Characteristics of radiation field generated by Pencil Beam Scanning nozzle.

On 16-18.10.2014 in Cyclotron Centre Bronowice at the IFJ PAN an experiment was held by the EURADOS Working Group 9, which investigates non-target patient doses and the related risks accompanying radiotherapy treatment. Over 25 scientists from 9 scientific institutions took part in this project, including: RBI Zagreb, IRP Munich, NPI Prague, IRSN Paris, UNT Newcastle, SCK-CEN Mol, NCBJ Świerk, UA Barcelona and IFJ PAN Kraków.

The main goal of the experiment was to establish the characteristics of the secondary radiation field generated during radiotherapy using Pencil Scanning Beam. The measurements were performed in clinical conditions of paediatric brain tumour irradiation. Simulated treatment of brain located tumour was performed using the IMPT technique by irradiating anthropomorphic phantoms of 1, 5 and 10 year old patients. Various passive dosimeters were used to measure dose to tissues and organs: thermoluminescent detectors (MTS-6, MTS-7, MCP), track etch detectors (CR-39) and detectors using optically stimulated luminescence (OSL) and radiophotoluminescence (RPL). Following active detectors were used to determine the characteristics of  the radiation field surrounding the patient: microdosimetric proportional counters (Far West Technology, HAWK), proportional counters type FHT WENDI-2 and recombination chambers.