Which factors influence RF lesion size? (three)

• A. Time, power, electrode tip size
• B. Temperature, impedance, blood flow
• C. Frequency, pulse duration, electrode material
• D. Color of electrode, patient age, ambient temp

Answer: (A)

In RF lesioning, how large the heated area becomes is mainly about how much energy you deposit and how widely that energy is applied. The time you deliver the current and the power you set together determine the total energy delivered to the tissue, so longer duration or higher power increases heating and expands the lesion. The size is also directly influenced by the electrode tip size: a larger tip contacts more tissue and distributes energy over a bigger area, producing a larger lesion.

Other factors can modulate the outcome but don’t establish the basic size as directly. Temperature is the result of the energy delivered and the tissue’s properties, so it reflects what you did rather than acting as a separate controllable driver. Impedance and blood flow affect how efficiently energy is converted to heat and how heat is removed, which can shrink or shape the lesion, but they don’t set the primary dimensions the way time, power, and tip size do. Frequency, pulse duration, and electrode material can influence lesion characteristics in certain contexts, yet the most consistent determinants of lesion size are the duration of energy delivery, the power applied, and the size of the electrode tip.