ABSTRACT
PURPOSE: To investigate the Gross Tumor Volumes (GTV) and its dosimetric impact of magnetic resonance imaging (MRI) assisted contouring for non-spinal metastasis treated with stereotactic ablative body radiotherapy (SABR). MATERIAL AND METHODS: Five observer contours on CT (GTVCT) and CT+MR (GTVCT+MR) were evaluated against expert team contours (GTVEC) for 14 selected cases. Dice Similarity Index (DSC) and Geographical Miss Index (GMI) quantify observer variation. We also analyze the maximum dose (Dmax) and dose received by 0.35cc (D0.35cc) of the spinal cord (SC) for GTVCT and GTVCT+MR, where optimization parameters and priorities were unchanged. Percent rank function is also evaluated for SC doses. RESULTS: The mean DSC and GMI scores for the CT-only dataset are 0.6974 and 0.2851 and for CT+MR dataset is 0.7764 and 0.1907 respectively. Statistically, significant results were found for mean GTV volumes between GTVEC versus GTVCT and GTVCT versus GTVCT+MR (P<0.001). Dosimetric analysis of Dmax and D0.35cc exceeded 84.2% and 88.5% of times its respective threshold doses for CT-only dataset, whereas for the CT+MR dataset, it exceeded only by 18% and 15.7% times. 'Percent rank' function analysis for SC doses also indicates the same. CONCLUSION: This study supports MRI fusion for GTV and OAR delineation for non-spinal metastasis. Our study showed that the dosimetric analysis is vital for observer variation studies and the addition of the MR data set is significant to improve the confidence of Stereotactic treatments.
Subject(s)
Bone Neoplasms/diagnostic imaging , Bone Neoplasms/radiotherapy , Magnetic Resonance Imaging/methods , Organs at Risk/diagnostic imaging , Radiosurgery/methods , Tumor Burden , Algorithms , Bone Neoplasms/pathology , Datasets as Topic , Dose Fractionation, Radiation , Female , Humans , Male , Observer Variation , Radiotherapy, Image-Guided/methods , Retrospective Studies , Spine , Tomography, X-Ray Computed/methodsABSTRACT
The chromanone scaffold is considered as a privileged structure in drug discovery. Herein, we report a highly efficient PhI(OAc)2 mediated regioselective, direct C-H hydroxylation of chromanones. This method offers easy access to substituted 6-hydroxy chromanones in moderate to good isolated yields, thus paving the way for their pharmaceutical studies.
ABSTRACT
The first total synthesis of hunanamycin A, an antibiotic natural product with a pyrido[1,2,3-de]quinoxaline-2,3-dione core from a marine-derived Bacillus hunanensis, is disclosed. The present effort provides access to sufficient amounts of scarce hunanamycin A for further biological evaluation and confirmation of the assigned absolute configuration. In addition, four new analogues of the natural product are reported.
