What instrument is commonly used for measuring isodose distributions during commissioning?

The RFA (Radiochromic Film Array) analyzer is commonly used for measuring isodose distributions during the commissioning phase of radiation therapy equipment. This instrument is particularly favored due to its high spatial resolution and ability to provide detailed dose distribution information. It utilizes radiochromic film, which changes color in response to radiation exposure, allowing for precise visualization of the isodose lines.

This capability is essential when commissioning new treatment plans or verifying machine outputs, as it can effectively map how doses are delivered throughout the treatment area, ensuring that the prescribed radiation levels are accurately administered. The ease of use and the ability to analyze complex geometries make RFA analyzers a key tool in confirming that the radiation therapy systems are accurately delivering the intended dose distributions.

Miniature ionization chambers, diode detectors, and field meters, while useful in their own right for specific measurements or conditions, do not provide the comprehensive visual mapping of isodose lines necessary for thorough commissioning evaluations.