Faculty Bibliography

Ethical decision-making is central to the practice of any profession. These decisions are often neither clear-cut nor easy. The AAPM Code of Ethics establishes a common set of expectations for the profession and is designed to guide each and every member as they practice ethical decision-making. A set of principles reflecting the moral values of the AAPM provides the foundation for the code. Practice of these principles often requires interpretation and adaptation to specific circumstance. To further navigate nuances of implementation, the Code provides guidelines expanding upon each principle in specific areas of professional practice, such as clinical care, research, business transactions, and educational activities. The purpose of the first part of this seminar is to introduce to attendees the revision of the Code of Ethics currently in progress. In this session we will present the draft revised AAPM Code of Ethics, propose a framework for identifying ethical dilemmas and exploring courses of action, and explain how AAPM addresses ethical issues. Members will become aware of the ethical values of AAPM and the expectation to abide by them. The Code of Ethics is designed as a guide for ethical decision-making in the practice of medical physics. The recently revised Code introduces the virtues of inclusivity and diversity while maintaining its allegiance to the principles of collegiality, competence, integrity, and responsibility. The second part of this seminar will delve further into ethical dilemmas in the workplace traced back to lack of inclusivity and diversity, present a framework for identifying these ethical dilemmas and exploring courses of action. The aim of the session is to help the attendees to realize the influence and responsibility each individual has in determining the culture of their workplace and the reputation of the medical physics profession. Learning Objectives: 1. Understand content and purpose of the revised AAPM Code of Ethics 2. Understand how to use it as a guide in implementing a framework for ethical decision making 3. Understand how AAPM addresses ethical issues

Purpose: Anti‐microbial silver wound dressing may be useful as a bolus material. This study measures the water‐equivalent‐thickness of a silver wound dressing to characterize it for clinical use. This nylon‐mesh dressing, with its permanently plated silver surface (546 mg Ag/100 cm2) may meet the need for bolus with fine variability of thickness and self‐sterilization. Methods: A percent depth dose (PDD) curve was measured in plastic water (CNMC Best Medical) using a parallel plate chamber (PTW N34001) for an 8×8 cm field size, 6 MV beam, 100 cm SSD with a linear accelerator. Measurements were repeated under varying thicknesses (0.5 mm, 1mm, and 2 mm) of silver dressing material, 10 cm × 11 cm (Silverlon™ Antimicrobial silver wound contact dressing WCD‐466). Control measurements were also made in a small water tank. Results: For every layer of dressing added (∼0.5mm) the PDD shifts to the left along the depth axis. A 2 mm offset applied to the position values of the 2 mm (4‐layers) PDD curve causes superposition with the control PDD. This suggests that 2 mm of silver dressing performs similarly to 2 mm of plastic water. This was verified with measurements under clinical setup conditions, 100 cm to the top of the parallel plate chamber, ie. to skin, with bolus placed on top, under 2 mm plastic water (73.40%) and under 2 mm silver dressing (73.41%). Measurements in a water tank for this equivalent depth agree within 1%. Conclusion: The bolus properties of silver‐mesh dressing appear to be water‐equivalent. Silver dressings can be used as bolus and may be particularly beneficial when fine variations are desired or when maintaining an anti‐microbial environment is of particular value

The goal of this study was to implement and validate a noninvasive, quantitative ultrasonic technique for accurate and reproducible measurement of normal-tissue toxicity in radiation therapy. The authors adapted an existing ultrasonic tissue characterization (UTC) technique that used a calibrated 1D spectrum based on region-of-interest analysis. They modified the calibration procedure by using a reference phantom instead of a planar reflector. This UTC method utilized ultrasonic radiofrequency echo signals to generate spectral parameters related to the physical properties (e.g., size, shape, and relative acoustic impedance) of tissue microstructures. Three spectral parameters were investigated for quantification of normal-tissue injury: Spectral slope, intercept, and midband fit. They conducted a tissue-mimicking phantom study to verify the reproducibility of UTC measurements and initiated a clinical study of radiation-induced breast-tissue toxicity. Spectral parameter values from measurements on two phantoms were reproducible within 1% of each other. Eleven postradiation breast-cancer patients were studied and significant differences between the irradiated and untreated (contralateral) breasts were observed for spectral intercept (p = 0.003) and midband fit (p < 0.001) but not for slope (p = 0.14). In comparison to the untreated breast, the average difference in the spectral intercept was 2.99 +/- 0.75 dB and the average difference in the midband fit was 3.99 +/- 0.65 dB. The preliminary clinical study demonstrated the feasibility of using the quantitative ultrasonic method to evaluate normal-tissue toxicity in radiation therapy