 I am Dr. Pauline Shanti, working as assistant professor in the Department of Anatomy Christian Medical College, Well Lord, India. The title of our study is comparison of CT numbers of organs before and after plastination using the standard STN technique. Plastination invented by Gunther von Higgins in the year 1977 has established itself as an indispensable contributor to the teaching armamentarium of clinical anatomists. It is the process where water and lipids in biological tissues are replaced with curable polymers like silicon, epoxy or polyester. Specimens thus preserved are called plastinates. They are dry, odorless and retain their appearance prior to preservation down to the microscopic level. The aim of this study was to make plastinates from cadavers using standard STN plastination technique and to compare the radiological tissue properties before and after plastination to see the suitability of using plastinates as phantom for treatment planning in radiotherapy. So for this purpose we obtained two specimens, an above diaphragm specimen from a male cadaver and a below diaphragm specimen from a female cadaver. These specimens were plastinated using the standard STN plastination technique by fixation, dehydration, forced impregnation and gas curing. CT imaging of the specimens were done before and after plastination. The images of pre-plastinate and post-plastinate were then compared for anatomical accuracy, volume of organs and CT numbers in harmful units on a treatment planning system called Varian Eclipse Medical Systems in the Department of Radiotherapy as seen here. Anatomical accuracy of the plastinate was confirmed by comparing CT images on a slice by slice basis. As you see here, the plastinate showed better image quality and tissue differentiation than the pre-plastinate. Volume estimation was done by contouring the organ from the cranial end to the porder end in all the slices of the CT images. This was further confirmed by 3D reconstructed volumes. There was an average shrinkage of 25% of all the organs, though it was not much in parenchymata organs like thyroid, parotid, kidney, liver, etc. as seen in this graph. Up to 10% of shrinkage in plastination is unavoidable. Different methods have been used by various authors to quantify the shrinkage like fluid displacement, morphometrics on scanned images, computer-assisted morphometry, etc. Our method of volume estimation could probably be more accurate than these methods which accounts for the excess of shrinkage. The CT numbers of tissues were obtained by taking an average of 5 CT numbers in different places within the same organ. CT numbers were uniformly increased in all tissues in the post-plastinate. But this was minimal in bone and air-filled sinuses as seen in this graph. The silicone in the tissues has increased the tissue density which has further increased the CT numbers. Plastination preserves the morphology of paren tissue very well and gives accurate anatomical details. It is specimens that closely represent the in vivo anatomy. Plastinates are stable over time and ensures repeatability and reproducibility. They have been used with different diagnostic imaging methodologies that see anatomy from a new and different perspective. Because of these properties, we were considering the possibility of using plastinates as phantom for treatment planning in radiotherapy. Phantoms are structures made of one or more tissue substitutes used to simulate radiation interactions in the human body. The aldousin rando phantom is currently used widely for radiation dosimetry. This is a section of the aldousin rando phantom. This shows that the rando phantom is made of bone and soft tissue and also lung substitutes. But it has no organs in it. On the other hand, the plastinated phantom has all the organs in it. This is a section of a plastinated phantom which shows all the organs intact. Since the plastinated phantoms has all the organs intact, it overcomes the disadvantage of the rando phantom. But the results of this study shows that plastination using standard S10 technique is not ideal to replace the rando phantom. Modification of the standard S10 technique is needed for this purpose. Thank you.