Evaluation of a planar diode matrix for SRS patient-specific QA in comparison with GAFchromic films.

Purpose: We validate the routine use of a two-dimensional (2D) diode matrix for patient specific pre-treatment verification for Cyberknife (CK) stereotactic radiosurgery and to compare it with film dosimetry.

Materials And Method: A total of 46 patients were selected according to the most frequent diseases treated at our institution with the CK system, that is, brain metastases, meningiomas, spine metastases, and prostate tumors. All cases were evaluated with GAFChromic EBT-3 films and SRS MapCHECK for Fixed cone, IRIS, and MLC collimators of the CK.

Zero field PDD and TMR data for unflattened beams in conventional linacs: A tool for independent dose calculations.

Purpose: To investigate the applicability of the formalism described in BJR supplement n.25 for Flattening Filter Free (FFF) beams in determining the zero-field tissue maximum ratio (TMR) for an independent calculation method of Percentage Depth Doses (PDDs) and relative dose factors (RDFs) at different experimental setups.

Methods: Experimental PDDs for field size from 40×40cm to 2×2cm with Source Surface Distance (SSD) 100cm were acquired.