Physica Medica: European Journal of Medical Physics - Volume 32 - Supplement 1 - February 2016

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can be collected with a concentration greater than 1 Bq/g depending on
trash weight, a procedure management of hospital trash from injected pa-
tients has to be established to avoid unsafe disposal of radioactive wastes.
D.403
EVALUATION OF MEDICAL RADIATION EXPOSURES IN TUSCANY
S. Ferretti C. Sottocornola A. Tofan A.C. Traino M. Tripodi
a Dipartimento di Fisica, Universita’ di Pisa, Pisa, Italy; b Azienda USL1,
Massa-Carrara, Italy; c Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy
Introduction: Radiations used in medical applications are the major source
of artificial radiation exposing the population of developed countries. Al-
though the use of ionizing radiations in medicine has originated undeniable
health benefits, this has also led to the necessity of monitoring potential-
ly harmful effects produced by radiations used for diagnostic purposes. These
effects are essentially stochastic. The main side effect produced by radia-
tion is the induction of cancers (solid tumors and leukemia) even after
several years from the exposure.
Legislative Decree 187/2000 requires Italian regions to provide an esti-
mate of medical exposure of their population. The region of Tuscany has
therefore planned (through resolution No. 994 of 11-10-2014) a project
aimed to assess the annual per-capita and collective effective dose due to
medical exposures.
Materials and Methods: Data were gathered from questionnaires filled out
by technical experts of several hospitals. The collected information in-
cluded exposure and geometric parameters of the specific exam, dosimetric
data, frequency and type of exams involving ionizing radiation for inpa-
tients, etc. The total number of exams carried out in all the hospitals during
a year, classified by type (according to a numerical code) was derived from
a specific regional database. Dedicated software packages were used, when
available, to assess the variability of effective dose for any specific exam.
Results: We show some preliminary results of effective dose evaluation for
the most important exams with ionizing radiations performed in some hos-
pitals of Tuscany.
Conclusions: Besides fulfilling legal requirements, this evaluation allows
to compare current data with those of previous surveys, and to outline any
statistically significant trend.
D.404
ASSESSMENT OF RADIONUCLIDE IMPURITIES IN 18F-METIL-CHOLINE
(18F-FMECH)
M. Iacco A. Rongoni S. Beneventi D. Saetta F. Sust P. Sabatini
M. Marcon R. Tarducci a Santa Maria della Misericordia Hospital, Medical
Physics Department, Perugia, Italy; b University of Perugia, Surgery and
Biomedicine Department, Perugia, Italy; c Santa Maria della Misericordia
Hospital, Hospital Pharmacy Department, Perugia, Italy; d Arpa Umbria, Perugia,
Italy
Introduction: Radionuclide impurities generated during the bombard-
ment of [18 O] water in the production of 18F-Metil-Choline (18F-FMeCh) were
assessed using high resolution gamma spectrometry and liquid scintilla-
tion spectrometry. The aim of this work was to determine the distribution
of impurity in the synthesis process and demonstrate the radiochemical
purity of the 18F-FMeCh.
Materials and methods: Samples from the different steps of production
process were collected: [18O] irradiated water, target’s waste water, Cromafix
cartridge, Cromafix’s waste water, WCX cartridge, final waste water and final
18F-FMeCh solution. To determine the gamma emitting radionuclides, the
samples were analyzed in a standard calibrated geometry using a High-
Purity Germanium gamma-ray spectrometer (EG&G Ortec). Moreover, we
assessed the activity of beta-emitting 3H by liquid scintillation counter
(Wallac Quantulus).
Results: Our data showed the presence of gamma-emitting 51Cr, 52Mn, 54 Mn,
56Co, 57Co, 58 Co, 95mTc, 96Tc, 109Cd, 184Re and 186Re in the [18O] irradiated water.
In the target’s waste water, we found the same radionuclides except for
51Cr, 95mTc and 186Re. The Cromafix cartridge showed the presence of all the
impurities except for 58Co, which was found in the Cromafix’s waste water.
The remaining nuclides were found in the final waste water. In the final
18F-FMeCh solution, the activity was lower of the minimum detectable ac-
tivity (MDA) of the spectrometer. We found the presence of 3H in [18O]
irradiated water. We also assessed the presence of 3H in the final 18F-
FMeCh solution, where the activity concentration was extremely low
(10−2 Bq/g).
Conclusions: The data demonstrated that purification methods, adopted
for the synthesis, provide 18F-FMeCh radionuclidically pure. Moreover the
activity of cartridges and wastes were lower than the exemption limits.
D.405
MONTE CARLO ESTIMATION AND MEASUREMENT OF THE ACTIVATION
PRODUCTS DUE TO AN ELECTRON LINEAR ACCELERATOR FOR MEDICAL
APPLICATIONS
L. Isolan G. Cucchi M. Iori R. Sghedon M. Sumini a University of
Bologna, Bologna, Italy; b IRCCS-ASMN Reggio Emilia, Reggio Emilia, Italy
Introduction: During radiotherapy treatments with high energy electron
sources some nuclear reactions take place. This means that several kinds
of radioisotopes are generated both in the device and then in the treat-
ment chamber walls and some additional dose is given to the patient and
to the staff of the radiotherapy unit, due to the decay processes, often im-
plying gamma-ray emissions. To show these effects a portable NaI(Tl)
monitor is used for gamma spectrometry.
Materials and Methods: The purpose of this work is to investigate the ac-
tivation products using both Monte Carlo simulations, with the MCNP family
codes, and an experimental measurement setup. The goal is to achieve the
ken of the induced radioactivity with the measures and identify the
source components of this with numerical model. To do this, standard cross
section libraries have been expanded and the study of the activation, due
both to photons and photoneutrons, has been done.
Results: The capability of the MCNPX/6 codes has been tested in terms of
convergence and reliability mainly comparing the results with the ones
coming frommeasurement. Considering the W187 produced in the primary
collimator of the accelerator as the reference isotope of the induced acti-
vation processes (evaluated in the order of 10−6 atoms/electron directly from
photons) we have linked up the Monte Carlo estimations with the exper-
imental analysis carried out also on the bunker wall.
Conclusions: In conclusion, the capability of MCNPX/6 to model the ac-
tivation induced by an electron accelerator for medical applications, with
the identification of the induced radioactivity, has been fully exploited and
compared with the results obtained by an experimental campaign.
Reference
[1]
D.406
WHY NOT USE EFFECTIVE DOSE INDEX (EDI) INSTEAD OF EFFECTIVE
DOSE (E) FOR THE INFORMATION RELATING TO PATIENT EXPOSURE?
A. Lazzari *, M. Quattrocchi. Usl2 Lucca – S.C.Fisica Sanitaria, Lucca, Italy
Introduction: One of the topics on the transposition of the Directive 2013/
59/EURATOM into Italian law is the choice of the information to be included
in the reports of the patient exposure. We have often argued that the data
to be reported are the dose indexes as PKA, CTDIvol and PKL, CT. Among
the physicians, but not only, many still require the use of the Effective Dose
(E). In the case that the choice falls on E, we propose to use it with the
meaning of an index and so to replace it with a new term Effective Dose
Index (EDI).
Materials and Methods: The effective dose use in medical imaging is based
on the simplicity of switching to a risk assessment. But we have to take
into account the warnings in ICRP Publication 103 that states that it cannot
be used for the assessment of individual risk in diagnostic radiology.
The reasons are well summarized in the literature and converge in con-
sidering that communication of E to the patient is essentially wrong.
e119 Abstracts/Physica Medica 32 (2016) e116–e123