Statistical analysis for obtaining optimum number of CT scanners in patient dose surveys for determining national diagnostic reference levels.

OBJECTIVES: To statistically determine an 'optimum number of CT scanners' for obtaining 'diagnostic reference levels' (DRLs) in CT examinations as close as possible to 'ideal DRLs' when all available CT scanners are considered. METHODS: First, six 'ideal DRLs' (CTDIVol and DLP) were determined for head, chest and abdomen/pelvis examinations by using patient-dose survey data of 100 CT scanners of different models in Tehran. Then, a 'random sampling method' was applied to different percent fractions of patient dose data of 100 CT scanners. The percent differences (PD) of the DRLs obtained from 'ideal DRLs' and their coefficients of variation (CVs) were calculated. The 'optimum number of CT scanners' determined met those of 'ideal DRL' criteria; i.e. precision (CV ≤ 10%) and accuracy (PD ≤ 10%). RESULTS: 'Optimum number of CT scanners' for determining DRLs as close as possible to 'ideal DRLs', fulfilling the stated criteria, is 43 instead of using 100. CONCLUSION: 'Optimum number of CT scanners' for obtaining DRLs as close as possible to 'ideal DRLs' was determined. This optimum number can be effectively applied in patient-dose survey situations with limited resources in a time- and cost-effective manner. KEY POINTS: • Ideal DRLs were determined by a CT patient-dose survey applied to available scanners. • 'Optimum number of CT scanners' statistically determined for DRLs is 43%. • Optimum number can be used for DRLs as if 'ideal DRLs' were determined by all scanners.

Enhancing electrostatic charge stability of corona charged Teflon electret films for radiation dosimetry by optimizing metal electrode backing material.

Metal electrode backing (MEB) material was found to have a significant role on the electrostatic surface charge stability of Teflon polytetrafluoroethylene (PTFE) electret films. PTFE films of different thicknesses were positively and negatively charged by using our home-made modified point-to-plane corona poling rotating systems. Different MEB materials and thicknesses; aluminum, copper, stainless steel, zinc, silver, and gold were applied. The electrostatic surface charge stability of charged PTFE films was monitored for 200 h at similar storage conditions. Proper MEB material enhances the electrostatic surface charge stability of electret films due to the work function of the metal electrodes and high potential barrier formation at the interface of MEB material and electret film. The studies show that thinner MEB materials provide higher electrostatic surface charge stability in PTFE films. Therefore, thinner MEB material with higher work function is an effective compromise for producing electret films with higher electrostatic surface charge stability. The findings are extremely important for the applications of highly stable electret films for different applications in particular for radiation dosimetry with special regards to radon monitoring.

Breakthrough electroneutron multi-response miniature dosimetry/spectrometry in medical accelerator.

Breakthrough multi-response miniature dosimetry/spectrometry of electroneutrons (EN) was made on surface and in-depths of whole-body polyethylene phantom under 10 cm × 10 cm electron beam of 20 MV Varian Clinac 2100C electron medical accelerator commonly applied for prostate treatment. While dosimetry/spectrometry of photoneutrons (PN) has been well characterized for decades, those of ENs lagged behind due to very low EN reaction cross section and lack of sensitive neutron dosimeters/spectrometers meeting neutron dosimetry requirements. Recently, Sohrabi "miniature neutron dosimeter/spectrometer" and "Stripe polycarbonate dosimeter" have broken this barrier and determined seven EN ambient dose equivalent (ENDE) (µSv.Gy-1) responses from electron beam and from albedo ENs including beam thermal (21 ± 2.63), albedo thermal (43 ± 3.70), total thermal (64 ± 6.33), total epithermal (32 ± 3.90), total fast (112.00), total thermal + epithermal (l96 ± 10), and total thermal + epithermal + fast (208 ± 10.23) ENs. Having seven ENDE responses of this study and seven PNDE responses of previous study with the same accelerator obtained at identical conditions by the same principle author provided the opportunity to compare the two sets of responses. The PNDE (µSv.Gy-1) responses have comparatively higher values and 22.60 times at isocenter which provide for the first time breakthrough ENDE responses not yet reported in any studies before worldwide.

Six Weeks to Wellness: The Role of Breathing Exercises Based on Motor Development Pattern in Improving Fitness and Quality of Life in Overweight Elderly Women.

Background: Being overweight is a major global health epidemic of the 20th and 21st centuries, which can affect the movement system function of older adult women. This study evaluated the effects of a breathing exercise based on motor development patterns on functional fitness and quality of life in overweight older adult women. Methods: A randomized controlled trial was conducted with 40 community-dwelling women aged 65-75. Participants were randomly assigned to an intervention group, which completed a 6-week breathing exercise program (three supervised and three home-based sessions per week), or a control group, which maintained usual routines. Outcome measures included cardiovascular fitness, upper and lower body flexibility, muscle strength, dynamic balance, and quality of life, assessed at baseline and post-intervention. Results: The intervention group showed significant improvements in cardiovascular fitness (p < .001, ES = 0.652), upper body flexibility (p < .001, ES = 0.652), lower body flexibility (p < .001, ES = 0.538), upper body strength (p < .001, ES = 0.538), lower body strength (p < .001, ES = 0.538), and dynamic balance (p < .001, ES = 0.475) compared to the control group. Quality of life also significantly improved in the intervention group (p < .001, ES = 0.475). Conclusion: Breathing exercises based on motor development patterns significantly enhance functional fitness and quality of life in overweight older adult women. Incorporating these exercises into regular physical activity routines may promote health and independence in older adults. Further research should explore long-term benefits and optimal exercise parameters for older adults.

Optimizing some parameters of air-filled ion pulse ionization chambers for effective radon detection.

Air-filled ionization chambers in pulse ion mode can provide precise low-level detection of indoor/outdoor radon. However, it suffers from relatively high collection duration of positive and negative charges as well as environmental changes. In order to overcome these shortcomings, the Garfield++ software which is a powerful toolkit to develop a realistic simulation framework for radiation detectors was applied. Also, Garfield++ interface to Magboltz was used to calculate the gas parameters for air at various humidity conditions for a wide range of electric field strengths in order to compare the results with other available data in the literature. The Garfield++ software was also used to calculate maximum charge collection duration for a wide range of tube radii, wire radii, and electric potentials which are the main parameters affecting the charge collection duration. Furthermore, the influence of environmental conditions including air pressure, temperature, and humidity on the charge collection duration was investigated. The results show that for an air-filled radon ionization chamber with a moderate size (e.g. 1 L) with a bias voltage of hundreds of volts, the time constant of the external circuit can be chosen to be less than 100 ms, which is much lower than the values used in other studies. Therefore, with a proper design of an ionization chamber and its electronic system, it is possible to determine radon activity concentrations of up to a few tens of kBq.m-3 in pulse mode. In conclusion, the data obtained in this study assists in developing radon air-filled ionization chambers in order to determine chamber dimensions and bias voltage as well as designing the readout electronics according to the characteristics required in an intended application.

Discovery of Third Possible Ion Generating Source in 4π Plasma Focus Device Space.

ABSTRACT: Discovery of a possible third source of ion generation in 4π Plasma Focus Device (PFD) space is reported. Unexpected observation of dense ion tracks, called "On Shadow Ion Tracks" (OSIT), on the "ion cathode shadows" (ICS) was discovered. These ions were formed on panorama mega-size cylindrical polycarbonate ion image detectors placed behind the cathodes in the PFD space on PFD wall, where no ion tracks are expected to exist. Such unexpected ion tracks were observed when different gases were used, in particular hydrogen, deuterium, and helium. An ICS is formed on the detector when each cathode shadows and removes all ions bombarding it from the "anode top" and "anode cathodes assembly." Such ion tracks forming the OSITs seem to be generated not from the "anode top" and "a node cathodes assembly" but also from a third possible ion source in PFD space bombarding the detector.

Spectrometry of leakage photoneutrons of 18 MV medical accelerator head by Sohrabi passive multi-directional spherical neutron spectrometry system.

PURPOSE: Spectrometry of leakage photoneutrons (PN) of a Siemens ONCOR medical linear accelerator head by applying recently invented Sohrabi passive multi-directional multi-detector neutron spherical spectrometry system; measurements of scientific interest and of importance for meeting the regulatory and safety standards. METHODS: The neutron spectrometry system applied consists of 6 polycarbonate/10B detectors mounted on 6 sides of a polyethylene cube used as bare and also embedded at center of 8 PE spheres of different diameters. Multi-directional and mean PN spectra at isocenter as well as at the left and right sides of head at 100 cm distance from the X-ray target on its plane of 10x10 cm2 18-MV X-ray beams were determined applying Multisphere Neutron Spectrometry Unfolding Code (MNSU + ). RESULTS: The well-resolved unfolded directional leakage PN spectra obtained at the 3 positions showed a thermal PN peak of lower intensityfollowed by a tail of epithermal PNs before reaching a fast PN higher peak." The mean PN energy are 0.47 ± 0.03 MeV and 0.48 ± 0.02 MeV respectively for the left and right sides of the head and 0.48 ± 0.02 MeV at the isocenter. CONCLUSIONS: Due to importance of leakage PN spectra of an accelerator head being of scientific interest and for meeting regulatory and safety standards, well-resolved leakage PN spectra of 3 locations of the medical accelerator head were determined using Sohrabi passive multi-directional neutron spectrometry system. It is a novel learning that the mean PN spectra and mean PN energy of the 3 locations are quite similar within statistical variations.

Whole-body photoneutron 360° angular distribution dosimetry by novel "Sohrabi neutron dosimetry methods".

PURPOSE: Whole-body photoneutron (PN) energy-specific dosimetry on phantom surfaces and 360°angular fast PN distribution dosimetry on and around polyethylene (PE) phantom organs for prostate cancer in 10 cm × 10 cm and 20 cm × 20 cm field sizes of 18 MV X-rays of Varian Clinac 2100C linear accelerator. METHODS: Novel "Sohrabi neutron dosimetry methods" including "miniature passive neutron dosimeter/spectrometer" and "strip polycarbonate neutron dosimeters" were applied. Energy-specific PN dose equivalents on surface as well as 360°fast PN dose equivalent angular distributions on and around PE phantom organs; head, neck, thorax, arms, pelvis, thighs and legs were determined. RESULTS: Matrix of surface (skin) energy-specific PN dose equivalents including total thermal, total epithermal, total fast, sum total thermal + epithermal and sum total thermal + epithermal + fast, and 360°angular fast PN dose equivalent responses were determined. The results indicate that data matrix of 20 cm × 20 cm field size provides higher PN dose equivalent values than those of 10 cm × 10 cm field size for surface points even remote from the central axis and for all 360°angular fast PN dose equivalent distributions on organs studied. CONCLUSIONS: Matrix of energy-specific PN dose equivalents was obtained demonstrating that the Sohrabi neutron dosimetry methods applied are unique for energy-specific PN dose equivalent studies as well as for 360°angular PN dose equivalent distribution data for PN-SPC risk estimation. The dosimetry methods can be specifically applied to many other exotic applications in health physics, medical physics, space flight dosimetry, and nuclear science and technology.

Variability and coordination patterns of walking with different speeds in active and non-active children with Down syndrome: A cross-sectional case-control study.

Purpose: Children with Down syndrome (DS) have multiple difficulties in gait pattern. So, the effect of the activity level and speed on the gait coordination and variability was investigated. Methods: In this case-control observational study, 24 participants in three groups of active and non-active children with DS, and the control group without intellectual disability were asked to walk on a treadmill with two speeds of 0.8 and 1.2 m/s. Continuous Relative Phase (CRP) and variability of CRP in thigh-leg and leg-foot coupling were assessed. Results: CRP and variability of CRP in the leg-foot coupling in the control group were significantly higher than active and non-active groups with DS. Speed led to increase the CRP of leg-foot in the active group with DS and increase the variability of this coupling in non-active group with DS. Conclusion: In this study, the activity level provided the compatibility with speed changes of walking in CRP of leg-foot in children with DS.

Breakthrough whole body energy-specific and tissue-specific photoneutron dosimetry by novel miniature neutron dosimeter/spectrometer.

Breakthrough whole body energy-specific photoneutron (PN) dosimetry was made in/out-of-field in polyethylene phantom organ surface/depths remote from isocenter of 10 × 10 cm2 field prostate cancer therapy in 18 MV X-rays Varian Clinac 2100C medical linear accelerator for PN tissue-specific second primary cancer (PN-SPC) risk estimation. A novel miniature neutron dosimeter/spectrometer with polycarbonate/10B/cadmium inserts was invented and applied. Each dosimeter determines seven tissue-specific dose equivalent (mSv)/Gy X-ray dose at each measurement point providing seven major energy-specific responses for beam thermal, albedo thermal, total thermal, total epithermal, total fast, sum of totals (thermal + epithermal) and sum of totals (thermal + epithermal + fast) PNs dose equivalents. The neutron dosimeter is simple, efficient, and unique with high spatial resolution and provides matrix of energy-specific PN dose equivalent (mSv)/Gy X-ray dose on surface and organ depths for tissue-specific PN-SPC risk estimation. The dosimeter also performs like a "miniature neutron spectrometer" and is unique for other applications in health physics in particular individual neutron dosimetry, medical physics, space flights, science and technology.

Photoneutron spectrometry by novel multi-directional spherical neutron spectrometry system.

Neutron spectrometry in science and technology applications in general and accurate exotic photoneutron (PN) dosimetry of cancer patients undergoing high-dose high-energy X-rays therapy in medical accelerators in particular is of vital need. In this study, a novel passive multi-directional multi-detector neutron spectrometry system was developed and home-made using 6 polycarbonate/10B detectors on 6 sides of polyethylene (PE) cubes used bare and also embedded at center of PE spheres of 8 different diameters. The system provided well-resolved unfolded directional PN spectra showing thermal and fast PN peaks of 6 sides and mean spectrum in 5 field sizes at isocenter and other locations in 18 MV Siemens ONCOR medical linear accelerator bunker. The neutron spectrometry system developed has unique characteristics such as being simple, efficient, low cost, practical, and insensitive to low-LET radiation with well-resolved directional and mean spectra easily applicable in medicine, health, environment, science and technology in developing and developed laboratories.

A New Application of Sohrabi Albedo Neutron Dosimeters around a Plasma Focus Device.

A new application of the Sohrabi albedo neutron dosimeters is reported for the first time for determination of very low-level neutron ambient dose equivalents on and around a 3.5 kJ plasma focus device (PFD). The Sohrabi dosimeters basically use a polycarbonate track detector as bare and/or in contact with B convertor(s) under special cadmium cover arrangements. Its sensitivity was improved by using enriched B under new cadmium arrangements in order to detect epithermal neutrons in addition to fast and thermal neutrons. Results of 12 dosimeters installed externally around the PFD at different azimuthal (φ) and polar (θ) angles showed that azimuthal (φ) fast, epithermal, thermal, and total neutron ambient dose equivalents were symmetric and isotropic, respectively, with values 55.15 ± 8.36, 1.36 ± 02, 0.53 ± 03, and 57.04 ± 8.62 µSv/shot at ~25 cm from anode top. Polar (θ) neutron ambient dose equivalent values on z-axis relative to 90 angle were relatively higher. Results of 38 dosimeters placed on PFD facility walls for workplace monitoring and on a BOMAB phantom at operator's location for personal dose equivalent determination showed values below minimum detection limits after exposure to 130 PFD shots. However, an operator's personal dose equivalents at ~1.0 and ~3.0 m from the anode top were estimated to be, respectively, ~13.7 and ~1.52 mSv y using azimuthal angle (φ) values if the PFD operates, for example, up to 20 shots per day for 200 d y. Even under such an extreme assumption, annual personal dose equivalent is still much below 20 mSv, the annual ICRP dose limit for workers.

The effect of training on variability and accuracy of overhand throwing in children with Down syndrome.

OBJECTIVE: People with Down syndrome (DS) have higher variability in their motor skills compared to other counterparts without intellectual disability. Given that the effect of physical training on the variability and accuracy is unclear, the purpose of this study was to examine the effect of nine sessions of overhand throwing training on the variability and accuracy of overhand throwing in children with DS. METHODS: Twenty-seven children with DS randomly assigned to experimental and control groups. In the pretest, two groups threw the tennis ball three times to the fixed target. Absolute error (AE) and the normalized root mean square (NoRMS) of segmental couplings of shoulder-elbow (NoRMS 1) and elbow-wrist (NoRMS 2) calculated from the scores of throwing and kinematics data, respectively. Then the experimental group participated in overhand throwing training for nine sessions. After that, the post-test was taken and ten days later, the retention test performed with pretest conditions. RESULTS: The results of two-way ANOVA with repeated measures on AE values showed the experimental group in the post-test and retention phases was more accurate than the control group. Also, AE values of the experimental group in the post-test and retention phases were significantly lower than the pretest. The results of two-way ANOVA with repeated measures showed that NoRMS 1 in the experimental group was significantly lower than control group in the post-test and retention phases. CONCLUSION: It seems the overhand throwing training can reduce the variability and increase the accuracy of overhand throwing in children with DS.

NOVEL 'PHOTONEUTRON VOLUME DOSE EQUIVALENT' HYPOTHESIS AND METHODOLOGY FOR SECOND PRIMARY CANCER RISK ESTIMATION IN HIGH-ENERGY X-RAY MEDICAL ACCELERATORS.

A novel 'photoneutron (PN) volume dose equivalent' methodology was hypothesized and applied for the first time for estimating PN second primary cancer (PN-SPC) risks in high-energy X-ray medical accelerators. Novel position-sensitive mega-size polycarbonate dosimeters with 10B converter (with or without cadmium covers) were applied for determining fast, epithermal and thermal PN dose equivalents at positions on phantom surface and depths. The methodology was applied to sites of tumors such as brain, stomach and prostate in 47 patients. The PN-SPC risks were estimated for specific organs/tissues using linear International Commission on Radiological Protection cancer risks and were compared with some available data. The corresponding PN-SPC risk estimates ranged from 1.450 × 10-3 to 1.901 cases per 10 000 persons per Gray. The method was applied to 47 patients for estimating PN-SPC risks in patients undergoing radiotherapy. The PN-SPC risk estimates well match those calculated by simulation but are comparatively different from those estimated by 'PN point dose equivalent' methods, as expected.

Effects of virtual reality training intervention on predictive motor control of children with DCD - A randomized controlled trial.

It has been hypothesised that deficits in the functions of predictive motor control and internal modeling may contribute to motor control issues of children with Developmental Coordination Disorder (DCD). Virtual reality (VR) technologies have great potential to provide opportunity for Motor observation and motor imagery (MI) which could enhance learning and development of motor skills in children with DCD. Thus, the present study aimed to investigate the benefits of a VR training intervention to improve predictive motor control functions of children with DCD. Forty female children with DCD (aged 7-10) were randomly assigned to VR and control groups. In this study, an experimental pre-post and follow-up design was used, and Predictive motor control functions were measured before and after the VR intervention and two-months later. Predictive motor control was evaluated using MI (by hand rotation task), action planning (by sword placement task), and rapid and online control (by rotational tracking task) tests. VR intervention consisted of a selection of Xbox 360 Kinect games that were performed for sixteen 30-min sessions over 8 weeks. Compared to the control group, the VR group improved significantly on measures of MI, motor planning, and rapid and online control scores from pre- to post-test and retained their performance to follow-up. Overall, it seems that virtual reality training program may be used as an appropriate intervention approach for developing the ability of MI and predictive motor control functions in DCD children.

Effects of Physical and Observational Practice on Intermanual Transfer.

Some studies have shown that different coordinate systems in the coding of movement sequences develop during observational and physical practice. According to Newell's (Newell, 1986) constraintsled approach, such contradictions could possibly depend on task characteristics. Accordingly, in the present study, two experiments were designed using a five-segment sequence timing task, in which the instructions on how to perform the sequence were different. The task in the first experiment comprised an alternating shift of fast and slow segments, whereas the second experiment involved an incremental procedure from slow to fast. In these experiments, the intermanual transfer of absolute and relative timing through observational and physical practice was examined. Transfer conditions were such that they required the same motor commands (mirror transfer) or the same visual-spatial coordinates (non-mirror transfer) as those in the practice conditions. The first experiment showed that the transfer to the non-mirror condition for relative timing in the physical group was better than that to the mirror condition, while the transfer was similar for both conditions in the observational group, indicating a different pattern of transfer for relative timing. The relative timing transfer pattern in the second experiment was the same for both experimental groups, such that the physical and observational practice resulted in a similar transfer to both mirror and non-mirror conditions. In both experiments, observational and physical practice participants exhibited similar intramanual transfer of absolute timing under both transfer conditions. Thus, the task itself as a constraint was revealed to be an effective factor influencing the behavioral results derived from physical and observational practice.

Effects of a Motor Intervention Program on Motor Skills and Executive Functions in Children With Learning Disabilities.

This study examined the effect of a motor intervention based on the attention, balance, and coordination (ABC) learning approach on motor proficiency and executive functions in children with learning disabilities (LD). Forty-five male elementary school students with LD aged 7-9 years were recruited and randomly assigned into one of three groups: two experimental groups and one control group. Experimental Group A received only the motor intervention. Experimental Group B simultaneously received both motor intervention and regular educational services. The control group received only regular educational services. The motor intervention involved sequential station exercises based on ABC; this training took place in 24 sessions, scheduled three times a week for eight weeks. We obtained children's scores on the Bruininks-Oseretsky Tests of Motor Proficiency, N-Back Test, Tower of London, and Continuous Performance Tests at pretest, posttest, and follow-up testing. Our results showed that both experimental groups significantly improved their motor skills and most measures of executive functions, relative to no significant improvement for the control group. The improvements on some measures of executive functions in Experimental Group B were just slightly better than in Experimental Group A. This study supported Blythe's ABC learning approach emphasizing ABC, and it extended earlier findings of benefits of this approach to populations of children with LD.

Pre-programming in overhand throwing of children with Down syndrome: role of the generalized motor program.

OBJECTIVE: It is unclear whether slowness and higher reaction time of individuals with Down syndrome (DS) are because of inability to pre-program and using the generalized motor program (GMP) or not. So, the purpose of this study was to examine the consistency of relative timing as a fixed feature of a GMP in overhand throwing with changing the distance to target as a varied feature. METHODS: Fifteen individuals with DS (age = 13 ± 2 y) and a control group of 12 individuals without intellectual disability (ID; age = 13 ± 2 y) were asked to throw a tennis ball to a fixed target from three distances of 2, 2.75, and 3.25 m, respectively. Instant of occurrence of the following discrete variables was recorded by motion analysis: initiation of elbow extension, maximum shoulder angular velocity, maximum elbow angular velocity, and maximum resultant hand velocity. RESULTS: Results of two-way analysis of variance test did not show any significant difference in any of the relative kinematic variables in distances and groups (p > 0.05). CONCLUSION: It seems that individuals with DS are able to motor preprogram and they use a GMP to overhand throwing from different distances as well as those without ID. Also, slowness and reaction time are unrelated to pre-programming and GMP as it relates to overhand throwing.

Is visuomotor training an effective intervention for children with autism spectrum disorders?

PURPOSE: Investigation of autism spectrum disorder (ASD) is somewhat dependent on addressing main core features of ASD. But it is not clear which kind of investigation can effect on more difficulties features. So, this study examines the effect of the visuomotor, motor, and computer-based training programs on social behavior, motor skills, and repetitive behaviors of children with ASD. PATIENTS AND METHODS: Sixty children with ASD aged 6-12 years were recruited and assigned to one of the three experimental groups and the control group (each group n=15). Training was provided in 30 sessions, scheduled 3 times a week. Social behavior and repetitive behaviors were determined objectively using the observation method, and motor skills were evaluated by the Test of Gross Motor Development-2. RESULTS: Our results suggested that children in the visuomotor group showed a significant reduction in the repetitive behaviors and an increase in gross motor skill scores in the post-test and follow-up. Also, the results exhibited that motor training group significantly improved in social behavior either in the post-test or follow-up. Although the post-test illustrated a considerable improvement of gross motor skills, this difference was not significant in follow-up. Similarly, no significant change was observed in visual training and control groups in relation to study variables. CONCLUSION: Given the improvement of repetitive behaviors and gross motor skills in post-test and follow-up, it seems that this investigation had a positive effect with a good retention effect on two core features of children with ASD. But according to group-based training protocol in motor training group and improvement in social communication, and mutual effect on gross motor skills, it seems that group-based practice can also be used to achieve the benefits of social communication in the investigations.

Fast, epithermal and thermal photoneutron dosimetry in air and in tissue equivalent phantom for a high-energy X-ray medical accelerator.

Photoneutron (PN) dosimetry in fast, epithermal and thermal energy ranges originated from the beam and albedo neutrons in high-energy X-ray medical accelerators is highly important from scientific, technical, radiation protection and medical physics points of view. Detailed dose equivalents in the fast, epithermal and thermal PN energy ranges in air up to 2m as well as at 35 positions from the central axis of 12 cross sections of the phantom at different depths were determined in 18MV X-ray beams of a Siemens ONCOR accelerator. A novel dosimetry method based on polycarbonate track dosimeters (PCTD)/10B (with/without cadmium cover) was used to determine and separate different PN dose equivalents in air and in a multilayer polyethylene phantom. Dose equivalent distributions of PNs, as originated from the main beam and/or albedo PNs, on cross-plane, in-plane and diagonal axes in 10cm×10cm fields are reported. PN dose equivalent distributions on the 3 axes have their maxima at the isocenter. Epithermal and thermal PN depth dose equivalent distributions in the phantom for different positions studied peak at ∼3cm depth. The neutron dosimeters used for the first time in such studies are highly effective for separating dose equivalents of PNs in the studied energy ranges (beam and/or albedo). The PN dose equivalent data matrix made available in this paper is highly essential for detailed patient dosimetry in general and for estimating secondary cancer risks in particular.