PubMed İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/11727/4810
Browse
2 results
Search Results
Item Novel Clinically Weight-Optimized Dynamic Conformal Arcs (WO-DC A) for Liver SBRT: A Comparison with Volumetric Modulated Arc Therapy (VMAT)(2021) Topkan, Erkan; 0000-0001-8120-7123; 34611405; AAG-2213-2021Purpose: To evaluate the feasibility of shortening the duration of liver stereotactic radiotherapy (SBRT) without jeopardizing dosimetry or conformity by utilizing weight-optimized dynamic conformal arcs (WO-DCA) as opposed to volumetric modulated arc therapy (VMAT) for tumors away from critical structures. Methods: Nineteen patients with liver metastasis were included, previously treated with 50 Gy in 4 fractions with VMAT technique using two partial coplanar arcs of 6 MV beams delivered in high-definition multi-leaf collimator (HD-MLC). Two coplanar partial WODCA were generated on Pinnacle treatment planning system (TPS) for each patient; and MLC aperture around the planning target volume (PTV) was automatically generated at different margins for both arcs and maintained dynamically around the target during arc rotation. Weight of the two arcs using optimization method was adjusted between the arcs to maximize tumor coverage and protect organs at risk (OAR) based on the RTOG-0438 protocol. Results: The WO-DCA plans successfully "agreed" with the standard VMAT for OAR (liver, spinal cord, stomach, duodenum, small bowel, and heart) and PTV (D-mean, D-98%, D-2%, CI, and GI), with superior mean quality assurance (QA) pass rate (97.06 vs 93.00 for VMAT; P < 0.001 and t = 8.87). Similarly, the WO-DCA technique additionally reduced the beam-on time (3.26 vs 4.43; P < 0.001) and monitor unit (1860 vs 2705 for VMAT; P < 0.001) values significantly. Conclusion: The WO-DCA plans might minimize small-field dosimetry errors and defeat patient-specific VMAT QA requirements due to the omission of MLC beam modulation through the target volume. The WO-DCA plans may additionally enable faster treatment delivery times and lower OAR without sacrificing target doses in SBRT of liver tumors away from critical structures.Item The Frequency of Lysosomal Acid Lipase Deficiency in Children With Unexplained Liver Disease(2019) Ozcay, Figen; Canan, Oguz; 0000-0002-5214-516X; 30540705; ABG-5684-2020Objectives: Evidence suggests that lysosomal acid lipase deficiency (LAL-D) is often underdiagnosed because symptoms may be nonspecific. We aimed to investigate the prevalence of LAL-D in children with unexplained liver disease and to identify demographic and clinical features with a prospective, multicenter, cross-sectional study. Methods: Patients (aged 3 months-18 years) who had unexplained transaminase elevation, unexplained hepatomegaly or hepatosplenomegaly, obesity-unrelated liver steatosis, biopsy-proven cryptogenic fibrosis and cirrhosis, or liver transplantation for cryptogenic cirrhosis were enrolled. A Web-based electronic data collection system was used. LAL activity (nmol/punch/h) was measured using the dried blood spot method and classified as LAL-D(<0.02), intermediate (0.02-0.37) or normal (>0.37). Asecond dried blood spot sample was obtained from patients with intermediate LAL activity for confirmation of the result. Results: A total of 810 children (median age 5.6 years) from 795 families were enrolled. The reasons for enrollment were unexplained transaminase elevation (62%), unexplained organomegaly (45%), obesity-unrelated liver steatosis (26%), cryptogenic fibrosis and cirrhosis (6%), and liver transplantation for cryptogenic cirrhosis (<1%). LAL activity was normal in 634 (78%) and intermediate in 174 (21%) patients. LAL-D was identified in 2 siblings aged 15 and 6 years born to unrelated parents. Dyslipidemia, liver steatosis, and mild increase in aminotransferases were common features in these patients. Moreover, the 15-year-old patient showed growth failure and microvesicular steatosis, portal inflammation, and bridging fibrosis in the liver biopsy. Based on 795 families, 2 siblings in the same family were identified as LAL-D cases, making the prevalence of LAL-D in this study population, 0.1% (0.125%-0.606%). In the repeated measurement (76/174), LAL activity remained at the intermediate level in 38 patients. Conclusions: Overall, the frequency of LAL-D patients in this study (0.1%) suggests that LAL-D seems to be rare even in the selected high-risk population.