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- Sundin, Maria, 1965, et al.
(författare)
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Mars - a target for teachers and science students
- 2020
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Ingår i: Contribution to IAU 367S, Education and Heritage in the Era of Big Data in Astronomy, 8-12 December 2020..
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A case study is here presented of an interdisciplinary course about Mars for teachers and science students. We aim to share the experience of creating an interdisciplinary approach with lecturers spanning physics, geology, radiation physics and philosophy. Issues in ethics, morality, rights and obligations, conflict management and human psychology as well as rocket orbits, fuel economy, radiation hazards and knowledge of the solar system have proven to be a valued and successful initiative for the further training of teachers and science students. The focus of the course is on planning for a journey with humans to the planet Mars. This provides a great opportunity to package complex societal problems in a physics context. The course is offered with a special sustainability content mark. Mankind has always had a strong and dependent relationship with the physical landscape. The land has given us food and shelter but also imposed challenges and disasters. Understanding the physical environment has been crucial for our survival and development. The same will be equally, or more important for Mars where life conditions are much more extreme. We highlight similarities and differences in the geologic processes that have shaped Earth and Mars. What conditions do the future explorers on Mars have to manage? We then enter the modern era and explore the dynamic Martian landscape of today. Also, by learning to read the landscape we may find locations of shelter such as vast systems of lava tubes, or locations of essential resources such as preserved glacial ice etc. A journey to Mars will cause substantially higher personal irradiation than obtained on Earth. The radiation part of the course lectures starts with defining the different radiation types and the biological effects these different types of radiation will cause. Then, the difference between the irradiation on Earth to the elevated irradiation in space and on Mars is described. Thereafter, it is discussed if this elevated radiation burden can cause acute biological effects, e.g. fatigue, vomiting and death, and late biological effects as cancer induction. Last, possible radiation protection strategies are described and discussed. The philosophy of space exploration consists of philosophical approaches to ethics, presently applied to the topic of Mars exploration and colonization, with environmental ethics (anthropocentric vs ecocentric) and value theory at its core. Four main uses of philosophy are distinguished: ethics, aesthetics, cognition and existentialism. Research has shown that visual representation is an important part for students to be able to create a deeper understanding of concepts as well as context about the material that is taught. Interdisciplinary and complex societal problems have also been shown to be important in science teaching. One way for the teacher to develop his/her teaching is to take further education courses in universities whose focus is to seek and discuss the complex societal problems as well as its solutions from a physics and teacher perspective. Future research could be done on the impact of this course on the education in different levels.
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| 2. |
- Sundin, Maria, 1965, et al.
(författare)
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Mars – a target for teachers and science students
- 2021
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Ingår i: Proceedings of the International Astronomical Union, Vol 15, Symposium 367S. - 1743-9213 .- 1743-9221.
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Konferensbidrag (refereegranskat)abstract
- An interdisciplinary course about Mars for teachers and science students is presented. The focus of the course is on planning for a journey with humans to the planet Mars. Issues in ethics, morality, rights and obligations, conflict management and human psychology as well as rocket orbits, fuel economy, radiation hazards and knowledge of the solar system are included. Examination of the teacher students include interpretation of the course material for future pedagogical usage.
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| 5. |
- Wikberg, Emma, et al.
(författare)
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Evaluation of reconstruction methods and image noise levels concerning visual assessment of simulated liver lesions in In-111-octreotide SPECT imaging
- 2023
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Ingår i: EJNMMI Physics. - 2197-7364. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Early cancer detection is crucial for patients' survival. The image quality in In-111-octreotide SPECT imaging could be improved by using Monte Carlo (MC)-based reconstruction. The aim of this observational study was to determine the detection rate of simulated liver lesions for MC-based ordered subset expectation maximization (OSEM) reconstruction compared to conventional attenuation-corrected OSEM reconstruction.MethodsThirty-seven SPECT/CT examinations with In-111-octreotide were randomly selected. The inclusion criterion was no liver lesions at the time of examination and for the following 3 years. SPECT images of spheres representing lesions were simulated using MC. The raw data of the spheres were added to the raw data of the established healthy patients in 26 of the examinations, and the remaining 11 examinations were not modified. The images were reconstructed using conventional OSEM reconstruction with attenuation correction and post filtering (fAC OSEM) and MC-based OSEM reconstruction without and with post filtering (MC OSEM and fMC OSEM, respectively). The images were visually and blindly evaluated by a nuclear medicine specialist. The criteria evaluated were liver lesion yes or no, including coordinates if yes, with confidence level 1-3. The percentage of detected lesions and accuracy (percentage of correctly classified cases), as well as tumor-to-normal tissue concentration (TNC) ratios and signal-to-noise ratios (SNRs), were evaluated.ResultsThe detection rates were 30.8% for fAC OSEM, 42.3% for fMC OSEM, and 50.0% for MC OSEM. The accuracies were 45.9% for fAC OSEM, 45.9% for fMC OSEM, and 54.1% for MC OSEM. The number of false positives was higher for fMC and MC OSEM. The observer's confidence level was higher in filtered images than in unfiltered images. TNC ratios were significantly higher, statistically, with MC OSEM and fMC OSEM than with AC OSEM, but SNRs were similar due to higher noise with MC OSEM.ConclusionOne in two lesions were found using MC OSEM versus one in three using conventional reconstruction. TNC ratios were significantly improved, statistically, using MC-based reconstruction, but the noise levels increased and consequently the confidence level of the observer decreased. For further improvements, image noise needs to be suppressed.
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| 6. |
- Wikberg, Emma, et al.
(författare)
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Improvements of 177Lu SPECT images from sparsely acquired projections by reconstruction with deep-learning-generated synthetic projections
- 2024
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Ingår i: EJNMMI PHYSICS. - 2197-7364. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Background For dosimetry, the demand for whole-body SPECT/CT imaging, which require long acquisition durations with dual-head Anger cameras, is increasing. Here we evaluated sparsely acquired projections and assessed whether the addition of deep-learning-generated synthetic intermediate projections (SIPs) could improve the image quality while preserving dosimetric accuracy. Methods This study included 16 patients treated with Lu-177-DOTATATE with SPECT/CT imaging (120 projections, 120P) at four time points. Deep neural networks (CUSIPs) were designed and trained to compile 90 SIPs from 30 acquired projections (30P). The 120P, 30P, and three different CUSIP sets (30P + 90 SIPs) were reconstructed using Monte Carlo-based OSEM reconstruction (yielding 120P_rec, 30P_rec, and CUSIP_recs). The noise levels were visually compared. Quantitative measures of normalised root mean square error, normalised mean absolute error, peak signal-to-noise ratio, and structural similarity were evaluated, and kidney and bone marrow absorbed doses were estimated for each reconstruction set. Results The use of SIPs visually improved noise levels. All quantitative measures demonstrated high similarity between CUSIP sets and 120P. Linear regression showed nearly perfect concordance of the kidney and bone marrow absorbed doses for all reconstruction sets, compared to the doses of 120P_rec (R-2 >= 0.97). Compared to 120P_rec, the mean relative difference in kidney absorbed dose, for all reconstruction sets, was within 3%. For bone marrow absorbed doses, there was a higher dissipation in relative differences, and CUSIP_recs outperformed 30P_rec in mean relative difference (within 4% compared to 9%). Kidney and bone marrow absorbed doses for 30P_rec were statistically significantly different from those of 120_rec, as opposed to the absorbed doses of the best performing CUSIP_rec, where no statistically significant difference was found. Conclusion When performing SPECT/CT reconstruction, the use of SIPs can substantially reduce acquisition durations in SPECT/CT imaging, enabling acquisition of multiple fields of view of high image quality with satisfactory dosimetric accuracy.
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| 7. |
- Andersson, Jonas, 1975-, et al.
(författare)
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Artificial intelligence and the medical physics profession-A Swedish perspective
- 2021
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Ingår i: Physica Medica-European Journal of Medical Physics. - : Elsevier BV. - 1120-1797 .- 1724-191X. ; 88, s. 218-225
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Tidskriftsartikel (refereegranskat)abstract
- Background: There is a continuous and dynamic discussion on artificial intelligence (AI) in present-day society. AI is expected to impact on healthcare processes and could contribute to a more sustainable use of resources allocated to healthcare in the future. The aim for this work was to establish a foundation for a Swedish perspective on the potential effect of AI on the medical physics profession. Materials and methods: We designed a survey to gauge viewpoints regarding AI in the Swedish medical physics community. Based on the survey results and present-day situation in Sweden, a SWOT analysis was performed on the implications of AI for the medical physics profession. Results: Out of 411 survey recipients, 163 responded (40%). The Swedish medical physicists with a professional license believed (90%) that AI would change the practice of medical physics but did not foresee (81%) that AI would pose a risk to their practice and career. The respondents were largely positive to the inclusion of AI in educational programmes. According to self-assessment, the respondents' knowledge of and workplace preparedness for AI was generally low. Conclusions: From the survey and SWOT analysis we conclude that AI will change the medical physics profession and that there are opportunities for the profession associated with the adoption of AI in healthcare. To overcome the weakness of limited AI knowledge, potentially threatening the role of medical physicists, and build upon the strong position in Swedish healthcare, medical physics education and training should include learning objectives on AI.
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| 8. |
- Baum, R. P., et al.
(författare)
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First-in-Humans Application of Tb-161: A Feasibility Study Using Tb-161-DOTATOC
- 2021
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Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 2159-662X. ; 62:10, s. 1391-1397
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Tidskriftsartikel (refereegranskat)abstract
- Tb-161 has decay properties similar to those of Lu-177 but, additionally, emits a substantial number of conversion and Auger electrons. The aim of this study was to apply Tb-161 in a clinical setting and to investigate the feasibility of visualizing the physiologic and tumor biodistributions of Tb-161-DOTATOC. Methods: Tb-161 was shipped from Paul Scherrer Institute, Villigen-PSI, Switzerland, to Zentralklinik Bad Berka, Bad Berka, Germany, where it was used for the radiolabeling of DOTATOC. In 2 separate studies, 596 and 1,300 MBq of Tb-161-DOTATOC were administered to a 35-y-old male patient with a metastatic, well-differentiated, nonfunctional malignant paraganglioma and a 70-y-old male patient with a metastatic, functional neuroendocrine neoplasm of the pancreatic tail, respectively. Whole-body planar g-scintigraphy images were acquired over a period of several days for dosimetry calculations. SPECT/CT images were reconstructed using a recently established protocol and visually analyzed. Patients were observed for adverse events after the application of Tb-161-DOTATOC. Results: The radiolabeling of DOTATOC with Tb-161 was readily achieved with a high radiochemical purity suitable for patient application. Planar images and dosimetry provided the expected time-dependent biodistribution of Tb-161-DOTATOC in the liver, kidneys, spleen, and urinary bladder. SPECT/CT images were of high quality and visualized even small metastases in bones and liver. The application of Tb-161-DOTATOC was well tolerated, and no related adverse events were reported. Conclusion: This study demonstrated the feasibility of imaging even small metastases after the injection of relatively low activities of Tb-161-DOTATOC using g-scintigraphy and SPECT/CT. On the basis of this essential first step in translating Tb-161 to clinics, further efforts will be directed toward the application of Tb-161 for therapeutic purposes.
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| 9. |
- Bernhardt, Peter, 1966, et al.
(författare)
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Dosimetric analysis of the short-ranged particle emitter161 tb for radionuclide therapy of metastatic prostate cancer
- 2021
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Ingår i: Cancers. - : MDPI AG. - 2072-6694. ; 13:9
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to analyze the required absorbed doses to detectable metastases (Dreq ) when using radionuclides with prostate specific membrane antigen (PSMA)-targeting radioligands to achieve a high probability for metastatic control. The Monte Carlo based analysis was performed for the clinically-used radionuclides yttrium-90, iodine-131, lutetium-177, and actinium-225, and the newly-proposed low-energy electron emitter terbium-161. It was demonstrated that metastatic formation rate highly influenced the metastatic distribution. Lower values generated few large detectable metastases, as in the case with oligo metastases, while high values generated a distribution of multiple small detectable metastases, as observed in patients with diffused visualized metastases. With equal number of detectable metastases, the total metastatic volume burden was 4–6 times higher in the oligo metastatic scenario compared to the diffusely visualized scenario. The Dreq was around 30% higher for the situations with 20 detectable metastases compared to one detectable metastasis. The Dreq for iodine-131 and yttrium-90 was high (920–3300 Gy). The Dreq for lutetium-177 was between 560 and 780 Gy and considerably lower Dreq were obtained for actinium-225 and terbium-161, with 240–330 Gy and 210–280 Gy, respectively. In conclusion, the simulations demonstrated that terbium-161 has the potential for being a more effective targeted radionuclide therapy for metastases using PSMA ligands. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
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| 10. |
- Busslinger, Sarah D., et al.
(författare)
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Comparison of the tolerability of 161Tb- and 177Lu-labeled somatostatin analogues in the preclinical setting
- 2024
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Ingår i: EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING. - 1619-7070 .- 1619-7089.
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Tidskriftsartikel (refereegranskat)abstract
- Purpose [Lu-177]Lu-DOTATATE is an established somatostatin receptor (SSTR) agonist for the treatment of metastasized neuroendocrine neoplasms, while the SSTR antagonist [Lu-177]Lu-DOTA-LM3 has only scarcely been employed in clinics. Impressive preclinical data obtained with [Tb-161]Tb-DOTA-LM3 in tumor-bearing mice indicated the potential of terbium-161 as an alternative to lutetium-177. The aim of the present study was to compare the tolerability of Tb-161- and Lu-177-based DOTA-LM3 and DOTATATE in immunocompetent mice. Methods Dosimetry calculations were performed based on biodistribution data of the radiopeptides in immunocompetent mice. Treatment-related effects on blood cell counts were assessed on Days 10, 28 and 56 after application of [Tb-161]Tb-DOTA-LM3 or [Tb-161]Tb-DOTATATE at 20 MBq per mouse. These radiopeptides were also applied at 100 MBq per mouse and the effects compared to those observed after application of the Lu-177-labeled counterparts. Bone marrow smears, blood plasma parameters and organ histology were assessed at the end of the study. Results The absorbed organ dose was commonly higher for the SSTR antagonist than for the SSTR agonist and for terbium-161 over lutetium-177. Application of a therapeutic activity level of 20 MBq [Tb-161]Tb-DOTA-LM3 or [Tb-161]Tb-DOTATATE was well tolerated without major hematological changes. The injection of 100 MBq of the Tb-161- and Lu-177-based somatostatin analogues affected the blood cell counts, however. The lymphocytes were 40-50% lower in treated mice compared to the untreated controls on Day 10 irrespective of the radionuclide employed. At the same timepoint, thrombocyte and erythrocyte counts were 30-50% and 6-12% lower, respectively, after administration of the SSTR antagonist (p < 0.05) while changes were less pronounced in mice injected with the SSTR agonist. All blood cell counts were in the normal range on Day 56. Histological analyses revealed minimal abnormalities in the kidneys, liver and spleen of treated mice. No correlation was observed between the organ dose and frequency of the occurrence of abnormalities. Conclusion Hematologic changes were more pronounced in mice treated with the SSTR antagonist than in those treated with the SSTR agonist. Despite the increased absorbed dose delivered by terbium-161 over lutetium-177, [Tb-161]Tb-DOTA-LM3 and [Tb-161]Tb-DOTATATE should be safe at activity levels that are recommended for their respective Lu-177-based analogues.
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