Publications by authors named "Vando Piccagli"

7 Publications

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How direct measurements on worker eyes with Scheimpflug camera can affect lens dose conversion coefficients in interventional radiology.

J Radiol Prot 2021 Apr 7. Epub 2021 Apr 7.

Industrial Engineering - Montecuccolino Laboratory, University of Bologna, Via dei Colli 16, 40136 Bologna, Italy, Bologna, BO, 40136, ITALY.

The Directive 2013/59/Euratom established a reduction of the occupational exposure limits to the lens. Since it is become crucial to estimate the lens absorbed dose, the individual variability of exposed worker's ocular conformations with respect to the data estimated with their personal dosimetry has been studied. The anterior eye conformation of 45 exposed workers was acquired with Scheimpflug imaging and classified according to eye vision conditions (emmetropia, myopia or hypermetropia). Three eye models were computed, with two lens reconstructions, and implemented in an interventional radiology scenario by using Monte Carlo (MC) code. The models were dosimetrically analysed simulating setup A, a theoretical monoenergetic and isotropic photon's source (10-150 keV) and setup B, a more realistic interventional conditions with an angiographic X-ray unit (50, 75, 100 kV-peak). Scheimpflug imaging provided an average anterior chamber depth of (6.4 ± 0.5) mm and a lens depth of (3.9 ± 0.3) mm, together with a reconstructed equatorial lens length of (7.1 - 10.1) mm. Using this data for model's reconstruction, the dose conversion coefficients (DCs) for all ocular structures were simulated. Regardless of the eye model used, DCs show a similar trend with radiation energy which highlights, for the same energy and setup used, no significant dependence on ocular morphology and worker's visual conditions. The maximum difference obtained does not exceed 1% for all eye models or structures analysed. Therefore, the individual variabilities of worker ocular anatomy do not require any additional correction compared to the personal dosimetry data measured with a dedicated lens dosimeter. To estimate the absorbed dose to the other eye structures, it is essential instead to know the spectrum of the source that has generated the irradiation since there are differences considering monoenergetic sources or more realistic angiographic units.
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http://dx.doi.org/10.1088/1361-6498/abf56fDOI Listing
April 2021

DNA damage in lens epithelial cells exposed to occupationally-relevant X-ray doses and role in cataract formation.

Sci Rep 2020 12 10;10(1):21693. Epub 2020 Dec 10.

Department of Medical Physics, St. Orsola-Malpighi University Hospital, Bologna, Italy.

The current framework of radiological protection of occupational exposed medical workers reduced the eye-lens equivalent dose limit from 150 to 20 mSv per year requiring an accurate dosimetric evaluation and an increase understanding of radiation induced effects on Lens cells considering the typical scenario of occupational exposed medical operators. Indeed, it is widely accepted that genomic damage of Lens epithelial cells (LEC) is a key mechanism of cataractogenesis. However, the relationship between apoptosis and cataractogenesis is still controversial. In this study biological and physical data are combined to improve the understanding of radiation induced effects on LEC. To characterize the occupational exposure of medical workers during angiographic procedures an INNOVA 4100 (General Electric Healthcare) equipment was used (scenario A). Additional experiments were conducted using a research tube (scenario B). For both scenarios, the frequencies of binucleated cells, micronuclei, p21-positive cells were assessed with different doses and dose rates. A Monte-Carlo study was conducted using a model for the photon generation with the X-ray tubes and with the Petri dishes considering the two different scenarios (A and B) to reproduce the experimental conditions and validate the irradiation setups to the cells. The simulation results have been tallied using the Monte Carlo code MCNP6. The spectral characteristics of the different X-ray beams have been estimated. All irradiated samples showed frequencies of micronuclei and p21-positive cells higher than the unirradiated controls. Differences in frequencies increased with the delivered dose measured with Gafchromic films XR-RV3. The spectrum incident on eye lens and Petri, as estimated with MCNP6, was in good agreement in the scenario A (confirming the experimental setup), while the mean energy spectrum was higher in the scenario B. Nevertheless, the response of LEC seemed mainly related to the measured absorbed dose. No effects on viability were detected. Our results support the hypothesis that apoptosis is not responsible for cataract induced by low doses of X-ray (i.e. 25 mGy) while the induction of transient p21 may interfere with the disassembly of the nuclear envelop in differentiating LEC, leading to cataract formation. Further studies are needed to better clarify the relationship we suggested between DNA damage, transient p21 induction and the inability of LEC enucleation.
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http://dx.doi.org/10.1038/s41598-020-78383-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7728785PMC
December 2020

Red blood cells metabolome changes upon treatment with different X-ray irradiation doses.

Ann Hematol 2018 Oct 7;97(10):1909-1917. Epub 2018 Jun 7.

Transfusion Medicine Unit, AUSL-IRCCS, Reggio Emilia, Italy.

The upholding of red blood cells (RBC) quality and the removal of leukocytes are two essential issues in transfusion therapy. Leukodepletion provides optimum results, nonetheless there are cases where irradiation is recommended for some groups of hematological patients such as the ones with chronic graft-vs-host disease, congenital cellular immunodeficiency, and hematopoietic stem cell transplant recipients. The European guidelines suggest irradiation doses from 25 to 50 Gray (Gγ). We evaluated the effect of different prescribed doses (15 to 50 Gγ) of X-ray irradiation on fresh leukodepleted RBCs bags using a novel protocol that provides a controlled irradiation. Biochemical assays integrated with RBCs metabolome profile, assessed by nuclear magnetic resonance spectroscopy, were performed on RBC units supernatant, during 14 days storage. Metabolome analysis evidenced a direct correlation between concentration increase of three metabolites, glycine, glutamine and creatine, and irradiation dose. Higher doses (35 and 50 Gγ) effect on RBC mean corpuscular volume, hemolysis, and ammonia concentration are considerable after 7 and 14 days of storage. Our data show that irradiation with 50 Gγ should be avoided and we suggest that 35 Gγ should be the upper limit. Moreover, we suggest for leukodepleted RBCs units the irradiation with the prescribed dose of 15 Gγ, value at center of bag, and ranging between 13.35-15 Gγ, measured over the entire bag volume, may guarantee the same benefits of a 25 Gγ dose assuring, in addition, a better quality of RBCs.
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http://dx.doi.org/10.1007/s00277-018-3386-6DOI Listing
October 2018

Skin dose saving of the staff in 90Y/177Lu peptide receptor radionuclide therapy with the automatic dose dispenser.

Nucl Med Commun 2016 Oct;37(10):1046-52

aMedical Physics Unit bNuclear Medicine Unit, Arcispedale Santa Maria Nuova - IRCCS, Reggio Emilia cDepartment of Industrial Engineering, University of Bologna, Bologna, Italy.

Objective: When handling Y-labelled and Lu-labelled radiopharmaceuticals, skin exposure is mainly due to β-particles. This study aimed to investigate the equivalent dose saving of the staff when changing from an essentially manual radiolabelling procedure to an automatic dose dispenser (ADD).

Materials And Methods: The chemist and physician were asked to wear thermoluminescence dosimeters on their fingertips to evaluate the quantity of Hp(0.07) on the skin. Data collected were divided into two groups: before introducing ADD (no ADD) and after introducing ADD.

Results: For the chemist, the mean values (95th percentile) of Hp(0.07) for no ADD and ADD are 0.030 (0.099) and 0.019 (0.076) mSv/GBq, respectively, for Y, and 0.022 (0.037) and 0.007 (0.023) mSv/GBq, respectively, for Lu. The reduction for ADD was significant (t-test with P<0.05) for both isotopes. The relative differences before and after ADD collected for every finger were treated using the Wilcoxon test, proving a significantly higher reduction in extremity dose to each fingertip for Lu than for Y (P<0.05). For the medical staff, the mean values of Hp(0.07) (95th percentile) for no ADD and ADD are 0.021 (0.0762) and 0.0143 (0.0565) mSv/GBq, respectively, for Y, and 0.0011 (0.00196) and 0.0009 (0.00263) mSv/GBq, respectively, for Lu. The t-test provided a P-value less than 0.05 for both isotopes, making the difference between ADD and no ADD significant.

Conclusion: ADD positively affects the dose saving of the chemist in handling both isotopes. For the medical staff not directly involved with the introduction of the ADD system, the analysis shows a learning curve of the workers over a 5-year period. Specific devices and procedures allow staff skin dose to be limited.
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http://dx.doi.org/10.1097/MNM.0000000000000548DOI Listing
October 2016

Radiation protection procedures in 131I treatments for thyroid cancer in patients requiring hemodialysis.

Nucl Med Commun 2014 Jun;35(6):626-30

aMedical Physics Unit bNuclear Medicine Unit, Arcispedale Santa Maria Nuova - IRCCS, Reggio Emilia, Italy.

Background: Hemodialysis is essential for patients with renal failure, and iodine-131 ((131)I) administration is the standard of care in thyroid carcinoma treatment. Although the need for hemodialysis during (131)I treatment is very rare, it raises some concerns due to the involvement of personnel not exposed to radiation and to the contamination of devices used for other patients. In this paper, a radioprotection protocol to perform hemodialysis safely on patients during (131)I treatment has been presented.

Patients And Methods: The exposure of personnel who assisted 13 patients over the course of 10 years was monitored: external exposure was measured through electronic dosimeters, and internal contamination was checked by thyroid uptake and urine sample gamma spectrometry. Over this period, room layout was optimized to allow an improvement of radioprotection procedures.Two nurses were involved in patient assistance.

Results: After hemodialysis, measurements of internal contamination were below the minimum detectable activity and external exposure was in the range of 1-82 μSv in terms of H(p)(10). A reduction in personnel exposure was observed after hospitalization room renovation: H(p)(10) normalized to the activity administered to the patient was about halved.

Conclusion: The data show that hemodialysis can be performed safely during I treatments when appropriate radioprotection actions are implemented.
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http://dx.doi.org/10.1097/MNM.0000000000000095DOI Listing
June 2014

Personnel exposure in labelling and administration of (177)Lu-DOTA-D-Phe1-Tyr3-octreotide.

Nucl Med Commun 2011 Oct;32(10):947-53

Department of Medical Physics, Nuclear Medicine, Arcispedale S. Maria Nuova, Reggio Emilia, Italy.

Objective: The introduction of peptide receptor radionuclide therapy, mainly performed with (90)Y and (177)Lu-labelled somatostatin analogues, has widened the therapeutic horizon of nuclear medicine.The handling of (177)Lu-labelled pharmaceuticals implies an increase of the personnel exposure and this aspect is evaluated in this paper, in comparison with personal exposure in (90)Y manipulation.

Materials And Methods: Personal dose measurements were performed during 26 (177)Lu-DOTATOC preparations by using a series of thin active layer LiF: Mg,Cu,P thermoluminescence dosimeters fixed at the operator's fingertips to evaluate the skin equivalent dose and by means of direct reading dosimeters positioned at the chest to evaluate the personal effective dose. Individual protection devices, such as shielded aprons and anti-X gloves, were also used.

Results: The 95th percentile of the skin equivalent dose distribution for (177)Lu operations by using 0.20-mm anti-X gloves was 0.080 mSv/GBq for the chemist and 0.011 mSv/GBq for the physician, whereas the 75th percentile was 0.058 mSv/GBq for the chemist and 0.006 mSv/GBq for the physician. The use of the 0.25 mm Pb-equivalent anti-X apron halved the personal equivalent dose measured over the apron by a direct reading dosimeter. Skin doses were compared with (90)Y-DOTATOC procedures: no relevant exposure reduction is observed for chemists, whereas doses are considerably lower during administration procedures performed by physicians.

Conclusion: In this study, an evaluation of the skin equivalent doses during (177)Lu-DOTATOC labelling and administration is presented. These data can be useful to assess the risk for workers in centres that are starting to implement PRRT using (177)Lu. The use of appropriate protection devices and procedures allows the observance of International Commission for Radiological Protection dose limits for exposed workers.
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http://dx.doi.org/10.1097/MNM.0b013e328349fd60DOI Listing
October 2011

Comparison of two different types of LiF:Mg,Cu,P thermoluminescent dosimeters for detection of beta rays (beta-TLDs) from 90Sr/90Y, 85Kr and 147Pm sources.

Health Phys 2011 May;100(5):515-22

Medical Physics Department, Santa Maria Nuova Hospital, Reggio Emilia, Italy.

Targeted radionuclide therapies in nuclear medicine departments increasingly depend on using unsealed beta radiation sources in the labeling of peptides and antibodies. Monitoring doses received by the fingers and hands during these procedures is best accomplished with TLD dosimeters that can be located at the fingertips. The present study examines the response of two TLD dosimeters (MCP-Ns and GR200A) to 90Sr/90Y, 85Kr, and 147Pm. The dosimeters were supplied by two different services, and all irradiations were performed at the PTB Institute in Germany. Each dosimetry service evaluated the dosimeters without knowledge that they had been purposefully irradiated. The accuracy and precision of the dosimeters were evaluated as a function of delivered dose, energy of beta particles and angular incidence. The results are compared to performance measures recommended by the IEC. Both dosimeter types displayed significant energy dependence. Angular dependence was moderate. Accuracy and precision as a function of dose (linearity) differed between the two systems, with the MCP-Ns being noticeably better than the GR200A. The superior precision makes the MCP-Ns much more useful for extremity dose measurements. The differences between these two dosimeter systems reinforce the need to evaluate a dosimeter carefully before using it in the daily work routine.
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http://dx.doi.org/10.1097/HP.0b013e3182092732DOI Listing
May 2011
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