Wrist dosimeter in nuclear medicine - An alternative for the ring dosimeter?

PURPOSE: Individual dosimetry is undoubtedly one of the best methods of assessing the exposure of personnel to ionizing radiation, however in case of nuclear medicine, the method applied to measure the dose does not always present a picture of the worker's actual exposure. The highly non-homogeneous dose distribution on the hand means that the ring dosimeter, routinely used to measure the Hp(0.07), provides only approximate dose values received by fingertips, the body part most exposed to ionizing radiation. This paper is an attempt to answer the question whether the wrist dosimeter used as a replacement for the ring dosimeter is able to provide information on doses for the most exposed fragments of the hand of an employee during handling procedures with the use of radiopharmaceuticals. MATERIALS: Throughout measurements performed in five nuclear medicine facilities, high-sensitivity thermoluminescent detectors were used. RESULTS: Correction coefficients have been determined, which constitute an amendment to be made to move from the dose recorded by the wrist dosimeter to the doses received by the most exposed hand fragments. The fingertips received on average 25 times higher doses, compared to the values recorded by the wrist dosimeter. CONCLUSIONS: A wrist dosimeter can be used to measure the Hp(0.07) in nuclear medicine, including as a gauge of the most exposed parts of the hand - the fingertips. However, the applicability of correction coefficients makes it necessary to ensure a stable position of the wrist dosimeter during routine procedures.

[Cryosurgery in the treatment of allergic and non-allergic rhinitis].

OBJECTIVE: Introduction: Pharmacological treatment of both allergic and non-allergic rhinitis is not always effective. The aim: Assessment of the effectiveness of treatment of patients with allergic and non-allergic vasomotor rhinitis using cryoablation procedures. PATIENTS AND METHODS: Material and methods: The study involved 60 patients, including 28 women and 32 men, aged 17-76 years (the average age 39) with rhinitis. All participants were assigned into two groups: I group - 18 patients with chronic allergic rhinitis; II group - 42 patients with chronic non-allergic vasomotor rhinitis. The research methodology included: anamnesis, otolaryngological physical examination, rhinomanometer test, performed before and 3 months after the procedure. The cryoablation of nasal turbinates was performed under local anesthesia,with a 1% xylocaine solution using the Cryo-S device from CryoFlex Poland. RESULTS: Results: After the cryoablation treatment, in both groups the statistically significant improvement was observed both in the subjective assessment of symptoms of nasal obstruction and in the mean rhinomanometry of air flows through the nasal passages during inspiration and exhalation. CONCLUSION: Conclusions: Cryosurgical treatment is not the first-line treatment for the treatment of allergic and non-allergic vasomotor rhinitis, it does not remove the causes of the disease. However, it may be an effective method of treatment for some patients and a supplement to existing treatment.

Occupational exposure to radon for underground tourist routes in Poland: Doses to lung and the risk of developing lung cancer.

OBJECTIVES: Radon concentrations for 31 Polish underground tourist routes were analyzed. The equivalent dose to the lung, the effective dose and the relative risk were calculated for employees of the analyzed routes on the grounds of information on radon concentrations, work time, etc. MATERIAL AND METHODS: The relative risk for lung cancers was calculated using the Biological Effects of Ionizing Radiation (BEIR) VI Committee model. Equivalent doses to the lungs of workers were determined using the coefficients calculated by the Kendall and Smith. The conversion coefficient proposed by the International Atomic Energy Agency (IAEA) in the report No. 33 was used for estimating the effective doses. RESULTS: In 13 routes, the effective dose was found to be above 1 mSv/year, and in 3 routes, it exceeded 6 mSv/year. For 5 routes, the equivalent dose to lungs was higher than 100 mSv/year, and in 1 case it was as high as 490 mSv/year. In 22.6% of underground workplaces the risk of developing lung cancer among employees was about 2 times higher than that for the general population, and for 1 tourist route it was about 5 times higher. The geometric mean of the relative risk of lung cancer for all workers of underground tourist routes was 1.73 (95% confidence interval (CI): 1.6-1.87). Routes were divided into: caves, mines, post-military underground constructions and urban underground constructions. CONCLUSIONS: The difference between levels of the relative risk of developing lung cancer for all types of underground tourist routes was not found to be significant. If we include the professional group of the employees of underground tourist routes into the group of occupational exposure, the number of persons who are included in the Category A due to occupational exposure may increase by about 3/4. The professional group of the employees of underground tourist routes should be monitored for their exposure to radon. Int J Occup Med Environ Health 2017;30(5):687-694.

Absorbed doses for patients undergoing panoramic radiography, cephalometric radiography and CBCT.

OBJECTIVES: Contemporary dental radiology offers a wide spectrum of imaging methods but it also contributes to an increase in the participation of dental radiological diagnosis in the patient's exposure to ionizing radiation. The aim of this study is to determine the absorbed doses of the brain, spinal column, thyroid and eye lens for patients during panoramic radiography, cephalometric radiography and cone beam computed tomography (CBCT). MATERIAL AND METHODS: The thermoluminescent dosimetry and anthropomorphic phantom was used for measuring the doses. The 15 panoramic, 4 cephalometric and 4 CBCT exposures were performed by placing high-sensitivity thermoluminescent detectors (TLD) in 18 anatomical points of the phantom. RESULTS: The maximum absorbed dose recorded during performed measurements corresponds to the point representing the brainstem and it is 10 mGy. The dose value recorded by the TLD placed in the thyroid during CBCT imaging in relation to the panoramic radiography differs by a factor of 13.5. CONCLUSIONS: Cone beam computed tomography, in comparison with panoramic or cephalometric imaging technique, provides higher radiation doses to the patients. Int J Occup Med Environ Health 2017;30(5):705-713.

[Evaluation of dental X-ray apparatus in terms of patient exposure to ionizing radiation]. / Ocena rentgenowskich aparatów stomatologicznych pod katem narazenia pacjentów na promieniowanie jonizujace.

BACKGROUND: The use of X-ray in dental procedures causes exposure of the patient to ionizing radiation. This exposure depends primarily on the parameters used in tooth examination. The aim of the study was to determine the patients exposure and to assess the technical condition of X-ray tubes. MATERIAL AND METHODS: Seventeen hundred dental offices were covered by the questionnaire survey and 740 questionnaires were sent back. Direct measurements were performed in 100 units by using the thermoluminescent detectors and X-ray films. RESULTS: The results showed that the most commonly used exposure time is 0.22±0.16 s. The average entrance dose for the parameters used most commonly by dentists is 1.7±1.4 mGy. The average efficiency of X-ray tube estimated on the basis of exposures is 46.5±23.7 µGy/mAs. CONCLUSIONS: The study results indicate that the vast majority of X-ray tubes meet the requirements specified in the binding regulations. Med Pr 2017;67(4):491-496.

Exposure of personnel and public due to using 153Sm-labelled EDTMP-Quadramet® in nuclear medicine procedures.

The main aim of this study was to highlight the problems of personnel exposure when administering (153)Sm-labelled ethylene diamine tetramethylene phosphonate-Quadramet(®) to patients and especially to evaluate hand exposure of the personnel. The exposure levels of patients' families and the people who takes care of the patients treated by Quadramet(®) were also estimated. Thermoluminescent detectors were used to measure the doses. The doses received during the injection of the Quadramet(®) by the nursing staff have been determined at the level of 1/150 dose limit for the skin. Exposure of members of the patient's family staying 1.5 m away from the patient being treated with Quadramet(®) has been estimated to be 0.40 mGy.

Estimate of radon exposure in geothermal spas in Poland.

OBJECTIVES: Geothermal waters may contain soluble, radioactive radon gas. Spa facilities that use geothermal water may be a source of an increased radiation dose to people who stay there. It has been necessary to assess the exposure to radon among people: workers and visitors of spa centers that use geothermal waters. MATERIAL AND METHODS: In 2013, workers of the Nofer Institute of Occupational Medicine measured concentrations of radon over the geothermal water surfaces in 9 selected Polish spa centers which use geothermal water for recreational and medicinal purposes. The measurements were performed by active dosimetry using Lucas scintillation cells. RESULTS: According to our research, the doses received by the personnel in Polish geothermal spas are < 0.6 mSv/year. In 1 of the investigated spas, the estimated annual dose to the staff may exceed 3 mSv/year. CONCLUSIONS: In Polish geothermal spas, neither the workers nor the visitors are at risk of receiving doses that exceed the safe limits.

[Occurrence of radon in the Polish underground tourist routes]. / Wystepowanie radonu w polskich podziemnych trasach turystycznych.

BACKGROUND: There are about 200 underground tourist routes in Poland. There are caves, mines or underground structures. This paper presents the results of the research intended to identify the extent of the occurrence of radon concentrations in underground areas of tourist routes. MATERIAL AND METHODS: We conducted the measurement of periodic concentrations of radon (1-2 months) in the summer using type Tastrak trace detectors. We determined the average concentrations of radon in air in 66 underground tourist routes in Poland. RESULTS: The research results comprise 259 determinations of average radon concentrations in 66 routes. The arithmetic average of the results was 1610 Bqm-3, and the maximum measured concentration was over 20,000 Bqm-3. The minimum concentration was 100 Bqm-3 (threshold method) considering the arithmetic average of the measurements. It was found that in 67% of the routes, the average concentration of radon has exceeded 300 Bqm-3 and in 22 underground routes it exceeded 1000 Bqm-3. CONCLUSIONS: Radon which occurs in many Polish underground tourist routes may be an organizational, legal and health problem. It is necessary to develop a program of measures to reduce radon concentrations in underground routes, especially routes located in the former mines.

[Patients' exposure to electromagnetic fields and radon in radon spas]. / Ekspozycja kuracjuszy na pola elektromagnetyczne i radon w uzdrowiskach radonoleczniczych.

BACKGROUND: Many patients of physiotherapeutic facilities using therapeutic radon are also referred to other treatments involving the use of electromagnetic field (EMF). However, in the light of the theory of EMF influence on free radicals, it is still an open question whether, application of EMF shortly after the radon treatment may alter the biological effects of radon or EMF. The aim of the study was to determine how large is the group of patients exposed to radon and EMF in Poland, and how high is the exposure of these patients to analyzed factors. The results of the study are to be used in the future assessment of the combined effects of radon and EMF in radon spas. MATERIAL AND METHODS: Based on the statistical data and interviews held in the major Polish radon spas, the analysis of treatment structure was performed and exposure to radon and EMF was assessed by measuring radon concentrations and characteristic values of exposure to EMF. RESULTS: More than 8000 people per year are subjected to combined exposure to radon and EMF. Significant differences were found between measured radon concentrations (they ranged from approximately 61 kBq/m3 for inhalations with inhaler to only 290 Bq/m3 for graduation towers, p = 0.049) and EMF intensities corresponded to those observed in hazardous and dangerous zones for occupational exposure. CONCLUSIONS: The results of the study showed significant differences between radon concentrations during various radon treatments. There is a need to develop clear and universal procedures for the application of radon or radon combined with EMF in radon spas. The effects of patients' exposure to radon, especially combined with EMF need to be further studied.

[Evaluation of exposure to ionizing radiation among gamma camera operators]. / Ocena narazenia na promieniowanie jonizujice techników obslugujacych gammakamery.

BACKGROUND: Protection of nuclear medicine unit employees from hazards of the ionizing radiation is a crucial issue of radiation protection services. We aimed to assess the severity of the occupational radiation exposure of technicians performing scintigraphic examinations at the Nuclear Medicine Department, Central Teaching Hospital of Medical University in Lódz, where thousands of different diagnostic procedures are performed yearly. MATERIALS AND METHODS: In 2013 the studied diagnostic unit has employed 10 technicians, whose exposure is permanently monitored by individual dosimetry. We analyzed retrospective data of quarterly doses in terms of Hp(10) dose equivalents over the years 2001-2010. Also annual and five-year doses were determined to relate the results to current regulations. Moreover, for a selected period of one year, we collected data on the total activity of radiopharmaceuticals used for diagnostics, to analyze potential relationship with doses recorded in technicians performing the examinations. RESULTS: In a 10-year period under study, the highest annual dose recorded in a technician was 2 mSv, which represented 10% of the annual dose limit of 20 mSv. The highest total dose for a 5-year period was 7.1 mSv, less than 10% of a 5-year dose limit for occupational exposure. Positive linear correlation was observed between total activity of radiopharmaceuticals used for diagnostics in the period of three months and respective quarterly doses received by technicians performing examinations. CONCLUSIONS: Doses received by nuclear medicine technicians performing diagnostic procedures in compliance with principles of radiation protection are low, which is confirmed by recognizing the technicians of this unit as B category employees.

[Radon concentrations in selected residential buildings in the city of Lódz]. / Stezenie radonu wwybranych budynkach mieszkalnych na terenie miasta Lodzi.

BACKGROUND: Radon and its decay products in the atmosphere are the most important contributors to human exposure from natural sources. In Poland, the total annual effective dose from indoor radon is 1.36 mSv. MATERIAL AND METHODS: Over the past twenty years, the measurements of radon concentration in the building indoor air were performed three times by the Nofer Institute of Occupational Medicine, Lódz, with the use of track detector CR-39 enclosed in NRPB cassette. Those measurements were taken in the ground floor of each building. RESULTS: The average annual radon concentration was 89 Bq/m3 in 1998/1999; 75 Bq/m3 in 2008/2009; and 52 Bq/m3 in 2005. CONCLUSIONS: Assuming that a human spends at home about 5000 hours per annum and using suitable conversion factors, the dose from radon the inhabitants under study are exposed to varies from 0.9 to 1.1 mSv and it is lower than average dose for the Polish population.

Mean annual (222)Rn concentration in homes located in different geological regions of Poland: first approach to whole country area.

The paper presents the results of year-long measurements of radon ((222)Rn) concentration inside 129 buildings in Poland in relation to the geological conditions of their foundation. The authors took into account the division of the country into tectonic units, as well as the lithology of the rocks forming the bedrock of these buildings. As expected, the highest value of mean annual (222)Rn concentration (845 Bq/m(3)) was recorded in a building situated in the area of the Sudetes, while the highest geometric mean (characteristic of the expected log-normal data distribution) was calculated based on measurements from buildings located within the East-European craton, in the area of Mazury-Podlasie monocline, where it reached 231 Bq/m(3). Such results reflect geological conditions - the occurrence of crystalline rocks (especially U- and Ra-enriched granites and orthogneisses) on the surface in the Sudetes, and of young post-glacial sediments containing fragments of Scandinavian crystalline rocks, also enriched with U and Ra, in the area of Mazury-Podlasie monocline. However, the least expected result of the investigations was finding out that, contrary to the hitherto widespread belief, none of the major tectonic units of Poland can be excluded from the list of those containing buildings with mean annual (222)Rn concentration exceeding 200 Bq/m(3). The mean annual concentration of radon for all the buildings were much higher than the mean concentration value (49.1 Bq/m(3)) of indoor radon in Poland quoted so far. These results cast a completely new light on the necessity to perform measurements of radon concentration in residential buildings in Poland, no more with reference to small areas with outcrops of crystalline rocks (especially the Sudetes, being the Polish fragment of the European Variscan belt), but for all the major tectonic units within Poland.

[Assessment of radiation exposure of miners to radon and its daughter products in selected non-ferrous metal mines]. / Ocena narazenia radiacyjnego górników w wybranych kopalniach metali niezelaznych na radon i produkty jego rozpadu.

BACKGROUND: For over 40 years already, the Nofer Institute of Occupational Medicine (NIOM) in Lodz has been supervising non-ferrous metal mines for miners' radiation risk of radon and its short-lived daughters products found in the air of mines. MATERIAL AND METHOD: The supervision involves the use of trace detectors placed in passive dosemeters worn by a representative group of miners. RESULTS: During the late 1960s, the exposure in some mines was as high as 50 mSv/year. Owing to the steps undertaken in the mines, including primarily the provision of improved ventilation systems, the exposure was reduced to 5 mSv/year, and then to 2 mSv/year during the 1980s and 1990s. CONCLUSION: The results of measurements, performed during the recent 10 years, show that the exposure in non-ferrous metal mines is now within the limits specified for worker category B, i.e., not exceeding 6 mSv/year. The mean annual effective dose for a ten-year (1998-2009) period was 2.1 +/- 0.9 mSv/year.

[An assay of the current exposure to radon of spa workers in Poland]. / Rozpoznanie aktualnego stanu narazenia na radon pracowników uzdrowisk w Polsce.

BACKGROUND: Owing to good solubility of radon 222Rn in water the gas is found almost in all surface and underground water basins. Radon released from water into the ambient atmosphere is a source of health hazard to the workers handling mineral water in Spa facilities. MATERIAL AND METHODS: Mean monthly radon concentrations were measured using closed dosimetry with CR-39 trace detectors. Of the 101 Spas included in the study, 76 returned the dosimeters. RESULTS: In two Spas, the measured concentrations were above 1000 Bqm(-3), and thus annual doses of over 6 mSv could be received by the workers of those Spas. In four of the Spas, radon concentrations were within the range of 500-1000 Bqm(-3). In the majority (75%) of the Spas, mean monthly radon concentrations were not higher than 150 Bqm(-3). CONCLUSIONS: One hundred sixty persons working in 13 Spas can be exposed to the doses, which are important from radiation protection point of view. In the remaining Spas, radon exposure is maintained at the level of average exposure of the general population in Poland.

Sentinel node biopsy in skin melanoma patients--measurements of absorbed doses of radiation to the hands of medical staff.

BACKGROUND AND OBJECTIVES: The goal of this study was to measure absorbed doses of radiation to the hands of medical staff performing sentinel node biopsy (SNB) in skin melanoma patients. METHODS: The study was conducted from January 2004 to May 2004, during SNBs (lymphoscintigraphy-(99m)Tc on albumin carrier, surgery after 24 hr; blue dye; intraoperative detection of gamma radiation) in 22 skin melanoma patients. During lymphoscintigraphy and surgical procedures, 57 highly sensitive thermoluminescent dosimeters (TLDs) were placed on different parts of the hands of the medical staff. RESULTS: Mean doses of radiation recorded on different parts of the hands of the physician injecting the radiotracer ranged from 2.43 to 84.11 microSv for single procedures, ranged from 3.20 to 5.84 microSv for the hands of surgeon, and ranged from 2.65 to 5.47 microSv for the hands of the remaining members of the medical staff. Absorbed doses of radiation to the hands of helping medical staff present in operating room was only slightly lower than absorbed doses to the hands of operating surgeon and assistant surgeon. CONCLUSION: The maximum recorded dose during this study was 1,900 times smaller than the current 1-year dose limit recommended by the International Commission on Radiological Protection (ICRP).

Application of pylon radon daughter standard for calibration of radiometers.

Radiometers for measurements of radon daughter potential energy used in the surveillance of the work environment need a systematic calibration. This paper presents how a commercially available device produced by the Pylon Company can be applied. This device allows to produce, simply and directly, standard sources of radon daughters, corresponding with the energy, geometry and properties of radiation originated from an air sample. The calibration yielded the results that proved to be in agreement with those obtained previously by means of radon chamber.