method was linear up to 1000 µg/L. The ivabradine concentration in the patient's serum was 375 µg/L. This concentration value was >30 times those measured after therapeutic doses intakes. Nevertheless, the bradycardia was no more severe than the one observed with therapeutic dosage. In conclusion, this case tends to show an absence of correlation between blood concentration and severity of the troubles in cases of overdosage.
