Development of a PMMA phantom as a practical alternative for quality control of gamma knife® dosimetry.

Background: To measure the absorbed dose rate to water and penumbra of a Gamma Knife® (GK) using a polymethyl metacrylate (PMMA) phantom.

Methods: A multi-purpose PMMA phantom was developed to measure the absorbed dose rate to water and the dose distribution of a GK. The phantom consists of a hemispherical outer phantom, one exchangeable cylindrical chamber-hosting inner phantom, and two film-hosting inner phantoms.

An effective calibration technique for radiochromic films using a single-shot dose distribution in Gamma Knife(®).

Purpose: A method of calibrating radiochromic films for Gamma Knife(®) (GK) dosimetry was developed. The applicability and accuracy of the new method were examined.

Methods: The dose distribution for a sixteen millimeter single-shot from a GK was built using a reference film that was calibrated using the conventional multi-film calibration (MFC) method.