Characterization of phenolic pellets for ESR dosimetry in photon beam radiotherapy

• DOI: 10.1007/s00411-017-0716-3
• Publication Date: 2017-09-19T02:48:13Z
• Authors: Salvatore Gallo; Giuseppina Iacovi...; Salvatore Panzeca; Ivan Veronese; Antonio Bartolotta; Daniele Dondi; Anna Maria Gueli; Gianfranco Loi; Anna Longo; Eleonora Mones; Maurizio Marrale
• Keywords: Models, Molecular; Molecular Conformation; IRGANOX 1076®; 03 medical and health sciences; 0302 clinical medicine; Phenols; Models; Dosimetry; ESR; Phenols; IRGANOX; Dosimetry; Radiotherapy; EPR; Microwaves; Radiometry; ESR; Photons; Radiation; Phenol; Radiotherapy; 2300; Electron Spin Resonance Spectroscopy; Molecular; Radiotherapy Dosage; Photon; Biophysic; Dosimetry; ESR; IRGANOX 1076 ®; Phenols; Radiotherapy; Electron Spin Resonance Spectroscopy; Microwaves; Models, Molecular; Molecular Conformation; Phenols; Photons; Radiometry; Radiotherapy Dosage; Biophysics; Radiation; 2300; Microwave

This work deals with the dosimetric features of a particular phenolic compound (IRGANOX 1076®) for dosimetry of clinical photon beams by using electron spin resonance (ESR) spectroscopy. After the optimization of the ESR readout parameters (namely modulation amplitude and microwave power) to maximise the signal without excessive spectrum distortions, basic dosimetric properties of laboratory-made phenolic dosimeters in pellet form, such as reproducibility, dose-response, sensitivity, linearity and dose rate dependence were investigated. The dosimeters were tested by measuring the depth dose profile of a 6 MV photon beam. A satisfactory intra-batch reproducibility of the ESR signal of the manufactured dosimeters was obtained. The ESR signal proved to increase linearly with increasing dose in the investigated dose range 1-13 Gy. The presence of an intrinsic background signal limits the minimum detectable dose to a value of approximately 0.6 Gy. Reliable and accurate assessment of the dose was achieved, independently of the dose rate. Such characteristics, together with the fact that IRGANOX 1076® is almost tissue-equivalent, and the stability of the ESR signal, make these dosimeters promising materials for ESR dosimetric applications in radiotherapy.