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- Joint EURADOS-EANM initiative for an advanced computational framework for the assessment of external dose rates from nuclear medicine patientsPublication . Struelens, Lara; Huet, Christelle; Broggio, David; Dabin, Jérémie; Desorgher, Laurent; Giussani, Augusto; Li, Wei Bo; Nosske, Dietmar; Lee, Yi-Kang; Cunha, Lidia; Raminhas Carapinha, Maria João; Medvedec, Mario; Covens, PeterBackground: To ensure adequate radiation protection of critical groups such as staff, caregivers, and the general public coming into proximity of nuclear medicine (NM) patients, it is necessary to consider the impact of the radiation emitted by the patients during their stay at the hospital or after leaving the hospital. Current risk assessments are based on ambient dose rate measurements in a single position at a specified distance from the patient and carried out at several time points after administration of the radiopharmaceutical to estimate the whole-body retention. The limitations of such an approach are addressed in this study by developing and validating a more advanced computational dosimetry approach using Monte Carlo (MC) simulations in combination with flexible and realistic computational phantoms and time activity distribution curves from reference biokinetic models. Results: Measurements of the ambient dose rate equivalent Ḣ*(10) at 1 m from the NM patient have been successfully compared against MC simulations with 5 different codes using the ICRP adult reference computational voxel phantoms, for typical clinical procedures with 99mTc-HDP/MDP, 18FDG and Na131I. All measurement data fall in the 95% confidence intervals, determined for the average simulated results. Moreover, the different MC codes (MCNP-X, PHITS, GATE, GEANT4, TRIPOLI-4®) have been compared for a more realistic scenario where the effective dose rate Ė of an exposed individual was determined in positions facing and aside the patient model at 30 cm, 50 cm, and 100 cm. The variation between codes was lower than 8% for all the radiopharmaceuticals at 1 m and varied from 5 to 16% for the face-to-face and side-by-side configuration at 30 cm and 50 cm. A sensitivity study on the influence of patient model morphology demonstrated that the relative standard deviation of Ḣ*(10) at 1 m for the range of included patient models remained under 16% for time points up to 120 min post-administration. Conclusions: The validated computational approach will be further used for the evaluation of effective dose rates per unit administered activity for a variety of close-contact configurations and a range of radiopharmaceuticals as part of risk assessment studies. Together with the choice of appropriate dose constraints, this would facilitate the setting of release criteria and patient restrictions.
- 4DCT versus 4DPET/CT na avaliação do movimento respiratório no planeamento da radioterapia no cancro do pulmão de não pequenas células: revisão da literaturaPublication . Dias, Paulo; Neves, Samuel; Raminhas Carapinha, Maria João; Caetano, MarcoIntrodução – Uma das abordagens terapêuticas no carcinoma do pulmão de não pequenas células (CPNPC) é a quimioterapia e radioterapia (RT) concomitante. O planeamento de RT pode ser realizado com base em diferentes técnicas de imagem, existindo vários fatores que podem influenciar a qualidade das mesmas, nomeadamente o movimento respiratório. Objetivos – Este estudo tem como objetivos: 1) avaliar a importância da 4DCT e da 4DPET/CT para a correção de movimento e definição do volume alvo no planeamento de RT para CPNPC; e 2) comparar a delimitação de volumes entre as técnicas PET/CT, 4DCT e 4DPET/CT, identificando as suas vantagens e limitações. Métodos – Revisão da literatura, recorrendo-se à metodologia PRISMA para a seleção de artigos nas bases de dados PubMed e Science Direct e outras fontes (b-on e Google Scholar). Foram considerados artigos publicados entre janeiro de 2014 e janeiro de 2020. Foram comparados volumes delimitados através de técnicas 3D e 4D, avaliando o impacto do movimento respiratório na aquisição de imagens e posterior planeamento de RT. Resultados – Obtiveram-se 230 artigos, mas apenas cinco foram elegíveis para estudo. As técnicas 4DCT e 4DPET/CT apresentaram melhores resultados, diminuindo os artefactos de movimento. Os volumes delimitados pelas várias técnicas em estudo foram semelhantes, apesar de se registarem pequenas variações quando a técnica 4D não é aplicada. Conclusão – Atualmente a 4DPET/CT apresenta melhores resultados na delimitação de volumes alvo para o planeamento de RT do que a técnica 4DCT.
- Impact of music intervention on psychological and physiological parameters of patients undergoing myocardial perfusion scintigraphyPublication . Vieira, Lina Oliveira; Rotaru, A.; Rodrigues, I.; Martins, A.; Carvalho, C.; Alvernaz, A.; Oliveira, L.; Grilo, Ana; Raminhas Carapinha, Maria JoãoAim/Introduction: Myocardial Perfusion Scintigraphy (MPS), a well-established imaging procedure for diagnosing ischemic heart disease, has multiple phases that can induce patients’ anxiety, discomfort, and dissatisfaction. Several non-pharmacological strategies have been used to alleviate anxiety and improve patient comfort and satisfaction, such as music intervention. This study aimed to evaluate the efficacy of musical intervention in the outcomes of patients undergoing MPS. Materials and Methods: A randomized clinical trial was conducted on patients undergoing an MPS one-day protocol stress-rest, in a Nuclear Medicine Department between January 15, and March 18, 2024. Patients were divided into a control group (CG) and an experimental group (EG). In the EG, a musical intervention was performed during the rest image acquisition, allowing patients to choose from a selection of musical tracks curated by a music lecturer. Anxiety levels were assessed at four different moments in both groups: before and after the stress image acquisition (T1 and T2), and before and after the rest image acquisition (T3 and T4), using physiological parameters at all times and psychological parameters for CG at T1 and T4 and for EG at T1, T3 and T4. Image quality analysis was performed using measures of contrast, noise, number, and amplitude of patients' movements. All studies were reviewed by two researchers and evaluated by three nuclear medicine technologists. Results: The sample comprised 30 participants with an average age of 71±11.02yrs [45-87yrs] with 15 participants enrolled in each group. Patients in EG reduced their anxiety scores from 36±9.44 at T1 to 33±7.07 at T3 and 28±9.11 at T4, while patients in CG reduced their anxiety scores from 39±10.62 at T1 to 33±9.66 at T4. Regarding patient motion, there was a reduction from the CG to EG in movements between 1-2 pixels (CG = 21, EG= 19) and movements higher than 2 pixels (CG =19, EG=6). In some myocardial walls on the three tomographic slices, the correlation between psychological parameters and image noise was lower in T4 for the EG. No significant results were found in image contrast. Conclusion: For the EG, the image noise was ~3% lower than in CG. Anxiety decreased throughout the MPS procedure with lower values at T4 for the EG. Additionally, the musical intervention seems to be effective as the EG showed lower values of patient movement.