 Hello everyone, I am Dr. Krishnamenik, third year of radiology post-graduate from Arguday Vedic Medical College, Pondicherry, titled for my prepared presentation as role of CT in primary oral cavity cancer with clinical surgical and histopathological correlation. Objective of the study is to determine the accuracy of CT in primary oral cavity cancers with clinical surgical and histopathological correlation, to determine the accuracy of CT in assessing the metastatic nodal disease in these patients with clinical surgical and histopathological correlation. This is a prospect to study done on 63 patients. The study period was from November 2020 to September 2021. All patients who underwent CT for oral cavity cancer who have undergone surgery with clinical and pathological correlations. Patient with previous radiation to the head and neck and patient with any head and neck surgery were excluded. So, coming to the results on age-wide distribution, it is most commonly seen in 61 to 70 years of 25.4 percentage and 41 to 50 years of 25.4 percentage and least commonly seen in 21 to 30 years. On gender-wise distribution, it is most commonly seen in females. Under distribution of the study patient based on their location, it is most commonly seen in the buccal mucosa followed by gingivore buccal sulcus, heart pallet, etc. So, distribution of study patient based on their habits is most commonly seen in patients who is having tobacco followed by tobacco, betel and smoking. So, diagnostic accuracy of CT scan surgery and clinical assessment versus HPE detecting the actual patient with T1 condition showed a sensitivity of 62% in surgery and clinical 50% specificity of 96.4 percentage and positive predictive value of 71.4 in surgery and clinical assessment 66 and negative predictive value of 94.6 in surgery and accuracy is 92.1 in surgical assessment and clinical assessment is 90.5 percentage. On T2 condition, the sensitivity was 66.7 percentage in surgery and 55.6 in clinical. Specificity was 88.9 in surgery and clinical assessment it was 83.3 percentage and positive predictive value 81.8 in surgery and in clinical assessment it is 71.4 percentage and negative predictive value is 78.1 percentage and 71.4 percentage with an accuracy of 79.4 percentage in the surgery and 71.4 percentage in clinical assessment. On the T3 condition, the sensitivity was low in surgery and clinical assessment specificity was high and positive predictive value of 50% seen in surgical assessment and 25 in clinical assessment negative predictive value of 82.5 and 80% seen on accuracy 79.4 percent was seen in surgery and 73 seen in clinical assessment. On T4 condition followed by the N1 condition where we saw the sensitivity is 62.5 percent in surgery and clinical assessment specificity was high in surgery and positive predictive value also high in surgery followed by negative predictive value is more seen in 94.3 percentage and 92.7 percentage and the accuracy was 87.3 percentage in surgery and 68.3 in clinical assessment. On N2A condition it was sensitivity was 0 percentage positive predictive value was 0 percentage with accuracy of 65.2 percentage seen in surgical assessment and 64.8 is seen in clinical assessment. On N2B condition sensitivity was 72.7 in surgical and 55 in clinical assessment specificity of 65.4 seen in surgery and 92.3 seen in clinical assessment. Positive predictive value of 30.8 percent is seen in surgery and 60 is seen in clinical assessment. Negative predictive value of 92 percentage is seen in surgery and clinical assessment of 90 was seen. Accuracy was clinical assessment it was 85.7 percentage. On N2C condition the accuracy was high specificity was high and the negative predictive value was high. Sensitivity was 50 percentage and positive predictive value is 50 percentage. N3 condition sensitivity was 0 in diagnostic accuracy of CT scan and 100 percentage in clinical and surgical assessment. And again specificity was high in all three negative predictive value was high in all three and the accuracy was 64.8 percentage in the CT scan and 100 percentage in the surgical and clinical assessment. In our study the primary tumor size and soft tissue involvement were identified with 95 to 100 percent accuracy by CT scan of the head and neck region whereas surgical and clinical accuracy were 78 to 92 percent and 72 90 percent respectively. The accuracy of detection bone involvement by CT scan of head and neck in this study was 93 percent whereas by intraoperative and clinical assessment it was found to be 73 percent. So conclusion CT scan of head and neck has the highest sensitivity specificity and accuracy in assessing the tumor size surrounding soft tissue and bone involvement along with nodal metastasis. Thus preoperative TN staging by CT head and neck is very important in deducting accurate stage of the carcinoma of oral cavity when compared to clinical and surgical stage. On coming to case one we can see a clinical photograph and postoperative specimen image in a patient with left buckle carcinoma. Axial CECD image shows an irregularly enhancing lesion in the left buckle mucosa. On case two we can see the clinical image showing right exophytic buckle mucosa lesion in contrast enhanced CT axial CECD section we can see the mass in the right submandibular lymph adenopathy mass with the right submandibular lymph adenopathy and a graft specimen image showing the restricted primary tumor. On case three we are seeing the clinical photograph showing lesion the right gingio buckle sulcus and intraoperative image while performing neck dissection. On axial CECD image showing the enhancing mass in the gingio buckle sulcus causing destruction of the mandible. On case four CECD axial image shows left gingio buckle sulcus lesion with extension into the infratemporal fossa causing destruction of the mandible. And we can see the postoperative receptor specimen image. Case five shows the lesion in right lateral border of the tongue. On axial CECD image we can see the enhancing lesion in the right lateral border of the tongue with the bilateral cervical lymph adenopathy. Case six shows CECD axial section showing solid enhancing lesion in the lower lip of the on the left side. On intraoperative image shows a receptor margin of the lesion. On case seven clinical image shows a lesion in the heart palate CECD axial image showing enhancing lesion in the heart palate causing destruction of the anterior aspect of the heart palate. On cross-references closed at all evaluated 60 patients and found that 88 persons were correctly evaluated by clinical examination which was similar to our results. Wanda and Brekittal reported 62% accuracy of clinical examination in productive bone involvement with the lower sensitivity and high specificity which was significantly lower than our study. These are my references. Thank you.