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Purpose: The purpose of this study was to identify the main pathologies for which CT is applied on pediatric patients and the related radiation doses as reported in the literature in order to facilitate justification and CT optimization., Methods: A critical analysis of a literature review was performed. Different search engines were used such as PubMed, Google Scholar and Science Direct. Various terms and keywords were used to locate pertinent articles such as Pediatric, Computed tomography, Radiation Dose, Organ dose, Effective dose., Results: The results showed that the main pathologies for which CT is applied are: Crohn's disease, hydrocephalus, cystic fibrosis and pediatric malignancies-mainly lymphoma. The related radiation dose data are extremely scarce and are in the range of 3.48-17.56, 0.2-15.3mSv, 0.14-6.20mSv, and 2.8-518.0mSv, respectively. The radiation doses reported are high especially in pediatric oncology., Conclusions: Pediatric patients with malignancies are those exposed to the higher levels of radiation during CT imaging. Literature is lacking reporting of dose in Pediatric CT imaging. More studies need to be realized for the determination of radiation dose in those patients. Special protocols need to be recommended in order to reduce the exposure of children in radiation., (Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.)

According to the European Federation of Organizations for Medical Physics (EFOMP) policy statement No. 13, "The rapid advance in the use of highly sophisticated equipment and procedures in the medical field increasingly depends on information and communication technology. In spite of the fact that the safety and quality of such technology is vigorously tested before it is placed on the market, it often turns out that the safety and quality is not sufficient when used under hospital working conditions. To improve safety and quality for patient and users, additional safeguards and related monitoring, as well as measures to enhance quality, are required. Furthermore a large number of accidents and incidents happen every year in hospitals and as a consequence a number of patients die or are injured. Medical Physicists are well positioned to contribute towards preventing these kinds of events". The newest developments related to this increasingly important medical speciality were presented during the 8th European Conference of Medical Physics 2014 which was held in Athens, 11-13 September 2014 and hosted by the Hellenic Association of Medical Physicists (HAMP) in collaboration with the EFOMP and are summarized in this issue., (Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.)

Introduction: The gender composition of the existing medical physicist (MP) workforce around the world is basically unknown. The International Organization for Medical Physics (IOMP) performed a survey in order to investigate the number of MPs in countries around the world and the percentage of women MPs compared to total number of MPs., Materials and Methods: A simple online questionnaire prepared as a Google Forms survey asking the country, the total number of MPs, the number of female MPs and finally the gender of the person providing the data was sent in mid-March 2013 to six regional member organizations of IOMP, as well as contact points in many member countries., Results: Sixty-six countries responded to the survey by mid-July 2013. Fifty two percent of those who filled the form were females, the rest males. The total number of MPs was 17,024, of which 28% were female (4807). The median values of percentages of females were 21% in the USA, 47% in Europe, 35% in Asia, 33% in Africa and 24% in Latin America., Conclusion: This is the first international survey that investigates the number and percentage of female MPs around the world. There are European countries that are far away from the target set by European Commission (40%) whereas in countries in the Middle East and Asia, female MPs actually outnumber males. This study is the first step in a more in-depth study that needs to be taken in near future., (Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.)

Background: Although the use of myocardial perfusion imaging (MPI) for prognostic purposes in general population is well understood, its role in very elderly patients is not extensively studied., Methods: 247 octgogenarians (79% male, 56% previous myocardial infarction-MI or revascularization) who underwent treadmill exercise testing (TET) with MPI were studied. TET and MPI-related data were registered per patient and prospective follow-up was performed to document all cause death (ACD), cardiac death (CD), non-fatal MI, and late revascularization (LR). Kaplan-Meier and Cox-regression analysis were used to compute event-free survival and identify significant predictors of these events., Results: After 7.3 years there were 48 deaths, 17 CDs, 8 MIs, and 21 LRs. 69 patients were classified as high and 103 as low risk by SSS with annual cardiac mortality rates of 5% and 0.9%, respectively. Differences between survival curves of SSS-based risk groups were significant for ACD, CD, CD/MI, and CD/MI/LR. Summed stress (SSS) and difference scores were the only significant predictors of all endpoints. LVEF and transient ischemic LV dilatation were significant predictors of CD and CD/MI. LVEF and all MPI variables were associated with the CD, MI, and LR endpoint while only Duke treadmill score and angina severity demonstrated such a relationship among TET variables., Conclusions: In octogenarians, MPI provides effective long-term risk stratification for both hard (ACD, CD, CD/MI) and soft (CD/MI/LR) endpoints and should be preferred over simple TET.

Objectives: We investigated whether myocardial perfusion imaging (MPI) can demonstrate the effect of classical preconditioning., Methods: 21 patients with documented coronary artery disease (stenosis>or=70%) underwent two exercise stress tests (EST) with concomitant MPI, using TL-201 for the first and tetrofosmin-Tc-99m for the second. A third MPI was performed at rest, using Tc-99m. Total defect score was derived by summing tracer uptake in a 17 segments left ventricle model, graded on a 5-point scale. Tomographic images were also analyzed quantitatively, to derive the total defect size., Results: Maximum ST depression did not differ significantly between the two EST (2.2+/-1 vs 2.2+/-1 mm, p=NS), however in the second EST longer times for onset of ischemic changes (228+/-94 vs 265+/-103 s, p=0.01) and appearance of angina (282+/-153 vs 328+/-177 s, p=0.04) were observed. Exercise perfusion abnormalities were significantly lower in the second MPI, in terms of both total defect score (19.2+/-11.5 vs 10+/-10.4, p<0.0001) and total defect size (28.3+/-16.9 vs 13.8+/-15.8, p<0.0001)., Conclusion: Significant improvement in perfusion pattern was demonstrated in the second MPI, accompanied by delayed appearance of ischemic manifestations. The improvement in myocardial perfusion extends far beyond the changes that can be attributed to differences in myocardial uptake between tracers, reflecting the effect of classical preconditioning., (Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.)

The rapid technological developments in computed tomography (CT) have enabled many new clinical applications in the abdominal region. Abdomen CT is considered as a high radiation dose examination due to the large number of radiosensitive organs in the field of view. CT radiation dose has received a lot of attention not only by the medical specialties and researchers, but also by patients and media. This article reviews the situation on radiation dose and risk and provides practical guidelines to effectively manage the radiation dose without losing the benefits and maintaining diagnostic confidence in CT procedures.

Objective: The purpose of our study was to investigate the level of radiation protection of patients and staff during interventional procedures in 20 countries of Africa, Asia, and Europe., Subjects and Methods: In a multinational prospective study, information on radiation protection tools, peak skin dose (PSD), and kerma-area product (KAP) was provided by 55 hospitals in 20 mainly developing countries (nine mostly in Eastern Europe, five in Africa, and six in Asia)., Results: Nearly 40% of the interventional rooms had an annual workload of more than 2,000 patients. It is remarkable that the workload of pediatric interventional procedures can reach the levels of adult procedures even in developing countries. About 30% of participating countries have shown a 100% increase in workload in 3 years. Lead aprons are used in all participating rooms. Even though KAP was available in almost half of the facilities, none had experience in its use. One hundred of 505 patients monitored for PSD (20%) were above the 2-Gy threshold for deterministic effects., Conclusion: Interventional procedures are increasing in developing countries, not only for adults but also for pediatric patients. The situation with respect to staff protection is considered generally acceptable, but this is not the case for patient protection. Many patients exceeded the dose threshold for erythema. A substantial number (62%) of percutaneous transluminal coronary angioplasty procedures performed in developing countries in this study are above the currently known dose reference level and thus could be optimized. Therefore, this study has significance in introducing the concept of patient dose estimation and dose management.

Objective: The objective of our study was to compare theoretic estimations of the dose to the patient's skin during CT-guided interventional procedures with measurements performed using radiation therapy verification films., Materials and Methods: In each of the 12 interventions studied, a Kodak EDR2 film was positioned under the patient's anatomic area of concern. After processing, each film was scanned with a medical-grade scanner to produce a digital image from which the gray-scale profiles were obtained using the appropriate software. From these data and respective data from a series of calibration films, the entrance skin dose (ESD) profiles were derived. These ESD profiles were compared with the ESD profiles produced using a theoretic model and its revised version, which utilizes the DICOM data of each slice (i.e., tube potential, tube loading, slice thickness, slice location, pitch, and table height) and air-kerma output measurements from the CT tube., Results: In general, the ESD profiles calculated using the revised theoretic method were in better agreement with the profiles derived from the verification films than the ESD profiles derived from the original theoretic method. The deviations from the peak skin doses (PSDs) derived from the digital film images were within -3% and 27% of the PSDs derived from the verification films. The respective deviations of the ESD profiles calculated with the original theoretic method were quite larger., Conclusion: The theoretic model provides a useful tool for estimating skin doses during CT-guided interventions with a reasonable level of accuracy. With further refinement and a little automation this method could be implemented for daily use.

Background and Purpose: It is known that interventional neuroradiology (IN) involves high radiation dose to both patients and staff even if performed by trained operators using modern fluoroscopic X-ray equipment and dose-reducing technology. Therefore, every new technology or imaging tool introduced, such as three-dimensional rotational angiography (3D RA), should be evaluated in terms of radiation dose. 3D RA requires a series with a large number of images in comparison with 2D angiography and it is sometimes considered a high-dose IN procedure. The literature is scarce on the 3D RA radiation dose and in particular there are no data on carotid arteriography (CA). The aim of this study was to investigate patient dose differences between 2D and 3D CA., Methods: The study included 35 patients undergoing 2D CA in hospital 1 and 25 patients undergoing 3D CA in hospital 2. Patient technical data collection included information on the kerma area product (KAP), fluoroscopy time (T), total number of series (S), and total number of acquired images (F)., Results: Median KAP was 112 Gy cm(2) and 41 Gy cm(2) for hospitals 1 and 2, respectively, median T was 8.2 min and 5.1 min, median S was 13 and 4, and median F was 247 and 242. Entrance surface air-kerma rate, as measured in "medium" fluoroscopy mode measured in 2D acquisition using a 20 cm phantom of polymethylmethacrylate, was 17.3 mGy/min for hospital 1 and 9.2 mGy/min for hospital 2., Conclusion: 3D CA allows a substantial reduction in patient radiation dose compared with 2D CA, while providing the necessary diagnostic information.

In this study the performance of a new mammographic film, the XMA (Retina), was evaluated in comparison with HT (Agfa). The comparison was made in terms of sensitometric characteristics and in terms of image quality and speed when combined with four different cassettes-HDS (Agfa), Min-R 2000 and Min-R 2190 (Kodak), and AD-MA (Fuji)-using the Leeds TOR(MAX) Mammographic Quality Control phantom. The entrance surface air kerma was calculated from exposure factors and the relative speed of each screen-film combination was determined. These tests revealed that XMA requires about 40% less dose than HT when combined with the same intensifying screen, at a penalty of less than 8% in image quality. When combined with AD-MA the XMA presents the greatest speed, whereas the Min-R 2190 is the best compromise between image quality and breast dose. The above values are indicative of the dilemma that medical physicists and radiologists face when it comes to the selection of a screen-film combination for mammography. Both image quality and breast dose should be considered, but strict instructions on what weight should be assigned to each parameter have not been established yet. Health Phys. 94(4):338-344; 2008.

In this study, a mathematical method was used to estimate the entrance surface dose (ESD) to the patient and the scattered dose (Ds) to the operating surgeon during various fluoroscopically guided surgical orthopaedic procedures. For 204 patients, the procedure type, the fluoroscopy time and the highest tube potential and current values observed during fluoroscopy were recorded. For the most often performed procedures (intramedullary nailing of peritrochanteric fractures, open reduction and internal fixation of malleolar fractures and intramedullary nailing of diaphyseal fractures of the femur), the respective mean fluoroscopy times were 3.2, 1.5 and 6.3 min while the estimated mean ESDs were 183, 21 and 331 mGy, respectively. The estimated Ds rates for the hands, chest, thyroid, eyes, gonads and legs of the operating surgeon were on average to 0.103, 0.023, 0.013, 0.012, 0.066 and 0.045 mGy min(-1), respectively, and compare well with the literature. The mathematical estimation of doses cannot replace actual measurements; however, it can be used for a preliminary assessment of the radiation dose levels during various surgical procedures, so that the operator, the surgeon and the rest of the medical staff involved could be aware of the associated radiation risk and the radiation protection measures required.

The objective was to investigate paediatric doses in coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA) in the largest cardiac hospital in Greece. Forty procedures were carried out by two board-certified senior interventional cardiologists. Data collected were: patient weight, height, age, fluoroscopy time (FT), total number of images (N) and kerma-area product (KAP). Median (range) age was 7.5 y (17 d to 17 y). Median FT, N and KAP were 4 min, 655, 2.1 Gy cm2 for CA and 12.1 min, 1296, 14.7 Gy cm2 for PTCA (corresponding adult diagnostic reference levels (DRLs) are: 6.5 min, 700, 45 Gy cm2 for CA and 15.5 min, 1000 and 85 Gy cm2 for PTCA). The highest percentage of cine dose was in newborns (0-1 y) (CA: 92% and PTCA: 100%). As age increased, cine dose percentage decreased, whereas total radiation dose increased. Median paediatric FT and N recorded reached or even exceeded adult DRL and should be optimised. Paediatric DRL should be set.

Objective: The purpose of this study was to determine patient effective dose (E) and peak absorbed dose to the skin of the patient from various CT-guided interventional procedures performed without CT fluoroscopy assistance., Materials and Methods: In total, 49 interventions were retrospectively studied: 14 biopsies, 14 radiofrequency ablations, 14 abscess drainages, and seven nephrostomies. CT images were acquired from the department's PACS system and reviewed to record the scan parameters of each slice. Entrance surface dose and E were estimated using the Impactscan database and the related Monte Carlo conversion coefficients., Results: Median values of E for biopsies, radiofrequency ablations, abscess drainages, and nephrostomies were 23, 35.3, 16.2, and 11.5 mSv, respectively. Respective ranges were 5.8-46.6, 18.4-57.2, 10.9-31.5, and 5.1-32.7 mSv. The corresponding median values and ranges for the peak absorbed dose were 281, 557, 155, and 145 mGy and 133-982, 147-699, 94-315, and 75-297 mGy. The diagnostic scans obtained before the interventions were responsible for 63%, 33% 40%, and 51% of E, respectively. The largest contribution to the peak absorbed dose was due to positioning of the tissue acquisition biopsy gun in biopsies (48%), the radiofrequency needle in ablations (57%), and the catheter in abscess drainages (41%) and nephrostomies (49%)., Conclusion: For the CT interventions studied, and especially for biopsies and radiofrequency ablations, patient effective doses were considerably high. Maximum peak absorbed dose observed was about 1 Gy, considerably lower than the threshold for deterministic effects (2 Gy).

Purpose: To measure radiation doses for computed tomography (CT) of the head, chest, and abdomen and compare them with the diagnostic reference levels, as part of the International Atomic Energy Agency Research coordination project., Materials and Methods: The local ethics committees of all participating institutions approved the study protocol. Written informed consent was obtained from all patients. All scanners were helical single-section or multi-detector row CT systems. Six hundred thirty-three patients undergoing head (n = 97), chest (n = 243), or abdominal (n = 293) CT were included. Collected data included patient height, weight, sex, and age; tube voltage and tube current-time product settings; pitch; section thickness; number of sections; weighted or volumetric CT dose index; and dose-length product (DLP). The effective dose was also estimated and served as collective dose estimation data., Results: Mean volumetric CT dose index and DLP values were below the European diagnostic reference levels: 39 mGy and 544 mGy . cm, respectively, at head CT; 9.3 mGy and 348 mGy . cm, respectively, at chest CT; and 10.4 mGy and 549 mGy . cm, respectively, at abdominal CT. Estimated effective doses were 1.2, 5.9, and 8.2 mSv, respectively., Conclusion: Comparison of CT results with diagnostic reference levels revealed the need for revisions, partly because the newer scanners have improved technology that facilitates lower patient doses., ((c) RSNA, 2006.)

Aim: To explore the factors that may influence the radiation dose imparted to the patient in PCI, and investigate whether the use of the latest digital X-ray system based on FP detector technology can have an impact on dose., Materials and Method: Demographic and clinical data such as number of lesions treated, number of stents placed, grade of tortuosity, and stage of occlusion, as well as use of double wire and double balloon technique, ostial stenting or bifurcation stenting, and presence of major complications were recorded, together with radiation parameters., Results: The factors that increased patient radiation dose were (1) patient gender, as men exhibited higher doses than women; (2) complex lesion; (3) increasing number of stents; (4) position of stent; (5) grade of tortuosity; and (6) stage of occlusion. The FP digital system appeared to be settled in a lower-dose rate for fluoroscopy (a factor of 6) and higher for dose per frame in cine (a factor of 3) in comparison with the image intensifier (II) system. There was a marked reduction of DAP when the FP technology was introduced., Conclusion: More extensive studies should be performed in the future so as to further investigate the influence of the FP detector in IC.

The biological elimination of therapeutic 131I in patients with differentiated thyroid cancer (DTC), post total or near-total thyroidectomy, was compared after withholding levothyroxine suppression against administration of recombinant human thyrotropin without stopping levothyroxine. In 163 patients (group G1) levothyroxine was withheld before 131I therapy: in 138 patients the tumor was limited to the thyroid bed (group G1.1) and in 25 patients metastases were present (group G1.2). A second group of patients (G2; n = 28) received 131I therapy after administration of recombinant human thyrotropin without stopping levothyroxine. Mean retained 131I activity (as a percentage of the administered dose) was 5%-29% (group G1.1), 20%-43% (group G1.2) and 1%-17% (group G2). The effective half-life of 131I was 0.59-0.69 days (group G1.1), 0.87-1.22 days (group G1.2) and 0.38-0.44 days (group G2). In conclusion, the use of recombinant human thyrotropin to prepare patients with thyroid cancer for therapy with 131I shortens its effective half-life and reduces its retained activity compared to preparation with discontinuation of levothyroxine suppression.

Radiation fields involved in angiographic suites are most uneven with intensity and gradient varying widely with projection geometry. The European Commission DIMOND III project addressed among others, the issues regarding optimization of staff doses with an attempt to propose preliminary occupational dose constraints. Two thermoluminescent dosemeters (TLD) were used to assess operators' extremity doses (left shoulder and left foot) during 20 coronary angiographies (CAs) and 20 percutaneous transluminal coronary angioplasties (PTCAs) in five European centres. X-ray equipment, radiation protection measures used and the dose delivered to the patient in terms of dose-area product (DAP) were recorded so as to subsequently associate them with operator's dose. The range of staff doses noted for the same TLD position, centre and procedure type emphasizes the importance of protective measures and technical characteristics of x-ray equipment. Correlation of patient's DAP with staff shoulder dose is moderate whereas correlation of patient's DAP with staff foot dose is poor in both CA and PTCA. Therefore, it is difficult to predict operator's dose from patient's DAP mainly due to the different use of protective measures. A preliminary occupational dose constraint value was defined by calculating cardiologists' annual effective dose and found to be 0.6 mSv.

The purpose of the study was to evaluate the dose performance of a flat-panel (FP) and an image intensifier (II) charge coupled device (CCD) digital fluoroscopy X-ray systems newly installed in an Interventional Cardiology (IC) department. Filter entrance dose rate, detector dose rate (during fluoroscopy) and filter entrance dose per image were measured at 70 cm from the focus using 2 mm copper sheets to mimic normal size patient. Image quality was also evaluated. The patient dose survey included 277 patients, which had either a Coronary Angiography (CA) or a Percutaneous Transluminal Coronary Angioplasty (PTCA). Dose area product (DAP), fluoroscopy time (T) and total number of frames (F) values were also collected. The results showed that both systems performed within international recommendations with the exception of higher cine radiation doses, stressing the fact that neither specific protocols of measurement nor reference values for digital equipment were provided by the official bodies.

This article describes the European DIMOND approach to defining reference levels (RLs) for radiation doses delivered to patients during two types of invasive cardiology procedures, namely coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA). Representative centres of six European countries recorded patients' doses in terms of dose-area product (DAP), fluoroscopy time and number of radiographic exposures, using X-ray equipment that has been subject to constancy testing. In addition, a DAP trigger level for cardiac procedures which should alert the operator to possible skin injury, was set to 300 Gyxcm2. The estimation of maximum skin dose was recommended in the event that a DAP trigger level was likely to be exceeded. The proposed RLs for CA and PTCA were for DAP 45 Gyxcm2 and 75 Gyxcm2, for fluoroscopy time 7.5 min and 17 min and for number of frames 1250 and 1300, respectively. The proposed RLs should be considered as a first approach to help in the optimisation of these procedures. More studies are required to establish certain "tolerances" from the proposed levels taking into account the complexity of the procedure and the patient's size.