Intensity modulated radiotherapy versus volumetric modulated arc therapy in breast cancer: A comparative dosimetric analysis

Purpose: Intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) has the capacity to optimize the dose distribution. We analyzed the dosimetric differences of plans in treatment planning system (TPS) between VMAT and IMRT in treating breast cancer. Methods: Fourteen patients were simulated, planned, and treated with VMAT using single, double or partial arcs. IMRT treatments were generated using 4 to 5 tangential IMRT fields for the same patients. All treatment plans were planned for 50 Gy in 25 fractions. The VMAT and IMRT plans were compared using the planning target volume (PTV) dose and doses to the other organs at risk (OARs). Results: For the PTV, comparable minimum, mean, maximum, median, and modal dose as well equivalent sphere diameter of the structure (Equis) were observed between VMAT and IMRT plans and found that these values were significantly equal in both techniques. The right lung mean and modal doses were considerably higher in VMAT plans while maximum value was considerably lower when compared with IMRT plans. The left lung mean and modal doses were higher with VMAT while maximum doses were higher in IMRT plans. The mean dose to the heart and maximum dose to the spinal cord was lower with IMRT. The mean dose to the body was higher in VMAT plans while the maximum dose was higher in IMRT plans. Conclusion: Four field tangential IMRT delivered comparable PTV dose with generally less dose to normal tissues in our breast cancer treatment study. The IMRT plans typically had more favourable dose characteristics to the lung, heart, and spinal cord and body dose when compared with VMAT. The only minor advantage of VMAT for breast cases was slightly better PTV coverage

Development of a novel diagnostic test for detection of bovine viral diarrhea persistently infected animals using hair

The purpose of this study was to determine whether manually plucked hairs might serve as an alternative sample for a quantitative real time polymerase chain reaction (qRT-PCR) testing. Twenty three, 1~3 week old, non-bovine viral diarrhea virus (BVDV) vaccinated calves, found to be positive for BVDV by immunohistochemical staining, were selected and hairs were manually plucked from the ear. qRT-PCR was performed on samples consisting of more than 30 hairs (30~100) and whole blood. All 23 animals were positive for the virus by qRT-PCR performed on the whole blood and when samples of more than 30 hairs were assayed. Additionally, qRT-PCR was performed on groups of 10 and 20 hairs harvested from 7 out of 23 immunohistochemical staining-positive calves. When groups of 20 and 10 hairs were tested, 6 and 4 animals, respectively, were positive for the virus

Optimal usage of cone beam computed tomography system with different field of views in image guided radiotherapy (IGRT)

Purpose: To find methods for optimal usage of XVI (X-ray volume imaging) system in Elekta synergy linear accelerator with different field of views for same lesion in order to minimize patient dose due to imaging.Methods: 20 scans of 2 individual patients with ca sigmoid colon and ca lung were used in this study. Kilo voltage collimators with medium field of view were used as per the preset information. Images were reconstructed for another collimator with small field of view. The set up errors were evaluated with XVI software. Shift results of both methods were compared. Results: Variation in treatment set up errors with M20 and S20 collimators were ≤ 0.2 mm in translational and 0.30 in rotational shifts. Results showed almost equal translational and rotational shifts in both medium and small field of views with different collimators in all the scans. Visualization of target and surrounding structures were good enough and sufficient for XVI auto matching.Conclusion: Imaging with small field of view results less patient dose compared with medium or large field of views. It is Suggestible to use collimators with small field of view wherever possible. In this study, collimators with small field of view were sufficient for both patients though the preset information indicated medium field of view. But, it always depends on the area required for matching purpose. So, individual selection is important than preset information in the XVI system

A prospective study of OAR volume variations between two different treatment planning systems in radiotherapy

Purpose: It has been seen that there is a clinically significant variation in the volume calculated across different planning systems for the same digital imaging and communication (DICOM) contours.The purpose of this study is to investigate the difference in volumes of organs at risk when the structure sets were exported from the Eclipse ((Palo Alto, USA Version 10.0) to XIO CMS (Electa, Crawley, UK Version 4.40.00) treatment planning system (TPS) and identify how the differences occur. Methods: We prospectively analyzed the volumes of organs at risk from computerized tomography (CT) data of 54 patients. Head and neck and brain tumors were taken for this study and contoured on Eclipse treatment planning system (TPS) after importing images from CT. These contoured images were then exported using radiotherapy DICOM transfer facility to XIO CMS planning system and compared the contoured volumes with Eclipse TPS structured volumes. Results: Our analysis showed that the differences in calculated volumes of the contours for the patients between the two planning systems can be large. Mixed results are shown for different organs with the absolute volume difference ranging from -0.25 cc to 319.73 cc. These results clearly shown that the two TPS interprets the contours differently when calculating the volume, and there is a closer match with the theoretical calculated volumes with XIO CMS calculated volumes. Conclusion: Observed discrepancies were consistent between the two planning systems. This impact of contouring variability could play a role on plan quality metrics which is used as criteria for clinical trial protocol compliance

A prospective study of OAR volume variations between two different treatment planning systems in radiotherapy

Purpose: It has been seen that there is a clinically significant variation in the volume calculated across different planning systems for the same digital imaging and communication (DICOM) contours.The purpose of this study is to investigate the difference in volumes of organs at risk when the structure sets were exported from the Eclipse ((Palo Alto, USA Version 10.0) to XIO CMS (Electa, Crawley, UK Version 4.40.00) treatment planning system (TPS) and identify how the differences occur. Methods: We prospectively analyzed the volumes of organs at risk from computerized tomography (CT) data of 54 patients. Head and neck and brain tumors were taken for this study and contoured on Eclipse treatment planning system (TPS) after importing images from CT. These contoured images were then exported using radiotherapy DICOM transfer facility to XIO CMS planning system and compared the contoured volumes with Eclipse TPS structured volumes. Results: Our analysis showed that the differences in calculated volumes of the contours for the patients between the two planning systems can be large. Mixed results are shown for different organs with the absolute volume difference ranging from -0.25 cc to 319.73 cc. These results clearly shown that the two TPS interprets the contours differently when calculating the volume, and there is a closer match with the theoretical calculated volumes with XIO CMS calculated volumes. Conclusion: Observed discrepancies were consistent between the two planning systems. This impact of contouring variability could play a role on plan quality metrics which is used as criteria for clinical trial protocol compliance.</p

Successful Protein Extraction from Over-Fixed and Long-Term Stored Formalin-Fixed Tissues

One of the major breakthroughs in molecular pathology during the last decade was the successful extraction of full-length proteins from formalin-fixed and paraffin-embedded (FFPE) clinical tissues. However, only limited data are available for the protein extraction efficiency of over-fixed tissues and FFPE blocks that had been stored for more than 15 years in pathology archives. In this study we evaluated the protein extraction efficiency of FFPE tissues which had been formalin-fixed for up to 144 hours and tissue blocks that were stored for 20 years, comparing an established and a new commercial buffer system. Although there is a decrease in protein yield with increasing fixation time, the new buffer system allows a protein recovery of 66% from 144 hours fixed tissues compared to tissues that were fixed for 6 hours. Using the established extraction procedure, less than 50% protein recovery was seen. Similarly, the protein extraction efficiency decreases with longer storage times of the paraffin blocks. Comparing the two buffer systems, we found that 50% more proteins can be extracted from FFPE blocks that were stored for 20 years when the new buffer system is used. Taken together, our data show that the new buffer system is superior compared to the established one. Because tissue fixation times vary in the routine clinical setting and pathology archives contain billions of FFPE tissues blocks, our data are highly relevant for research, diagnosis, and treatment of disease

Intensity modulated radiotherapy versus volumetric modulated arc therapy in breast cancer: A comparative dosimetric analysis

Purpose: Intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) has the capacity to optimize the dose distribution. We analyzed the dosimetric differences of plans in treatment planning system (TPS) between VMAT and IMRT in treating breast cancer. Methods: Fourteen patients were simulated, planned, and treated with VMAT using single, double or partial arcs. IMRT treatments were generated using 4 to 5 tangential IMRT fields for the same patients. All treatment plans were planned for 50 Gy in 25 fractions. The VMAT and IMRT plans were compared using the planning target volume (PTV) dose and doses to the other organs at risk (OARs). Results: For the PTV, comparable minimum, mean, maximum, median, and modal dose as well equivalent sphere diameter of the structure (Equis) were observed between VMAT and IMRT plans and found that these values were significantly equal in both techniques. The right lung mean and modal doses were considerably higher in VMAT plans while maximum value was considerably lower when compared with IMRT plans. The left lung mean and modal doses were higher with VMAT while maximum doses were higher in IMRT plans. The mean dose to the heart and maximum dose to the spinal cord was lower with IMRT. The mean dose to the body was higher in VMAT plans while the maximum dose was higher in IMRT plans. Conclusion: Four field tangential IMRT delivered comparable PTV dose with generally less dose to normal tissues in our breast cancer treatment study. The IMRT plans typically had more favourable dose characteristics to the lung, heart, and spinal cord and body dose when compared with VMAT. The only minor advantage of VMAT for breast cases was slightly better PTV coverage.</p

Synthesis of 4-hydroxy-3-formylideneamino-1H/methyl/phenylquinolin-2-ones

255-260An efficient method for the synthesis of 4-hydroxy-3-formylideneamino-1H/methyl/phenylquinolin-2-ones by the condensation of corresponding 4-hydroxy-3-formyl-1H/methyl/phenylquinolin-2-one with substituted anilines/aliphatic primary amines is reported. The carboxaldehyde in turn is prepared starting either from substituted anilines or benzoic acid. The structures of compounds are established by the elemental analysis and spectral data