Background/aim: Interfractional anatomical variations cause considerable differences between planned and actual radiotherapy doses. This study aimed to investigate the efficacy of robust and planning target volume (PTV) margin-based optimizations for the anatomical variations in helical tomotherapy for prostate cancer.
Patients And Methods: Ten patients underwent treatment-planning kilovolt computed tomography (kVCT) and daily megavolt computed tomography (MVCT). Two types of nominal plans, with a prescription of 60 Gy/20 fractions, were created using robust and PTV margin-based optimizations on kVCT for each patient. Subsequently, the daily estimated doses were recalculated using nominal plans, and all available MVCTs modified the daily patient-setup errors. Due to the difference in dose calculation accuracy between kVCT and MVCT, three scenarios with dose corrections of 1, 2, and 3% were considered in the recalculation process. The dosimetric metrics, including target coverage with the prescription dose, Paddick's conformity index, homogeneity index, and mean dose to the rectum, were analyzed.
Results: A dosimetric comparison of the nominal plans demonstrated that the robust plans had better dose conformity, lower target coverage, and dose homogeneity than the PTV plans. In the daily estimated doses of any dose-corrected scenario, the target coverage and dose sparing to the rectum in the robust plans were significantly higher than those in the PTV plans, whereas dose conformity and homogeneity were identical to those of the nominal case.
Conclusion: Robust optimization is recommended as it accounts for anatomical variations during treatment regarding target coverage in helical tomotherapy plans for prostate cancer.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10756445 | PMC |
http://dx.doi.org/10.21873/invivo.13453 | DOI Listing |
Comput Methods Programs Biomed
January 2025
Faculty of Engineering Sciences, Kyushu University, Fukuoka, Japan.
Background And Objective: Coughing events are eruptive sources of virus-laden droplets/droplet nuclei. These increase the risk of infection in susceptible individuals during airborne transmission. The oral cavity functions as an exit route for exhaled droplets.
View Article and Find Full Text PDFCureus
December 2024
Medicine for Older People, Stoke Mandeville Hospital, Aylesbury, GBR.
Accessory ribs are rare anatomical variations, typically cervical or lumbar, with intrathoracic accessory ribs being particularly uncommon. These anomalies are often asymptomatic but can cause issues like thoracic outlet syndrome. This case report describes a 36-year-old woman who was incidentally found to have an intrathoracic accessory rib on a chest X-ray.
View Article and Find Full Text PDFJ Anat
January 2025
Research and Development Center for Precision Medicine, University of Tsukuba, Ibaraki, Japan.
J Anat
January 2025
Department of Pathology, New York University Grossman School of Medicine, New York, New York, USA.
The absence of a clear consensus on the definition and significance of fascia and the indiscriminate use of the term throughout the clinical and scientific literature has led to skepticism regarding its importance in the human body. To address this challenge, we propose that: (1) fasciae, and the fascial interstitia within them, constitute an anatomical system, defined as a layered body-wide multiscale network of connective tissue that allows tensional loading and shearing mobility along its interfaces; (2) the fascial system comprises four anatomical organs: the superficial fascia, musculoskeletal (deep) fascia, visceral fascia, and neural fascia; (3) these organs are further composed of anatomical structures, some of which are eponymous; (4) all these fascial organs and their structural components contain variable combinations and arrangements of the four classically defined tissues: epithelial, connective, muscle, and neural; (5) the overarching functions of the fascial system arise from the contrasting biomechanical properties of the two basic types of layers distributed throughout the system: one predominantly collagenous and relatively stiff, the other rich in hyaluronic acid and viscous, allowing for the free flow of fluid; (6) the topographical organization of these layers in different locations is related to local variations in function (e.g.
View Article and Find Full Text PDFInt J Surg Case Rep
January 2025
General Surgery Department, Military Hospital of Tunis, Mont Fleury, 1008 Tunis, Tunisia; Faculty of Medicine of Tunis, 15, Djebel Lakhdhar Street, Bab Saadoun, 1007 Tunis, Tunisia.
Introduction And Importance: Superior mesenteric artery (SMA) syndrome, or aorto-mesenteric clamp syndrome, is a rare condition where the third portion of the duodenum is compressed between the aorta and the superior mesenteric artery. This syndrome often affects adolescents and young adults, with predisposing factors including significant weight loss, anatomical variations, and spinal deformities. Early diagnosis and intervention are critical for managing symptoms and preventing complications.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!