Sonja Adebahr

Impact of 4D-18FDG-PET/CT imaging on target volume delineation in SBRT patients with central versus peripheral lung tumors. Multi-reader comparative study

PURPOSE Evaluation of the effect of co-registered 4D-(18)FDG-PET/CT for SBRT target delineation in patients with central versus peripheral lung tumors. METHODS Analysis of internal target volume (ITV) delineation of central and peripheral lung lesions in 21 SBRT-patients. Manual delineation was performed by 4 observers in 2 contouring phases: on respiratory gated 4DCT with diagnostic 3DPET available aside (CT-ITV) and on co-registered 4DPET/CT (PET/CT-ITV). Comparative analysis of volumes and inter-reader agreement. RESULTS 11 cases of peripheral and 10 central lesions were evaluated. In peripheral lesions, average CT-ITV was 6.2 cm(3) and PET/CT-ITV 8.6 cm(3), resembling a mean change in hypothetical radius of 2 mm. For both CT-ITVs and PET/CT-ITVs inter reader agreement was good and unchanged (0.733 and 0.716; p=0.58). All PET/CT-ITVs stayed within the PTVs derived from CT-ITVs. In central lesions, average CT-ITVs were 42.1 cm(3), PET/CT-ITVs 44.2 cm(3), without significant overall volume changes. Inter-reader agreement improved significantly (0.665 and 0.750; p<0.05). 2/10 PET/CT-ITVs exceeded the PTVs derived from CT-ITVs by >1 ml in average for all observers. CONCLUSION The addition of co-registered 4DPET data to 4DCT based target volume delineation for SBRT of centrally located lung tumors increases the inter-observer agreement and may help to avoid geographic misses.

User Interaction in Semi-Automatic Segmentation of Organs at Risk: a Case Study in Radiotherapy

Accurate segmentation of organs at risk is an important step in radiotherapy planning. Manual segmentation being a tedious procedure and prone to inter- and intra-observer variability, there is a growing interest in automated segmentation methods. However, automatic methods frequently fail to provide satisfactory result, and post-processing corrections are often needed. Semi-automatic segmentation methods are designed to overcome these problems by combining physicians’ expertise and computers’ potential. This study evaluates two semi-automatic segmentation methods with different types of user interactions, named the “strokes” and the “contour”, to provide insights into the role and impact of human-computer interaction. Two physicians participated in the experiment. In total, 42 case studies were carried out on five different types of organs at risk. For each case study, both the human-computer interaction process and quality of the segmentation results were measured subjectively and objectively. Furthermore, different measures of the process and the results were correlated. A total of 36 quantifiable and ten non-quantifiable correlations were identified for each type of interaction. Among those pairs of measures, 20 of the contour method and 22 of the strokes method were strongly or moderately correlated, either directly or inversely. Based on those correlated measures, it is concluded that: (1) in the design of semi-automatic segmentation methods, user interactions need to be less cognitively challenging; (2) based on the observed workflows and preferences of physicians, there is a need for flexibility in the interface design; (3) the correlated measures provide insights that can be used in improving user interaction design.

Erfassung möglicher Verbesserungen im Ablauf der Strahlentherapie — eine Patientenbefragung

ZusammenfassungEinleitung und HintergrundIm Rahmen der Qualitätssicherung werden an den Ablauf einer Strahlentherapie zunehmend größere Anforderungen gestellt. Die direkt betroffenen Patienten bemerken in der täglichen Therapie jedoch viele Maßnahmen der Qualitätskontrolle, z. B. zusätzliche Sicherheitschecks, nicht. Durch eine gezielte Befragung der Patienten sollten Verbesserungsmöglichkeiten des Behandlungsablaufs aus deren Perspektive identifiziert werden.Patienten und MethodenMittels eines neu entwickelten Fragebogens wurden in einem definierten Erhebungszeitraum von 1 Monat insgesamt 624 Strahlentherapiepatienten (Rücklauf: n = 600, 96,2 %) über verschiedene Aspekte des Therapieablaufs befragt. Weiterhin wurden bei der befragten Stichprobe Auskünfte über ihre spezifischen Bedürfnisse sowie Vorschläge zu konkreten Verbesserungsmöglichkeiten im Kontext einer strahlentherapeutischen Behandlung erhoben.ErgebnisseInsgesamt waren die Patienten mit den Therapieabläufen zufrieden. So gab es z. B. zu der Aussage „Mein erster Kontakt zur Klinik für Strahlenheilkunde verlief so, dass mir sowohl mit Freundlichkeit als auch mit Kompetenz das Gefühl gegeben wurde: Hier werde ich gut betreut“ über 90 % Zustimmung. Bezüglich des Organisationsablaufs legte eine große Mehrheit der Patienten Wert auf einen festgelegten Bestrahlungstermin. Kritikpunkte waren Wartezeiten wegen Wartung oder Ausfall der Bestrahlungsgeräte. Kleinere bzw. kostengünstigere Verbesserungen wie Musik im Bestrahlungsraum sahen die Patienten insgesamt als genauso wichtig an wie teure bauliche Maßnahmen, beispielsweise Tageslicht im Bestrahlungsraum. Positiv hervorgehoben wurde die freundliche Betreuung der Patienten durch das Personal.SchlussfolgerungenDie Situation der Strahlentherapiepatienten war insgesamt zufriedenstellend. Weitere Verbesserungen für die Zukunft sind vor allem aus einer reibungslosen Organisation der Planung und Therapie zu erwarten, wie sie durch elektronische Betriebsablaufsysteme zu erreichen ist. Die Ergebnisse der Befragung konnten in der eigenen Klinik bereits in vielen Bereichen umgesetzt werden. Die Strahlentherapie mit ihren komplexen Abläufen kann hier als Vorbild für andere Bereiche genutzt werden.AbstractIntroduction and BackgroundIn the context of quality assurance, increasing demands are placed on the whole radiotherapy treatment process. The patients directly concerned generally do not realize most aspects of the quality assurance program (e.g., additional safety checks) during their daily therapy. It was the aim of this study to systematically ask patients about potential improvements during the course of radiotherapy treatment from their own perspective.Patients and MethodsIn the defined time span (1 month), 624 radiotherapy patients (600 questionnaires were returned, 96.2%) were interviewed using a questionnaire newly developed to inquire about several aspects of their treatment. Furthermore, they were asked for their specific needs and suggestions for improvements that could be made during the course of radiotherapy treatment.ResultsOverall, the patients were satisfied with the course of their radiotherapy treatment and with patient care. As an example, about 90% agreed with the statement: “My first contact with the radiation oncology unit proceeded with kindness and competence so that I was given the impression that I will be well cared for in this clinic.” Considering the organization of the course of radiotherapy, a large majority of patients attached great value to set appointments for the therapy fractions. A main point of criticism was waiting times or delays caused by servicing or machine failures. Small, low cost improvements as music in the therapy room were considered as important as expensive measures (e.g., daylight in the therapy room). The patients emphasized the importance of staff friendliness.ConclusionThe situation of radiotherapy patients was, in general, satisfactory. Future improvements can be mainly expected from smooth organisation of both planning and treatment which can be achieved by electronic scheduling systems. Many results of the survey could be easily implemented in daily practice. In matters of organization radiation oncology with its complex procedures can be used as a model for other clinical departments.

Using GOMS and NASA-TLX to Evaluate Human-Computer Interaction Process in Interactive Segmentation

ABSTRACT HCI plays an important role in interactive medical image segmentation. The Goals, Operators, Methods, and Selection rules (GOMS) model and the National Aeronautics and Space Administration Task Load Index (NASA-TLX) questionnaire are different methods that are often used to evaluate the HCI process. In this article, we aim at improving the HCI process of interactive segmentation using both the GOMS model and the NASA-TLX questionnaire to: 1) identify the relations between these two methods and 2) propose HCI design suggestions based on the synthesis of the evaluation results using both methods. For this, we conducted an experiment where three physicians used two interactive segmentation approaches to segment different types of organs at risk for radiotherapy planning. Using the GOMS model, we identified 16 operators and 10 methods. Further analysis discovered strong relations between the use of GOMS operators and the results of the NASA-TLX questionnaire. Finally, HCI design issues were identified, and suggestions were proposed based on the evaluation results and the identified relations.

[The situation of radiation oncology patients' relatives. A stocktaking].

Hintergrund und Ziel:Untersuchungen haben gezeigt, dass die Angehörigen aus Patientensicht einen sehr hohen Stellenwert bei der Entscheidungsfindung zur Durchführung medizinischer Behandlungsmaßnahmen einnehmen. Durch eine gezielte Befragung der nächsten Angehörigen von Strahlentherapiepatienten wurde daher die Situation dieser Personengruppe im Sinne einer Bestandsaufnahme untersucht.Befragte Stichprobe und Methodik:Mittels eines neu entwickelten Fragebogens wurden in einem definierten Erhebungszeitraum von 6 Wochen insgesamt 470 Angehörige von Strahlentherapiepatienten (auswertbarer Rücklauf: n = 287, Rücklaufquote = 61%) über die Zufriedenheit mit ihrer Einbindung in den Therapieablauf befragt. Des Weiteren wurden bei der befragten Stichprobe Auskünfte über die spezifischen Bedürfnisse von Angehörigen sowie Vorschläge zu konkreten Verbesserungsmöglichkeiten im Kontext einer strahlentherapeutischen Behandlung erhoben.Ergebnisse:Insgesamt waren die Angehörigen mit ihrer Einbindung in die Therapieabläufe und mit der Betreuung der Patienten zufrieden. So gab es z.B. zu der Aussage „Hier in der Klinik wird mein kranker Angehöriger gut betreut“ zu über 95% Zustimmung. Unmittelbare Verbesserungsmöglichkeiten ergaben sich jedoch im Bereich der interdisziplinären Information über onkologische Themen sowie beim Organisationsablauf.Schlussfolgerung:Die Situation der Angehörigen von Strahlentherapiepatienten war in der Bestandsaufnahme insgesamt zufriedenstellend. Weitere Verbesserungen für die Zukunft sind vor allem aus dem Bereich interdisziplinärer Tumorzentren zu erwarten, die im Bedarfsfall die besten Voraussetzungen für eine Betreuung der Angehörigen haben. Als Vorbild können Strukturen aus der Palliativmedizin dienen.Background and Purpose:Recent studies have shown a very high importance of relatives in decisions about medical interventions. Therefore, the situation of this group was investigated in the sense of a stocktaking by interviewing the closest relatives of radiotherapy patients.Interviewed Persons and Methods:In a defined span of time (6 weeks), a total of 470 relatives (evaluable: n = 287, 61%) of radiotherapy patients were interviewed by a newly developed questionnaire about their contentment with their inclusion in the therapy course. Further, they gave information about specific needs of relatives as well as proposals for direct improvements in the context of a radiation therapy.Results:In total, the relatives were satisfied with their inclusion in the radiotherapy course and with the patient care. As an example, more than 95% of the relatives agreed with the statement “Here in the hospital my ill relative is cared for well.” Nevertheless, direct possibilities for improvements were found in the interdisciplinary information about oncologic topics and in the organization of the therapy course.Conclusion:In the stocktaking the situation of radiotherapy patients’ relatives was generally satisfactory. Further improvements for the future can be expected mainly from interdisciplinary cancer centers having the best suppositions to care for the relatives, if necessary. Structures known from palliative care can be used as a model.

[Survey of potential improvements during the course of the radiotherapy treatment--a patient questionnaire].

ZusammenfassungEinleitung und HintergrundIm Rahmen der Qualitätssicherung werden an den Ablauf einer Strahlentherapie zunehmend größere Anforderungen gestellt. Die direkt betroffenen Patienten bemerken in der täglichen Therapie jedoch viele Maßnahmen der Qualitätskontrolle, z. B. zusätzliche Sicherheitschecks, nicht. Durch eine gezielte Befragung der Patienten sollten Verbesserungsmöglichkeiten des Behandlungsablaufs aus deren Perspektive identifiziert werden.Patienten und MethodenMittels eines neu entwickelten Fragebogens wurden in einem definierten Erhebungszeitraum von 1 Monat insgesamt 624 Strahlentherapiepatienten (Rücklauf: n = 600, 96,2 %) über verschiedene Aspekte des Therapieablaufs befragt. Weiterhin wurden bei der befragten Stichprobe Auskünfte über ihre spezifischen Bedürfnisse sowie Vorschläge zu konkreten Verbesserungsmöglichkeiten im Kontext einer strahlentherapeutischen Behandlung erhoben.ErgebnisseInsgesamt waren die Patienten mit den Therapieabläufen zufrieden. So gab es z. B. zu der Aussage „Mein erster Kontakt zur Klinik für Strahlenheilkunde verlief so, dass mir sowohl mit Freundlichkeit als auch mit Kompetenz das Gefühl gegeben wurde: Hier werde ich gut betreut“ über 90 % Zustimmung. Bezüglich des Organisationsablaufs legte eine große Mehrheit der Patienten Wert auf einen festgelegten Bestrahlungstermin. Kritikpunkte waren Wartezeiten wegen Wartung oder Ausfall der Bestrahlungsgeräte. Kleinere bzw. kostengünstigere Verbesserungen wie Musik im Bestrahlungsraum sahen die Patienten insgesamt als genauso wichtig an wie teure bauliche Maßnahmen, beispielsweise Tageslicht im Bestrahlungsraum. Positiv hervorgehoben wurde die freundliche Betreuung der Patienten durch das Personal.SchlussfolgerungenDie Situation der Strahlentherapiepatienten war insgesamt zufriedenstellend. Weitere Verbesserungen für die Zukunft sind vor allem aus einer reibungslosen Organisation der Planung und Therapie zu erwarten, wie sie durch elektronische Betriebsablaufsysteme zu erreichen ist. Die Ergebnisse der Befragung konnten in der eigenen Klinik bereits in vielen Bereichen umgesetzt werden. Die Strahlentherapie mit ihren komplexen Abläufen kann hier als Vorbild für andere Bereiche genutzt werden.AbstractIntroduction and BackgroundIn the context of quality assurance, increasing demands are placed on the whole radiotherapy treatment process. The patients directly concerned generally do not realize most aspects of the quality assurance program (e.g., additional safety checks) during their daily therapy. It was the aim of this study to systematically ask patients about potential improvements during the course of radiotherapy treatment from their own perspective.Patients and MethodsIn the defined time span (1 month), 624 radiotherapy patients (600 questionnaires were returned, 96.2%) were interviewed using a questionnaire newly developed to inquire about several aspects of their treatment. Furthermore, they were asked for their specific needs and suggestions for improvements that could be made during the course of radiotherapy treatment.ResultsOverall, the patients were satisfied with the course of their radiotherapy treatment and with patient care. As an example, about 90% agreed with the statement: “My first contact with the radiation oncology unit proceeded with kindness and competence so that I was given the impression that I will be well cared for in this clinic.” Considering the organization of the course of radiotherapy, a large majority of patients attached great value to set appointments for the therapy fractions. A main point of criticism was waiting times or delays caused by servicing or machine failures. Small, low cost improvements as music in the therapy room were considered as important as expensive measures (e.g., daylight in the therapy room). The patients emphasized the importance of staff friendliness.ConclusionThe situation of radiotherapy patients was, in general, satisfactory. Future improvements can be mainly expected from smooth organisation of both planning and treatment which can be achieved by electronic scheduling systems. Many results of the survey could be easily implemented in daily practice. In matters of organization radiation oncology with its complex procedures can be used as a model for other clinical departments.

Die Situation der Angehörigen von Strahlentherapiepatienten

Hintergrund und Ziel:Untersuchungen haben gezeigt, dass die Angehörigen aus Patientensicht einen sehr hohen Stellenwert bei der Entscheidungsfindung zur Durchführung medizinischer Behandlungsmaßnahmen einnehmen. Durch eine gezielte Befragung der nächsten Angehörigen von Strahlentherapiepatienten wurde daher die Situation dieser Personengruppe im Sinne einer Bestandsaufnahme untersucht.Befragte Stichprobe und Methodik:Mittels eines neu entwickelten Fragebogens wurden in einem definierten Erhebungszeitraum von 6 Wochen insgesamt 470 Angehörige von Strahlentherapiepatienten (auswertbarer Rücklauf: n = 287, Rücklaufquote = 61%) über die Zufriedenheit mit ihrer Einbindung in den Therapieablauf befragt. Des Weiteren wurden bei der befragten Stichprobe Auskünfte über die spezifischen Bedürfnisse von Angehörigen sowie Vorschläge zu konkreten Verbesserungsmöglichkeiten im Kontext einer strahlentherapeutischen Behandlung erhoben.Ergebnisse:Insgesamt waren die Angehörigen mit ihrer Einbindung in die Therapieabläufe und mit der Betreuung der Patienten zufrieden. So gab es z.B. zu der Aussage „Hier in der Klinik wird mein kranker Angehöriger gut betreut“ zu über 95% Zustimmung. Unmittelbare Verbesserungsmöglichkeiten ergaben sich jedoch im Bereich der interdisziplinären Information über onkologische Themen sowie beim Organisationsablauf.Schlussfolgerung:Die Situation der Angehörigen von Strahlentherapiepatienten war in der Bestandsaufnahme insgesamt zufriedenstellend. Weitere Verbesserungen für die Zukunft sind vor allem aus dem Bereich interdisziplinärer Tumorzentren zu erwarten, die im Bedarfsfall die besten Voraussetzungen für eine Betreuung der Angehörigen haben. Als Vorbild können Strukturen aus der Palliativmedizin dienen.Background and Purpose:Recent studies have shown a very high importance of relatives in decisions about medical interventions. Therefore, the situation of this group was investigated in the sense of a stocktaking by interviewing the closest relatives of radiotherapy patients.Interviewed Persons and Methods:In a defined span of time (6 weeks), a total of 470 relatives (evaluable: n = 287, 61%) of radiotherapy patients were interviewed by a newly developed questionnaire about their contentment with their inclusion in the therapy course. Further, they gave information about specific needs of relatives as well as proposals for direct improvements in the context of a radiation therapy.Results:In total, the relatives were satisfied with their inclusion in the radiotherapy course and with the patient care. As an example, more than 95% of the relatives agreed with the statement “Here in the hospital my ill relative is cared for well.” Nevertheless, direct possibilities for improvements were found in the interdisciplinary information about oncologic topics and in the organization of the therapy course.Conclusion:In the stocktaking the situation of radiotherapy patients’ relatives was generally satisfactory. Further improvements for the future can be expected mainly from interdisciplinary cancer centers having the best suppositions to care for the relatives, if necessary. Structures known from palliative care can be used as a model.

Is serum level of CC chemokine ligand 18 a biomarker for the prediction of radiation induced lung toxicity (RILT)

The CC chemokine ligand 18 (CCL18) is produced by alveolar macrophages in patients with fibrosing lung disease and its concentration is increased in various fibrotic lung diseases. Furthermore CCL18 is elevated in several malignancies as it is produced by tumor associated macrophages. In this study we aimed to analyze the role of CCL18 as a prognostic biomarker for the development of early radiation induced lung toxicity (RILT), i.e. radiation pneumonitis after thoracic irradiation and its significance in the course of the disease. Sixty seven patients were enrolled prospectively in the study. Patients were treated with irradiation for several thoracic malignancies (lung cancer, esophageal cancer, thymoma), either with conventionally fractionated or hypo-fractionated radiotherapy. The CCL18 serum levels were quantified with ELISA (enzyme-linked immunosorbent assay) at predefined time points: before, during and at the end of treatment as well as in the first and second follow-up. Treatment parameters and functional tests were also correlated with the development of RILT.Fifty three patients were evaluable for this study. Twenty one patients (39%) developed radiologic signs of RILT Grade >1 but only three of them (5.6%) developed clinical symptoms (Grade 2). We could not find any association between the different CCL18 concentrations and a higher incidence of RILT. Statistical significant factors were the planning target volume (odds ratio OR: 1.003, p = 0.010), the volume of the lung receiving > 20 Gy (OR: 1.132 p = 0.004) and age (OR: 0.917, p = 0.008). There was no association between serial CCL18 concentrations with tumor response and overall survival.In our study the dosimetric parameters remained the most potent predictors of RILT. Further studies are needed in order to estimate the role of CCL18 in the development of early RILT.

Visualization of 4D multimodal imaging data and its applications in radiotherapy planning

Abstract Purpose To explore the benefit of using 4D multimodal visualization and interaction techniques for defined radiotherapy planning tasks over a treatment planning system used in clinical routine (C‐TPS) without dedicated 4D visualization. Methods We developed a 4D visualization system (4D‐VS) with dedicated rendering and fusion of 4D multimodal imaging data based on a list of requirements developed in collaboration with radiation oncologists. We conducted a user evaluation in which the benefits of our approach were evaluated in comparison to C‐TPS for three specific tasks: assessment of internal target volume (ITV) delineation, classification of tumor location in peripheral or central, and assessment of dose distribution. For all three tasks, we presented test cases for which we measured correctness, certainty, consistency followed by an additional survey regarding specific visualization features. Results Lower quality of the test ITVs (ground truth quality was available) was more likely to be detected using 4D‐VS. ITV ratings were more consistent in 4D‐VS and the classification of tumor location had a higher accuracy. Overall evaluation of the survey indicates 4D‐VS provides better spatial comprehensibility and simplifies the tasks which were performed during testing. Conclusions The use of 4D‐VS has improved the assessment of ITV delineations and classification of tumor location. The visualization features of 4D‐VS have been identified as helpful for the assessment of dose distribution during user testing.

Evaluation of an Integrated Minimally Interactive Tool for the Segmentation of Relevant Oar in Lung Cancer

Purpose/Objective(s). Radiation therapy aims at delivering the highest possible dose to the GTV while minimizing the irradiation of surrounding healthy tissue. Therefore an accurate delineation of organs at risk (OAR) is an absolute prerequirement for radiation treatment planning (RTP). However, it is maybe a very time consuming and tedious task. In this work we present and evaluate a software prototype which integrates fully automatic and minimally interactive algorithms to perform segmentation for relevant OAR in lung cancer.