Dosimetric verification of stereotactic head treatments performed with Helical Tomotherapy using alanine dosimeters and gafchromic films

Phenol compounds as new materials for Electron Paramagnetic Resonance dosimetry in clinical photon and electron beams,

In the last decades several research laboratories have shown an increasing interest aimed at extending the applicability of Electron Paramagnetic Resonance (EPR) dosimetry to radiotherapy with different types of radiation beams. EPR is a spectroscopic method for investigating the structure and dynamics of such paramagnetic species. Free radicals are known to be produced when a compound is irradiated with ionizing radiations. The concentration of radiation-induced free radicals is proportional to the energy released inside in the medium and this allows for dosimetric measurements through EPR technique. The use of alanine as a dosimetric material gave the possibility to apply EPR spectroscopy…

Characterization of phenolic pellets for ESR dosimetry in photon beam radiotherapy.

We report a study of the dosimetric features of phenolic compounds for applications in radiation therapy dosimetry of clinical photon beams by using ESR spectroscopy. After the optimization of the ESR readout parameters, basic dosimetric properties (such as intra-batch reproducibility, dose-response, sensitivity, linearity, dose rate dependence, tissue-equivalence and signal stability) of laboratory-made phenolic dosimeters in form of pellets were investigated. Furthermore, these dosimeters were tested for measuring the depth dose profile of a 6 MV clinical photon beam. The results reported show that these dosimeters are promising materials for ESR dosimetric applications in radiation thera…

Comparison of EPR response of pure alanine and alanine with gadolinium dosimeters exposed to TRIGA Mainz reactor

The development of Neutron Capture Therapy (NCT) for cancer treatments has stimulated the research for beam characterization in order to optimize the therapy procedures. The NCT has found to be promising for treatments of tumours which hardly can be treated with other techniques, such as gliomas. Alongside with the improvements of this technique, the development of procedures for the beam characterization arouses great interest in order to optimize the therapy protocol by reliably determining the various (neutronic and photonic) components of the mixed beam usually employed for therapy. Electron Paramagnetic Resonance (EPR) dosimetry for electron and photon beams with alanine has attracted …

Caratterizzazione dosimetrica della facility a neutroni termici del reattore TRIGA di Pavia: studio della dose da fotoni mediante rivelatori ESR di alanina

The optimization of the procedures of Neutron Capture Therapy (NCT) for cancer treatments involves research for beam characterization. One major issue for this therapy is the reliable dosimetric determination of the various (neutronic and photonic) components of the employed beam. In particular, the precise and accurate measurements of the gamma photon component is fundamental for evaluating the risks to healthy tissues hit by the mixed field. Among solid state dosimeters the alanine detectors read by Electron Paramagnetic Resonance (EPR) technique present several advantages such as: tissue equivalence for photon and electron beams, linearity of its dose-response over a wide range, high sta…

Determinazione della componente gamma nella colone termica del reattore TRIGA di Pavia tramite Dosimetri ESR di alanina

Negli ultimi anni il crescente interesse verso la radioterapia a cattura neutronica (internazionalmente nota come Neutron Capture Therapy - NCT) per il trattamento di neoplasie ha stimolato diverse attività di ricerca finalizzate alla caratterizzazione del fascio utilizzato e all'ottimizzazione delle procedure radioterapiche. Tra i vari sistemi dosimetrici trovano largo impiego i rivelatori a stato solido ESR (Risonanza di Spin Elettronico) a base di alanina che presentano diversi vantaggi come la tessuto equivalenza, la linearità della risposta in un ampio intervallo di dose, l'elevata stabilità dei radicali liberi radioindotti, la non distruttività della lettura del dosimetro e il basso c…

Calcolo dei livelli di dose gamma e dei livelli di radon dovuta ai materiali da costruzione

La radioattività delle famiglie di radionuclidi naturali contenuti nei materiali da costruzione è responsabile in una certa misura dell'equivalente di dose riferibile al fondo naturale delle radiazioni. Tale radioattività contribuisce a due fattori di dose: la dose gamma esterna e la dose alfa interna legata all'introduzione e all'accumulo del radon nonché ad un contributo dovuto all’inalazione di polveri nelle quali le concentrazioni dei capostipiti naturali sono alte. I materiali da costruzione sono la sorgente principale del rateo di dose gamma nelle abitazioni. Tutti gli edifici in pietra contengono nuclei radioattivi come 226Ra, 232Th e 40K. É noto che i livelli di radon sono legati al…

Dosimetric analysis of phenolic solid state pellets exposed to radio-therapeutic photon and electron beams through electron spin resonance technique

Analisi dei vetri di orologi tramite risonanza paramagnetica elettronica (EPR) e termoluminescenza (TL) per dosimetria retrospettiva

Negli ultimi anni è cresciuto il rischio di esposizioni radiologiche non controllate della popolazione, sia a causa di incidenti associati ad applicazioni industriali e mediche delle radiazioni ionizzanti sia in seguito ad incidenti legati all’abbandono o alla dismissione di sorgenti ma anche ad un uso criminale di materiale radioattivo [1–3]. Gli effetti biologici prodotti dalle radiazioni ionizzanti dipendono fortemente dalla quantità di energia impartita per unità di massa (dose assorbita) [4]. Pertanto, nell’ambito di un incidente radiologico, disporre di procedure di ricostruzione della dose assorbita da un individuo può contribuire oltre che ad identificare i membri della popolazione …

Nuovi composti fenolici per la dosimetria a risonanza di spin elettronico (ESR) in campo misto neutroni-gamma

Dosimetry to Electron Spin Resonance (ESR) using organic compounds (alanine and ammonium tartrate) for mixed neutron-gamma fields

Alongside with the development of Neutron Capture Therapy (NCT) and the use of thermal neutrons for radiotherapeutic purposes, many efforts have been devoted to the characterization of the beam in order to optimize therapy procedures. Reliable dose measurements should be able to determine the various (neutrons and photonic) components of the mixed beam usually employed for therapy. This paper studies the effect of additives such as Boric and Gadolinium nuclei on the sensitivity of neutron organic (alanine and ammonium tartrate) dosimeters analyzed through Electron Spin Resonance (ESR) technique. These dosimeters were exposed to a mixed (neutron-gamma) field mainly composed of thermal neutro…

Caratterizzazione del campo misto neutroni-gamma nella colonna termica del reattore TRIGA di Pavia tramite attivazione neutronica e rivelatori ad alanina

Phenol compounds for EPR dosimetry in radiation therapy

EPR/alanine dosimetry in Stereotactic Radiosurgery treatments through Helical Tomotherapy

Uso della spettroscopia ESR per la caratterizzazione di composti fenolici irradiati con fasci clinici di fotoni ed elettroni

In the last decades several research laboratories have shown an increasing interest aimed at extending the applicability of Electron Spin Resonance (ESR) dosimetry to radiotherapy with different types of radiation beams. ESR is a spectroscopic method for investigating the structure and dynamics of such paramagnetic species. Free radicals are known to be produced when a compound is irradiated with ionizing radiations. The concentration of radiation-induced free radicals is proportional to the energy released inside in the medium and this allows for dosimetric measurements through ESR technique which able to quantitatively determine the radical concentration. The use of alanine as a dosimetri…