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4 results on '"Satu Strengell"'

1. Palliative radiotherapy of soft tissue tumoral masses based on diagnostic instead of planning computed tomography scans

Author

Satu Strengell, Suvi Larjavaara, Mikko Tenhunen, and Anu Anttonen

Subjects
Palliative treatment, Radiotherapy setup errors, Radiotherapy planning, Computer-assisted, Neoplasm metastasis, Medical physics. Medical radiology. Nuclear medicine, R895-920, Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282
Abstract

Background and purpose: Radiotherapy (RT) treatment planning is based on a planning computed tomography scan (pCT), while the decision to treat is often already established on a diagnostic CT scan (dCT). The objective of this study was to evaluate the usage of dCT for palliative radiation planning of soft tissue tumoral masses (STTMs), removing the need for a pCT scan and associated attendances. Materials and methods: RT planning was performed retrospectively to 38 STTMs of 7 anatomical sites using volumetric modulated arc therapy techniques in dCT and transferred to pCT. The dose of clinical target volumes (CTV), D(95 %,50 %), were compared between the plans. The patient setup was assessed in cone-beam CT scans. Results: The differences of D(95 %,50 %) between dCT and pCT plans were the lowest in the STTMs of the thoracic cage (0.9 %,0.9 %), STTMs in the inguinal area (0.8 %,1.3 %) and in mediastinal masses associated with superior vena cava syndrome (SVCS) (1.1 %,1.3 %), while the differences increased for other sites. The patient setup was acceptable for 88 % of mediastinal masses associated with SVCS and ≤ 60 % of cases in other sites comparing pCT and CBCT images with a strict margin of 6 mm, but all cases fitted to increased 2 cm margin. Conclusions: This study demonstrated the possibility of using dCT scans for palliative RT planning of STTMs for mediastinal masses associated with SVCS and for STTMs in the thoracic cage and in the inguinal area, indicating the potential feasibility of this procedure for clinical use.

Published
2024
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2. Palliative intensity modulated radiotherapy of bone metastases based on diagnostic instead of planning computed tomography scans

Author

Suvi Larjavaara, Satu Strengell, Tiina Seppälä, Mikko Tenhunen, and Anu Anttonen

Subjects
Palliative care, Radiotherapy setup errors, Radiotherapy planning, Computer-assisted, Neoplasm metastasis, Medical physics. Medical radiology. Nuclear medicine, R895-920, Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282
Abstract

Background and purpose: Radiotherapy (RT) treatment planning is as a standard based on a computed tomography (CT) scan obtained at the planning stage (pCT), while most of the decisions whether to treat by RT are based on diagnostic CT scans (dCT). Bone metastases (BM) are the most common palliative RT target. The objective of this study was to investigate if a palliative RT treatment plan of BMs could be made based on a dCT with sufficient accuracy and safety, without sacrificing any treatment quality. Materials and methods: A retrospective study with 60 BMs of 8 anatomical sites was performed. RT planning was performed using intensity-modulated radiation therapy/volumetric modulated arc therapy techniques in dCT and transferred to pCT. The dose of clinical target volumes (CTVs), D(CTVV95%, V50%), were compared between plans for dCT and pCT. Patient setup was investigated in cone-beam CT scans. Results: The differences of D(CTVV95%, V50%) between dCT and pCT plans were the lowest in the pelvis (1.0%, 1.1%), lumbar spine (0.6%, 0.7%) and thoracic spine (0.7%, 2.1%), while the differences were higher in cervical spine (3.7%, 1.9%), long bones (2.3%, 0.8%), and costae (1.6%, 1.4%). The patient set-up was acceptable for 100% of the pelvic and lumbar, for 92% of thoracic spine cases, and for

Published
2023
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3. Quantitative Imaging of Regional Aerosol Deposition, Lung Ventilation and Morphology by Synchrotron Radiation CT

Author

Sam Bayat, Ferenc Peták, Gergely Albu, Liisa Porra, Pekka Suortti, Ludovic Broche, Anssi Sovijärvi, Heikki Suhonen, Loïc Dégrugilliers, Gergely H. Fodor, Walid Habre, Satu Strengell, Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Helsinki University Hospital, CHU Amiens-Picardie, Périnatalité et Risques Toxiques - UMR INERIS_I 1 (PERITOX), Institut National de l'Environnement Industriel et des Risques (INERIS)-Université de Picardie Jules Verne (UPJV)-CHU Amiens-Picardie, European Synchrotron Radiation Facility (ESRF), Recherche en Pharmaco-épidémiologie et Recours aux Soins (REPERES), Université de Rennes (UR)-École des Hautes Études en Santé Publique [EHESP] (EHESP), École des Hautes Études en Santé Publique [EHESP] (EHESP), Département Méthodes quantitatives en santé publique (METIS), HUS Medical Imaging Center, Department of Physics, Clinicum, Department of Diagnostics and Therapeutics, and University of Helsinki

Subjects
0301 basic medicine, medicine.medical_treatment, Respiratory Medicine and Allergy, [SDV]Life Sciences [q-bio], Synchrotron radiation, Multimodal Imaging, law.invention, 0302 clinical medicine, law, Lung, Methacholine Chloride, IN-VIVO, Lungmedicin och allergi, Multidisciplinary, BRONCHOCONSTRICTION, ddc:617, K-EDGE, CONTRAST AGENT, respiratory system, SUBTRACTION, 3. Good health, medicine.anatomical_structure, Deposition (aerosol physics), Ventilation (architecture), METHACHOLINE, Medicine, Rabbits, HEALTH, Iodine, 030103 biophysics, Quantitative imaging, Materials science, Science, Article, 03 medical and health sciences, Aerosol deposition, Administration, Inhalation, medicine, Animals, Humans, COMPUTED-TOMOGRAPHY, Aerosols, Mechanical ventilation, business.industry, 217 Medical engineering, Asthma, Aerosol, MECHANICAL VENTILATION, Disease Models, Animal, 030228 respiratory system, Pulmonary Ventilation, Tomography, X-Ray Computed, Nuclear medicine, business, EMISSION, Synchrotrons
Abstract

To understand the determinants of inhaled aerosol particle distribution and targeting in the lung, knowledge of regional deposition, lung morphology and regional ventilation, is crucial. No single imaging modality allows the acquisition of all such data together. Here we assessed the feasibility of dual-energy synchrotron radiation imaging to this end in anesthetized rabbits; both in normal lung (n = 6) and following methacholine (MCH)-induced bronchoconstriction (n = 6), a model of asthma. We used K-edge subtraction CT (KES) imaging to quantitatively map the regional deposition of iodine-containing aerosol particles. Morphological and regional ventilation images were obtained, followed by quantitative regional iodine deposition maps, after 5 and 10 minutes of aerosol administration. Iodine deposition was markedly inhomogeneous both in normal lung and after induced bronchoconstrition. Deposition was significantly reduced in the MCH group at both time points, with a strong dependency on inspiratory flow in both conditions (R2 = 0.71; p

Published
2018
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4. Pressure-regulated volume control vs. volume control ventilation in healthy and injured rabbit lung: An experimental study

Author

Sam Bayat, Iliona Malaspinas, Camille Doras, Gergely Albu, Ferenc Peták, Ludovic Broche, Satu Strengell, Liisa Porra, and Walid Habre

Subjects
Male, Acute Lung Injury, Ventilation perfusion mismatch, Respiratory physiology, Volume control, Positive-Pressure Respiration, 03 medical and health sciences, Random Allocation, 0302 clinical medicine, Respiration, medicine, Pressure, Tidal Volume, Animals, 030212 general & internal medicine, Lung, Random allocation, ddc:617, business.industry, respiratory system, Respiration, Artificial, Anesthesiology and Pain Medicine, medicine.anatomical_structure, 030228 respiratory system, Anesthesia, Breathing, Respiratory Mechanics, Rabbits, business
Abstract

It is not well understood how different ventilation modes affect the regional distribution of ventilation, particularly within the injured lung.We compared respiratory mechanics, lung aeration and regional specific ventilation ((Equation is included in full-text article.)) distributions in healthy and surfactant-depleted rabbits ventilated with pressure-regulated volume control (PRVC) mode with a decelerating inspiratory flow or with volume control (VC) mode.Randomised experimental study.New Zealand white rabbits (n = 8) were anaesthetised, paralysed and mechanically ventilated either with VC or PRVC mode (tidal volume: 7 ml kg; rate: 40 min; positive end-expiratory pressure (PEEP): 3 cmH2O), at baseline and after lung injury induced by lung lavage.Airway resistance (Raw), respiratory tissue damping (G) and elastance (H) were measured by low-frequency forced oscillations. Synchrotron radiation computed tomography during stable xenon wash-in was used to measure regional lung aeration and specific ventilation and the relative fraction of nonaerated, trapped, normally, poorly and hyperinflated lung regions.Lung lavage significantly elevated peak inspiratory pressure (PIP) (P 0.001). PIP was lower on PRVC compared with VC mode (-12.7 ± 1.7%, P 0.001). No significant differences in respiratory mechanics, regional ventilation distribution, strain or blood oxygenation could be detected between the two ventilation modes.A decelerating flow pattern (PRVC) resulted in equivalent regional ventilation distribution, respiratory mechanics and gas exchange, in both normal and mechanically heterogeneous lungs with, however, a significantly lower peak pressure. Our data suggest that the lower PIP on PRVC ventilation was because of the decelerating flow pattern rather than the ventilation distribution.

Published
2016

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