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Purpose: To compare the dose area products of pediatric VCUG in daily practice with the dramatically reduced official German diagnostic reference levels, which are based on selected data., Materials and Methods: 413 consecutive pediatric VCUG examinations were analyzed., Results: The mean dose area product of all examinations was 0.97 dGycm². This is below the lowest reference level that is valid for neonates. In 12 cases (5.6 %) the achieved dose area product was higher than the corresponding reference level., Conclusion: Using the available techniques for radiation protection, it is possible in the daily routine to meet the official diagnostic reference levels for children, which have been reduced by up to 80 %, even though these levels are based on a selected, possibly non-representative data set., (© Georg Thieme Verlag KG Stuttgart · New York.)

Unlabelled: Aim of the study was to determine the annual incorporation of staff on a radioiodine therapy ward and the resulting annual effective dose (aed). Following the German incorporation guideline (gig), incorporation monitoring is not necessary for potential aed below 0.5 mSv/a. For aed > 0.5 mSv/a adherence to the 1 mSv dose limit must be verified. For doses > 1 mSv/a incorporation has to be monitored by the authority. Furthermore, the (131)I incorporation factor from the gig should be verified., Methods: To determine the actual work related incorporation, the (131)I activity concentration in urine samples (collection over 24 h) of 14 employees of different professions were examined over a period of 27 months., Results: Measured activity concentrations were related to the individual time of exposure. A constant activity supply for at least three days was assumed. The mean annual effective doses were 2.4 · 10⁻¹ mSv/a (nursing staff; n = 3), 5.6 · 10⁻² mSv/a (cleaning staff; n = 2), 2.8 · 10⁻³ mSv/a (technical staff; n = 2) and 5.2 · 10⁻³ mSv/a (physicians; n = 7). All aed were below the dose limits of the gig. The calculated mean incorporation factors ranged from 3.0 · 10⁻⁸ for the nursing staff to 3.6 · 10⁻¹⁰ for the technical staff (cleaning staff: 7 · 10⁻⁹; physicians: 6.5 · 10⁻¹⁰) and were therefore well below the (131)I incorporation factor defined by the gig., Conclusions: To estimate the aed caused by incorporation of (131)I it has to be subdivided for the different requirements in the diverse fields of activity of the employees. Regarding those who spend most of their time nearby the patient an incorporation monitoring by the authority might be required. The (131)I incorporation factor from the guideline (10⁻⁶) can be reduced by a factor of 10. For (99m)Tc and (18)F an incorporation factor of 10⁻⁷ is accepted.

This short paper reflects on the current situation after the Fukushima nuclear accident and the potential health consequences of the disaster. We discuss perspectives related to radiation protection activities as well as to epidemiologic monitoring and research in the affected regions in order to assess long-term effects of the accident.

Oblique incidence of electron beams is a rare clinical application which can be used e.g. at the irradiation of the internal mammary lymph nodes in the case of mamma carcinoma. 3-D treatment planning systems are accepted standard for photon beams but not for electron beams. The investment for measuring, implementing and testing basic data seems many customers not to be worthwhile when considering the well known inaccuracies of conventional algorithms. From Monte-Carlo (MC) based algorithms however higher accuracies can be expected. It was the aim of this paper to test the MC algorithm of the treatment planning system Oncentra Treatment Planning (OTP, Theranostic) in the application for oblique incidence of electron beams. Measured and simulated values are compared for electron energies from 4 MeV up to 18 MeV. For standard electron applicators, even at extended source-surface distances, satisfying results are achieved. However, the agreement gets lost with increasing oblique incidence, especially for small individual and asymmetrical cut outs. We therefore still use measured values instead of simulated dose distributions., (Copyright 2009. Published by Elsevier GmbH.)

The check of dosimetry of the intraoperative radiotherapy system Intrabeam is predefined by the manufacture (Zeiss). The purpose of the study was to develop and implement a method to verify the internal dosimetry of Intrabeam (Zeiss). Additionally the long-term stability of Intrabeam was checked for dose and isotropy. For dose to water measurements an Unidos was combined with a soft jet chamber (TM 23342) which was calibrated in water absorbed dose and as a phantom the type 2962 (PTW Freiburg) was used. RW1 plates were inserted as build up material. The applicators were placed in a bag filled with water to consider the side-scattering. At the surface of the applicator there was a mean difference of 3 percent between the dose to water measurement and the internal dosimetry. The constancy of the dose rate showed a mean deviation of 0.3% at the reference point. The analysis of the dose distribution perpendicular to the applicator axis z (reference z-axis) resulted in a mean deviation of -2.7% (x-direction) and -7,1% (-x-direction) for the x-axis and, respectively -4.1% (y-direction) and -5.3% (-y-direction) for the y-axis. The proposed method is suitable to verify the absolute dose of Intrabeam. The dose values measured by this method were congruent to the dosimetry of the manufacture (Zeiss). From our point of view it is sufficient to verify the absolute dosimetry only at time of commissioning of the system or in the case of changing the applicator. For the daily routine the check of constancy specified by the manufacture is adequate, because the dose rate is checked on a daily basis. Additionally the test of constancy showed a high long-term stability in terms of dose rate and symmetry.

Purpose: Reconstruction of the entrance dose from radiographic settings and exposure data acquired during chest X-ray examinations of children of various age groups performed at Dr. von Hauner's Kinderspital (children's hospital of the university of Munich, DvHK), between 1976 and 2007. Comparison of these entrance doses with dose values published by other radiological departments., Materials and Methods: All relevant data of all X-ray examinations performed since 1976 at DvHK, in particular the individual radiographic settings and dose measurements (dose area product), were stored electronically in a database. After 30 years of data gathering, the database now covers 305,107 radiological examinations (radiographs and fluoroscopies), especially 119 150 chest radiographs of all age groups. With the computer program PADOS developed by the authors, a specific algorithm was created to calculate radiation doses from the database using the individual dose area product values and other known exposure parameters., Results: The entrance dose values of the chest X-rays at DvHK were able to be reduced in the last 30 years by a factor of 2 to 3 depending on the patients' age group and the beam projection. In our sample, the measured dose values for chest X-rays were far below the reference dose levels set by the Bundesamt für Strahlenschutz (BfS) in 2003 and far below the entrance dose values reported by other radiological departments in Europe as well. Nevertheless, in the last years an increase in the entrance doses has been observed that easily corresponds to the introduction of a digital storage phosphor system in the department., Conclusion: Chest radiography is a frequently performed X-ray examination at a very low dose level. However, because of its frequency, it makes a notable contribution to the collective radiation risk of the population. Therefore, for the reduction of the collective radiation exposure, the optimization of the dose level required by chest X-rays continues to be of great importance. A reduction can be achieved with a consistent and simultaneous optimization of beam quality, exposure field and image processing system. Because of the statistically relevant number of analyzed cases, the entrance dose values presented in this paper can provide a basis for the definition of new reference dose levels.

The application of electron beams in radiotherapy is still based on tables of monitor units, although 3-D treatment planning systems for electron beams are available. This have several reasons: The need for 3-D treatment planning is not recognized; there is no confidence in the calculation algorithm; Monte-Carlo algorithms are too time-consuming; and the effort necessary to measure basic beam data for 3-D planning is considered disproportionate. However, the increasing clinical need for higher dosimetric precision and for more conformal electron beams leads to the requirement for more sophisticated tables of monitor units. The present paper summarizes and discusses the main aspects concerning the preparation of tables of monitor units for electron beams. The measurement equipment and procedures for measuring basic beam data needed for tables of monitor units for electron beams are described for a standard radiation therapy linac. The design of tables of monitor units for standard electron applicators is presented; this design can be extended for individual electron inserts, to variable applicator surface distances, to oblique beam incidence, and the use of bolus material. Typical data of an Elekta linac are presented in various tables.

Purpose: To determine the values of effective dose and partial body dose for the radiologist and the assistant during transarterial chemoembolization (TACE) of hepatocellular carcinoma (HCC) und to compare the doses with the dose limits., Materials and Methods: In 65 TACE of HCC cases, values of various surface doses for the radiologist and the assistant were measured. The measurements were performed with the help of thermoluminescence dosemeters (TLD) that were attached to the eyebrows, over the lobes of the thyroid gland, to the breasts, abdomen and symphysis, and to the hands and the lower legs. The measured surface dose values were used as indicators of the exposure of the organs and tissues located near the surface, i. e. eye lens, thyroid gland, breast, testes and tibia. They were also seen as conservative estimations of tissues deep inside the body and the extremities., Results: The highest surface dose for the radiologist was measured at the lower leg (0.58 +/- 0.28 mSv) and the highest surface dose for the assistant was measured at the right lower leg (0.24 +/- 0.20 mSv) since it was closer to the tube than the left side, followed by the dose values at the also unprotected areas of the eyebrows, lobes of the thyroid gland and the hands. The estimated value of the effective dose was 0.06 +/- 0.03 mSv for the radiologist and 0.04 +/- 0.01 mSv for the assistant. With regard to the relationship between the dose limits according to the German X-ray regulation and the measured values and with regard to the maximum possible number of interventions per year, the partial body dose of the red bone marrow in the lower leg provided the greatest limitation, followed by the partial body dose of the muscle in the lower leg and the effective dose., Conclusion: In order to meet the dose limits, especially the lower leg should be protected, and the effective dose should also be reduced.

Aim: The personnel in nuclear medicine therapy wards must be monitored according to German guidelines for incorporations of (131)I. A surveillance with the employees measuring themselves similarly to the autonomous contamination survey using hand-foot-clothing monitors is presented as an alternative to the monitoring according to the official guidelines., Method: The employees use a dedicated device to measure themselves every working day. The automatic individual positioning of the device ensures reliable and reproducible results. The thyroid dose is determined from the measured time activity curve. The individual values of depth and mass of the thyroid are taken into account for activity measurement and dose evaluation, respectively., Results: The employees measure themselves regularly and utilize the device to check for activities in the thyroid at an early stage after suspected incorporation. The almost complete surveillance permits a dosimetry with slight uncertainty. The determined thyroid doses of all monitored persons average to 0.35 mSv per month., Conclusion: The incorporation surveillance by autonomous monitoring allows a more reliable and more precise dosimetry than the monitoring according to the official guidelines. Despite numerous measurements the practice saves time and money as a result of the automation.

The regular annual monitoring of patient exposure in radiation diagnostics, as performed by the Federal Office for Radiation Protection (BfS), plays an important role in evaluating the awareness of radiological quality and safety in Germany and the risk-benefit optimization for patients. For the reporting year 1997, X-ray diagnostics resulted in a mean effective dose of 2 +/- 0.5 mSv per head of population. The underlying frequency of medical X-ray examinations was approximately 136 million, i.e., 1.7 examinations annually per head of population. In terms of nuclear medicine diagnostics, the patients exposure amounted to approximately 0.15 mSv effective dose per head of population. In this case, the number of examinations amounted to approximately 4 million, corresponding to a frequency of approximately 0.05 examinations annually per head of population. The paper discusses factors influencing the calculation of exposure, as well as the lack of an internationally accepted protocol to evaluate patient exposure.

Systematic gender-specific differences in anatomy and physiology are mostly neglected in standard methodologies for the determination of effective doses. This paper presents and discusses three different concepts for the derivation of gender-specific effective doses. Based on the most convincing approach--especially through the influence of tissue weighting factors for the breast--the effective dose for a serial CT scan of the chest is higher for women (+11%) and lower (-11%) for men in comparison to the "gender-neutral" average value. These differences amount to +/- 30% for coronary serial CT applications.

Aim: Estimation of the radiation exposure to neighbouring patients, personnel and relatives deriving from patients undergoing 123I-MIBG scintigraphy., Methods: For scintigraphic studies, 16 patients with suspected pheocromocytoma were injected with 340 +/- 30 MBq 123I-MIBG. Dose rates were measured at a distance of 0.5 m, 1 m, and 2 m after 10 min, 3 h, 21 h, 45 h, and 68 h using three calibrated portable radiation detectors. The emasured values were background corrected., Results: Ten minutes after injection the dose rate was 10.5 microS/h at a distance of 0.5 m, 3.78 microS/h at 1 m, and 0.95 microS/h at 2 m. The effective half-life was estimated to 8.68 +/- 0.15 h. The maximum dose in a distance of 1 m for neighbouring patients was 46 microS/h, for personnel in a ward 27 microS/h, and to relatives in a distance of 2 m 12 microS/h., Conclusion: This study demonstrates that the calculated exposure to people around patients after 123I-MIBG injection is well below the maximum permissible annual dose limit of 1 mSv for not professionally exposed persons.

Natural and artificial UV radiation are environmental factors with both beneficial and harmful biological effects. This article will explain the physical measurement quantities and their relation to the biologically effective dose and will summarize the present technical state of the art of personal UV monitoring. In practical use are dosimeters based on polysulphone, a polymer which undergoes changes in its optical properties upon irradiation with UV. Other systems determine the UV dose by quantifying damage induced in Bacillus subtilis spores upon UV exposure. An electronic UV sensor represents a new and interesting development. Personal UV dosimeters will become an useful tool in both clinical and scientific areas within dermatology.

Aim: Patients exhale I-131 after radioiodine therapy. In this study we quantify the amount of radioactivity and resulting thyroid doses found in people living in close contact to patients treated with I-131 after their release from a therapy ward., Methods: For 31 relatives of 25 patients treated with I-131 the incorporation was monitored using the thyroid probe of a whole body counter. These values are used for a determination of thyroid doses., Results: 11 of the 31 monitored persons had a thyroid activity of less than the minimal detectable activity of 13 Bq. The mean value of the remaining 20 people was 104 Bq in the thyroid resulting in a mean thyroid dose of 0.2 mSv (Maximum: 2 mSv)., Conclusion: The intake of I-131 for persons in close contact to patients after dismissal from a therapy ward is low. In no case an effective dose exceeding 1 mSv was observed.

Although UV exposure is present at many workplaces, it has not gained much attention. Particularly with regard to UVA, the UV threshold limit values for acute effects used to date are insufficient, and there are no obligatory limits to prevent the sequels of chronic UV exposure. More precise threshold limit values have been published only preliminarily (DIN-Standard No. 5031, part 10). There is a need for regulations governing the supervision of occupational UV exposure and the individual protection of exposed persons.

A measuring method for the detection of ultra-weak photon-radiation from living matter is described. Also the fluorescence-radiation is provable. The latter is of necessity for special-fluorescence investigations. A proof-sensibility of phi = 1.483 10(-16)W (respectively 7.63 10(-17)W for the distance of 65.5 mm-filter - slide replaced by trial-slide) is calculable for lambda = 554 nm with the device constant found out.

Scatter tomography (ST) is a method to acquire information about biological structures using Compton scattered photons. In contrast to previously published methods high resolution in ST is achieved by using conventional x-ray energies. From a general model for the calculation of the radiation exposure, a minimum of the x-ray dosis relative to the spatial resolution is predicted at 60 keV. A simple experimental set-up for recording scatter tomograms is described. First measurements on bovine lungs seem to confirm the expected advantages of the proposed method.

Described are two methods of evaluation of the uptake of 35S by chondrosarcomas, i.e. autoradiography and external monitoring of the Bremsstrahlung. A higher concentration of sulfur in the tumor area of three patients was demonstrated after the injection of aliquots of both diagnostic and therapeutic activities. Apart from the simple handling and the quickly obtained results, the external monitoring of the Bremsstrahlung permits quantitative evaluation of the degree of uptake and a simple control over the progress of therapy.

To estimate risks involved in x-ray diagnosis, it is useful to employ the concepts of organ dose and integral dose, whereas the surface dose should be considered as unsuitable. Although the methods of measurement differ from each other, they can lead to comparable results, as is demonstrated in this article, eg, for computerised tomography of the skull.

An irradiation phantom was used to measure dose increases using the backscatter of different materials (titanium, steel, lead, aluminum). Telecobalt 60 and 8 MeV photons were used for the irradiation. The radiation dose was measured by means of a defined x-ray film blackening. The most important parameter was to find out whether under stimulated conditions the undesirable hot spots occur. We were able to demonstrate that a 12.5 to 16% increase of the radiation dose can be observed for titanium and steel at a distance of .45 mm from the metal specimen. A comparison between titanium and steel did not demonstrate a relevant advantage for titanium. Therefore adjuvant percutaneous radiation therapy should not have any influence on the life of the implant, if the soft tissue layer is of sufficient thickness. The available literature was reviewed and presented in tables.

In spite of small geometrical dimensions of the ionization chambers, the sensitivity distribution throughout the entire chamber must be considered if conditions are extreme (small size of field, short distances). Various types of chambers were studied with regard to their response threshold along their axis. Taking the different wall thicknesses into consideration, different ionization chambers show good agreement with regard to the accumulation effect of Co-60 gamma radiation.

The radioactive noble gas radon, a member of the natural decay chains of uranium and thorium, enters the indoor environment in regionally highly diverging amounts. Subsoil of dwellings, building materials and drinking water are the main sources. In Switzerland and in many other countries, exposure of the lung tissue to the short lived radon decay products is the most important component of the radiation dose of the general public. Annual doses in areas with crystalline rock of high uranium content may reach the limits set up for occupational exposure. However, a clear link between cumulative exposure to radon daughters and elevation of the lung cancer incidence exists only for underground miners. The majority of human epidemiological studies point to a linear dose effect relationship. The indoor radon levels are determined by geology, building materials and techniques, climate and behaviour of the occupants. Experiences from Scandinavia and the Northern parts of America clearly indicate the possibility of cost-efficient remedial measures to reduce indoor radon levels.

In medical x-ray departments, industrial facilities and nuclear reactors, local radiation was measured with film dosimeters in more than 1700 different places. These were fixed over a period of about 30 days in different spots of the controlled rooms. The obtained measurements are classified into different groups. The advantage of film dosimeters compared with usual measurements of the dose rates is the fact that they give an average of the real dose over a period of time at low cost. The obtained results are of interest for radioprotection technique.

In the radiotherapy of malignant tumors of the oral cavity, the exact distribution of radiation dosage in the neighborhood of metallic dental replacement has been uncertain so far. Many authors therefore asked that crowns and bridges be removed before radiotherapy. By means of lithium fluoride thermo-luminescence dosimetry, punctate measurements of doses are possible for the first time. In view of the dose values obtained, removal of metallic dental replacement before the beginning of radiotherapy as a prophylactic measure to prevent radioosteomyelitis appears not to be necessary.

The results presented in this article lead to the conclusion that it would be appropriate to demand control or monitoring of radiation via CT whenever complicated exposure to radiation is required. Such control appears mandatory in order to guarantee a sufficiently high tumour dosage and satisfactory protection or minimum burdening of the surrounding tissue. At first sight, it may seem that such CT operations are relatively costly. However, once the teamwork has been properly established, both the time required and the cost involved remain within reasonable limits and will probably not be greater than control via therapy simulator. The decisive factor is that computerised tomography should offer sufficient possibilities of translating such control into reality by effecting the necessary dosage adjustments in accordance with given requirements.

Phantom measurements in the vicinity of an angiographic installation with the image intensifier below the table and subsequently with the intensifier above the table have shown that the former arrangement produces three times as much radiation to the head, gonads and leg during screening than when the intensifier is above the table. This has been confirmed in clinical practice during angioplastic procedures in other units. There is also a factor of 2.6 in favour of the above table intensifier applied to the lens of the eye of the investigator Radiation to the hand of the investigator is at least half with the above table arrangement.

In judging the risk incurred by persons professionally exposed to radiation, there is at present a more distinct tendency towards consideration of somatic effects - as e.g. somatic "crossing over", accidents of development, induction of cancer; thus more attention is paid to individual risk. For assessment of this radiation risk, the organ doses in question must be known; they can be estimated by means of the ascertained tissue-air-ratios, if the field of stray radiation from the X-ray equipment is known. To obtain data for statements with regard to the radiation load on the examiner during radioscopies with a therapy simulator, it was necessary to determine the stray radiation field of the X-ray apparatus. Therefore, using an Alderson-Man-phantom, the angular distribution of the local dose rate were measured at a tube voltage of 84 kV. The skin irradiation fields had dimensions of 25 cm2, 100 cm2, and 400 cm2 at the distances 50 cm, 100 cm, 150 cm, and 200 cm of the ionization chamber from the central ray. The measurements were performed on levels of 90 cm, 130 cm, and 160 cm above the floor. Some additional measurements aimed at a more exact investigation of the dependency of scattered radiation upon the tube voltage, the area of the radiation field, the distance from the central ray, and the height above the floor. The attenuation capacity of a light radioprotective apron (0.25 mm lead equivalence) was also determined. It turned out that, at a tube voltage of 84 kV, the apron still was passed by about 3.6% of the hitting stray radiation. The present measurements yield important indications of the best possible locations of the examiner during radioscopy. A practical example is given showing how to assess the radiation load on single organs; the results show that the examiner is exposed to a gonadal load of about 2 mR and to a load of about 17 mR on the crystalline lenses, while engaged in preparative roentgenologic measures for intrauterine transfusions.