Small static radiosurgery field dosimetry with small volume ionization chambers.

Purpose: To evaluate the response of the four smallest active volume thimble type ionization chambers commercially available (IBA-dosimetry RAZOR Nano Chamber, Standard Imaging Exradin A16, IBA-dosimetry CC01 and PTW T31022) when measuring SRS cone collimated Flattening Filter Free (FFF) fields.

Methods: We employed Monte Carlo simulation for calculating correction factors as defined in IAEA TRS-483. Monte Carlo simulation beam model and ion chamber geometry definitions were supported by an extensive set of measurements.

Multiparametric magnetic resonance imaging-guided salvage radiotherapy in prostate cancer.

Aim: To analyse the efficacy and toxicity of postprostatectomy SRT in patients with a BCR evaluated with mpMRI.

Background: Multiparametric magnetic resonance imaging (mpMRI) has the ability to detect the site of pelvic recurrence in patients with biochemical recurrence (BCR) after radical prostatectomy (RP). However, we do not know the oncological outcomes of mpMRI-guided savage radiotherapy (SRT).

On flattening filter-free portal dosimetry.

Varian introduced (in 2010) the option of removing the flattening filter (FF) in their C-Arm linacs for intensity-modulated treatments. This mode, called flattening filter-free (FFF), offers the advantage of a greater dose rate. Varian's "Portal Dosimetry" is an electronic portal imager device (EPID)-based tool for IMRT verification.