Total Kerma Research Articles

MONITORING EFFECTS OF MEDICAL EXPOSURE ON INTERVENTION AL EXAMINATION PATIENTS IN ADAM MALIK GENERAL HOSPITAL CATHLAB MEDAN: PRELIMINARY STUDY

MONITORING EFFECTS OF MEDICAL EXPOSURE ON INTERVENTION AL EXAMINATION PATIENTS IN ADAM MALIK GENERAL HOSPITAL CATHLAB MEDAN: PRELIMINARY STUDY. Efforts have been made to monitor medical exposure to patients with interventional examinations at the Cathlab to determine the value of medical exposure and the effects of erythema radiation. This initial study was carried out using a retrospective method of total kerma data, fluoro time and type of examination, and dose estimation for Dose Area Product (DAP) patients using X-ray intervention brands GE Medical System and Phillips Allura Xper FD20 for the period 2019 to May 2022, at Adam Malik Hospital. Conduct patient observations after the intervention examination by giving questionnaires to doctors and nurses to monitor intervention actions. Measure the air kerma within 1m from the source, then analyze the data. The results obtained from monitoring patient doses, fluoro time values , and total kerma can cause erythema, which results in stochastic and non-stochastic effects. Hence, it is crucial to record patient doses and monitor them as information to doctors and nurses on the impact. The conclusion is that the Fluoro time and total kerma values are directly at risk according to the reference, which has not been adequately monitored during intervention actions. As a suggestion by the regulation of the Nuclear Energy Supervisory Agency (BAPETEN) and the International Commission Radiological Protection (ICRP) to maintain patient safety by direct monitoring and informing doctors of the total dose of medical exposure in the Cathlab and as reference material for further research. Keywords: Medical Exposure, Interventional Measures, Radiation Safety.

Gadolinium neutron capture therapy: Calculation of 157Gd kerma factor and a dosimetry study using MCNP Monte Carlo code

In this paper, computational dosimetry studies for gadolinium-157 neutron capture therapy (157GdNCT) were carried out using MCNP Monte Carlo code, and the total equivalent dose rate was calculated in a Snyder head phantom with convenient and more accurate methods compared to the previous methods. The potential effectiveness of such therapy was assessed by calculating the therapeutic ratio based on the calculated dose distribution.The total neutron kerma factor for 157Gd was calculated according to the latest nuclear data. The 157Gd dose was calculated by kerma approximation and also directly by 157Gd capture reactions. The kerma of 157Gd photons was calculated in tumor and compared with the photon dose calculated from the transport of the produced electrons.The results reveal that, due to the severe neutron flux depression and high photon production in the tumor, the kerma approximation does not properly estimate the 157Gd dose and dose of 157Gd photons in a small-size tumor. Increasing the size of the tumor, the 157Gd kerma without considering neutron flux depression and photon kerma approach the dose of 157Gd and photons, respectively. If 157Gd is incorporated into the nucleus of the cancer cells, the therapeutic ratio of 157GdNCT will be greater than one and 157Gd might, therefore, be a good candidate for neutron capture therapy.

Features of Distributions Created in a Water Phantom by Narrow Bremsstrahlung Radiation Beams from 10 to 20 MV

The paper analyzes the features of the spatial and energy distributions of photons in depth, in radius
 and in energy for small fields created in water by narrow beams of high-energy bremsstrahlung radiation from medical accelerators and mono-directional, monoenergetic beams of photons. In particular,
 the relationship between the spatial dependences of the absorbed dose, total kerma, and ionization
 kerma is discussed. Using numerical simulation, the features of photon spectra in small fields at a
 depth of 10 cm in a water phantom for bremsstrahlung beams with maximum energies of 10, 15, 18
 and 20 MeV were determined as applied to the design of Varian accelerator heads. It is shown that, in
 contrast to wide fields, the energy distribution of photons in these fields practically does not change
 within the central region of the field and strongly softens when leaving this region. With a decrease in
 the size of small fields from 4.04.0 to 0.50.5 cm, a certain hardening of the spectra is observed in the
 central region (the average energy increases by 2–4 %) and is much more significant outside this region.
 The work also determined the values of the clinical dimensions of small fields generated by high-energy
 beams of Varian accelerators of different energies in a water phantom at a depth of 10 cm, depending on
 the settings of the collimation system.
 This work was carried out with the financial support of the Russian Foundation for Basic Research and
 SITMA within the framework of scientific project No. 18-52-34008.

A study of dose indicators during intra-arterial catheter implantation for liver chemotherapy

The aim of the present study was to describe patient dose indicator levels during intra-arterial catheter (IAC) implantation for liver chemotherapy, and to determine factors affecting the dose indicators. Between January 2017 and January 2019, 61 patients with hepatic metastases from colorectal cancer were retrospectively included. Interventions were carried out in a standardised manner by three experienced radiologists on the same angiographic table without changes in protocol parameters. For each patient, clinical, radiological and dosimetry data were collected, including the air kerma area product (KAP), part of KAP due to the fluoroscopy and fluoroscopy time (FT), total kerma at the reference interventional point and peak skin dose (PSD). Local dose reference levels (RLs) were determined as the third quartile of the patient dose distributions. Univariate and multivariate analysis of factors affecting dose indicators was performed. The mean KAP was 111 Gy cm2, the mean reference point air kerma (Ka,r) was 648 mGy, the mean PSD was 613 mGy, and the mean FT was 3190 s (62% of the KAP). The mean cone beam computed tomography dose was 37.3 ± 11.8 Gy cm2, which accounted for 37% of the KAP. The RL could be proposed taking into account the third quartiles (KAP = 164.6 Gy cm2, Ka,r = 904.5 mGy, FT = 4011 s and standard deviation = 772.7 mGy). The factors affecting dose indicators were related to the patients (sex, cardiovascular risk factors, weight, body mass index), to the vascular anatomies (coeliac trunk angulation) and to the procedures (number of embolised arteries). This study allowed a better understanding of dose indicators and factors affecting these indicators during the implantation of IACs for hepatic chemotherapy, which is a long and difficult procedure. Local dose RLs were determined. Multicentre, multi-equipment studies are necessary.

Intraoperative completion cone-beam computed tomography for the assessment of residual lesions after primary treatment of proximal venous outflow obstructions.

Report the usefulness of completion cone-beam computed tomography (CBCT) as an adjunct tool during femoro-ilio-caval recanalization post stent placement. Data from patients who underwent complex endovenous recanalization for chronic proximal outflow obstruction from January 2018 to May 2020 were analyzed. Two groups of patients were obtained based on the execution or not of completion CBCT. Outcomes, radiation, and contrast doses in the two groups were compared. Fifteen patients (9 female, mean age 46.9 ± 13.3) in the control group and ten patients (7 female, 58.3 ± 14) in the CBCT group were included. In the CBCT group, one patient underwent an intraprocedural revision due to a residual lesion. The median total kerma area product (KAPtotal) and the total volume of contrast injected were not statistically different in the two groups. Completion CBCT after endovenous procedures might identify residual stenosis or stent malposition without a significant increase of total contrast injected and KAPtotal.

Digital Subtraction Myelography is Associated with Less Radiation Dose than CT-based Techniques

Both CT myelogram (CTM) and digital-subtraction myelogram (DSM) can be used to evaluate patients for possible cerebrospinal fluid (CSF) leaks. DSM is a relatively new technique. No data exists on the radiation dose associated with this procedure, and how it compares with CTM. All patients who underwent DSM for spontaneous intracranial hypotension (SIH) refractory to blood patching from Dec 2016 - Sept 2019 were retrospectively assessed. DSM dose factors were then recorded (cumulative fluoroscopy time, total kerma area product (KAP, mGy.cm2), cumulative air kerma (mGy), as well as CTM dose factors (included CTDIvol (mGy) and dose-length product (DLP, mGy.cm). These indices were then used to calculate the effective dose for both procedures using standardized conversion factors. 61 DSMs were performed in 42 patients, 33 of which also underwent CTM. The median effective dose was 6.6 mSv per DSM study (range: 1.2 - 17.7). On a per-patient basis (i.e. those patients who underwent more than one DSM (as the initial one was negative), the median total effective dose was 13 mSv for their total DSM imaging (range: 2.6 -31.7). For the CTM, the median effective dose was 19.7 mSv (range: 3.2 - 82.4 mSv). The radiation dose with DSM appears to be significantly lower than that of CTM (p = 0.0005), when looking at CTM doses both from our institution and in the published literature.

Ionization Chambers to Determine Neutron and Gamma-Ray Kerma in a Research Reactor

Ionization chambers were designed and constructed to determine the kerma rates in various materials within several centimeters of a Training, Research, Isotopes, General Atomics (TRIGA) reactor core operating at 1 MW. The primary aim of this article was to compare kerma measurements with the advanced Monte Carlo code calculations of nuclear heating. Wall thickness, collection gap, and fill gas pressure were chosen to satisfy Bragg–Gray criteria, so that the measured ionization current was related to the kerma rate in the wall material. Chamber wall materials composed of low mass number elements, including hydrogen-rich C552 air-equivalent plastic and beryllium, were selected to measure the kerma due to fast neutron elastic scattering. By operating these neutron sensitive chambers coincidentally with relatively neutron insensitive chambers composed of aluminum and Zircaloy-4, we were able to measure the total heating due to fast neutrons and gamma rays in a material and to differentiate these heating components. A chamber composed of borated stainless steel was used in a similar fashion to measure the thermal neutron flux. The total kerma rate was also measured in various materials typically found in a reactor core. Chamber collection volumes were initially determined using ambient air fill gas and National Institute of Standards and Technology (NIST)-traceable air-kerma rates from a 60Co source. All chambers were sealed with argon gas to provide thermal and compositional stability. Chamber properties, including stability, saturation, and gas-phase mass subject to charge collection, were determined using the 60Co source. Chambers were operated for approximately 30 min adjacent to the reactor core, and the integrity of gas seals was subsequently verified by repeating the measurement with the 60Co source.

Strategies to optimise occupational radiation protection in interventional cardiology using simultaneous registration of patient and staff doses

The International Commission on Radiological Protection recommends that occupational protection and patient protection be managed in an integrated approach. This paper describes the experience and the initial results of a system able to register and to process simultaneously staff and patient doses in interventional cardiology and the practical use of this system in the optimisation of occupational exposure. The system used simultaneously collects and manages patient and staff doses for all radiation events. The personal electronic dosimeters worn over the protective apron of health professionals working inside catheterisation laboratories can send (wireless) doses and dose rate values to an X-hub and provide the operators inside the catheterisation rooms with real-time information. Individual and global reports for all the health professionals may be periodically obtained from the system to help with the optimisation. The results for eight cardiologists, one fellow and four nurses for a total of 2468 interventional cardiology procedures and 3207 occupational dose values collected over one year are presented here. Annual doses Hp(10) measured over the apron for cardiologists ranged from 0.3 to 6.3 mSv. For the cardiologist, the ratio between occupational doses (over the apron) and patient doses ranged from 0.05 to 0.23 μSv Gy−1 cm−2, with a mean value of 0.12 μSv Gy−1 cm−2. The system allows defining optimisation strategies by comparing the results between the different operators while considering the workload and complexity of the procedures (based on the total Kerma Area Product managed by the different operators). The registration of the date and time of the occupational radiation doses allows auditing the use of the personal dosimeters worn by the various operators.

REFERENCE NEUTRON FIELDS IN CALIBRATION LABORATORY; SIMPLE DOSIMETRIC PARAMETERS AND THEIR CHANGES IN TIME.

The calibration laboratory revises periodically the dosimetric properties of its calibration fields. For reference neutron fields based on radionuclide sources, it is due to presence of isotopic impurities in the source ingredients. Consequently, in long term, the admixtures and their decay products become significant. Neglecting the impact of such effect leads to inconsistencies between the neutron emission rate observed during the measurements and the emission rate derived from the decay curve of the main isotope. In the Radiation Protection Measurements Laboratory at the National Centre for Nuclear Research the neutron fields of the bare sources of 252Cf, 241AmBe and 239PuBe have been examined for nearly 30 years, regularly, in fixed geometry. Additionally, at the particular point of a calibration bench, determination of neutron fluence rate, ambient dose equivalent rate and its scattered component, total neutron and gamma dose rate, gamma to total dose ratio, radiation quality factor and total tissue kerma are occasionally determined. In this article, we would like to present recently achieved results and their comparison with the measurement data formerly presented. The growth of the neutron emission of 239PuBe source, as well as discrepancies between the decay curves of relevant isotopes and the emission rate of 252Cf and 241AmBe will be presented.

Patient radiation exposure and influencing factors at interventional cardiology procedures

Introduction Interventional cardiology (IC) procedures result in substantial patient radiation doses due to prolonged fluoroscopy time and radiographic exposure. Purpose To calculate the radiation burden of patients undergoing various IC procedures and to study the contribution of various influencing factors such as doctor experience, angiography unit type and patient body habitus. Materials and methods We retrieved patient and procedural data from the Catheterization and Electrophysiology Laboratory of Athens Euroclinic for IC procedures performed during a prolonged period (1998–2015), specifically: type of IC procedure, type of angiography unit, identity of primary interventional cardiologist, patient sex, weight and height, total Kerma Air Product (KAP) and fluoroscopy time. Patient radiation burden was assessed by effective dose which was calculated from KAP and procedure specific conversion factors. Results We considered 6960 hemodynamic procedures, 949 electrophysiology procedures, 908 device implantations and 20 transcatheter aortic valve replacements (TAVR). The mean effective doses were 7.6 ± 6.0 mSv for coronary angiography (including procedures with ventruculography, IVUS, OCT or FFR), 21.5 ± 18.6 mSv for angioplasty, 22.4 ± 16.5 mSv for coronary angiography plus angioplasty, 2.0 ± 3.3 mSv for electrophysiology studies, 13.3 ± 15.7 mSv for ablation procedures, 4.6 ± 9.8 mSv for pacemaker implantations, 11.1 ± 16.1 mSv.for defibrillator implantation and 25.6 ± 6.2 mSv for TAVR. Operator experience had a statistically significant impact on patient exposure since the total KAP of procedures performed by experienced operators was significantly lower and, additionally, procedural KAP of initially inexperienced operators reduced with time. The replacement of an angiography system with image intensifier to a modern system with a flat panel detector reduced procedural KAP. Patient body habitus significantly affected procedural KAP. Conclusion The radiation burden of IC procedures varies considerably and it is significantly affected by factors such as operator experience, angiography system type and patient body habitus.

Occupational doses of medical staff and their relation to patient exposure incurred in coronary angiography and intervention

Patient kerma–area product PKA, cumulative kerma in the air KIRP, fluoroscopic time t, personal dose equivalent (in terms of Hp(10), Hp(0.07) and Hp(3)) for most common interventional cardiology procedures were measured. PKA and KIRP measurements were used for patients and thermoluminescent dosimetry for the personnel. Dosemeters for personal doses measurements containing MCP-N (LiF: Mg, Cu, P) type thermoluminescence detectors (TLDs), were read out at the Institute of Nuclear Physics Polish Academy of Science (IFJ PAN) dosimetry service.The patient and personal doses were similar to those reported by other authors. The mean values of total kerma–area product (PKA) were 22.7 (7.3–50.9) Gy·cm2 for coronary angiography (CA) and 43.1 (3.2–86.4) Gy·cm2 for percutaneous coronary intervention (PCI). In general, doses received by the staff performing PCI procedures were found to be systematically higher than those after CA procedures, by some 30% or more. Within the medical team, operators always received the highest doses, followed by nurses and technicians. Maximum eye lens doses, skin doses and whole body doses were 165 μSv, 962 μSv and 30 μSv per procedure, respectively. Annual eye lens doses received by the operators, especially in PCI procedures, may well exceed the value of the recently recommended annual dose limit of 20 mSv and should be monitored.No meaningful correlation could be established between occupational doses and patient exposure, however some degree of correlation was observed between values of dose to the eye lens and whole body dose.

SU-E-T-554: Comparison of Electron Disequilibrium Factor in External Photon Beams for Different Models of Linear Accelerators

Purpose: The dose in the buildup region of a photon beam is usually determined by the transport of the primary secondary electrons and the contaminating electrons from accelerator head. This can be quantified by the electron disequilibrium factor, E, defined as the ratio between total dose and equilibrium dose (proportional to total kerma), E = 1 in regions beyond buildup region. Ecan be different among accelerators of different models and/or manufactures of the same machine. This study compares E in photon beams from different machine models/ Methods: Photon beam data such as fractional depth dose curve (FDD) and phantom scatter factors as a function of field size and phantom depth were measured for different Linac machines. E was extrapolated from these fractional depth dose data while taking into account inverse-square law. The ranges of secondary electron were chosen as 3 and 6 cm for 6 and 15 MV photon beams, respectively. The field sizes range from 2x2 to 40x40 cm2. Results: The comparison indicates the standard deviations of electron contamination among different machines are about 2.4 - 3.3% at 5 mm depth for 6 MV and 1.2 - 3.9% at 1 cm depth for 15 MV for the same field size. The corresponding maximum deviations are 3.0 - 4.6% and 2 - 4% for 6 and 15 MV, respectively. Both standard and maximum deviations are independent of field sizes in the buildup region for 6 MV photons, and slightly decreasing with increasing field size at depths up to 1 cm for 15 MV photons. Conclusion: The deviations of electron disequilibrium factor for all studied Linacs are less than 3% beyond the depth of 0.5 cm for the photon beams for the full range of field sizes (2-40 cm) so long as they are from the same manufacturer.

Model calculation of neutron kerma coefficient for n+ 56Fe below 20 MeV

Model calculations for the n+ 56Fe reaction have been performed by using extended UNF code, which is based on the unified Hauser–Feshbach and exciton model. Based on the excellent agreement with the experimental double-differential cross-sections of neutron, alpha and proton, the total kerma coefficients are derived naturally with the formula K Φ = ∑ i K Φ i = N ∑ ijk E ¯ ijk ( E n ) σ ijk ( E n ) ( Sun et al., 2008), which contains more comprehensive parameter information. The discrepancies of total kerma coefficients between the experimental data, evaluated data and the calculated results of this paper have been further analyzed, and one can have some confidence in predicting the kerma coefficients derived naturally by this model calculation.

The role of the 14N(n,p)14C reaction in neutron irradiation of soft tissues

Abstract The cell-killing potential of the 14N(n,p)14C reaction was considered with regard to neutron absorption in human nuclear DNA and respiratory phosphates for: (A) 1012 thermal neutrons in 1 kg of soft tissue, (B) a mono-energetic beam of 2 MeV neutrons incident in 1 kg of soft tissue such that the total collision kerma was 10 J/kg, and (C) an evenly distributed 0–66 MeV neutron beam, also incident in 1 kg such that the total collision kerma was 20 J/kg. For case (A) 0.0017 14N(n,p)14C reactions could be expected per DNA double strand, case (B) 0.053, and case (C) 0.0039. The probabilities that a proton emitted outside the nucleus would cross nuclear DNA were estimated from 14N tissue content for adult skeletal muscle, liver, and kidney tissues, for (1) nuclear DNA being concentrated in a sphere of 1.8 μm diameter, and (2) nuclear DNA being evenly distributed in a spherical nucleus 5 μm in diameter. It was concluded that even in a nitrogen-rich tissue exposed to a collision kerma of 20 J/kg by a 0–66 MeV fast neutron beam, the 14N(n,p)14C reaction directly kills at most 10 cells in every 1000, 4 of these by DNA nitrogen absorption and 6 by the 14N(n,p)14C protons emitted elsewhere in the cell. However, the dose due to the 14N(n,p)14C reaction should be measured where exposure to thermal neutron fluxes is significant. For therapeutic neutron doses the number of respiratory phosphate molecules in which the 14N(n,p)14C reaction occurs is insignificant, and doses from 14C-decay after neutron therapy are also negligible.

C/O Kerma coefficient ratio for 96 MeV neutrons deduced from microscopic measurements

Double-differential cross sections for neutron-induced light-ion production at 96 MeV have been measured for a variety of nuclei at The Svedberg Laboratory. Using the measured cross-section data, we deduce the Kerma coefficient from carbon and oxygen for p, d, t, He-3 and alpha particles. In order to get the total Kerma for C and O, we add GNASH calculation values where experimental data are not available and obtain a Kerma coefficient of 7.85 +/- 0.63 fGy m(2) for carbon and 7.09 +/- 0.57 fGy m(2) for oxygen. The C/O Kerma coefficient ratio then becomes 1.11 +/- 0.11. In addition we determine the Kerma ratio between ICRU muscle and A-150, again adding calculations with the GNASH code where no experimental data are available, and obtain a value of 0.98 +/- 0.05. While the Kerma coefficients for carbon and oxygen do not agree with the prediction in ICRU Report 63, the ratio values are in good agreement with existing predictions.

Theoretical calculation of kerma coefficients for n+16 O reaction below 30 MeV

On the basis of the light nuclear reaction model, a new kerma coefficient formula has been developed. In terms of the analysis for n+16 O reactions below 30 MeV, the average energies of all kinds of the emitted particles are presented. The calculated partial kerma coefficients agree well with the existing experimental data. The discrepancies of the total kerma coefficients between the calculation and the measurement are analyzed in detail.

New calculation method of neutron kerma coefficients for carbon and oxygen below 30 MeV

On the basis of the statistical theory of a neutron-induced light nucleus reaction, a new kerma coefficient calculation formula, expressed as ${k}_{\ensuremath{\Phi}}=N\ensuremath{\sum}_{\mathit{ijk}}{\overline{E}}_{\mathit{ijk}}({E}_{n}){\ensuremath{\sigma}}_{\mathit{ijk}}({E}_{n})$, is developed in this paper. In an analysis of the $n+{}^{12}\mathrm{C}$ and $n+{}^{16}\mathrm{O}$ reactions below 30 MeV, the average energies ${\overline{E}}_{\mathit{ijk}}$ of emitted particles of all kinds in the laboratory frame are derived in detail for different channels, allowing an exact energy balance. The optical model parameters of neutron and charged particles, which had reproduced very well the outgoing neutron double-differential cross sections in our early works, are used to obtain the cross sections ${\ensuremath{\sigma}}_{\mathit{ijk}}$. The calculated partial, elastic recoil, and total kerma coefficients for carbon and oxygen are consistent with existing experimental kerma coefficient data. The elastic cross sections and the first Legendre coefficients of elastic angular distribution derived from EBDF/B-VIIb3 are used in this paper to improve significantly the elastic recoil and total kerma coefficients.

Experimental kerma coefficients for carbon deduced from microscopic cross sections at 96 MeV incident neutron energy

The double-differential cross sections for (n, px), (n, dx), (n, tx), (n, 3Hex) and (n, αx) reactions in carbon have been measured at 96 MeV incident neutron energy. The various charged particles (inclusive spectra) were identified using ΔE–E techniques. From the experimental data, energy- and angle-differential as well as production cross sections were determined, and subsequently the partial and total kerma coefficients. The deduced partial and total kerma coefficients were compared to previous experimental results and theoretical calculations. The findings indicate that the deduced kerma coefficients for the hydrogen isotopes are in good agreement with those deduced from a previous measurement, and that the kerma coefficient values, in particular of the hydrogen isotopes, are systematically higher than values obtained from recent model calculations, which consequently resulted in a total kerma coefficient which is up to 30% higher than predicted by the calculations.

Cross Section Data and Kerma Coefficients at 95 MeV Neutrons for Medical Applications

Motivated by the need of data on neutron-induced reactions with biologically relevant materials, e.g., carbon and oxygen, we have constructed and installed the MEDLEY detector array at the neutron beam facility of the The Svedberg Laboratory in Uppsala. The central detection elements of MEDLEY are three-detector telescopes, consisting of two silicon detectors and a Csl crystal. To cover wide energy and angle ranges, we have mounted eight such telescopes at 20° intervals. We have used ΔE − ΔE − E techniques to obtain good particle identification for protons, deuterons, tritons, 3He and α particles over an energy range from a few MeV up to 100 MeV. To define the detector solid angle, plastic scintillators were employed to serve as active collimators.We have up to now measured double-differential cross sections of inclusive light-ion production induced by 95 MeV neutrons on carbon and oxygen. From these data production cross sections, as well as partial kerma coefficients, are being determined. We have found that especially the proton kerma coefficient for carbon is substantially larger than that of a recent evaluation, leading to a larger total kerma coefficient. The obtained data supports a trend observed for similar data at lower energies.

Secondary Light Charged Particle Emission from the Interaction of 25- to 65-MeV Neutrons on Silicon

Double-differential cross sections for the production of protons, deuterons, tritons, and alpha particles from a silicon target were determined using fast incident neutrons. The inclusive charged particle emission spectra were measured at six laboratory angles, 20, 40, 60, 70, 110, and 140 deg, over the neutron energy range of 25 to 65 MeV. Representative results are shown for the cross-section differentials in energy and angle as well as for angle-integrated cross sections. The spectra are compared to existing data and with predictions from nuclear model calculations. Since the data for 62.7-MeV incident neutrons are the most complete, we emphasized these results; from the experimental energy-differential cross sections, the total charged particle production cross sections are determined as well as the partial and total kerma coefficients for silicon. Moreover, a comparison is done with our data on aluminum, for which exists a consistent set of measured cross sections in the same neutron energy region.