Stages Of Treatment Planning Research Articles

Возможности сохранения репродуктивной функции у пациенток с атипической гиперплазией и начальным раком эндометрия

Due to the childbearing shift to the fourth decade of life, the probability of detecting endometrial cancer (EС) in female patients who did not have time to realize their reproductive life plan increases. If cancer is detected in female patients of reproductive age and they want to realize their fertility in the future, this option should be considered at the stage of treatment planning. Discussion concerning the admissibility and safety of conservative EC treatment is extremely relevant in the current demographic conditions. The article considers the decision-making algorithm on the conservative therapy indication in the cancer manifestation in a female patient of reproductive age with unrealized fertility, as well as the protocol when making such a decision. Data on the frequency of pregnancy in female patients after conservative treatment of EC are given. The accumulated experience showed that drug treatment of atypical hyperplasia and initial EC is effective, and upon condition of subsequent pregnancy does not aggravate the oncological prognosis. KEYWORDS: endometrial cancer, uterine cancer, atypical hyperplasia, pregnancy, assisted reproductive technologies, conservative therapy. FOR CITATION: Serova O.F., Dobrokhotova Yu.E., Borovkova E.I., Charkhifalakyan A.V. Possibilities of preserving reproductive function in female patients with atypical hyperplasia and endometrial cancer at an early stage. Russian Journal of Woman and Child Health. 2023;6(4):352–361 (in Russ.). DOI: 10.32364/2618-8430-2023-6-4-5.

Machine Learning Applications in Dentistry

Artificial Intelligence has emerged as a breakthrough in many fields including medicine and dentistry where new approaches can be employed to solve challenging decision making processes faced in the dental field. Artificial intelligence can be used as a decision support mechanism to solve the increasing population and consequently the increasing dental treatment needs. It also assists dentists in diagnosis and treatment planning stages that require expert opinion. This mini-review covers some of the recent studies in this area and envisions future directions on the use of machine learning in dental problems.

PO032 / #766 HYPER U-NET: COMBINING TISSUE AND STROKE SEGMENTATION USING HIERARCHICAL NETWORK FOR PERSONALIZED TRANS-CRANIAL DIRECT CURRENT STIMULATION: E-POSTER VIEWING

A segmentation of stroke is one of the significant stages of treatment planning. However, the tissue segmentation involving stroke lesion is very challenging due to the abnormalities appeared in both intensity and positions We propose the novel segmentation framework with hierarchical structure to identify brain tissues when stroke lesion exists for further usage with personalized trans-cranial direct current stimulation.

Torque change of anterior teeth based on CBCT using a universal table

Aim. The thickness of bone tissue in patients with pathological dental inclinations planning orthodontic treatment with fixed equipment.Materials and methods. The CBCT scans of patients with pathological dental inclinations was studied, bone tissue deficiency was described, a universal table was given that helps to calculate the necessary thickness of bone tissue at various levels of root length at the stage of treatment planning when the torc of the frontal teeth changes.Results. Bone tissue deficiency is described in two study groups, however, in patients with retrusion, the deficiency is most pronounced in the cervical third from the vestibular side, in the group with protrusion, the deficiency is described in the cervical third from the oral surface in the cervical third.Conclusions. The article describes a clinical case of orthodontic treatment using a universal table. The principle of operation of the universal table is shown, as well as its own clinical results proving the effectiveness of the universal table are described.

Uncertainties in the measurement of relative doses in radiotherapy

Abstract Both the measurement of the dose and the measurement of its distribution, like any other measurements, are subject to measurement uncertainties. These uncertainties affect all dose calculations and dose distributions in a patient’s body during treatment planning in radiotherapy. Measurement uncertainty is not a medical physicist’s error, but an inevitable element of their work. Planning the dose distribution in a patient’s body, we often try to reduce it in the volume of critical organs (OaR - Organ at Risk) or increase the minimum dose in the PTV region by a few percent. It is believed that the measurement uncertainty should be taken into account in these calculations at the stage of treatment planning. The paper presents the method of calculating the measurement uncertainty for different physical quantities in radiotherapy as percentage depth dose, profile function and output factor, due to the fact that these quantities have a particular impact on the calculated dose distributions in a patient’s body. The uncertainties that must be taken into account in planning treatment the planned dose per fraction and real in PTV, maybe different up to 4%.

Methodology of Defining of the Radiation Therapy Components for Various Methods of Patients’ Treating Using Medical Linear Accelerators and Gamma-Therapeutic Devices

One of the main factors affecting the effectiveness of radiation therapy is the constancy of the patient’s position on the treatment table created by immobilization devices of various designs and held throughout the entire irradiation procedure, which guarantees the accuracy of the delivery of the prescribed dose distribution. The purpose of the work was to establish the numerical values of the dominant components of a radiation therapy session for each of the irradiation techniques most commonly used in clinical practice of the radiation therapy.To determine the numerical values of the components of the radiation therapy session, the authors have measured each component for some clinical cases of patients’ irradiation placed. The patients had been diagnosed with the following malignant tumours: prostate cancer, breast cancer, lung cancer, head and neck tumours. More than 2000 individual measurements have been carried out with the help of such medical linear accelerators as "Clinac", "Unique", "Truebeam", and the gamma-therapeutic apparatus named "Theratron".The numerical values of the time spent on 3 groups of parameters of an irradiation session were established: the mechanical parameters of the radiation therapy equipment, the functional characteristics of the irradiation systems and the parameters that directly depend on the personnel involved in an irradiation procedure.According to the measurement results, the flow diagram for the procedures of verifying a patient’s position on the therapeutic table (2 different techniques), preceding their irradiation and the radiation therapy procedures themselves was proposed. It has been shown that a number of session components can run in parallel to each other thus optimizing the time spent by a patient in the treatment room.Using the obtained values of the time spent on the radiation session parameters it is possible to actualize the mathematical model that will allow the medical physicist to determine in advance the duration of the irradiation session at the stage of treatment planning and choose a radiation therapy technique taking into account the individual parameters of the irradiation session in each particular clinical case.

Тhe effect of cancer patients’ positioning accuracy during radiation therapy sessions using medical linear electron accelerators on the parameters of their individual 3D dose distribution

Due to the rapid development and further improvement of radiation treatment technologies oncologists have an opportunity to precisely deliver individual dose distributions to the tumor, minimizing the doses obtained by critical organs and healthy structures. For the correct and successful application of these complex methods of radiation therapy, it was necessary to enforce the requirements for the technical and dosimetric parameters of the radiotherapy equipment. The purpose of the research is to determine the magnitude of the possible error for patients’ positioning during their radiotherapy treatments using medical linear accelerators by modeling the impact of the patient’s body on the treatment couch. To determine the values of a possible error, the authors have considered the design and characteristics of a typical treatment couch, developed a model of the “average” patient’s body (phantom), which allowed changing the load to the treatment couch with a step of 1 kg. The position parameters of treatment couches were determined for the main types of localization of radiation therapy for malignant tumors: head and neck tumors, breast tumors and pelvic tumors. Numerical values of the treatment coach deviations from prescribed horizontal position were experimentally established for a load from 40 to 180 kg for a treatment couch used at the N.N. Alexandrov National Cancer Centre of Belarus. Based on the obtained experimental data, the necessity to correct the patient's treatment conditions at the stage of treatment planning were confirmed in order to ensure the delivery accuracy of individual dose distributions as required by the radiation therapy protocols. Authors stated that an analysis of the dependence of the deviations in the dose delivered to the patients on the deviation of the radiotherapy table from its horizontal position should be carried out for each radiotherapy table used in clinical practice. The development and implementation of a mechanism that will allow considering this information when choosing the parameters of the patient’s treatment session and prescribing the dose for any localization of malignant neoplasms is needed.

Evaluation of Airway Dimensions Following Mandibular Setback with Surgery-First Orthognathic Versus Conventional Orthognathic Approach.

To evaluate changes in airway dimensions following mandibular setback with conventional orthognathic approach (COA) and surgery-first orthognathic approach (SFOA). Treatment records of 20 patients who underwent mandibular setback with SFOA/COA were divided into two groups (COA and SFOA, ten patients in each group). Acoustic pharyngometry values were obtained at T0 (01week prior to surgery), T1 (01-month post-surgery) and T2 (01-year post-surgery). Percentage change in mean volume and area was obtained at T1 (T1-T0) to evaluate airway changes and at T2 (T2-T1) to compare relapse of airway changes in both groups. Changes in airway per mm setback at T1 (T1-T0) and T2 (T2-T1) were also obtained in both groups. For both parameters, SFOA showed greater reduction at T1 and greater relapse at T2 as compared to COA. The reduction in airway volume at T1 was 0.56mm/mm setback in COA compared to 1.06mm/mm setback in SFOA (P-value > 0.05). The relapse in airway volume at T2 was 0.15mm/mm setback in COA compared to 0.25mm/mm setback in SFOA (P-value > 0.05). The reduction in area at T1 was 0.062mm/mm setback in COA compared to 0.110mm/mm setback in SFOA (P-value > 0.05). The relapse in area at T2 was 0.016mm/mm setback in COA compared to 0.034/mm setback in SFOA (P-value < 0.05). In setback cases, SFOA has greater airway reduction immediate post-surgically and greater relapse at 01-year follow-up. Predicting these changes at diagnostic and treatment planning stage may prevent potential adverse events on airway.

Dose Response Relationship and Prognostic Factors of Nodal Control Rate of Metastatic Lymph Nodes in Cervical Cancer

In contrast to excellent local control in definitive aim radiation therapy (RT) of cervical cancer, control rate of metastatic lymph nodes remains insufficient. Therefore, radiation boost to metastatic lymph nodes has been attempted, but little is known about the optimal dose and prognostic factors of regional nodal control. In this study, we retrospectively investigated the dose response relationship of metastatic lymph nodes as well as prognostic factors of nodal control, and attempted to propose optimal dose for individual metastatic lymph nodes. We identified 90 patients (295 lymph nodes) who received definitive aim RT for node positive cervical cancer between 2013 and 2017. Total prescribed dose to each metastatic lymph node was converted to 2 Gy equivalent dose (EQD2, α/β = 10 Gy). Each node was tracked individually from initial diagnosis to any recurrence in the same specific node. Any tumor or treatment factors predictive of nodal control were searched. In addition, we attempted to stratify risk groups in order to find optimal dose for nodal control in a certain risk group. The median number of metastatic lymph nodes per patient was 2 (range, 1-14). Regarding total lymph nodes, the most common pathology was squamous cell carcinoma (85.6%) followed by adenocarcinoma (8.9%) and others (5.6%). The mean nodal volume at initial diagnosis was 5.0 ± 9.2 mL, and the mean total prescribed dose in EQD2 for each node was 55.0 ± 6.8 Gy. With median follow up of 25 months (range, 3-57 months), 32 nodal failures occurred, and 2-year nodal control rate was 89%. In multivariate analysis, neutrophil-to-lymphocyte ratio (NLR) higher than 3.0 (p<0.001), para-aortic nodes (vs. pelvic nodes, p=0.013), larger initial nodal volume (p<0.001) and lower total dose (HR 0.90 for increase of 1 Gy in EQD2; 95% CI 0.85-0.95; p<0.001) were identified as risk factors for poor nodal control. Each node was stratified into two risk groups; low risk group with none or one risk factor, and high risk group with two or three risk factors. For risk group analysis, initial nodal volume was dichotomized (≤ 5.3 mL or > 5.3 mL). ROC curve analysis showed that 53.1 Gy and 62.0 Gy was the optimal cut-off dose for predicting nodal control rate in low and high risk group, respectively. In low risk group, doses higher than 53.1 Gy showed significantly superior nodal control rate (p=0.050) with 2-year nodal control rate of 99% (vs. 93% for ≤ 53.1 Gy). In high risk group, doses equal to or higher than 62.0 Gy showed superior nodal control rate with marginal significance (p=0.053) with 2-year nodal control rate of 80% (vs. 62% for < 62.0 Gy). Our data demonstrated that nodal control depends on the prescribed dose to lymph node, NLR, location of lymph node, and initial nodal volume. Therefore, these factors should be considered to enhance nodal control at the stage of treatment plan.

Balancing Value Bracketing with the Integration of Moral Values in Psychotherapy: Evaluation of a Clinical Practice from the Perspective of Catholic Moral Theology.

Value bracketing is a clinical practice proposed by graduate-level mental health counseling educators to help therapists-in-training learn how to avoid imposing their private values on clients as well as how to manage value conflicts with clients that emerge during the course of therapy. With value bracketing during professional work, a therapist does not refer to his or her private values so as not to influence a client's decision-making process. When some academic writers describe this practice, however, they risk overemphasizing the distinction made between a therapist's private values and the professional values that regulate his or her clinical work. This overemphasis is especially apparent in the assertion that a therapist's religious morality must be entirely separated from the ethics of professional practice. In contrast with this viewpoint, I maintain that a Catholic therapist can both avoid imposing values on clients while at the same time balance value bracketing with the integration of religious morality into professional work. I approach this integration in two ways. First, I approach therapy from the perspective of the intellectual tradition from which value bracketing originates (the tradition of qualitative research involving phenomenological interviewing). From this perspective, I agree that bracketing is methodologically necessary during the stage of clinical interviewing but not necessarily during the stage of treatment planning (when both therapist and client consent to seek particular treatment goals). Second, I outline moral criteria derived from the Catholic intellectual tradition that can help therapists exercise practical wisdom when discerning their professional involvement in how clients will apply treatment outcomes outside of the therapy. Summary: The goal of the foregoing discussion has been to explore how therapists might balance the clinical practice of value bracketing with a supplemental practice of value integration. Ways were sought for Catholic therapists to adopt the practice of value bracketing without it requiring the professional affirmation (in thought, word, or deed) of client decisions and behaviors that contradict the therapist's private value system. An integration strategy to professional acculturation was explored where students and professionals seek to balance value bracketing with value integration. This balance is primarily to be located in the collaborative work of the therapist and the client when formulating a treatment plan together. At this stage of clinical work, a Catholic therapist consents to seek goals not only as a professional but also as a follower of Christ.

Patient satisfaction after rehabilitation with tooth-supported fixed partial dentures: A cross-sectional study

Introduction: Patients' perceptions of their oral health status are important outcomes in prosthodontics. There is an increasing realization that patient evaluation of the satisfaction with the worth of such treatment must be a consideration in any measure of overall prosthodontic success. Aims and Objectives: This study aimed to evaluate the patients' satisfaction after rehabilitation with fixed partial dentures (FPDs) considering esthetic and functional outcome as well as comfort and overall quality of life after treatment. Materials and Methods: Two hundred patients undergoing FPD treatment at the Department of Prosthodontics, VSPM Dental College and Research Centre, Nagpur, were selected to participate in the cross-sectional study using a patient satisfaction questionnaire after a week of insertion of the FPD prosthesis. Results: About 86.3% of the examined patients were satisfied with the fixed prosthesis, whereas 13.7% were not satisfied with their fixed prosthesis. Ninety-four percent of the patients were satisfied with the appearance of the prosthesis immediately after placement which increased to 98% after a week of cementing the prostheses. Regarding the functioning masticatory ability, 91% of the examined patients were satisfied with the fixed prosthesis. On evaluation of the patient satisfaction for cleansability and awareness of oral hygiene practices, 58% of patients were happy with the cleansability of the prosthesis, whereas 42% were unsatisfied with the cleaning of their prosthesis. Three percent of patients complained of bad taste and foul odor from the base of the prosthesis. Conclusion: Factors such as cleansability and comfort of the fixed prosthesis also play an important role along with appearance and masticatory ability while considering the patient satisfaction and success of prosthesis. Counseling the patients regarding unrealistic expectations should be taken care of right from the diagnosis and treatment planning stage to ensure high satisfaction level and overall success of the fixed prosthodontic treatment.

I207] Ion-based imaging and in-vivo range verification in ion beam therapy: Status and perspectives

Swift ions in matter exhibit favorable physical and biological properties, particularly owing to the ability of concentrating their energy deposition at a well-localized depth at their end of range, so-called Bragg peak. Compared to conventional external beam radiotherapy modalities, ion beams thus promise superior tumour-dose conformality and optimal sparing of surrounding critical organs and healthy tissue, with expected benefits for deep-seated, inoperable tumour sites as well as pediatric patients. Hence, interest in this emerging technology has rapidly increased worldwide in the last decade(s). To date, about 70 ion therapy facilities (of which ∼20 in Europe) are operational, predominantly with proton beams, and about the same amount is under construction or planning. Despite considerable recent technological advances, particularly regarding ion accelerators and scanning beam delivery systems, along with integration of in-room volumetric X-ray imaging, full clinical exploitation of the favorable ballistic properties of ion beams is still hampered by the yet unsolved problem of range uncertainties, preventing an exact localization of the Bragg peak (hence dose maximum) in tissue. Although these uncertainties can be mitigated by the introduction of cautious safety margins and careful choice of beam directions, new approaches are being extensively investigated to tackle this issue at the stage of treatment planning or treatment delivery. Here, emphasis will be given to unconventional imaging modalities exploiting energetic ion beams for refined assessment of the tissue stopping properties pre-treatment, as well as to online/post-treatment detection of acoustic and nuclear-based emissions induced by ion interaction in tissue for in vivo verification of the beam range. This contribution will critically review the main ongoing developments and initial pre-clinical or clinical experience, discussing the prospects of unconventional imaging modalities for eventually harnessing the ballistic selectivity of ion beam therapy in the clinical practice.

Influence of α2-adrenomimetics on incidence of choroidal effusion following laser trabeculoplasty in primary open angle glaucoma

To evaluate the influence of different topical hypotensive drugs on incidence of choroidal effusion (CE) following laser trabeculoplasty as the second stage of combined laser-surgical treatment plan in patients with primary open-angle glaucoma (POAG). The study included 60 patients with previously operated stage I and II POAG who has 'b-c' intraocular pressure (IOP) on maximum hypotensive therapy. Fistulizing subscleral removal of the outer wall of Schlemm's canal (a.k.a. subscleral sinusotomy) was the first stage of treatment plan. The second stage took place 14 days later in the form of laser trabeculoplasty. In order to reduce the risk of IOP spikes, all patients were prescribed specific hypotensive therapy 5 days prior to the procedure. The 1st group included 30 patients (30 eyes) who were asked to use Brimonidine-Purite (0.15%). The 2nd group included 30 patients (30 eyes) who used either nonselective β-blockers, or carbonic anhydrase inhibitors. IOP was measured on days 1, 5, 9, and 12 after stage 1, as well as after laser trabeculoplasty. Ophthalmic examination included ultrasound imaging and optical coherence tomography. After the combined laser-surgical treatment, the IOP reliably decreased in both groups. Choroidal effusion was observed in 7 cases in the 1st group and in 15 cases in the 2nd group. Change in IOP was less prominent in patients who had received instillations of α2-adrenomimetic (p<0.05). Patients who received Brimonidine-Purite 0.15% before laser trabeculoplasty had lower IOP drop than those on pre-surgical therapy with nonselective β-blockers or carbonic anhydrase inhibitors. Topical application of 0.15% Brimonidine-Purite 5 days prior to laser trabeculoplasty as the second stage of combined laser-surgical treatment resulted in statistically significant reduction of the incidence of postoperative choroidal effusion, likely due to α2-adrenomimetics inhibiting the secretory function of the ciliary Body to the lesser extent than drugs of other groups that were tested.

Evaluation of Predictability of Suitable Implant Lengths as related to Accurate Treatment Planning using Recent Roentgenographic Measures: A Key to Success

Selection of suitable length of dental implants is very subjective and largely depends on clinical evidences and operator's expertise. The present study was aimed to assess the role of cone beam computed tomography (CBCT) and cephalograms as far as the selection of right implant length is concerned. The study includes 220 patients for whom radiographic and follow-up records were obtained. There were 105 males and 115 females in the age range of 22 to 58 years. A total of 98 implant sites in different edentulous areas were studied. Length of implant was predicted at treatment planning and compared with finally placed implant at surgical stages. It also includes the in-depth exploration of (1) number of implants placed per patient, (2) implant per edentulous areas, (3) implant location, and (4) implant region. For prediction of implant lengths, CBCT results were obtained and compared with cephalometric findings. Accuracies of implant lengths as planned by CBCT and cephalometric images were also studied at treatment planning and surgical stages. Statistical analysis and results: Upon statistical comparisons, we found that larger implant lengths chosen at treatment planning stage did not change in 65.5% of patients. In addition, the smaller length implants were just about the same as that with larger dimensions. The CBCT results were satisfactory (up to 98.5%). Cephalometry was performed well in this prediction, especially in posterior mandible (87.9%). However, its performance in anterior maxillary region was not satisfactory (69.6%). Intergroup comparisons of CBCT and cephalometric results at different regions were significant (p < 0.001). Our study results show insignificant changes in the length of implants that was exactly planned using CBCT scans. Therefore, accurate prediction of implant lengths can be done using CBCT scans as they have superior and advanced tools that facilitate presurgical decision-making. Lateral cephalometric evaluation has been shown as an imperative radiographic tool for determining implant lengths as it confirmed the significance bone resorption on the selection of implant length at different sites. The CBCT and lateral cephalogram offer excellent anatomical details that can be judiciously applied for treatment planning and other clinical decision-making, including selection of correct implant length. Our study advocates thorough cephalometric evaluations of mandible wherein implants are to be placed for implant-supported overdentures.

The cumulative risk associated with demographic background characteristics among substance use treatment patients

Background: A significant amount of research has been conducted on the association between demographic background characteristics and substance use treatment outcomes among adults, but this body of work has not yet examined how multiple factors in combination magnify the risk for post-treatment substance use.Methods: The current study utilized a sample of 12,320 adults drawn from the Comprehensive Assessment and Treatment Outcome Research (CATOR) system to investigate how multiple demographic risk factors increase the likelihood of substance use after treatment.Results: A series of bivariate analyses and multivariate binary logistic regression results demonstrated a clear pattern of increased risk in the presence of a greater number of positive demographic risk factors. These demographic risk factors also amplified the risk of post-treatment substance use in the presence of additional clinical indicators of treatment prognosis.Conclusion: Select patient demographic background characteristics must be taken into consideration in the early treatment planning stages to improve long-term clinical outcomes.

Impact of target volume segmentation accuracy and variability on treatment planning for 4D-CT-based non-small cell lung cancer radiotherapy

Background. Accurate target volume segmentation is crucial for success in image-guided radiotherapy. However, variability in anatomical segmentation is one of the most significant contributors to uncertainty in radiotherapy treatment planning. This is especially true for lung cancer where target volumes are subject to varying magnitudes of respiratory motion.Material and methods. This study aims to analyze multiple observer target volume segmentations and subsequent intensity-modulated radiotherapy (IMRT) treatment plans defined by those segmentations against a reference standard for lung cancer patients imaged with four-dimensional computed tomography (4D-CT). Target volume segmentations of 10 patients were performed manually by six physicians, allowing for the calculation of ground truth estimate segmentations via the simultaneous truth and performance level estimation (STAPLE) algorithm. Segmentation variability was assessed in terms of distance- and volume-based metrics. Treatment plans defined by these segmentations were then subject to dosimetric evaluation consisting of both physical and radiobiological analysis of optimized 3D dose distributions.Results. Significant differences were noticed amongst observers in comparison to STAPLE segmentations and this variability directly extended into the treatment planning stages in the context of all dosimetric parameters used in this study. Mean primary tumor control probability (TCP) ranged from (22.6 ± 11.9)% to (33.7 ± 0.6)%, with standard deviation ranging from 0.5% to 11.9%. However, mean normal tissue complication probabilities (NTCP) based on treatment plans for each physician-derived target volume well as the NTCP derived from STAPLE-based treatment plans demonstrated no discernible trends and variability appeared to be patient-specific. This type of variability demonstrated the large-scale impact that target volume segmentation uncertainty can play in IMRT treatment planning.Conclusions. Significant target volume segmentation and dosimetric variability exists in IMRT treatment planning amongst experts in the presence of a reference standard for 4D-CT-based lung cancer radiotherapy. Future work is needed to mitigate this uncertainty and ensure highly accurate and effective radiotherapy for lung cancer patients.

Applications of imaging processing to MRgFUS treatment for fibroids: a review

Magnetic resonance guided focused ultrasound (MRgFUS) is an innovative technology that can treat many oncological diseases. Among these, uterine fibroids are well suited to be treated by focused ultrasound, because the treatment, unlike traditional surgical resection, is non-invasive and thus preserves the desired reproductive capacity of patients. There are some methodological issues in MRgFUS treatment that should be addressed. First, there is operator dependence; this is related to the use of manual approaches for the segmentation of regions of interest (ROIs) for treatment, both in the initial stages of treatment planning and in the post-treatment evaluation of the ablated area. From this scenario, we understand the need to integrate MRgFUS technology with methods for the automatic detection of the regions affected by the treatment. Temperature monitoring techniques, based on proton resonance shift (PRF), although not always able to provide correct measurements, are the most used in the treatments guided by magnetic resonance. The dependence on a reference image makes the thermal maps obtained through PRF subject to artefacts and, consequently, to temperature measurement errors. It is therefore crucial to develop new techniques, perhaps based on referenceless thermometry approaches, in order to avoid overheating in unwanted areas that could lead to patients suffering burns. Closely linked to the two above mentioned problems , there is the motion compensation that would improve the current method (this requires re-planning MRgFUS treatment in cases of patient movement) as well as temperature monitoring since it would overcome limitations related to a fixed baseline image, uncorrelated to the real patient position. This paper addresses these important issues, providing for each of them a high-level discussion able to give a brief overview. Specific technical details are provided about one of the approaches in the literature, in order to make the discussed problem more complete and easier to understand.

A Comparison of Incident Learning in the Academic and Community Radiation Oncology Setting

Purpose/Objective(s): Incident reporting systems are now frequently used in academic centers to identify errors that can occur in a radiation oncology setting. It is important to understand how the patterns of such events depend on environment of care. A comparison of incidents reported in an electronic Variance Reporting System (VRS) from both academic and community centers since 2011 was performed. Materials/Methods: A total of 1057 incidents were reported into the VRS from 3 different locations in a large hospital system, including both academic and community centers, from February 2011 to November 2013. All incidents were scored for severity using the previously validated French Nuclear Safety Authority (ASN) 5-point scoring system. These incidents were further categorized by error type into four groups: (1) human only, (2) human-software interface, (3) human-human interface, and (4) software/ hardware only. The incidents were also categorized by the reporter and by the origin of the incident. These groups were analyzed using descriptive statistical analysis including chi-squared tests. Results: A total of 955 incidents were reported from two academic centers and 102 incidents were reported from the community setting. 31 incidents, 28 at academic centers and 3 in the community setting, were considered to potentially have negative clinical consequences with a severity score of 2. There were no incidents that surpassed a severity score of 2. The majority of incidents (428 incidents, 44.8%) occurring in academic centers were due to human only error; in contrast the majority (46 incidents, 45.0%) of incidents reported in the community setting were due to human/software interface error (p Z 0.034). The majority of incidents that occurred at academic centers were reported by dosimetrists (43.5%). 463 (48%) incidents occurred in the treatment planning stages, 258 (27%) occurred in the imaging stage of treatment delivery and 76 (8%) occurred between treatment review and verification. The majority of incidents that occurred at community centers were reported by therapists (56.8%). Thirty-eight (37%) incidents occurred in the treatment planning stages, 20 (20%) occurred in the initial patient assessment and 12 (12%) occurred in the imaging stage for treatment delivery. Conclusions: The majority of incidents at academic centers were linked directly to human error and potentially related to hand-offs. In contrast, the majority of incidents in the community setting was due to errors with the human/software interface and might be due to lack of education or experience with software. This raises the question of whether process deviations may differ depending on the environment of care. Identifying such factors may lead to improved workflow design in an effort to reduce incidents. Author Disclosure: S. Moningi: None. K. Smith: None. E.C. Ford: None. T.L. DeWeese: None. S.A. Terezakis: None.

Development of a Structured Education and Evaluation Program to Standardize and Improve Target and Organ-at-Risk Contouring Ability Among Radiation Oncology Residents

Current methods employed in the training of radiation oncology residents generally do not utilize a standardized approach to teach or provide quantitative evaluation of the proper delineation of target volumes and organs-at-risk delineated during the treatment-planning stage of radiation therapy. As a consequence, inter-planner variability in the contouring of gross tumor volume (GTV), clinical target volume (CTV), and organs at risk (OAR) is a well-established deficiency of the current educational paradigm.

A novel approach for superficial intraoperative radiotherapy (IORT) using a 50 kV X‐ray source: a technical and case report

The use of IORT as a treatment modality for patients with close or positive margins has increased over the past decade. For situations where a flat area (up to 6 cm in diameter) has to be treated intraoperatively, new applicators for superficial treatment with a miniature X‐ray source (INTRABEAM system) were developed. Here we report our evaluation of the dosimetric characteristics of these new applicators and their first clinical use. Each of these flat and surface applicators consists of a radiation protective metal tube and a flattening filter, which converts the spherical dose distribution of the X‐ray source into a flat one. The homogeneity of each dose distribution and depth‐dose measurements were evaluated using film dosimetry in a solid water phantom and a soft X‐ray ionization chamber in a water tank. The first patient was treated with 5 Gy delivered in 5 mm using a 4 cm FLAT applicator over 21 minutes. The flat applicators show the maximum homogeneity, with a uniformity ratio of 1.02‐1.08 in certain depths. In 1 mm depth surface applicators show a uniformity ratio of 1.15‐1.28. They also show a higher dose rate and a steeper dose gradient compared to the flat applicators. The results of this investigation demonstrated that the flat and surface applicators have unique dosimetric characteristics that need to be considered during the treatment planning stages. This work also showed that it is possible to perform a superficial localized IORT which provides new application possibilities for use of the INTRABEAM system.PACS number: 87.55.ne