Partial amputation due to tongue bite in death-associated with eclampsia.

Eclampsia is one of the most dangerous complications of pregnancy and has a high incidence in developing countries. It is characterized by coma and the occurrence of generalized tonic-clonic seizures in pregnant women with hypertension. Deep bites on the tongue and other orofacial injuries have been described as consequences of these seizures. We present a case of death associated with eclampsia in which the bite during the seizure episode caused almost total amputation of an enlarged tongue (macroglossia). The medico-legal value of this finding and the situation due to antecedent pathological conditions and lack of routine screening in pregnant women who may migrate legally or illegally to give birth with better medical care are discussed.

A novel conservative technique to allow oral opening and overcome rigor mortis during medicolegal autopsy.

This study presents a novel conservative technique to increase oral opening and overcome rigor mortis during medicolegal autopsy (MLA). The method proposes a myotomy of the temporalis and masseter muscles, taking advantage of the incisions of the cranial opening procedures, to achieve a significant oral opening (≥ 30 mm) in fresh cadavers with established rigor mortis without altering facial aesthetics. The study was performed on 48 individuals aged between 18 and 66 years (20 males and 28 females) who were autopsied at the Instituto Nacional de Patología Forense Dr. Sergio Sarita Valdez (Santo Domingo, Dominican Republic). The proposed technique not only allowed the oral access to all autopsied cadavers but also complied with current ethical standards for preserving facial aesthetics, taking into account the concerns of family members by allowing respectful viewing of the cadaver. This advancement not only contributes to the efficiency of oral autopsies but also influences public perception of forensic procedures and highlights the importance of ethical and aesthetic considerations in the context of MLAs. The proposed technique represents a significant step towards more respectful and ethical forensic practices, and offers practical advantages for a more complete and accurate assessment during MLA.

Digital matching of palatal rugae patterns for forensic identification in edentulous denture wearers.

Identifying edentulous victims in forensic contexts poses a significant challenge. It has been reported that having a denture to reproduce and compare Palatal Rugae (PR) patterns is crucial for identifying edentulous individuals, yet there are no validated protocols for conducting this procedure. In this study, a new method was developed and validated for plaster molding of the internal surface of upper dentures, along with a protocol involving focus-stacked photographs and reference scales. Thirty-eight edentulous subjects participated in the study, obtaining plaster models of the patients (PM), and their dentures (AM) were standardized. The AM/PM model was highlighted and photographed with ten shots in different z-focuses for each model, using standard lighting and aligning the position of the PR perpendicular to the photographic axis using tubular spirit levels and modeling clay. The images were processed using the stacking technique and analyzed by three observers through the proposed protocol using Adobe® Photoshop®. The results were analyzed based on the intra-observer and inter-observer agreement levels, with a 95% confidence interval. This study demonstrated high-precision intra-observer and inter-observer agreement (k = 1) in the matching of Palatal Rugae (PR) and maxillary morphology obtained from participants and their dentures. The protocol is simple, cost-effective, and precise. It enables standardization of the technique for obtaining plaster models, and the exposure of PR and photographic protocol minimizes the presence of artifacts in the images, thereby reducing the likelihood of errors and promoting the reproducibility of both the recording technique and the comparison of the PR.

Integrating morphological, molecular and cytogenetic data for F2 sea turtle hybrids diagnosis revealed balanced chromosomal sets.

Hybridization could be considered part of the evolutionary history of many species. The hybridization among sea turtle species on the Brazilian coast is atypical and occurs where nesting areas and reproductive seasons overlap. Integrated analysis of morphology and genetics is still scarce, and there is no evidence of the parental chromosome set distribution in sea turtle interspecific hybrids. In this study, chromosome markers previously established for pure sea turtle species were combined with morphological and molecular analyses aiming to recognize genetic composition and chromosome sets in possible interspecific hybrids initially identified by mixed morphology. The data showed that one hybrid could be an F2 individual among Caretta caretta × Eretmochelys imbricata × Chelonia mydas, and another is resulting from backcross between C. caretta × Lepidochelys olivacea. Native alleles of different parental lineages were reported in the hybrids, and, despite this, it was verified that the hybrid chromosome sets were still balanced. Thus, how sea turtle hybridism can affect genetic features in the long term is a concern, as the implications of the crossing-over in hybrid chromosomal sets and the effects on genetic function are still unpredictable.

Undergraduate dental students and their potential role in disaster victim identification procedures: A scoping review under a Chilean perspective.

BACKGROUND: A mass fatality incident is an unexpected event that can cause the death of many people, which has motivated careful analysis and development of appropriate strategies for planning and response with all available resources. As these events involve multiple victims, their identities must be confirmed using the highest possible quality standards. Forensic Odontology (FO) has proven to be a scientific resource for disaster victim identification (DVI) procedures; however, it is highly dependent on the proper management not only of material resources but also of human resources. Chile is a country recognised as prone to natural disasters, but an insufficient number of forensic odontologists has been reported. The aim of the study was to review the literature on a dental undergraduate (UG) student's potential value in a DVI process. METHODOLOGY: A scoping review was performed using a specific search strategy in PubMed/Medline, Web of Science, Scopus, SciELO and EBSCO databases. RESULTS: The search identified 27 articles in which the basic dental degree, the necessary training and the need for human resources are variables considered in different priorities by those articles. DISCUSSION: It is vital to assess the local needs of Chile based on its UGs, considering that FO is an underestimated resource that should be included early on in dental curriculums. Furthermore, it should align with public policies to ensure viability and inclusion in standardised protocols. CONCLUSION: Although there is "potential" usage of UG dental students in DVI is not ideal, circumstances will dictate their use. The better trained they are as students, the more valuable their "potential" contribution will be.

Forensic odontology and dental age estimation research: a scoping review a decade after the NAS report on strengthening forensic science.

Dental age estimation (DAE) is one of the most reliable and useful scientific methods employed by forensic odontology (FO) for human identification. In 2009, the US National Academy of Sciences (NAS) report highlighted the need to deepen research in many disciplines, among which FO received strong criticism for specific expertise. The aim of this review is to provide a comprehensive overview in order to systematically map the latest original research done in FO, as well as identify DAE within this field. A systematic search was performed from 2014 to 2019. In total, 644 studies were identified for qualitative analysis: DAE was the most studied topic (41.30%). Asia was the most productive continent with 58.27% of the global production on DAE; India was the most productive Asian country, with 32.33% and 55.48% of global and Asian production, respectively. The University of Macerata (Italy), KU Leuven (Belgium), University of Split (Croatia), and University of São Paulo (Brazil) led DAE research. Authors from leading countries on DAE research demonstrated great individual productivity, which is evidence of their scientific efforts, but also possible risks if the continuity of this line of research depends on them. Although FO has significantly focused its research on DAE, the absence of publications on controversial topics but necessary for research according to the NAS report shows the possible lack of interest of authors or journals to address them.

Histological changes in lingual striated muscle tissue of human cadavers to estimate the postmortem interval.

Although there are physiological methods to determine the postmortem interval (PMI), interval forensic histopathology can be applied to obtain accuracy. The aim was to describe the histological changes in human lingual striated musculature at different PMI. Seven groups were formed according to increasing PMI of 6, 12, 24, 48, 72, 96 and 120 h postmortem (PM). Each group was made up of 16 samples of tongues from each cadaver. The samples were fixed in buffered formaldehyde at 10% and processed for embedding in paraplast. Section 5 µm thick were cut and dyed with H&E for analysis. The study was approved by the Bioethics Committee of the Universidad San Francisco de Quito, Ecuador. The histological changes in the striated muscle cells of the tongue were associated with the different PMI. From 6 to 24 h PM, there were initial changes in the cellular and nuclear morphology. At 48 h PM, at least 50% of the samples presented poorly conserved and reduced muscle striations. At 72 h PM, 100% of the cases presented myofibers with altered morphology, cytoplasmic vacuoles (93.75%), edema (68.55%) and pyknosis (93.75%). At 96 and 120 h PM, the myofibers presented pyknotic nuclei, and they were absent in the rest. The changes in the histology of the human lingual striated muscle make it possible to estimate the PMI, either in the early phase (0-72 h) or the late phase (92-120 h). However, further research is needed to verify, refine and expand on these results.

Cameriere's open apices methodology for dental age estimation in children: a scoping review from a Latin American perspective.

Dental age estimation (DAE) is key to establishing an individual's identity, and this is relevant in minors. A widely used method for DAE in children is Cameriere's open apices (CAM). Despite its wide dissemination, there are no clear reports of its use in Latin American populations. A scoping review was conducted using a search strategy in the PubMed/MEDLINE database, Web of Science, and a complementary manual search. Only papers using CAM or its regression equation models for evaluating Latin American populations were included. Ten studies published between 2007 and 2020 responded to the search objective. Brazil was the country with the most studies using CAM (7/10), and the University of Macerata (Italy) was the most declared affiliation (6/10). Seven studies used the original CAM formula in populations from Brazil and Peru, while the European formula (EuCAM) was applied in Mexico, Colombia, and Brazil. Although the method underestimated the age values with acceptable error margins, the correction factor substantially improved the predictive power of the method. Some limitations of the method are highlighted. CAM and its variants can be useful for validation in Latin American settings, but attention to population structures and terminologies is suggested for future research.

Age estimation by evaluation of obliteration of the palatine sutures: a scoping review.

The age estimation (AE) of human remains is a challenging task since it is dependent on the state in which these remains are found. Since the macroscopic evaluation of palatal sutures has been proposed as a method for AE, the aim of this study was to review the literature on this method, considering that the cases of edentulous elderly are among the greatest challenges in anthropological and forensic contexts. A scoping review was performed using a specific search strategy in PubMed, Web of Science, SciELO, LILACS, and Google Scholar. The search identified 13 articles, among which the USA yielded the most information with 3 articles. Only 1 study was identified in Latin America (Peru). There was great diversity regarding the origin of samples, and the studies were carried out on both historical and modern populations. Only 6 articles exceeded the average sample size (168.08) and 4 articles studied samples of fewer than 100 individuals. Although 6 different methods were identified, Mann et al.'s revised method was the most used. The selection of appropriate methods for AE depends on what skeletal elements are present and the general age of the specimens. Although evaluation of the obliteration of the palatal sutures has been found to be simple and promising for AE in individuals over 60 years of age, this method has been reported to have less precision than other more complex methods, which makes the use of a combination of methods necessary to increase the level of confidence and the percentage of success. Further research could resolve this weakness, and methodological refinement (perhaps the digitization and automation of processes, or the application of Bayesian methodology) could provide the necessary solidity to comply with international standards in the forensic scenario.

Behavior of 4 types of paper with printed QR codes for evaluating denture marking in conditions of extreme heat.

STATEMENT OF PROBLEM: Quick response (QR) codes are a fast and efficient technology for linking and accessing identifying information, and their use has been proposed in forensics. The heat resistance and esthetics of denture marking methods (DMMs) have been recommended by the American Dental Association (ADA), but studies on these aspects of printed QR codes are lacking. PURPOSE: The purpose of this study was to determine the optimal printed material with QR codes for implementation as a DMM adjusted to the recommendations of the ADA. MATERIAL AND METHODS: The behavior of 4 types of paper, bond paper, fiberglass filter paper, ultralong hydroxyapatite nanowire paper, and polyolefin and silica paper with printed QR codes was analyzed. They were exposed to temperatures between 100 °C and 1000 °C in a heat muffle for 1 hour. Each specimen was subjected to both a morphological and a thermogravimetric analysis (TGA) and scanned by using 3 different smartphones. RESULTS: The scans were positive for bond paper (33.3%), fiberglass fiber paper (50%), ultralong hydroxyapatite nanowire paper (100%), and polyolefin and silica paper (70.4%). The TGA revealed continuous decomposition curves (average 16.5 minutes at 624 °C). CONCLUSIONS: Printed QR codes on ultralong hydroxyapatite nanowire paper appear to be suitable as information reservoirs, even surviving incineration, and may be implemented as a DMM conforming to the ADA recommendations.

Dental age estimation based on pulp chamber/crown volume ratio measured on CBCT images in a Spanish population.

Dental age estimation in living individuals is one of the most frequent requests undertaken by forensic odontologists. The aim of this study was to estimate the dental age by pulp/tooth volume ratio, as measured on cone beam computed tomography (CBCT) images, in a Spanish population. This study included 313 teeth from 107 adult individuals, 56 females and 51 males with a mean age of 44 ± 14 years. The statistical analysis of the results took account of clustering (multiple teeth in individuals). Linear regression models were constructed on the relationship between pulp/tooth volume ratio and chronological age for each tooth type. The highest coefficient of determination (R2) value was provided by the upper incisors (36.6%), and the difference between chronological and estimated age was less than 5 years in 31.3% of the sample and less than 10 years for 65.7%. CBCT is an accurate imaging technique to measure dental volume with a relatively low radiation dose, and it can be used to assess dental age in living adult individuals. Volumetric changes in the pulp cavity with increasing age proved valuable to estimate dental age in this Spanish population.

Quality control of fresh strawberries by a random forest model.

BACKGROUND: Strawberry quality is one of the most important factors that guarantees consistent commercialization of the fruit and ensures the consumer's satisfaction. This work makes innovative use of random forest (RF) to predict sensory measures of strawberries using physical and physical-chemical variables. Furthermore, it also employs these same physical and physical-chemical variables to classify strawberries in the classes "satisfied" or "not satisfied" and "would pay more" or "wouldn't pay more. The RF-based model predicts the acceptance, expectation, ideal of sweetness, ideal of acidity, and the ideal of succulence based on the physical and physical-chemical data. Then, the predicted parameters are used as input for the RF-based classification model. RESULTS: The RF achieved a coefficient of determination R2 > 0.72 and a root-mean-squared error (RMSE) smaller than 0.17 for the prediction task, which indicates that one can estimate the sensory measures of strawberries using physical and physical-chemical data. Furthermore, the RF was able to classify 87.95% of the strawberry samples correctly into the classes 'satisfied' and 'not satisfied' and 78.99% in the classes 'would pay more' or 'would not pay more'. A two-step RF model, which employed both physical and physical-chemical data to classify strawberry samples regarding the consumer's response also correctly classified 100% and 90.32% of the samples with respect to consumers' satisfaction and their willingness to pay more, respectively. CONCLUSION: The results indicate that the developed models can be used in the quality control of strawberries, supporting the establishment of quality standards that consider the consumer's response. The proposed methodology can be extended to control the sensory quality of other fruits. © 2021 Society of Chemical Industry.

Importance of physical detraining in functional capacity of individuals with chronic peripheral arterial occlusive disease: a cross-sectional pilot study.

BACKGROUND: Physical training is a well-established strategy for rehabilitation of the functional capacity of individuals with chronic peripheral arterial occlusive disease (PAOD). However, some individuals quit training after participating in a physical training program, undergoing detraining. There is scant literature on the effects of physical detraining in individuals with PAOD and it is therefore important to investigate the effects of this phenomenon. OBJECTIVES: The objective of this article was to evaluate the effects of physical detraining on functional capacity in individuals with PAOD. METHODS: Cross-sectional study with 22 individuals. Participants were divided into two groups: a detraining group (DG) and a control group (CG). The distance covered in the 6-minute walk test (6MWTD) and the pain-free walking distance (PFWD) were evaluated. The PFWD is the distance covered until claudication begins, i.e., the distance covered without pain. RESULTS: Mean age was 66 ± 8 in the DG and 67 ± 7 in the CG. There were no differences between the groups in either the 6MWTD or the PFWD (p = 0.428; p = 0.537, respectively). CONCLUSIONS: The present pilot study allows us to conclude that the functional capacity of individuals with PAOD who participated in a physical training program and subsequently underwent detraining was not superior in relation to individuals who did not participate in a physical training program. The results of the present study serve to encourage maintenance of physical exercise, since physical training is no longer effective if detraining occurs.

Evaluation of a cone-beam computed tomography system calibrated for accurate radiotherapy dose calculation.

Background and purpose: Dose calculation on cone-beam computed tomography (CBCT) images has been less accurate than on computed tomography (CT) images due to lower image quality and discrepancies in CT numbers for CBCT. As increasing interest arises in offline and online re-planning, dose calculation accuracy was evaluated for a novel CBCT imager integrated into a ring gantry treatment machine. Materials and methods: The new CBCT system allowed fast image acquisition (5.9 s) by using new hardware, including a large-size flat panel detector, and incorporated image-processing algorithms with iterative reconstruction techniques, leading to accurate CT numbers allowing dose calculation. In this study, CBCT- and CT-based dose calculations were compared based on three anthropomorphic phantoms, after CBCT-to-mass-density calibration was performed. Six plans were created on the CT scans covering various target locations and complexities, followed by CBCT to CT registrations, copying of contours, and re-calculation of the plans on the CBCT scans. Dose-volume histogram metrics for target volumes and organs-at-risk (OARs) were evaluated, and global gamma analyses were performed. Results: Target coverage differences were consistently below 1.2 %, demonstrating the agreement between CT and re-calculated CBCT dose distributions. Differences in Dmean for OARs were below 0.5 Gy for all plans, except for three OARs, which were below 0.8 Gy (<1.1 %). All plans had a 3 %/1mm gamma pass rate > 97 %. Conclusions: This study demonstrated comparable results between dose calculations performed on CBCT and CT acquisitions. The new CBCT system with enhanced image quality and CT number accuracy opens possibilities for off-line and on-line re-planning.

Time-resolved clinical dose volume metrics, calculations and predictions based on source tracking measurements and uncertainties to aid treatment verification and error detection for HDR brachytherapy-a proof-of-principle study.

Objective.High-dose-rate (HDR) brachytherapy lacks routinely available treatment verification methods. Real-time tracking of the radiation source during HDR brachytherapy can enhance treatment verification capabilities. Recent developments in source tracking allow for measurement of dwell times and source positions with high accuracy. However, more clinically relevant information, such as dose discrepancies, is still needed. To address this, a real-time dose calculation implementation was developed to provide more relevant information from source tracking data. A proof-of-principle of the developed tool was shown using source tracking data obtained from a 3D-printed anthropomorphic phantom.Approach.Software was developed to calculate dose-volume-histograms (DVH) and clinical dose metrics from experimental HDR prostate treatment source tracking data, measured in a realistic pelvic phantom. Uncertainty estimation was performed using repeat measurements to assess the inherent dose measuring uncertainty of thein vivodosimetry (IVD) system. Using a novel approach, the measurement uncertainty can be incorporated in the dose calculation, and used for evaluation of cumulative dose and clinical dose-volume metrics after every dwell position, enabling real-time treatment verification.Main results.The dose calculated from source tracking measurements aligned with the generated uncertainty bands, validating the approach. Simulated shifts of 3 mm in 5/17 needles in a single plan caused DVH deviations beyond the uncertainty bands, indicating errors occurred during treatment. Clinical dose-volume metrics could be monitored in a time-resolved approach, enabling early detection of treatment plan deviations and prediction of their impact on the final dose that will be delivered in real-time.Significance.Integrating dose calculation with source tracking enhances the clinical relevance of IVD methods. Phantom measurements show that the developed tool aids in tracking treatment progress, detecting errors in real-time and post-treatment evaluation. In addition, it could be used to define patient-specific action limits and error thresholds, while taking the uncertainty of the measurement system into consideration.

Image quality evaluation of a new high-performance ring-gantry cone-beam computed tomography imager.

Objective. Newer cone-beam computed tomography (CBCT) imaging systems offer reconstruction algorithms including metal artifact reduction (MAR) and extended field-of-view (eFoV) techniques to improve image quality. In this study a new CBCT imager, the new Varian HyperSight CBCT, is compared to fan-beam CT and two CBCT imagers installed in a ring-gantry and C-arm linear accelerator, respectively.Approach. The image quality was assessed for HyperSight CBCT which uses new hardware, including a large-size flat panel detector, and improved image reconstruction algorithms. The decrease of metal artifacts was quantified (structural similarity index measure (SSIM) and root-mean-squared error (RMSE)) when applying MAR reconstruction and iterative reconstruction for a dental and spine region using a head-and-neck phantom. The geometry and CT number accuracy of the eFoV reconstruction was evaluated outside the standard field-of-view (sFoV) on a large 3D-printed chest phantom. Phantom size dependency of CT numbers was evaluated on three cylindrical phantoms of increasing diameter. Signal-to-noise and contrast-to-noise were quantified on an abdominal phantom.Main results. In phantoms with streak artifacts, MAR showed comparable results for HyperSight CBCT and CT, with MAR increasing the SSIM (0.97-0.99) and decreasing the RMSE (62-55 HU) compared to iterative reconstruction without MAR. In addition, HyperSight CBCT showed better geometrical accuracy in the eFoV than CT (Jaccard Conformity Index increase of 0.02-0.03). However, the CT number accuracy outside the sFoV was lower than for CT. The maximum CT number variation between different phantom sizes was lower for the HyperSight CBCT imager (∼100 HU) compared to the two other CBCT imagers (∼200 HU), but not fully comparable to CT (∼50 HU).Significance. This study demonstrated the imaging performance of the new HyperSight CBCT imager and the potential of applying this CBCT system in more advanced scenarios by comparing the quality against fan-beam CT.

Forensic odontology: Wrong convictions, "bad apples" and "the innocence files".

Forensic odontology (FO) provides expert testimony; however, new criticism has identified FO as one of the fields that must strengthen its scientific foundations. The recent Netflix documentary titled "The Innocence Files", featuring wrongful convictions, dedicates three of its nine episodes almost exclusively to bite mark identification (BMI), one of the most questioned tests performed by FO. Although most of the FO fields have an undoubted utility in forensic and juridical context, only BMI has been questioned in recent years; the derogatory expression "Junk science" is used continuously in the documentary almost as a synonym for FO. We present a scoping review of cases reported in the US National Registry of Exonerations in which FO was false or misleading forensic evidence (F/MFE) leading to wrongful convictions. Although in the 26 cases identified the only declared F/MFE was the BMI (excluding any other type of dental expertise), only in 2 cases (7.69%) was F/MFE the sole contributing factor, and in 4 cases (15.38%) there was F/MFE plus three additional factors. Official misconduct was detected in 19 cases (73.08%) and perjury or false accusation in 16 cases (61.54%). It has already been mentioned how dangerous it is to consider FO as synonymous with "bite mark identification", or even to publicly provide incorrect or decontextualized information. This review shows that erroneous convictions have been exclusively in the field of BMI, and that FO encompasses much more than just BMI. The relationship between the media and forensic sciences has been strained. The perspective of the new culture of risk management in forensics is also discussed.

Dual-energy CT evaluation of 3D printed materials for radiotherapy applications.

Objective. There is a continuous increase in 3D printing applications in several fields including medical imaging and radiotherapy. Although there are numerous advantages of using 3D printing for the development of customized phantoms, bolus, quality assurance devices and other clinical applications, material properties are not well known and printer settings can affect considerably the properties (e.g. density, isotropy and homogeneity) of the printed parts. This study aims to evaluate several materials and printer properties to identify a range of tissue-mimicking materials.Approach. Dual-energy CT was used to obtain the effective atomic number (Zeff) and relative electron density (RED) for thirty-one different materials including different colours of the same filament from the same manufacturer and the same type of filament from different manufacturers. In addition, a custom bone equivalent filament was developed and evaluated since a high-density filament with a composition similar to bone is not commercially available. Printing settings such as infill density, infill pattern, layer height and nozzle size were also evaluated.Main results. Large differences were observed for HU (288), RED (>10%) andZeff(>50%) for different colours of the same filament due to the colour pigment. Results show a wide HU variation (-714 to 1104), RED (0.277 to 1.480) andZeff(5.22 to 12.39) between the printed samples with some materials being comparable to commercial tissue-mimicking materials and good substitutes to a range of materials from lung to bone. Printer settings can result in directional dependency and significantly affect the homogeneity of the samples.Significance. The use of DECT to extract RED, andZeffallows for quantitative imaging and dosimetry using 3D printed materials equivalent to certified tissue-mimicking tissues.

Treatment verification in high dose rate brachytherapy using a realistic 3D printed head phantom and an imaging panel.

PURPOSE: Even though High Dose Rate (HDR) brachytherapy has good treatment outcomes in different treatment sites, treatment verification is far from widely implemented because of a lack of easily available solutions. Previously it has been shown that an imaging panel (IP) near the patient can be used to determine treatment parameters such as the dwell time and source positions in a single material pelvic phantom. In this study we will use a heterogeneous head phantom to test this IP approach, and simulate common treatment errors to assess the sensitivity and specificity of the error-detecting capabilities of the IP. METHODS AND MATERIALS: A heterogeneous head-phantom consisting of soft tissue and bone equivalent materials was 3D-printed to simulate a base of tongue treatment. An High Dose Rate treatment plan with 3 different catheters was used to simulate a treatment delivery, using dwell times ranging from 0.3 s to 4 s and inter-dwell distances of 2 mm. The IP was used to measure dwell times, positions and detect simulated errors. Measured dwell times and positions were used to calculate the delivered dose. RESULTS: Dwell times could be determined within 0.1 s. Source positions were measured with submillimeter accuracy in the plane of the IP, and average distance accuracy of 1.7 mm in three dimensions. All simulated treatment errors (catheter swap, catheter shift, afterloader errors) were detected. Dose calculations show slightly different distributions with the measured dwell positions and dwell times (gamma pass rate for 1 mm/1% of 96.5%). CONCLUSIONS: Using an IP, it was possible to verify the treatment in a realistic heterogeneous phantom and detect certain treatment errors.

A MC-based anthropomorphic test case for commissioning model-based dose calculation in interstitial breast 192-Ir HDR brachytherapy.

PURPOSE: To provide the first clinical test case for commissioning of 192 Ir brachytherapy model-based dose calculation algorithms (MBDCAs) according to the AAPM TG-186 report workflow. ACQUISITION AND VALIDATION METHODS: A computational patient phantom model was generated from a clinical multi-catheter 192 Ir HDR breast brachytherapy case. Regions of interest (ROIs) were contoured and digitized on the patient CT images and the model was written to a series of DICOM CT images using MATLAB. The model was imported into two commercial treatment planning systems (TPSs) currently incorporating an MBDCA. Identical treatment plans were prepared using a generic 192 Ir HDR source and the TG-43-based algorithm of each TPS. This was followed by dose to medium in medium calculations using the MBDCA option of each TPS. Monte Carlo (MC) simulation was performed in the model using three different codes and information parsed from the treatment plan exported in DICOM radiation therapy (RT) format. Results were found to agree within statistical uncertainty and the dataset with the lowest uncertainty was assigned as the reference MC dose distribution. DATA FORMAT AND USAGE NOTES: The dataset is available online at http://irochouston.mdanderson.org/rpc/BrachySeeds/BrachySeeds/index.html,https://doi.org/10.52519/00005. Files include the treatment plan for each TPS in DICOM RT format, reference MC dose data in RT Dose format, as well as a guide for database users and all files necessary to repeat the MC simulations. POTENTIAL APPLICATIONS: The dataset facilitates the commissioning of brachytherapy MBDCAs using TPS embedded tools and establishes a methodology for the development of future clinical test cases. It is also useful to non-MBDCA adopters for intercomparing MBDCAs and exploring their benefits and limitations, as well as to brachytherapy researchers in need of a dosimetric and/or a DICOM RT information parsing benchmark. Limitations include specificity in terms of radionuclide, source model, clinical scenario, and MBDCA version used for its preparation.